AU2021106564A4

AU2021106564A4 - Method for comprehensive exploration of polymetallic ore

Info

Publication number: AU2021106564A4
Application number: AU2021106564A
Authority: AU
Inventors: Qiang Ma; Zhongyuan Ma; Shengshun SU; Aikui Zhang; Daming Zhang; Yong Zhang; Mingfeng ZHONG
Original assignee: Third Geological Exploration Institute of Qinghai Province
Current assignee: Third Geological Exploration Institute of Qinghai Province
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2021-11-11
Anticipated expiration: 2029-08-23

Abstract

OF THE DISCLOSURE The present disclosure provides a method for comprehensive exploration of a polymetallic ore. The present disclosure pushes forward a prospecting method combined with the "metallogenic system+stream sediment survey+debris survey+large-scale geophysical and geochemical profiling/high-accuracy magnetic survey+engineering verification", and makes a huge breakthrough in prospecting. The combination method can effectively avoid restrictions of shallow covered conditions on conventional geological mapping, and can quickly shrink the prospecting target in a quaternary covered area to spatially position the mineralized alteration zone and the ore-bearing geobody, thereby improving the prospecting success rate. The method has the advantages of a short exploration period, a high efficiency and a low exploration cost, and is applied to exploring shallow vein copper-lead-zinc-silver-gold ores and skarn iron-copper ores. Moreover, as the wide-field electromagnetic method (WFEM) has the absolute advantage of a large detection depth, the method is applied to exploring the deep concealed porphyry copper and molybdenum ores in combination with a prospecting predictive geological model established according to the geological feature, and the speculated range of the concealed ore-bearing porphyry. ABSTRACT DRAWING Indosinian-Yanshanian porphyry metallogenic system Northwest trending and nearly north-south trending granite area in the eastern segment of East Kunlun Mountain Preferrable copper-zinc-silver-gold anomaly in1/ 25,000 stream sediment surve Preferrable copper-zinc-silver-gold anomaly in1/ 10,000 debris survey Anomaly in zonal distribution delineated in 1/5,000 rock (soil) profiling, 1/5,000 IP intermediate gradient profiling and 1/100,000 high-accuracy magnetic survey Surface inspection to find an ore-containing geobody Exposure by trenching and shallowdrilling Delineation of an ore zone or an orebody Verification in drilling engineering Control of a shallow veinorebody Porphyry-hydrothermal vein metallogenic seriesand 1/10,000 WFEM Determination of a favorable position of a concealed porphyry, and delineation of a saccate anomaly Practice in deep drilling engineering Evaluation of a concealed porphyry ore FIG. 1

Description

ABSTRACT DRAWING

Indosinian-Yanshanian porphyry metallogenic system

Northwest trending and nearly north-south trending granite area in the eastern segment of East Kunlun Mountain

Preferrable copper-zinc-silver-gold anomaly in1/ 25,000 stream sediment surve

Preferrable copper-zinc-silver-gold anomaly in1/ 10,000 debris survey

Anomaly in zonal distribution delineated in 1/5,000 rock (soil) profiling, 1/5,000 IP intermediate gradient profiling and 1/100,000 high-accuracy magnetic survey

Surface inspection to find an ore-containing geobody

Exposure by trenching and shallowdrilling

Delineation of an ore zone or an orebody

Verification in drilling engineering

Control of a shallow veinorebody

Porphyry-hydrothermal vein metallogenic seriesand 1/10,000 WFEM

Determination of a favorable position of a concealed porphyry, and delineation of a saccate anomaly

Practice in deep drilling engineering

Evaluation of a concealed porphyry ore

FIG. 1

METHOD FOR COMPREHENSIVE EXPLORATION OF POLYMETALLIC ORE TECHNICAL FIELD

[01] The present disclosure relates to the technical field of geological prospecting, and in particular to a method for comprehensive exploration of a polymetallic ore.

BACKGROUNDART

[02] Working methods and technical measures taken for the sake of finding ore resources are collectively called prospecting methods. The prospecting is the geological work carried out in certain areas to find and evaluate ores for the national economy, i.e., to find various ores with the comprehensive utilization of basic knowledge and theories of the geoscience under the assistance of necessary exploration technologies, so as to explore and control them. Specifically, on the basis of researching geotectonic backgrounds and ore distribution laws in working regions, and particularly the geological conditions closely tied with the ore formation and distribution, it is to predict favorable ore zones, prospect ores therein with the comprehensive utilization of effective technical means and prospecting methods, and find deposits, thereby providing necessary ore resource data as well as geological, technical and economic data to further select deposit exploratory areas (or zones) and formulate the far-seeing development plan for the national economy.

[03] Located on two sides of the Chahanwusu River overall, the eastern segment of East Kunlun Mountain has the well-developed meadow in local areas. Except some hilltops where the integrally exposed bedrock can be seen, these areas are basically covered by vegetation on the earth's surface and provide a humus soil layer mostly under the vegetation to form the typical shallow covered areas. In this sense, directly discovery of outcrops such as the structure, mineralization and alteration traces on the earth's surface is difficult, the geological mapping effect is undesirable and the direct prospecting efficiency is low, all of which will present great difficulties for further expansion of the prospecting space and delineation of new favorable metallogenic zones.

[04] The Nagengkangqieergou-Harzhaz-Narimalahei zone in the eastern segment of East Kunlun Mountain is the silver polymetallic ore-concentrated area found in recent two or three years with the most outstanding exploration outcomes. There are the large-scale Harzhaz and Nagengkangqieergou silver deposits, and the emerging silver polymetallic ore exploration projects in the west of Harzhaz and the north of Nagengkangqieer. The ore-concentrated area has the submitted silver resources of more than 6,400 tons, up to 80% or more in the total amount of silver ore resources explored in Qinghai Province. In this area, the mineralization is associated with the Indosinian-Yanshanian tectonic-magmatic intrusive activities. It has been discovered that the orebodies are obviously controlled by the northwest trending deep major fracture and secondary fractures thereof; and the Ag, Pb and Zn hypabyssal low-temperature hydrothermal vein ores associated with the quartz (rhyolite) porphyry as branches of deep Cu-Mo-bearing concealed porphyry are mainly formed. It is of great significance to control the branches of the porphyry to find the deep large-scale porphyry Cu and Mo ores.

[05] The eastern segment of East Kunlun Mountain in the Qinghai-Tibet plateau is adjacent to the conjunction of Qinling, Qilian and Kunlun, and has a large area of well-developed Late Triassic continental volcanic rocks of Elashan formation. It has been found that ore-bearing sites of the superficial silver-copper-lead-zinc polymetallic ores are mainly distributed on fracture zones and are not selectable for surrounding rocks, and the volcanic rock stratum of Elashan formation has a high Ag background valve and provides the essential ore-forming material sources for enrichment of the silver ores.

[06] Mining areas in the eastern segment of East Kunlun Mountain take different measures during exploration. Among the numerous and complicated prospecting methods and technologies, there is a lack of research on effective prospecting methods. Hence, it is desirable to push forward an effective prospecting method for this area, so as to lock the target geobody as soon as possible in subsequent exploration for evaluations.

[07] Therefore, how to research a method for exploring porphyry-hydrothermal vein-skarn iron-copper-lead-zinc-silver-gold polymetallic and precious metallic ores of the shallow covered area in the eastern segment of East Kunlun Mountain according to exploration work in the shallow covered area has become a problem to be solved urgently for a person skilled in the art.

SUMMARY

[08] An objective of the present disclosure is to provide a method for comprehensive exploration of a polymetallic ore, to solve the above problems in the prior art and improve the prospecting success rate in the shallow covered area.

[09] To achieve the above objective, the present disclosure provides the following solutions: A method for comprehensive exploration of a polymetallic ore includes the following steps: delineating a magmatite zone according to a spatio-temporal feature and a regional geological background at an output of magmatite, carrying out a 1/25,000 stream sediment survey on the magmatite zone to preliminarily delineate a prospecting target, classifying the target, and determining a segment having a strong anomaly or a desirable anomaly register in copper, lead, zinc, silver and gold as a first preferable target;

[10] selecting, after carrying out a 1/10,000 debris survey on the first preferable target according to a surface bedrock exposure condition to delineate an anomaly, a segment having a strong anomaly or a desirable anomaly register in copper, lead, zinc, silver and gold as a second preferable target;

[11] carrying out, according to a feature that a surface ore is distributed along a secondary tectonic zone, a 1/5,000 soil geochemical profiling or a 1/5,000 rock geochemical profiling or a 1/5,000 induced polarization (IP) intermediate gradient profiling or a 1/10,000 high-accuracy magnetic survey on the second preferable target to decompose an anomaly, and delineating a geophysical and geochemical anomaly zone in a zonal distribution as a third preferable target, i.e., determining a surface ore-bearing geological position;

[12] carrying out a reconnaissance survey on the third preferable target to find a surface ore-bearing geobody position and a mineralization tracing area in an anomaly zone; and carrying out shallow exposure and tracing on the ore-bearing geobody position and the mineralization tracing area by trenching or shallow drilling, controlling a specific position, a shape and a feature of a mineralized zone or a mineralized body, and determining an inclination of an orebody under the assistance of a 1/5,000 IP joint profiling;

[13] determining a change of a deep area of the mineralized body in grade, thickness, scale and attitude with a drilling technology, and controlling vein silver, copper, lead and zinc orebodies or ore zones; and

[14] preliminarily determining, according to mineralization features of the vein orebody in change of a high-low temperature ore and change of a vein width as well as an alteration zoning feature of propylitization-argillization-silicification-potassic alteration, a range of a concealed ore-bearing porphyry, and delineating a saccate low-resistivity body in a deep area with a 1/10,000 wide-field electromagnetic method (WFEM) profiling, i.e., determining a specific position and a buried depth of the concealed ore-bearing porphyry; and exploring a concealed thick and large ore-bearing porphyry in the deep area with a deep drilling technology for the saccate low-resistivity body within the range of the concealed ore-bearing porphyry, and controlling porphyry copper and molybdenum ores.

[15] Preferably, the vein orebody may be dominated by copper, lead, zinc, silver and gold ores or lead, zinc and silver ores, and accompanied by a tin ore; and the concealed porphyry ores may be copper and molybdenum ores.

[16] Preferably, a metallogenic system may be a porphyry metallogenic system in a continental collision orogenic environment, and form a porphyry-hydrothermal vein-skarn metallogenic series.

[17] Preferably, the 1/25,000 stream sediment survey may be implemented by controlling a sampling density at 16-20 points/i km 2 , preparing an integrated anomaly map for test data, carrying out an intra-class sequence evaluation on same major elements, classifying an anomaly according to an anomaly feature, a geological condition and a prospecting significance, preliminarily delineating the prospecting target in combination with a regional geological feature and a geology outcome from former geophysical and geochemical prospecting and heavy mineral anomaly, and classifying the target.

[18] Preferably, the 1/10,000 debris survey may be implemented by arranging a sampling line at 90-270°, positioning with a high-accuracy global positioning system (GPS), arranging a grid basically at 100*40 m for the debris survey, and directly carrying out multi-point chip sampling when a bedrock is exposed; carrying out, in case of coverage of soil or eolian less, exposure until the bedrock is exposed, sampling multiple points at 2-10 mm to form a sample having a weight of >300 g, preparing an integrated anomaly map for test data with software, carrying out an intra-class sequence evaluation on same major elements, and classifying an anomaly according to an anomaly feature, a geological condition and a prospecting significance; and delineating an integrated anomaly of the debris survey in combination with a geological feature of an mining area and an anomaly range of a former 1/25,000 stream sediment survey, and determining the segment having the strong anomaly or the desirable anomaly register in copper, lead, zinc, silver and gold as the second preferable target.

[19] Preferably, the carrying out a 1/5,000 soil geochemical profiling or a 1/5,000 rock geochemical profiling or a 1/5,000 IP intermediate gradient profiling or a 1/10,000 high-accuracy magnetic survey on the second preferable target to decompose an anomaly, and delineating a geophysical and geochemical anomaly zone in a zonal distribution as a third preferable target or a third anomaly zone may be to determine a position of an ore-bearing zone;

[20] the 1/5,000 soil geochemical profiling may specifically include: arranging a profile in perpendicular to a long-axis direction of a 1/10,000 debris anomaly and enabling the profile to pass through a high-value point of a stream anomaly concentration center; positioning a start of the profile with a uniformly corrected GPS, orienting a profile line with a compass, measuring a distance with a measuring rope, providing a sampling point at 10 m, increasing a density to 3 m for a structural fractured alteration zone and a mineralized zone, and collecting a sample within a 1/3 range of the distance around the sampling point, where the sample is collected at one point or 3-5 points in a same medium and a same horizon; and a soil sample is collected in a substratum at 30-80 cm beneath the earth's surface, and if the substratum is not collected due to a thick coverage, the sample is collected at a bottom of a subsoil layer, with a weight of 500-1,000 g for ensuring that the sample has the weight of 200 g after sieved;

[21] the 1/5,000 rock geochemical profiling may specifically include: arranging a profile in perpendicular to a long-axis direction of a 1/10,000 debris anomaly and enabling the profile to pass through a high-value point of a stream anomaly concentration center; positioning a start of the profile with a uniformly corrected GPS, orienting a profile line with a compass, measuring a distance with a measuring rope, providing a sampling point at 10 m, increasing a density to 3 m for a special zone; collecting an optical thin-section sample for complex lithohorizon and mineralization feature for authentication and analysis; and collecting a chemical sample with a chip method in case of an ore-bearing horizon or a zone with desirable mineralization;

[22] the 1/5,000 IP intermediate gradient profiling may specifically include: arranging a profile in perpendicular to a stratum, a contact zone, an anomalous long axis or a mineralized zone, carrying out a positioning survey on the profile with a uniformly corrected real-time kinematic (RTK), observing with an IP intermediate gradient device and recording an apparent resistivity ps and an apparent polarizability is, where working parameters include a power-supply polar distance AB=1,200 m, a measurement polar distance NIN=40 m, and a measurement point distance of 10 m; and during work, power-supply electrodes A and B are unmovable, measurement electrodes M and N move point by point at the same time along the profile, a measurement length is two thirds of a distance between the power-supply electrodes A and B, a recorded point is a midpoint between the M and the N, and power-supply time is 20 s; and

[23] the 1/10,000 high-accuracy magnetic survey may specifically include: arranging a surveyed grid and a profile in perpendicular to a stratum, and making a measurement dynamically in real time with a double-frequency GPS, where the magnetic survey has an overall accuracy of 5 nT, a geomagnetic total field serves as an observation parameter, a magnetometer has a sensitivity of up to 0.1 nT, and an error of the magnetometer in noise level, consistency, correction for diurnal variation, operation and point measurement is less than an overall error of the magnetic survey.

[24] Preferably, the carrying out shallow exposure and tracing by trenching, and controlling a specific position, a shape and a feature of a mineralized zone or a mineralized body may include: specifically arranging a trenching project on the basis of the field reconnaissance survey by using the preliminarily determined surface ore-bearing geobody position and mineralized horizon, where the trenching project is arranged in an ore-bearing zone having a coverage thickness of not more than 3 m, and perpendicular to a long-axis direction of a target geobody and a trending direction of a rock stratum; a trench has a bottom width of not less than 0.8 m and a depth of not more than 3 m, and is embedded into the bedrock by 0.3-0.5 m, until a roof, a floor or a layered interface of the mineralized body can be observed clearly and elements of an attitude can be measured; a chemical sample trench is provided at a junction between a trench wall and a trench bottom, labeled with a sample number, and is sampled with a channel method; the sample trench has copper-lead-zinc mineralization of 10*3 cm, gold-bearing silver mineralization of 10*5 cm, and a sample weight error rate of not more than 10%; during sampling, a rock surface on a sampling point is cleaned, an apron is suspended to ensure that the sample is not contaminated and splashed, a collection method strictly follows a standard, and samples are arranged according to a same orientation and a same inclination angle and connected end by end; except the zone where the chemical sample is collected, a rock sample is collected at 3-5 m and controlled by the whole trench; and through the trenching, the mineralized zone and the mineralized body are exposed and controlled, the shape, the attitude and the scale of the mineralized body are found out preliminarily, and the surface mineralized body is delineated; and

[25] when an attitude of some mineralized layer cannot be determined, an attitude of an orebody may be determined with the assistance of a 1/2,000 IP joint profiling, specifically including: arranging a profile in perpendicular to a stratum, a contact zone, an alteration zone or a mineralized zone, carrying out a positioning survey on the profile with a uniformly corrected RTK, observing with the IP joint profiling, and recording an apparent resistivity ps and an apparent polarizability 9s, where a power-supply polar distance OA=BO is 100 m, 200 m and 400 m, the corresponding MN/2 is respectively 5 m, 10 m and 20 m, a working point is provided at 5-10 m, and a power-supply electrode C is provided at infinity, with OC>5 times of OA; and during measurement, A, M, N and B move point by point along a measuring line, psA, sA and psB, rsB are respectively observed at each measuring point, and a recorded point is a midpoint between the M and the N.

[26] Preferably, the determining a change of a deep area of the mineralized body in grade, thickness, scale and attitude with a drilling technology to find orebodies or deposits may specifically include: drilling the delineated surface mineralized body, where a drill hole is specifically positioned in a surface mineralization enrichment zone with reference to an attitude and a topography of a rock mass or a stratum; the orebody has an attitude of 60-85°, and when the orebody has the attitude of more than 60, 80° inclined-hole drilling and large-diameter directional drilling are used, with an outer diameter of a drilling tool being not less than 75 mm; an ore core and a rock core in the orebody and within 3-5 m of the roof and floor thereof have an average core recovery rate of not less than 90%, a continuous length of an ore core having a core recovery rate of less than 90% in the thick and large orebody is not more than 5 m, and an ore core of a surrounding rock has an average core recovery rate of not less than 80% on each layer; a drilling sampling method is to cut the ore core and the rock core into two halves along a long axis and a mineralization homogeneity, one half being delivered to a test unit as a basic analytical sample for processing and testing, and the other half being preserved for checking and researching; and sampling on the mineralized body does not cross any layer, gold and silver on the sample are mineralized into 1.0 m, and multimetals such as copper, lead and zinc are mineralized into 1.5 m, an edge sample is taken on two sides of the mineralized body, and thus the change of the deep area of the mineralized body in grade, thickness, scale and attitude is determined by the drilling.

[27] Preferably, the preliminarily determining, according to mineralization features of the vein orebody in change of a high-low temperature ore and change of a vein width as well as an alteration zoning feature, a range of a concealed ore-bearing porphyry, and delineating a saccate low-resistivity body in a deep area with a 1/10,000 WFEM profiling may be to determine the specific position and the buried depth of the concealed ore-bearing porphyry;

[28] the mineralization feature of the vein orebody in change of the high-low temperature ore may be as follows: The vein orebody is mineralized and zoned in sequence from a heat source center into: Cu and Mo--Cu, Au and As->Cu, Pb, Zn, Ag and Sn--Pb, Zn and Ag--Ag, and changes from a high temperature ore to a low temperature ore;

[29] the alteration zoning feature may change as follows: a potassic zone--*a silicified zone-an argillic zone-a propylitic zone in sequence from a heat source center, where a thin-section sample is collected from an altered rock to research an alteration zonality systematically; and the ore is distributed in the silicified zone in a form of veinlet dissemination, dense dissemination, and veinlet dissemination superimposed vein zonation; and

[30] the 1/10,000 WFEM profiling may specifically include: arranging the 1/10,000 WFEM profiling at a favorable position of the concealed ore-bearing porphyry that is speculated according to the mineralization features and the alteration feature, where a wide-field electromagnetic system includes a wide-field electromagnetic transmitter, a wide-field electromagnetic receiver and a high-power generator; the wide-field electromagnetic transmitter has a signal source of an an-sequence pseudo-random signal, can transmit seven frequencies at the same time and has a voltage of <1,000 V, a current of <200 A and a frequency of 0.0117-8,192 Hz; and the wide-field electromagnetic receiver has the following specific indicators: an analog-to-digital converter (ADC) has a resolution of 24 bit and a rate of more than 600 KSPS, a signal input ranges from -37.5 mV to +37.5 mV, a signal frequency ranges from 0.0117 Hz to 10 KHz, a detection sensitivity is > 0.05 mV, a potential difference (PD) measurement accuracy is 0.5%, an input impedance is 3 MQ, a fixed gain is 100, a program controlled gain is 1-2n times, n=0-12, i.e., 1-4,096 times, a power frequency suppression at 50 Hz is 60 dB, a measurement point is provided at 40 m, and according to a detection depth to be reached, a test distance between the transmitter and the receiver is more than 15 km.

[31] Preferably, the exploring a concealed thick and large ore-bearing porphyry in the deep area with a deep drilling technology for the saccate low-resistivity body within the favorable range of the porphyry may specifically include: determining, in combination with a position and a depth of the saccate low-resistivity body delineated with the WFEM, a position and a depth of a drill hole at the favorable position of the concealed ore-bearing porphyry that is speculated according to the mineralization features and the alteration feature, where straight-hole drilling and large-diameter directional drilling are used, with an outer diameter of a drilling tool being not less than 75 mm; a rock core and an ore core drilled actually have a diameter of about 49 mm; an ore core and a rock core in the orebody and within 3-5 m of the roof and floor thereof have an average core recovery rate of not less than 90%, a continuous length of an ore core having a core recovery rate of less than 90% in the thick and large orebody is not more than 5 m, and an ore core of a surrounding rock has an average core recovery rate of not less than 80% on each layer; a drilling sampling method is to cut the ore core and the rock core into two halves along a long axis and a mineralization homogeneity, one half being delivered to a test unit as a basic analytical sample for processing and testing, and the other half being preserved for checking and researching; and sampling on the mineralized body does not cross any layer, gold and silver on the sample are mineralized into 1.0 m, and multimetals such as copper, lead and zinc are mineralized into 1.5 m, an edge sample is taken on two sides of the mineralized body, and thus the thickness, scale, mineralization type and orebody grade of the ore-bearing porphyry are determined by the drilling.

[32] The present disclosure achieves the following technical effects compared with the prior art: The method for comprehensive exploration of a polymetallic ore provided by the present disclosure pushes forward a prospecting method combined with the "metallogenic system+stream sediment survey+debris survey+large-scale geophysical and geochemical profiling/high-accuracy magnetic survey+engineering verification", and makes a huge breakthrough in prospecting. The Nagengkangqieergou mining area and the Harzhaz mining area have submitted silver resources of more than 6,400 tons, up to 80% or more in the total amount of silver ore resources explored in Qinghai Province. The combination method can effectively avoid restrictions of shallow covered conditions on conventional geological mapping, and can quickly shrink the prospecting target in a quaternary covered area to spatially position the mineralized alteration zone and the ore-bearing geobody, thereby improving the prospecting success rate. The method has the advantages of a short exploration period, a high efficiency and a low exploration cost, and is applied to exploring shallow vein copper-lead-zinc-silver-gold ores and skarn iron-copper ores. Moreover, as the WFEM has the absolute advantage of a large detection depth, the method is applied to exploring the deep concealed porphyry copper and molybdenum ores in combination with a prospecting predictive geological model established according to the geological feature, and the speculated range of the concealed ore-bearing porphyry.

BRIEF DESCRIPTION OF THE DRAWINGS

[33] To describe the technical solutions in the embodiments of the present disclosure or in the prior art more clearly, the accompanying drawings required for the embodiments are briefly described below. Apparently, the accompanying drawings in the following description show merely some embodiments of the present disclosure, and a person of ordinary skill in the art may still derive other accompanying drawings from these accompanying drawings without creative efforts.

[34] FIG. 1 is a flow chart of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[35] FIG. 2 is an integrated anomaly map of a 1/25,000 stream sediment survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[36] FIG. 3 is an integrated anomaly map of a 1/10,000 debris survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[37] FIG. 4 is an anomaly resolution map of a 1/5,000 rock geochemical profiling of a V ore zone in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[38] FIG. 5 is an anomaly resolution map of a 1/5,000 rock geochemical profiling of a VI ore zone in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[39] FIG. 6 is an anomaly map of a 1/5,000 IP intermediate gradient profiling in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[40] FIG. 7 is an anomaly map of a 1/2,000 IP joint profiling in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[41] FIG. 8 is an integrated anomaly map of a 1/10,000 high-accuracy magnetic survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[42] FIG. 9 is an anomaly map of a 1/10,000 WFEM survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[43] FIG. 10 is a profile map and a real picture of 11 prospecting lines of a VI ore zone of a metal mining area in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[44] FIG. 11 is a prospecting predictive geological model diagram of a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[45] In the FIG. 6: 1. Early Jurassic monzonite granite-porphyry, 2. Early Permian monzogranite, 3. Early Permian granodiorite, 4. Early Permian porphyaceous monzogranite, 5. crystal tuff of Elashan formation, 6. fault, 7. geological boundary, 8. alteration fracture zone, 9. anomaly zone with low resistivity and high polarizability, 10. No. of prospecting line, 11. position of drill hole, 12. No. of drill hole, 13. orebody grade/thickness, 14. No. of IP profile, 15. resistivity curve, and 16. polarizability curve.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[46] The technical solutions of the embodiments of the present disclosure are clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are merely a part rather than all of the embodiments of the present disclosure. All other examples obtained by a person of ordinary skill in the art based on the examples of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

[47] An objective of the present disclosure is to provide a method for comprehensive exploration of a polymetallic ore, to solve the above problems in the prior art and improve the prospecting success rate in the shallow covered area.

[48] To make the above-mentioned objectives, features, and advantages of the present disclosure clearer and more comprehensible, the present disclosure will be further described in detail below with reference to the accompanying drawings and the specific implementation.

[49] Referring to FIG. 1-11, FIG. 1 is a flow chart of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 2 is an integrated anomaly map of a 1/25,000 stream sediment survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 3 is an integrated anomaly map of a 1/10,000 debris survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 4 is an anomaly resolution map of a 1/5,000 rock geochemical profiling of a V ore zone in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 5 is an anomaly resolution map of a 1/5,000 rock geochemical profiling of a VI ore zone in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 6 is an anomaly map of a 1/5,000 IP intermediate gradient profiling in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 7 is an anomaly map of a 1/2,000 IP joint profiling in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 8 is an integrated anomaly map of a 1/10,000 high-accuracy magnetic survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 9 is an anomaly map of a 1/10,000 WFEM survey in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, FIG. 10 is a profile map and a real picture of 11 prospecting lines of a VI ore zone of a metal mining area in a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure, and FIG. 11 is a prospecting predictive geological model diagram of a Harzhaz area in a specific implementation of a method for comprehensively prospecting a polymetallic ore according to the present disclosure.

[50] With the Harzhaz copper-lead-zinc-silver-gold ores in the eastern segment of East Kunlun Mountain as an example, the embodiment describes the prospecting effects of combinations of prospecting technologies and methods.

[51] Understanding on ore-forming material sources and ore-controlling factors of porphyry-hydrothermal vein-skarn ores from metallogenic system:

[52] There are a number of silver-copper-lead-zinc polymetallic deposits in the eastern segment of East Kunlun Mountain, mainly including the Harzhaz deposit, the Nagengkangqieergou deposit, the Narimalahei deposit, the deposit in the south slope of Zhama Mountain, etc. Some silver deposits have a large scale. The silver polymetallic deposits are mainly of the epithermal type (Nagengkangqieergou) and the porphyry-hydrothermal vein type (Harzhaz), followed by the skarn type (Shiduolong). Different ore zones in the same deposit are formed by different reasons.

[53] 1. (1) Geotectonic background: The East Kunlun Mountain is the desired tectonomagmatic zone for formation of porphyry deposits, with the underplating combination, continental crust anatexis combination and delamination combination in the post-collision stage as the background. The deep fault combination mainly refers to the Central East Kunlun and Qimantage-Dunan deep major fractures and the connected secondary fractures, which are the important tectonomagmatic conditions for mineralization. According to features of the tectonic evolution and magmatic activity, the collision-type porphyry and intracontinental strike-slip porphyry are present in the zone, and the magma is mainly derived from the mantle source, crust and mantle mixed source, and melting of the juvenile lower crust. The calc-alkaline-high-K calc-alkaline rock associated with the adakite serves as an important condition for mineralization of porphyry in the East Kunlun Mountain.

[54] (2) Mineralization of porphyry metallogenic series ores: The porphyry metallogenic series ores in the Harzhaz area mainly undergo two stages. The first stage is that copper polymetallic ore-forming elements carried in volatiles migrate upward and outward during Indosinian-Yanshanian magmatic intrusion. The magma is cooled once contacting the surrounding rock, and minerals such as accessory minerals, dark minerals, plagioclase and quartz and elements such as copper polymetallic elements are crystallized therefrom. Along with further evolution of the magma, the copper elements are gathered constantly to form the concealed ore-bearing quartz porphyry around the Harzhaz. During the evolution, the magma is gradually condensed and crystallized over time from the edge to the center, and many copper elements are remained in the magma and enriched continuously with the evolution of the magma (the concealed ore-bearing porphyry). The second stage is to form ores such as copper, lead, zinc, tin, gold and silver ores in the Harzhaz. Along with the cooling, contraction and regional structure development, the ore-bearing hydrothermal solution migrates along fissures of the surrounding rocks and the northwest and northeast trending structural fracture zones under the driving of volatile components such as H2s-, F- and Cl-. During migration, the ore-bearing hydrothermal solution forms different ores at different temperatures, and this stage mainly focuses on filling mineralization, followed by metasomatism. From the porphyry to outside, the hydrothermal vein II and III mineralized zones, IV and V mineralized zones, VI mineralized zone, and VII mineralized zone as well as skarn Shengli iron-copper deposit are formed in sequence. Hence, the Harzhaz area possesses the features of the typical porphyry metallogenic series (porphyry-hydrothermal vein-skam) ores.

[55] (3) Silver enrichment in ore-bearing fluid: There is a large area of Late Triassic continental volcanic rocks of Elashan formation in the eastern segment of East Kunlun Mountain. The volcanic rock stratum of Elashan formation has a high Ag background value. The ore-bearing hydrothermal solution migrates under the driving of volatile components such as H2s-, F- and Cl-. When the surrounding rocks are the volcanic rocks of Elashan formation, Ag is extracted from the surrounding rocks to form the silver-enriched ore-bearing fluid. Hence, silver-enriched orebodies are typically delineated in structural zones of the volcanic rocks of Elashan formation.

[56] (4) Ore-controlling factors: Metallogenic zones are strictly controlled by the regional geologic structure. During long geological age, the area undergoes several times of complex and violent tectonic movements, and is under the control of North Kunlun, Central Kunlun and Wahongshan-Wenquan deep major fractures. The deep major fractures provide necessary substance migration channels for the magma and ore solution in the area. The secondary fractures are characterized as multi-stage activities. As is known to all, the silver polymetallic deposits are obviously controlled by the north-south or northwest trending secondary fractures, so the northwest trending fractures and interlaminar fractures are main ore-bearing structures.

[57] 2. Stream sediment survey: No. GA101, GA108, GA119, GA123, GA137, GA147, GA136 and GA130 delineated by the 1/25,000 stream sediment survey have an irregular elliptical and nearly circular anomaly that is distributed from northwest to southeast, as shown in FIG. 2. The Pb, Zn, Ag, Cu and Sn have the good register, and the accompanied elements include As, Sb, Bi, Mo, etc. The Cu, Pb and Ag elements that are typically distributed at the periphery of the anomaly of Zn, Sn, As and the like have the large area of anomaly, followed by the Sn element that is mostly distributed at the southeast of the anomaly of the Cu element. The Cu, Pb, Zn and Ag show the high anomalous peak value, large intensity, clear concentration center and desired three-level concentration zonage. The Pb and Ag basically have the same concentration site. The development of faulted structure and the anomalous shape in the anomaly zone are coincided with the structural line of the mining area and the delineated ore zone, which indicates that the prospect for finding the ores such as Cu, Ag, Pb, Zn, Sn and Au is desirable.

[58] 3. Anomaly features of debris survey: No. VIAYX1, VIAYX2, VIAYX3, VIAYX4, VIAYX5, VIAYX6, VIAYX7, VIAYX8, VIAYX9, VIAYX1O, VIIAYXI, VIIAYX2, VIIAYX3, VIIAYX4, VIIAYX5 and VIIAYX6 delineated by the 1/10,000 debris survey have the irregular elliptical and nearly circular anomaly that is distributed from northwest to southeast, as shown in FIG. 3. The anomaly in VIAYXI-VIAYX10 is mainly dominated by Cu and accompanied by Pb, Zn, W, Sn, Ag, Au, As and Bi. Generally, there are malachite mineralization, pyritization, ferritization and the like on the earth's surface. On the earth's surface, several malachite mineralization, ferritization and alteration fracture zones, the copper-bearing granodiorite-porphyry vein as well as the large-scale copper orebody are delineated. The VIIAYX1 has the northwest trending irregular elliptical anomaly, desired element register and intensive distribution of ore-forming elements, and is dominated by the Pb, Zn, Ag and As and accompanied by the anomaly of Au, Sb, Sn, Mo with the large area and high intensity. The Pb, Zn and Ag respectively have a peak value of 29,758*10-9, 881*10-9 ad >3,200*10-9. The VIIAYX2 has the irregular elliptical anomaly, and is dominated by As and Sb and accompanied by a small amount of Au, Ag and Mo with the general register. The VIIAYX3 has the irregular anomaly, and is dominated by As and Ag and accompanied by Au and a small amount of Pb and Zn with the small scale and poor register. Through verification, the V ore zone is delineated in sbl2 of the anomaly of the VIIAYX1 and there are copper, lead, zinc, tin, silver and gold ores, which can basically explain the anomaly. However, the anomaly has the large scale in east and west directions, and the orebody in the V ore zone cannot explain the width of the anomaly well, which indicates that the prospect for finding the copper, lead, zinc, tin, silver and gold ores is still desirable. The VIIAYX4 has the northwest trending irregular elliptical anomaly overall, good element register and intensive distribution of the ore-forming elements, and is most evidently reflected by anomalous shapes of the Pb, Zn and Ag and accompanied by the anomaly of the Cu. It is found that there are sb15, sb20 and sb19 alteration fracture zones in the anomaly, and strong kaolinization, ferritization, beresitization and the like on the earth's surface. Through verification, the VI lead-zinc-silver ore zone with the large scale has been discovered on the earth's surface and in the deep area. The VIIAYX5 has the east-west trending elliptical anomaly overall, good element register for Cu, Pb, Ag, Mo, Sn and Bi, and intensive distribution of the ore-forming elements. The anomaly is mainly controlled by the ductile shear zone. There are weak silicification, ferritization and the like on the earth's surface. The gold mineralized body is revealed by trenching. The VIIAYX6 has the elliptical anomaly, good element register for Cu, Pb, Zn, As, W and Sn, and intensive distribution of the ore-forming elements. However, the area of the anomaly is small. To sum up, the delineated debris anomaly is obviously controlled by the seven delineated ore zones, which indicates that the debris survey achieves the desirable effect, provides a good basis for selection of the favorable zone in geological prospecting, and further indicates the key for each ore zone in next work.

[59] 4. Rock geochemical profiling: The 1/5,000 rock profile is mainly distributed in debris VIIAYX1, VIIAYX2, VIIAYX3 and VIIAYX4 and is perpendicular to the long-axis direction of the anomaly. Some profile passes through the high-value point of the anomaly. It is mainly intended to decompose the anomaly and implement mineralization and localization. 12 1/5,000 rock profiles are distributed on the anomaly of the VIIAYX1, VIIAYX2 and VIIAYX3 at a large space, and are respectively numbered as YP13, YP14, YP15, YP16, YP17, YP18, YP19, YP20, YP21, YP22, YP23 and YP24, as shown in FIG. 4. With the Early Permian intrusive rocks as the surrounding rocks, the area forms batholith mostly and does not have the feature of a source bed in itself. The profiling results show that the Au, Ag, Cu, Pb, Zn, W, Sn, Bi and Mo have a small content. However, corresponding faults and ore-bearing alteration fracture zones in the profiles show a high element anomaly, and particularly, the anomaly is in the zonal distribution. In this sense, the prospecting range can further be shrunk to offer guidance for the next project. Six "#"-shaped rock profiles are distributed on the VIIAYX4 at a large space, and are respectively numbered as YP3, YP4, YP5, YP6, YP7 and YP8, as shown in FIG. 5. As can be seen, the anomaly is desirable and is in the approximately parallel zonal distribution. The Pb, Zn and Ag have the good element register and show the high anomaly. The Pb element has a maximum value of 13,056*10-6, and an average value of 1,049*10-6; the Zn element has a maximum value of 1,100*10-6, and an average value of 342*10-6; and the Ag element has a maximum value of 3,819*10-9, and an average value of 1,574*10-9. In the profiles, corresponding to the anomaly, there are the faults and alteration fracture zones, and particularly, the anomaly is in the zonal distribution. In this sense, the prospecting range can further be shrunk to offer guidance for the next project.

[60] 5. IP intermediate gradient profiling: The 1/5,000 IP intermediate gradient profile is mainly distributed in the debris VIIAYX, VIIAYX2, VIIAYX3 and VIIAYX4, and is perpendicular to the long-axis direction of the anomaly. There are 10 IP intermediate gradient profiles numbered as WP1-WP10. With analysis on an IP anomaly curve of this area, the normal field of the apparent resistivity is about 400-600 2-m, while that of the apparent polarizability is about 2-4%; the apparent-resistivity curve overall has the feature of being high in the north and low in the south, and high in the east and low in the west; and the apparent-polarizability curve has the feature of being high in middle and low on two sides, and the apparent polarizability in the south is low. A northwest trending anomaly zone can be separated in the south according to the high resistivity feature of the apparent-resistivity curve. The anomaly zone is coincided with the northwest trending faulted structure. The Early Permian monzogranite mainly exposed in the zone features medium-low resistivity and low polarizability according to a result from the measurement of electrical and physical properties and shows the anomaly in the rock contact zone or rock transition zone. In the middle of the profile, a northwest trending anomaly zone can be separated according to the high polarizability feature. The anomaly zone features low resistivity and high polarizability overall, shows a low apparent resistivity at a position where the apparent polarizability is high, and has the apparent resistivity of about 400 9-m at a maximum apparent polarizability of about 8%. The anomaly zone is about 3.2 km from the WP1 to the WP10, with the width being narrowed gradually from the north to the south, as shown in FIG. 6. With inspection on the earth's surface, ferritization and alteration fracture zones in the zonal distribution are found, which indicates that the ferritization and alteration fracture zones controlled by the faulted structures are favorable zones for mineralization, i.e., the IP anomaly of the low resistivity and high polarizability is the ore-forming anomaly.

[61] 6. IP joint profiling: The 1/2,000 IP joint profiling is mainly carried out on the developed zone of the alteration fracture zone on the earth's surface. The mineralization enrichment zone is discovered by trenching. However, in view that the inclination of the ore bed cannot be determined on the earth's surface, the method mainly assists in determining the attitude, buried depth, extension and the like of the orebody. The apparent resistivity ps and apparent polarizability Ts will be observed and recorded in the IP joint profiling. The power-supply polar distance OA=BO is 70 m, 140 m and 280 m and the corresponding MN/2 is respectively 10 m, m and 40 m; the working point is provided at 10 m, and the power-supply electrode C is provided at infinity, OC=1500 m; and during measurement, A, M, N and B move point by point along a measuring line, and Pa, Ia and Pb, 7b are respectively observed at each measuring point. As can be seen from FIG. 7, the apparent-resistivity curve in LP2 changes a lot, the apparent-polarizability curve is gentle overall with the background value of about 3%, and the apparent-resistivity curve and the apparent-polarizability curve are intersected obviously. When the polar distance is 70 m, the apparent polarizability is intersected at the point 146, the corresponding apparent resistivity shows the high resistivity, and the apparent-resistivity curve jumps zigzag and is inclined to the south with a steep angle. When the polar distance is 140 m, the apparent polarizability is intersected at the point 146, the corresponding apparent resistivity shows the low resistivity, and the na curve is unsmooth with the anomalous extremum; and when the polar distance is 280 m, the curve obviously indicates that the polarization body extends stably toward the deep area. The polarization body on the profile is overall inclined to the south with a steep and nearly upright angle, and the roof is close to the point 146. In LP3, the apparent-resistivity curve and the apparent-polarizability curve are intersected obviously. When the polar distance is 70 m, the apparent polarizability is intersected at the point 144, and the corresponding apparent resistivity shows the low resistivity and is inclined to the south with a steep angle. When the polar distance is 140 m, the apparent polarizability is intersected at the point 146, the corresponding apparent resistivity shows the low resistivity and the lb curve is smooth with the anomalous extremum; and when the polar distance is 280 m, the curve obviously indicates that the polarization body extends stably toward the deep area, the polarization body is overall inclined to the south with a steep angle, and the roof is close to the point 146. With analysis on anomalies of the IP joint profiling, it is found that the two profiles have the basically similar anomalous shapes and are characterized as the low resistivity and high polarizability. The apparent resistivity increases gradually from the west to the east, the background value of the apparent polarizability changes at about 3%, and the apparent resistivity and the apparent polarizability are intersected obviously and show obvious anomaly. When the polar distance is 70 m, 140 m and 280 m, the apparent-polarizability curve well reflects and indicates that the orebody extends to some extent in the deep area; and with analysis according to the curve feature of the IP joint profiling, the orebody is overall inclined to the south with the steep angle, and the attitude of the orebody changes locally due to the southwest trending fracture zone.

[62] 7. High-accuracy magnetic anomaly feature: The magnetic iron ores in marbles of the

Palaeoproterozoic Jinshuikou Group in the mining area show the strongest magnetism, with the average magnetic suspectibility of about 68,835-10- 5*4[-SI and the average remanent magnetization intnsity of about 25,328-10-3A/m. The plagioclasite hornblende schist and Early Jurassic syenogranite in the Palaeoproterozoic Jinshuikou Group show intermediate but non-uniform magnetism. The Late Triassic continental volcanic rocks of Elashan formation have the non-uniform magnetism, with some rocks showing the intermediate magnetism and some rocks showing the weak magnetism. The Early Permian granodiorite, altered granodiorite, and Late Ordovician gneissic granodiorite are main magnetic substances to result in the anomaly of the intermediate magnetism, and can lead to hundreds to thousands of nats of magnetic anomaly. The regular and zigzag anomaly is the disturbing anomaly of the area. The copper-bearing mineralized monzogranite, malachite mineralized granodiorite-porphyry and granodiorite-porphyry show weak magnetism, can only lead to several to hundreds of nats of magnetic anomaly, and can basically distinguished from the background field.

[63] Magnetic anomaly features and explanations and inferences: As shown in FIG. 7, according to the anomalous shape, the intensity and the located geological site, eight magnetic anomalies are delineated in total at the periphery of Harzhaz, and numbered as C-C8.

[64] Main anomaly features relevant to the mineralization are described as follows: 1/10,000 Magnetic anomaly scale and Explanations and Anomaly anomaly feature inferences Type No. As the meta-feldspar The C2 anomaly is located in the sandstone is extremely west of the surveyed area, and weak in magnetism and moves toward the northeast. The cannot result in the anomaly in the south is nearly anomaly, it is preliminarily circular. The anomaly in the north is inferred that the anomaly Ore-forming C2 divided into two branches, one may be associated with the branch being north-south trending contact between the anomaly and the other branch being meta-feldspar sandstone northeast trending. The positive and and the Late Triassic crystal negative anomaly peaks are at about tuff of Elashan formation in ±100 nT. the Palaeoproterozoic Jinshuikou Group. The C4 anomaly is northwest The anomaly is located at a trending, positive in the south and site where the Early negative in the north, and has a Permian granodiorite length of about 700 m and a width contacts the marble and of about 500 m. The intensity of the meta-feldspar sandstone of Ore-forming C4 positive anomaly in the south the Palaeoproterozoic anomaly increases from the south to the Jinshuikou Group. The north and the anomaly is nearly widespread distriution of elliptical. The positive anomaly has the Late Triassic a mean value of about 300 nT, and a continental volcanic rocks maximum value of 908.640 nT. of Elashan formation and the locally strong skarnization of the marble indicate that the anomaly is associated with the mineralization of a skarn iron and copper deposit. The C5 anomaly is accompanied by a large amplitude of positive and negative anomalies. Each anomaly There are the skarn iron has the peak value. The positive and copper deposits. anomaly has a mean value of about Results collected from the 400 nT and a maximum value of magnetic measurement of Ore-forming C5 1,404.1 nT, while the negative physical properties on the anomaly anomaly has a mean value of about magnetic iron ore reveal -250 nT and a minimum value of that the anomaly is the -1,283 nT. Herein, the marble of the ore-formingl anomaly. Palaeoproterozoic Jinshuikou Group is exposed. The C7 anomaly is located in the middle east of the surveyed area and is present in the Early Permian It is preliminarily inferred granodiorite surrounded by the that the anomaly may be marble vein. It is accompanied by a associated with the skarn Ore-forming C7 small amplitude of positive and polymetallic mineralization anomaly negative anomalies. The positive in the contact zone of deep anomaly has an intensity peak of marble and monzogranite. about 150 nT, and the negative anomaly has a small peak of about -50 nT.

[65] 8. Exposure by trenching and verification in drilling engineering

[66] With the 1/25,000 stream sediment survey and 1/10,000 debris survey, the distributions of preferable ores are determined. The anomaly in the zonal distribution is further delineated in the geochemical anomaly zone with the 1/5,000 rock profiling, 1/5,000 IP intermediate gradient profiling and 1/10,000 high-accuracy magnetic survey. Furthermore, through positioning the mineralization and trenching the earth's surface, VIII iron-copper-lead-zinc-silver-gold orebodies, which have a length of 200-2,800 m, a thickness of 1.5-31.24 m, a copper average grade of 0.48%, a lead average grade of 0.91%, a zinc average grade of 0.77%, a silver average grade of 89.63 g/t, a total iron grade of 34.17% and a gold average grade of 1.39 g/t, are delineated in the Harzhaz area.

[67] The mineralization enriched zone is found by trenching the V ore zone. However, the inclination of the ore bed cannot be determined on the earth's surface. Hence, with the IP joint profiling, it is determined that the deep orebody is inclined to the south to offer good guidance for verification and evaluation of drilling engineering on the deep area.

[68] 9. WFEM survey: With the 1/10,000 WFEM survey, the deep electrical tentonic feature of the VI ore zone in the Harzhaz area is known, and the underlying tentonic feature is detected. The resistivity parameter is obtained with the WFEM sounding method to know the deep electrical feature of the area. By explaining the electrical parameter, the deep feature of the rock mass and the faulted structure is known, and the position of the concealed ore-bearing porphyry is delineated to direct the deep ore prospecting in the area. During construction, 11-line electromagnetic profiling is carried on the VI ore zone. During the WFEM, data are inversed with least-square constraints based on a priori model. Terrain referenced static calibration may be carried out on the platform. Model constraints based on known physical properties may be carried out to be better approximate to the actual geological model.

[69] The GY3 profile has an azimuth of 40. Throughout the whole profile, the shallow layer is a low resistivity layer arising from the Late Triassic continental volcanic rocks of Elashan formulation (T3e). From the apparent resistivity, the shallow vein orebody and the Late Triassic continental volcanic rocks of Elashan formulation in the VI ore zone have a little difference and are distinguished difficultly. There is a low resistivity zone at points 230-264 on the profile. The zone extends 1,500 m from the shallow area to the deep area, and the deep area extends from the east to the north of the profile. As shown in FIG. 9, from the wide-field two-dimensional inversion outcomes, the apparent resistivity in the west shows no obvious low resistivity. However, there is one time of low resistivity with the apparent resistivity of 300-1,000 9-m, as well as a local low resistivity body at 1,100 m of the points 202-214 with the apparent resistivity of 300 9-m.

[70] 10. Establishment of prospecting predictive geological model: With analysis on the mineralization features of the VI ore zone, it is found that, from the near surface to the deep area, the mineralization changes from the hydrothermal vein type to the porphyry type, i.e., the typical "up veins+underneath mineralized granite" is present. According to FIG. 10, from shallow to deep, the lead, zinc and silver are sequentially mineralized in the quartz vein including the veinlet (1 mm)-medial vein (2-5 mm)-coarse vein (0.5-5 cm), to form typical hydrothermal vein ores; and toward the deep area, altered granite-porphyry of sparse disseminated mineralization is found. The deep mineralization presents the large thickness and uniform grade, and thus the typical porphyry ores are formed. From FIG. 11, the thick and large alteration zoning feature is found at the bottom of the vein orebody: propylitization (chlorite and epidote)-argillization (kaolin)-silicification (quartz)-potassic alteration (potassium feldspar), such that the range of the concealed ore-bearing porphyry can be preliminarily inferred. Therefore, the deep porphyry containing the thick and large orebody is the mother rock of the VI ore zone, which is also the key point to be explored in future. Through further exploration on the silicified zone and phyllic zone under the argillic zone, it is hopeful to find the thick and large porphyry copper and molybdenum orebodies to greatly increase the resources in the mining area.

[71] The typical porphyry-hydrothermal vein-skarn type is present in the mining area. With analysis according to the geological feature, and element combinations in geophysical anomaly and geochemical anomaly, the denudation degree of the mining area is shallow. In combination with the verification in drilling engineering, summarization in ore-forming rules and corroborative evidences from the geophysical prospecting WFEM, the Harzhaz mining area has the promising prospect to find the concealed porphyry copper and molybdenum ores.

[72] Through testing the exploring and prospecting technologies and methods in recent years, the present disclosure takes the silver-copper-lead-zinc-gold-tin deposit in the Harzhaz area as the key research object, finds a batch of silver polymetallic ore spots and mineralized spots at the peripheral and surrounding areas, and makes a great breakthrough to find the silver polymetallic ores. Therefore, the exploring method has the desirable prospecting effect to find the porphyry-hydrothermal vein-skarn iron-copper-lead-zinc-silver-gold polymetallic and precious metallic ores in the shallow covered area in the eastern segment of East Kunlun Mountain. It is to be noted that the method for comprehensive exploration of a polymetallic ore does not only take the silver-copper-lead-zinc-tin deposit in the Harzhaz area as an object, but makes the detailed description with the silver-copper-lead-zinc-tin deposit in the Harzhaz area as an example.

[73] Specific embodiments are used for illustration of the principles and implementations of the present disclosure. The description of the embodiments is used to help illustrate the method and its core principles of the present disclosure. In addition, those skilled in the art can make various modifications in terms of specific implementations and scope of application according to the teachings of the present disclosure. In conclusion, the content of the present specification should not be construed as a limitation to the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. A method for comprehensive exploration of a polymetallic ore, comprising the following steps: delineating a magmatite zone according to a spatio-temporal feature and a regional geological background at an output of magmatite, carrying out a 1/25,000 stream sediment survey on the magmatite zone to preliminarily delineate a prospecting target, classifying the target, and determining a segment having a strong anomaly or a desirable anomaly register in copper, lead, zinc, silver and gold as a first preferable target; selecting, after carrying out a 1/10,000 debris survey on the first preferable target according to a surface bedrock exposure condition to delineate an anomaly, a segment having a strong anomaly or a desirable anomaly register in copper, lead, zinc, silver and gold as a second preferable target; carrying out, according to a feature that a surface ore is distributed along a secondary tectonic zone, a 1/5,000 soil geochemical profiling or a 1/5,000 rock geochemical profiling or a 1/5,000 induced polarization (IP) intermediate gradient profiling or a 1/10,000 high-accuracy magnetic survey on the second preferable target to decompose an anomaly, and delineating a geophysical and geochemical anomaly zone in a zonal distribution as a third preferable target, i.e., determining a surface ore-bearing geological position; carrying out a reconnaissance survey on the third preferable target to find a surface ore-bearing geobody position and a mineralization tracing area in an anomaly zone; carrying out shallow exposure and tracing on the ore-bearing geobody position and the mineralization tracing area by trenching or shallow drilling, controlling a specific position, a shape and a feature of a mineralized zone or a mineralized body, and determining an inclination of an orebody under the assistance of a 1/5,000 IP joint profiling; determining a change of a deep area of the mineralized body in grade, thickness, scale and attitude with a drilling technology, and controlling vein silver, copper, lead and zinc orebodies or ore zones; and preliminarily determining, according to mineralization features of the vein orebody in change of a high-low temperature ore and change of a vein width as well as an alteration zoning feature of propylitization-argillization-silicification-potassic alteration, a range of a concealed ore-bearing porphyry, and delineating a saccate low-resistivity body in a deep area with a 1/10,000 wide-field electromagnetic method (WFEM) profiling, i.e., determining a specific position and a buried depth of the concealed ore-bearing porphyry; and exploring a concealed thick and large ore-bearing porphyry in the deep area with a deep drilling technology for the saccate low-resistivity body within the range of the concealed ore-bearing porphyry, and controlling porphyry copper and molybdenum ores.

2. The method for comprehensive exploration of a polymetallic ore according to claim 1, wherein the vein orebody is dominated by copper, lead, zinc, silver and gold ores or lead, zinc and silver ores, and accompanied by a tin ore; and the concealed porphyry ores are copper and molybdenum ores.

3. The method for comprehensive exploration of a polymetallic ore according to claim 2, wherein a metallogenic system is a porphyry metallogenic system in a continental collision orogenic environment, and forms a porphyry-hydrothermal vein-skarn metallogenic series; wherein the 1/25,000 stream sediment survey is implemented by controlling a sampling density at 16-20 points/1 km 2 , preparing an integrated anomaly map for test data, carrying out an intra-class sequence evaluation on same major elements, classifying an anomaly according to an anomaly feature, a geological condition and a prospecting significance, preliminarily delineating the prospecting target in combination with a regional geological feature and a geology outcome from former geophysical and geochemical prospecting and heavy mineral anomaly, and classifying the target; wherein the 1/10,000 debris survey is implemented by arranging a sampling line at 90-270°, positioning with a high-accuracy global positioning system (GPS), arranging a grid basically at 100*40 m for the debris survey, and directly carrying out multi-point chip sampling when a bedrock is exposed; carrying out, in case of coverage of soil or eolian less, exposure until the bedrock is exposed, sampling multiple points at 2-10 mm to form a sample having a weight of >300 g, preparing an integrated anomaly map for test data with software, carrying out an intra-class sequence evaluation on same major elements, and classifying an anomaly according to an anomaly feature, a geological condition and a prospecting significance; and delineating an integrated anomaly of the debris survey in combination with a geological feature of an mining area and an anomaly range of a former 1/25,000 stream sediment survey, and determining the segment having the strong anomaly or the desirable anomaly register in copper, lead, zinc, silver and gold as the second preferable target; wherein the carrying out a 1/5,000 soil geochemical profiling or a 1/5,000 rock geochemical profiling or a 1/5,000 IP intermediate gradient profiling or a 1/10,000 high-accuracy magnetic survey on the second preferable target to decompose an anomaly, and delineating a geophysical and geochemical anomaly zone in a zonal distribution as a third preferable target or a third anomaly zone are to determine a position of an ore-bearing zone; the 1/5,000 soil geochemical profiling specifically comprises: arranging a profile in perpendicular to a long-axis direction of a 1/10,000 debris anomaly and enabling the profile to pass through a high-value point of a stream anomaly concentration center; positioning a start of the profile with a uniformly corrected GPS, orienting a profile line with a compass, measuring a distance with a measuring rope, providing a sampling point at 10 m, increasing a density to 3 m for a structural fractured alteration zone and a mineralized zone, and collecting a sample within a 1/3 range of the distance around the sampling point, wherein the sample is collected at one point or 3-5 points in a same medium and a same horizon; and a soil sample is collected in a substratum at 30-80 cm beneath the earth's surface, and if the substratum is not collected due to a thick coverage, the sample is collected at a bottom of a subsoil layer, with a weight of 500-1,000 g for ensuring that the sample has the weight of 200 g after sieved; the 1/5,000 rock geochemical profiling specifically comprises: arranging a profile in perpendicular to a long-axis direction of a 1/10,000 debris anomaly and enabling the profile to pass through a high-value point of a stream anomaly concentration center; positioning a start of the profile with a uniformly corrected GPS, orienting a profile line with a compass, measuring a distance with a measuring rope, providing a sampling point at 10 m, and increasing a density to 3 m for a special zone; collecting an optical thin-section sample for complex lithohorizon and mineralization feature for authentication and analysis; and collecting a chemical sample with a chip method in case of an ore-bearing horizon or a zone with desirable mineralization; the 1/5,000 IP intermediate gradient profiling specifically comprises: arranging a profile in perpendicular to a stratum, a contact zone, an anomalous long axis or a mineralized zone, carrying out a positioning survey on the profile with a uniformly corrected real-time kinematic (RTK), observing with an IP intermediate gradient device and recording an apparent resistivity ps and an apparent polarizability qs, wherein working parameters comprise a power-supply polar distance AB=1,200 m, a measurement polar distance MN=40 m, and a measurement point distance of 10 m; and during work, power-supply electrodes A and B are unmovable, measurement electrodes M and N move point by point at the same time along the profile, a measurement length is two thirds of a distance between the power-supply electrodes A and B, a recorded point is a midpoint between the M and the N, and power-supply time is 20 s; and the 1/10,000 high-accuracy magnetic survey specifically comprises: arranging a survey grid and a profile in perpendicular to a stratum, and making a measurement dynamically in real time with a double-frequency GPS, wherein the magnetic survey has an overall accuracy of 5 nT, a geomagnetic total field serves as an observation parameter, a magnetometer has a sensitivity of up to 0.1 nT, and an error of the magnetometer in noise level, consistency, correction for diurnal variation, operation and point measurement is less than an overall error of the magnetic survey; wherein the carrying out shallow exposure and tracing by trenching, and controlling a specific position, a shape and a feature of a mineralized zone or a mineralized body comprises: specifically arranging a trenching project on the basis of the field reconnaissance survey by using the preliminarily determined surface ore-bearing geobody position and mineralized horizon, wherein the trenching project is arranged in an ore-bearing zone having a coverage thickness of not more than 3 m, and perpendicular to a long-axis direction of a target geobody and a trending direction of a rock stratum; a trench has a bottom width of not less than 0.8 m and a depth of not more than 3 m, and is embedded into the bedrock by 0.3-0.5 m, until a roof, a floor or a layered interface of the mineralized body are observed clearly and elements of an attitude are measured; a chemical sample trench is provided at a junction between a trench wall and a trench bottom, labeled with a sample number, and is sampled with a channel method; the sample trench has copper-lead-zinc mineralization of 10*3 cm, gold-bearing silver mineralization of 10*5 cm, and a sample weight error rate of not more than 10%; during sampling, a rock surface on a sampling point is cleaned, an apron is suspended to ensure that the sample is not contaminated and splashed, a collection method strictly follows a standard, and samples are arranged according to a same orientation and a same inclination angle and connected end by end; except the zone where the chemical sample is collected, a rock sample is collected at 3-5 m and controlled by the whole trench; and through the trenching, the mineralized zone and the mineralized body are exposed and controlled, the shape, the attitude and the scale of the mineralized body are found out preliminarily, and the surface mineralized body is delineated; and when an attitude of some mineralized layer is not determined, an attitude of an orebody is determined with the assistance of a 1/2,000 IP joint profiling, specifically comprising: arranging a profile in perpendicular to a stratum, a contact zone, an alteration zone or a mineralized zone, carrying out a positioning survey on the profile with a uniformly corrected RTK, observing with the IP joint profiling, and recording an apparent resistivity ps and an apparent polarizability fs, wherein a power-supply polar distance OA=BO is 100 m, 200 m and 400 m, the corresponding MN/2 is respectively 5 m, 10 m and 20 m, a working point is provided at 5-10 m, and a power-supply electrode C is provided at infinity, with OC>5 times of OA; and during measurement, A, M, N and B move point by point along a measuring line, pA, isA and pB, isB are respectively observed at each measuring point, and a recorded point is a midpoint between the M and the N; wherein the determining a change of a deep area of the mineralized body in grade, thickness, scale and attitude with a drilling technology to find orebodies or deposits specifically comprises: drilling the delineated surface mineralized body, wherein a drill hole is specifically positioned in a surface mineralization enrichment zone with reference to an attitude and a topography of a rock mass or a stratum; the orebody has an inclination angle of 60-85°, and when the orebody has the attitude of more than 60, 80° inclined-hole drilling and large-diameter directional drilling are used, with an outer diameter of a drilling tool being not less than 75 mm; an ore core and a rock core in the orebody and within 3-5 m of the roof and floor thereof have an average core recovery rate of not less than 90%, a continuous length of an ore core having a core recovery rate of less than 90% in the thick and large orebody is not more than 5 m, and an ore core of a surrounding rock has an average core recovery rate of not less than 80% on each layer; a drilling sampling method is to cut the ore core and the rock core into two halves along a long axis and a mineralization homogeneity, one half being delivered to a test unit as a basic analytical sample for processing and testing, and the other half being preserved for checking and researching; and sampling on the mineralized body does not cross any layer, gold and silver on the sample are mineralized into 1.0 m, and multimetals such as copper, lead and zinc are mineralized into 1.5 m, an edge sample is taken on two sides of the mineralized body, and thus the change of the deep area of the mineralized body in grade, thickness, scale and attitude is determined by the drilling.

4. The method for comprehensive exploration of a polymetallic ore according to claim 2, wherein the preliminarily determining, according to mineralization features of the vein orebody in change of a high-low temperature ore and change of a vein width as well as an alteration zoning feature, a range of a concealed ore-bearing porphyry, and delineating a saccate low-resistivity body in a deep area with a 1/10,000 WFEM profiling are to determine the specific position and the buried depth of the concealed ore-bearing porphyry; the mineralization feature of the vein orebody in change of the high-low temperature ore is as follows: The vein orebody is mineralized and zoned in sequence from a heat source center into: Cu and Mo--Cu, Au and As->Cu, Pb, Zn, Ag and Sn--Pb, Zn and Ag--Ag, and changes from a high temperature ore to a low temperature ore; the alteration zoning feature changes as follows: a potassic zone--a silicified zone--*an argillic zone-a propylitic zone in sequence from a heat source center, wherein a thin-section sample is collected from an altered rock to research an alteration zonality systematically; and the ore is distributed in the silicified zone in a form of veinlet dissemination, dense dissemination, and veinlet dissemination superimposed vein zonation; and the 1/10,000 WFEM profiling specifically comprises: arranging the 1/10,000 WFEM profiling at a favorable position of the concealed ore-bearing porphyry that is speculated according to the mineralization features and the alteration feature, wherein a wide-field electromagnetic system comprises a wide-field electromagnetic transmitter, a wide-field electromagnetic receiver and a high-power generator; the wide-field electromagnetic transmitter has a signal source of an an-sequence pseudo-random signal, transmits seven frequencies at the same time and has a voltage of <1,000 V, a current of <200 A and a frequency of 0.0117-8,192 Hz; and the wide-field electromagnetic receiver has the following specific indicators: an analog-to-digital converter (ADC) has a resolution of 24 bit and a rate of more than 600 KSPS, a signal input ranges from -37.5 mV to +37.5 mV, a signal frequency ranges from 0.0117 Hz to 10 KHz, a detection sensitivity is > 0.05 mV, a potential difference (PD) measurement accuracy is ±0.5%, an input impedance is 3 ME, a fixed gain is 100, a program controlled gain is 1-2n times, n=0-12, i.e., 1-4,096 times, a power frequency suppression at 50 Hz is 60 dB, a measurement point is provided at 40 m, and according to a detection depth to be reached, a test distance between the transmitter and the receiver is more than 15 km.

5. The method for comprehensive exploration of a polymetallic ore according to claim 1, wherein the exploring a concealed thick and large ore-bearing porphyry in the deep area with a deep drilling technology for the saccate low-resistivity body within the favorable range of the porphyry specifically comprises: determining, in combination with a position and a depth of the saccate low-resistivity body delineated with the WFEM, a position and a depth of a drill hole at the favorable position of the concealed ore-bearing porphyry that is speculated according to the mineralization features and the alteration feature, wherein straight-hole drilling and large-diameter directional drilling are used, with an outer diameter of a drilling tool being not less than 75 mm; an ore core and a rock core in the orebody and within 3-5 m of the roof and floor thereof have an average core recovery rate of not less than 90%, a continuous length of an ore core having a core recovery rate of less than 90% in the thick and large orebody is not more than 5 m, and an ore core of a surrounding rock has an average core recovery rate of not less than % on each layer; a drilling sampling method is to cut the ore core and the rock core into two halves along a long axis and a mineralization homogeneity, one half being delivered to a test unit as a basic analytical sample for processing and testing, and the other half being preserved for checking and researching; and sampling on the mineralized body does not cross any layer, gold and silver on the sample are mineralized into 1.0 m, and multimetals such as copper, lead and zinc are mineralized into 1.5 m, an edge sample is taken on two sides of the mineralized body, and thus the thickness, scale, mineralization type and orebody grade of the ore-bearing porphyry are determined by the drilling.

ͨ1/11ͨ 23 Aug 2021

DRAWINGS Indosinian-Yanshanian porphyry metallogenic system

Northwest trending and nearly north-south trending granite area in the eastern segment of East Kunlun Mountain 2021106564

Preferrable copper-zinc-silver-gold anomaly in 1/ 25,000 stream sediment survey

Preferrable copper-zinc-silver-gold anomaly in 1/ 10,000 debris survey

Surface inspection to find an ore-containing geobody

Exposure by trenching and shallow drilling

Delineation of an ore zone or an orebody

Verification in drilling engineering

Control of a shallow vein orebody

Porphyry-hydrothermal vein metallogenic series, and 1/10,000 WFEM

Practice in deep drilling engineering

Evaluation of a concealed porphyry ore

FIG. 1

ͨ2/11ͨ 23 Aug 2021

Integrated anomaly map of 1/25,000 geochemical prospecting in Harzhaz area, Dulan County, Qinghai Province 2021106564

FIG. 2

FIG. 3 ͨ3/11ͨ

FIG. 4 ͨ4/11ͨ

FIG. 5 ͨ5/11ͨ

FIG. 6 ͨ6/11ͨ

ͨ7/11ͨ 23 Aug 2021 2021106564

Point No. Point No.

FIG. 7

FIG. 8 ͨ8/11ͨ

FIG. 9 ͨ9/11ͨ

ͨ10/11ͨ 23 Aug 2021

Profile map of 11 prospecting lines for VI ore zone in Harzhaz orefield Scale 1:1000 2021106564

Legen d No. of main orebody No. of drill hole Lead-zinc- solver ore

FIG. 10

ͨ11/11ͨ 23 Aug 2021

Trending profile map of VI ore zone in Harzhaz polymetallic mining area 23 line 15 line 3 line m 19 line 11 line 0 line 7 line 4 line 8 line

m 2021106564

m

Prophylitic zone Argillic zone Silicified zone Late Triassic continental volcanic rocks Legend

of Elashan formulation Plagioclasite hornblende schist of palaeoproterozoic Jinshuikou Group Late intrusive granite Orebody

FIG. 11