The W-Sn-Ag-Pb-Zn polymetallic deposit in the Bozhushan ore concentration area is closely related to Late Cretaceous magmatic activity, and the diagenetic age of the granite body is 88.8-87.1 Ma. The granites in the Bozhushan ore district are characterized by high silica and aluminium contents, high abundances of Rb, Sr, Sn and Th, and low contents of Ba, P and Ti. The granites are peraluminous S-type granites that underwent fractional crystallization during magmatic evolution. The epsilon Hf(t) values of the zircons from -17.92 to -1.77, with T DM2 age ranging from 1.1 to 2.0 Ga, indicate that they may be mainly derived from partial melting of the lower crust without the addition of mantle-derived materials. The Late Cretaceous magmatic activity in the Bozhushan area formed in a syn-collisional tectonic environment and transitioned to a post-collisional orogenic environment. In the later stage, it transforms into a post-collisional extensional environment. The upwelling of deep-seated asthenospheric melts has provided substantial fluxes of W, Sn, Pb, Zn and other ore-forming elements. The ore-forming fluid and materials carried by magma rise and migrate along favourable parts of the structure to precipitate and mineralize. Therefore, understanding the tungsten-tin metallogenic history in the Bozhushan ore district is important.

The Bainiuchang Ag-polymetallic ore deposit,located in southeastern Yunnan,China,is one of the region's largest deposits.However,the hypabyssal granite porphyry within this mining area has yet to be comprehensively investigated.In this study,we conducted geochemical,geochronological,whole-rock Sr-Nd isotope,and zircon Hf isotope analyses on granite porphyry samples collected from the Bainiuchang deposit.The results indicate that the granite porphyry formed between 87.5 and 87.4 Ma in the Late Yanshanian period.Geochemically,the granite is strongly peraluminous,with high silica and alkali contents consistent with S-type granite characteristics.The granite porphyry is enriched in large-ion lithophile elements(Rb,Th,U,and K)and is relatively depleted in Ba and Sr.The initial 87 Sr/86 Sr ratios are high(0.71392-0.71585),accompanied by low ε Nd(t)values(-8.9 to-8.2).The zircons exhibited similarly low ε Hf(t)values(-9.31 to-3.6).These data suggest that the porphyry-forming magma originated from a continental crustal source.The two-stage Hf and Nd model ages are estimated at 1534-1216 Ma and 1615-1561 Ma,respectively.Thus,the granite porphyry likely formed under a strike-slip extensional setting in the Late Yanshanian period and resulted from the re-melting of Proterozoic basement metagreywackes.This porphyry shares a similar magmatic origin with concealed granite bodies within the deposit and is associated with structural reactivation during the Yanshanian.The findings of this study provide valuable insights into the tectonomagmatic mineralization processes in the Bainiuchang area.

Southeastern Yunnan lies within a composite zone at the convergence of the South China, Yangtze, and Indochina (Tibet-Yunnan) blocks. Its complex regional structure provides favorable conditions for metallogenesis, making it a major metallogenic province in Southern China. The Bainiuchang Ag-polymetallic deposit is a representative super-large deposit in the area, whose genetic classification has long been controversial. Based on field investigations, this study conducted petrographic analysis, LA-ICP-MS in-situ laser ablation, and elemental mapping of pyrite ore samples from the Bainiuchang deposit. The results distinguish two macroscopic ore types: layered, bedded, and lenticular synsedimentary tectonic pyrite; disseminated, stockwork, and lumpy metasomatic structural pyrite. The study confirms that the Bainiuchang Ag-polymetallic deposit is a polygenetic system characterized by the spatiotemporal superposition of multistage mineralization events. During the Late Caledonian, Sedimentary Exhalative (SEDEX) processes formed early-stage pyrite, and sulfosalt minerals, establishing a metal-enriched precursor for subsequent mineralization. During the Late Yanshanian, Magmatic-Hydrothermal activity overprinted the pre-existing mineralization. Proximal to granitic intrusions, contact metamorphism generated skarn-hosted Sn-W mineralization at deep structural levels. At intermediate distances, hydrothermal fluids cooled and decompressed along the F3 fault system, precipitating Ag-Pb-Zn-dominant ore bodies with associated Fe-Cu sulfides. At shallower epithermal depths, continued fluid ascent formed stibnite-dominated Sb mineralization.

The Bainiuchang Ag polymetallic deposit in Yunnan Province is located at the junction of the Cathaysia, Yangtze and Indosinian blocks. It has favorable conditions for mineralization due to the influence of multi-phase geological effects. In this paper, the analysis data of major element formed in the course of exploration and development of the deposit for many years has an in-depth mining on the basis of the establishment of prospecting database and ore body model by the method of geochemistry and statistics. The triangle plots of the ore-forming elements show that the Zn/Pb values are concentrated between the 0.70 and 3.50 range, with higher grades of Ag, Sn and Cu in this range, and that the Zn/Pb values are indicative of ore-forming fluid. The results of the principal component analysis show that two principal components, P1 and P2 are able to explain most of the information in the original variables, and the element assemblage of P1 is Ag-Pb-Zn, which represents the mesothermal ore-forming element assemblage. The element assemblage of P2 is Sn-Zn/Pb, representing high temperature ore-forming element assemblage. Therefore, the source of the ore-forming fluid is located in the southern part of the mining area, and the ore-forming fluid was transported and deposited from south to north to form the above mineralization zoning regularities. The metal-element assemblages and spatial mineralization regularities obtained based on geostatistical analysis will provide a theoretical basis for the studies of deposit genesis, and resource exploration and development in mining areas.

>1. Objective The Gejiu-Bozhushan-Laojunshan tin-tungsten polymetallic metallogenic belt is located in southeastern Yunnan. It is bounded by the Mile-Shizong Fault and the Yangzi Plate to the north and west, respectively, while the Honghe Fault represents its southwestern boundary. It is adjacent to the Ailaoshan Fault, and extends to Guangxi and Vietnam to the southeast (Fig.1a; Liu JP et al., 2021).

The Yinachang Fe-Cu-Au-U-REE deposit is hosted by the lower part of the Paleoproterozoic Kunyang Group in the central Yunnan Province of SW China in an area known to contain iron-oxide Cu-Au mineralisation. The deposit includes: (i) the sulphide assemblage chalcopyrite - pyrite - magnetite - cobaltite - molybdenite - cassiterite; (ii) Rare Earth Element assemblage bastnaesite - parasite - fergusonite - xenotime - monazite; (iii) the uranyl hydroxide mineral vandendriesscheite; (iv) gold commonly hosted by ankerite; and (v) the gangue mineral assemblage apatite - biotite - fluorspar - quartz - calcite. The ore is commonly massive, disseminated, banded, or in calcite veins. The banded mineralisation contains high concentration of Au, Co, Mo, U, Fe, Cu and REE, and the vein-type mineralisation has abundant REE minerals of bastnaesite, parisite, fergusonite and xenotime. Monazite exists as inclusions in apatite or as discrete grains on the surface of magnetite, and the uranium is associated with chalcopyrite. The mineralising process can be divided into an initial Na-alteration followed by the ore-forming assemblages of Fe-REE and Cu-Au-U-REE mineralisation. The average delta O-18(H2O) values in the quartz and calcite change are between 3.5 and 10.7 parts per thousand, with delta DV-SMOW values ranging between -98.2 and -47.7 parts per thousand. The calcite, siderite and ankerite have delta C-13 isotope composition ranges from -14 to +1 parts per thousand and delta O-18 compositions of +6.9 to +22 parts per thousand. The H-O-C isotope systematics indicate that the mineralising fluids have mixed magmatic and metamorphic sources, whereas the carbon is sourced from marine carbonate, and the low temperature alternation of polyphase mantle material. In situ delta S-34 sulphide value ranges between 1.1 and 11.9 parts per thousand, and the bulk delta S-34 value ranges between -4.7 and 10.5 parts per thousand. In situ Pb isotopes of sulphide samples have Pb-206/Pb-204 values of 18.58-18.76, Pb-207/Pb-204 values of 15.51-15.66 and Pb-208/Pb-204 values of 37.47-38.06. These values plot in the upper crust Pb-evolution curve, indicative of a complex source of Pb in the deposit. The Pb is interpreted to have a deep-seated magmatic source with a contribution from the crust. It is also proposed that the REE-mineralised fluids are derived from a late stage of alkaline magma differentiation. The 40Ar-39Ar biotite date indicates that the Precambrian rocks in the Kangdian region were regionally metamorphosed at ca. 900 Ma. The Yinachang Fe-Cu-Au-U-REE deposit is interpreted as an IOCG deposit based on geological and isotopic studies. The banded ore and vein type ore are the main exploration targets for uranium, gold and REE. This study helps us better understand IOCG deposits in China.

The Yinachang Fe-Cu-Au-U-REE deposit is located in the Kangdian region at the southwestern margin of the Yangtze Block. This contribution presents petrological, geochronological, whole rock geochemical, and Rare Earth Elements (REE) geochemistry of zircons of gabbro and diorite dykes associated with the Yinachang Fe-Cu-Au-U-REE deposit, aiming to constrain the age of the mineralisation and help refine our understanding of the tectonic setting of the region. Zircons from diorite have a Palaeoproterozoic U-Pb age of 2014 +/- 30 Ma, and zircons from the gabbro could not be dated because they are metamict, having a high concentration of uranium. The ca. 2014 Ma age of the zircons in the diorite indicates that the southwestern part of the Yangtze Block is partly synchronous with the Columbia Supercontinent. Geochemically, the diorite and gabbro are enriched in large-ion lithophile elements (LILEs) such as Rb and U, and depleted in high-field-strength elements (HFSEs) such as Nb, P, Ti, Ba, and Sr. The diorite is enriched in light REEs (LREEs) and has a slight to negligible Eu anomaly, which are characteristic of ocean-island basalts containing mantle-derived high potassic calc-alkaline rocks. In contrast, the gabbro is weakly enriched in LREES and has a slightly negative Eu anomaly similar to those of potassic calc-alkaline enriched mid-ocean-ridge basalt. The average combined REE content of zircons from the gabbro is 19401 ppm and is significantly higher than that of the zircons from the diorite averaging 1020 ppm. This indicates that the gabbro is closely related with the REE mineralisation at the deposit. The geochemistry of the diorite indicates that it formed at the continental margin of a volcanic-arc. It also indicates that the magmatic rocks in the region have a possible mantle plume origin contaminated by crustal material and located at a transitional zone between a rift and an ocean-continent tectonic setting.

The Laojunshan mining district is an important part of the SE Yunnan W-Sn polymetallic mineral belt. Previous geochronologic data have shown that the main metallogenic stages in this area are Indosinian and Yanshanian in age. In this paper, we present a new dating result that differs from those published previously by using the in situ LA-MC-ICP-MS geochronologic method on a cassiterite sample from the giant Xinzhai tin deposit. Analyses of this sample yielded a U-Pb Tera Wasserburg age of 419.1 +/- 6.7 Ma. This new date identifies a Caledonian metallogenic event at the Xinzhai tin deposit and this age is also consistent with Caledonian magmatic and tectonic activity previously recognized in the Laojunshan mining district. Therefore, not only Yanshanian and Indosinian metallogenic stages but also a Caledonian mineralization event must have occurred in the study area. This new result may play an important role in ore prospecting and metallogenic study in the Laojunshan mining district and, more importantly, in all of SE Yunnan.

Jiangfeng magnetite ore deposit locates in south of Menglong county in Jinghong city, Yunnan prov-ince. Strata in this ore district is mainly lower Damenglong Formation, Proterozoic, and Menghai granite body is developed. Based on the analysis of engineering dxploration, we conclude that the Jiangfeng magnetite ore body belongs to a large ore deposit. The deposit can be divided into Jiangfeng and Hongshao ore sections. This paper only discusses the Jiangfeng ore section. By means of drilling, field logging, data treatment, sample analysis and regional comparison, we discover that primary magnetite ore deposit is hosted in the metamorphic series where diopside skarn developed. The specific location is the second (Ptdm1-2) and third (Ptdm1-3) layer of the lower sec-tion of Daxulong Formation. The ore bodies, most stratiform-like, are basically consistent with strata. The results of rock-mineral identification show that the deposit is closely related with the volcano sedimentary and hydrother-mal contact. Conclusion demonstrated that iron ore source layer in Early Proterozoic experienced complicated re-gional metamorphism and Hydrothermal metasomatism from acid igneous rock, and during this process iron sepa-rated out. Skarn type magnetite deposit then enriched in favorable topographic position.

This article mainly analyzed and discussed the origin of exposed phosphate rock mine in Huaning area.We preliminary think the ore was started from basin phosphate deposits in the early and get rich from transportation and modification by the water repeatedly.Also at the diagenesis phase,the Eh value is lower and Ph value is higher which makes phosphate concentration of interstitial water higher.With the affection of rich phosphorus interstitial water,the sediment get further phosphatization and makes the rock more rich.At the same time,the calcium phosphate of intergranular water cements particles what makes the apatite has the characteristics of girdles.The analyzation leads that the cause of formation of phosphorus deposits in this area was sedimentation and modification.

云南澜沧老厂多金属矿区是“三江”成矿带中重要的多金属矿床.位于滇西澜沧江断裂以西的昌宁一孟连裂谷带南段的澜沧裂谷中.该区构造环境演化历经了大陆裂谷期、封闭、碰撞造山期3次重大体制的转变.三大有利成矿构造环境更替,多种重要成矿地质作用的叠加和耦合特征明显.矿区深部揭露的Ⅵ号厚大钼(铜)矿体群属喜山期斑岩有关的夕卡岩、斑岩型矿床,是矿区取得找矿重大突破的成矿类型和资源类型之一.本文结合了澜沧老厂矿区的地、物、化、遥等信息对钼资源进行研究、预测,预测钼资源规模达大-超大型.通过对澜沧老厂钼矿特征及资源前景研究分析,以期引起澜沧老厂及外围深部找矿的重视,为该区找矿突破提供深远影响.

Based on the investigation of ore-forming geological background, ore material source and metallogenic process of Lufeng-Wuding area in comparison with the metallogenic conditions of the Dongchuan type iron-copper polymetallic deposits, the authors further prove that the Lufeng-Wuding area is a concentration area of Dongchuan type iron-copper polymetallic deposits, that the ore materials were mostly derived from the mantle source in the interior of the earth in relation to magmatic activity, with a minor part derived from the underlying strata and sea basin, and that the ore deposits resulted from syngenetic exhalative hydrothermal deposition with the addition of late reformation. Three types of ore deposits, i.e., Xikuangshan type, Luoxue type and Taoyuan type, constitute a complete post-volcanic marine hydrothermal spout, hot-water deposition-reformation style metal-logenic series in the folded basement bed within this region. The results obtained by the authors are of impor-tant significance for ore-prospecting work in iron-copper polymetallic ore-forming belt of Lufeng-Wuding area and also provide the reference for enrichment and improvement of the study of the metallogenic mechanism of iron-copper polymetallic deposits in this area.

With abundant sedimentary bauxite deposits and accumulative bauxite deposits, Wenshan area of Yunnan Province is one of the concentrative areas of explored bauxite reserves and also one of the most promising areas of ore-prospecting potential. This paper has made prospective prognosis in the aspects of ore-forming background, mineral deposit characteristics, enrichment regularity and ore-searching criteria. The bauxite resources in Wenshan area are divided into seven ore-forming prospective areas.