The Song Chay Dome in southeastern Yunnan Province, China, is intruded by the Late Cretaceous Laojunshan granites. New apatite and zircon fission-track data for the Laojunshan granites allow us to reconstruct the exhumation history of the Song Chay Dome. The fission-track dating indicates that the Laojunshan granites experienced four main stages of rapid cooling and exhumation at 75–63, 53–43, 31–20, and 12–4 Ma. The first stage was related to the thermal equilibration with surrounding rocks after magma emplacement. The rapid cooling and exhumation at 53–43 Ma were caused by normal faulting in the Late Mesozoic–Early Cenozoic extensional setting of southwestern South China, which resulted in the Laojunshan granites and Song Chay Dome being exhumed in the footwall of faults. The third stage (31–20 Ma) was the result of southeastward extrusion of the Tibetan Plateau and sinistral strike-slip movement on the NW-SE-trending Nanwenhe and Maguan-Dulong faults. The 31 Ma representing the beginning of the interaction between the Tethyan Himalayan tectonic domain and the South China Block. The final stage was mainly due to activity on the Nanwenhe Fault to the north of the Laojunshan granites, caused by lateral extrusion of the southeastern Tibetan Plateau since ca. 15 Ma. These cooling and exhumation events since the Late Cretaceous indicate that the Song Chay Dome and southwestern South China Block have been affected by the Himalayan Orogeny since the Oligocene.

The NE‐trending Jiangnan orogenic belt has experienced multi‐tectonic episodes since the Mesozoic separates the Yangtze Block in the north‐west from the Cathaysia Block in the south‐east. The Taqian–Fuchun thrust zone in north‐east Jiangxi Province is located in the eastern Jiangnan orogenic belt. It is considered as an essential unit to understand the geometry, kinematics and dynamics of the Mesozoic nappe structures in the eastern Jiangnan orogenic belt and an ideal region to reveal the Mesozoic tectonic evolution in South China. Here, we present new detailed structural data coupled with zircon U–Pb and apatite fission‐track dating studies, establishing a four‐stage deformation history and describing the geometry, kinematics, ages and dynamic background. The Middle–Late Triassic NW–SE compression event (D 1 , 243–226 Ma) is mainly characterized by regional angular unconformity between the Lower and Upper Triassic and asymmetric folding of the underlying strata. The associated regional NW–SE shortening was related to the intercontinental collision. The Middle–Late Jurassic NW–SE compression event (D 2 , 175–160 Ma) is characterized by the angular unconformity between the Middle Jurassic and Cretaceous and the SE‐vergent imbricate nappe structures. The shortening has been associated with the NW‐ward subduction of the Paleo‐Pacific Plate. The Late Jurassic–Cretaceous NW–SE extension event (D 3 , 160–67 Ma) includes the transition stage from compression to extension (160–145 Ma) and the intensive extension stage (145–67 Ma). The former is characterized by the development of the extensional detachment structures and intermediate‐acid magmatism, while the latter is characterized by the development of Cretaceous extensional sedimentary basins and A‐type granites. This extension was correlated to the slab roll‐back of the Paleo‐Pacific Plate. The Paleocene–Eocene compression event (D 4 , 67–35 Ma) is manifested by the thrusting of metamorphic rocks in the Shuangqiaoshan Group to the Cretaceous red beds. This shortening possibly originated from the collision between the India and Eurasian Plates. This study provides new constraints on the Mesozoic structural style and establish a reliable geochronological framework of the Mesozoic tectonic evolutions of the eastern Jiangnan orogenic belt.

The Nanwenhe metamorphic dome contains a rare Silurian granitic pluton that developed in the SE Yangtze Block during early Palaeozoic orogenesis, and this pluton comprises the Nanwenhe gneissic granites. The petrogenetic and structural deformation histories of the gneissic granites recorded the multi-stage interaction of the SE Yangtze Block with other blocks during the Palaeozoic and Mesozoic, including the Cathaysia, Indochina, and Paleo-Pacific blocks. Zircon U–Pb and Hf isotopes and geochemical data indicate that the Early Palaeozoic granites (433–420 Ma) are S-type granitic rocks, and they were derived from the partial melting of ancient continental crust with no contribution from mantle material. And the large variations and positive values of εHf(t) (−12.25 to +10.69) of the gneissic granites are ascribed to a heterogeneous source and disequilibrium melting. Here we compare early Palaeozoic granitoids in the SE Yangtze Block (foreland belt) with those in the orogenic core, and suggest that the SE Yangtze Block underwent limited syn-collisional crustal thickening and metamorphism, and following which post-collisional granitoids were formed through partial melting of continental crust. Structural analysis of the Nanwenhe gneissic granites allows two stages of deformation to be identified: northward detachment (D1) and northwestward thrusting (D2). 40Ar–39Ar isotope dating of muscovites from the gneissic granites yields a well-defined plateau age of 229.61 Ma, which is interpreted as the timing of Late Triassic structural overprinting associated with the formation of the Nanwenhe metamorphic dome. Integration of our new results with previous research findings from the dome and South China allows us to conclude that the detachment deformation (D1) represents Late Triassic post-collisional extension, and D2 represented Jurassic intracontinental orogeny associated with subduction of the Paleo-Pacific Block.

华南大陆中生代以来受华北板块、 西南缘特提斯洋以及东部古太平洋板块会聚作用形成了多序次的构造变形及多期岩浆与成矿事件,并造就了多个重要的多金属成矿区带.文章在梳理成矿区带典型矽卡岩型矿床矿化期次、 矿体分布及成矿机理等关键科学问题的基础上,利用构造变形序次及其控岩控矿的规律性完善了典型矿床成矿过程及成因机理.通过对闽西南铁多金属成矿带、 赣东北塔前-赋春钨铜多金属成矿带以及滇东南老君山钨锡矿集区开展构造变形解析,结合已有研究成果,厘定出相对完整的印支期、 中晚侏罗世及白垩纪3期变形序列,但其作用时限、 构造性质、 规模强度及变形样式却表现不一.通过构造控岩分析并结合已有同位素年代学得出,不同成矿区带都存在与变形序列相一致的岩浆或变质热事件,进而利用变形序列与岩浆期次对应规律明确了与马坑式铁多金属矿床、 朱溪钨铜矿床以及南秧田钨矿床相关的多期岩浆活动.在此基础上识别出多阶段矿化事件并提出3个典型矿床都存在多期叠加复合成矿的认识.从构造对矿床就位机制控制的角度分析了马坑式矿床分散多变矿体、 朱溪矿床垂向大跨度矿化及深部巨型矿体、 南秧田矿床层-脉叠加矿体分别受赋矿地层褶皱拆离、 大规模双重逆冲以及2期构造变形复合控制的机理.文章最后探讨了不同阶段华南重要成矿区带构造变形及岩浆成矿的动力学背景.

Southeastern (SE) Yunnan contains one of the most economically important Mesozoic W-Sn metallogenic belts in South China. The belt comprises three well-known W-Sn ore-concentration areas, namely, the Gejiu, Bainiuchang, and Laojunshan areas from west to east. Numerous skarn W-Sn deposits have been identified in association with Late Cretaceous granites in these areas, although the genesis and geodynamics of the deposits remain uncertain. The Nanyangtian W deposit, which is located in the southern part of Youjiang Basin and the eastern margin of the Laojunshan granitic pluton, consists of skarn and superimposed scheelite-mica-quartz (SMQ) vein mineralization. Multiple stages of structural deformation and mineralization, and geochronological data indicate the Nanyangtian deposit contains important clues to the genesis and geodynamics of W mineralization in SE Yunnan. Structural analysis of the Song Chay dome allows four stages of deformation to be identified from early to late, namely, north-directed detachment (D1), northwest-directed thrusting (D2), dextral transtensional faulting (D3), and late sinistral strike-slip faulting (D4). Laser ablation-inductively coupled plasma-mass spectrometry U-Pb dating of zircons from plagio-amphibolite and altered granitoid yielded ages of 220.37 +/- 0.59 and 162.5 +/- 3.0 Ma, respectively, indicating the timings of regional detachment deformation (D1) with related metamorphism, and the emplacement of coeval granite related to skarn W mineralization, respectively. 40Ar-39Ar isotope dating of muscovites from Laochengpo gneissic granite yielded well-defined plateau ages of 224.12 +/- 0.35 and 141.2 +/- 0.2 Ma, indicating the timing of D1 deformation and Early Cretaceous tectono-thermal event, respectively. 40Ar-39Ar isotope dating of biotite from an SMQ vein within the deposit yielded a well-defined plateau age of 97.81 +/- 0.70 Ma, which is interpreted to represent the timing of SMQ vein W mineralization. 834S values of sulfide in skarn ores range from 7.46%o to 9.55%o, and 818O values of skarn-type scheelite vary from 2.9%o to 4.0%o. However, 818O values obtained for vein-type scheelite range between 4.4%o and 5.7%o, indicating a different material source of W mineralization from that of the skarn ores. Based on our analysis of ore-controlling structures, isotopes, and geochronology, we propose that the inter-layer fractures that formed during D2 controlled the Late Jurassic skarn mineralization and associated granitic magmatism, and that Late Cretaceous SMQ vein mineralization resulted from dextral transtension (D3). Integration of the sequence of deformation and the two periods of W mineralization in combination with well-defined geochronological constraints indicates four stages of tectonism and mineralization in SE Yunnan: Late Triassic-Early Jurassic D1 deformation and early Sn mineralization, late Early-Late Jurassic D2 deformation and subsequent skarn mineralization and associated granitic magmatism, Cretaceous D3 deformation and associated W and late Sn polymetallic mineralization within a regional extensional setting, and Cenozoic postmineralization strike-slip D4 deformation. By combining our new results with other research findings from SE Yunnan and South China, the inferred sequence suggests that the multiple stages of deformation and mineralization were influenced by geodynamic processes involving the Indochina and Paleo-Pacific Plates with the South China Block.

Since the Mesozoic, the convergence of the Tethys ocean plate and the Paleo-Pacific plate on the South China block has resulted in the multi-sequence tectonic deformation as well as the multi-stage magmatic and metallogenic events, and has formed many important polymetallic metallogenic belts in South China. In this context, mineralization stages, distribution of ore bodies and metallogenic mechanisms of typical skarn deposits in metallogenic areas were sorted out. And then the mineralization processes and genetic mechanisms of typical deposits are completed using the sequence of tectonic deformation and its rock/ore-control regularity. A structural deformation analysis was made on the southwestern Fe polymetallic metallogenic belt, the northeastern Jiangxi Taqian-fuchun W-Cu metallogenic belt and the Laojunshan W-Sn ore concentration area to set up three relatively complete periods of deformation sequence during the Indosinian period, the middle-late Jurassic and the Cretaceous, combined with previous research results; however, the three deformation sequences differ in duration of tectonics, structural property, scale and strength, and deformation style. The analysis of rock-control by tectonics together with the existing isotope chronology data both revealed that the magmatic or metamorphic thermal events were consistent with the deformation sequence occurred in each mineralization zone, and then the multi-stage magmatic events related to the Makeng-type Fe polymetallic deposit, the Zhuxi W-Cu deposit and the Nanyangtian W deposit were clarified using the corresponding laws between deformation sequence and magmatic stage. On this basis, we identified the multi-stage mineralization events and supposed that multi-stage superposition occurred in the mineralization process of all three typical deposits. From the point of view of structural control over the emplacement mechanism of the ore deposit, this paper analyzed the mechanism of the decentralized polymorphic orebody of the Makeng-type deposit, the vertical large-span mineralization and deep giant orebody of the Zhuxi deposit, and the stratiform-vein superposition orebody of the Nanyangtian deposit, which are controlled by the folding detachment of the ore-bearing strata, the large-scale thrust duplex and the two-stage tectonic compounding respectively. The dynamic background of tectonic deformation and magmatic mineralization in the important metallogenic belts of South China at different stages were discussed.

都龙锡锌铟多金属矿床位于华南板块西南缘之滇东南老君山矿集区南部,是中国重要的锡锌铟多金属资源产地,构造控矿特征明显.对铜街、 曼家寨两个典型矿段及外围构造变形分析及控矿构造解析表明:区内各地质体之间均为构造接触,构造变形主要存在伸展滑脱及左行走滑等构造样式;F0、F1、F2三条南北向断裂组成的早白垩世伸展滑脱构造控制了矿区的矿化蚀变及矿体空间产出形态,是矿区最主要的控矿构造;成矿后北西向马关—都龙左行走滑断裂为破矿构造,但其正断的性质使矿区受剥蚀程度相对较低,对矿床保存有利.根据控矿构造组合特征及区域构造背景建立了构造控矿模式,认为矿区南部深部、 西部寒武系地层与新寨岩组深部为进一步寻找锡锌铟矿的有利区域,矿区深部找矿潜力较大.

Jingdezhen area is located in the northeastern Jiangxi province,which belongs to the Yangzi plate,and has undergone long-term tectonic activities.According to the study of regional tectonic section,the Mesozoic thrust-nappe structure direction of the study area is from NW to SE,the upper Shuangqiaoshan group has been pushed to the top of Carboniferous-Triassic strata,and the structural styles of the thrust belt are characterized by imbricate fans and duplexes and the maximum principal compressive stress is SE-NW trend.The study of undeformed granite zircon U-Pb isotope dating shows that the U-Pb isotope age is 157 ～ 172 Ma,and the time of tectonic movement is during early Yanshanian period.The Mesozoic thrust-nappe structure produced the magmatic mineralization process in the Jingdezhen area,and the granites of Jingdezhen area may have invaded from intracontinental subductionrelated transformation tectonic setting during the early Yanshanian.The nappe structure constrains the magmatic evolution and in space associated with mineralization.Then it controls the mineralization process of the deposit.

滇东南麻栗坡一带位于Song Chay穹窿的北部,华南板块的西南部,经历了多期强烈的构造活动.该区主要地质体野外构造变形解析表明,麻栗坡一带深部深变质岩到浅部浅变质沉积地层均受到SE-NW向挤压构造变形作用,并在不同地质体之间发育多条自SE向NW运动的低角度逆冲推覆构造.在穹窿内部,逆冲推覆构造形成了两套变质沉积岩地层(洒西岩组和南秧田岩组)以断片的形式夹在火成岩(团田+老城坡片麻状花岗岩和南捞构造片麻岩)之间的空间叠置关系.在穹窿外围,外来岩系(寒武系泥盆系地层)逆冲推覆到原地岩系(二叠系三叠系地层)之上.这期逆冲推覆运动沿构造带形成了飞来峰、断夹块、糜棱岩带、斜歪褶皱、矿物剪切变形等构造现象,强烈改造了该区早期构造格局.结合与推覆构造变形密切相关的主要地质体锆石U-Pb同位素年代学以及前人研究成果,认为上述推覆构造运动发生在中—晚三叠世到159 Ma,区域上与中生代古太平洋板块向NW挤压华南板块的构造事件一致.中生代构造变形在研究区不仅控制了区域钨多金属矿床赋矿层位的展布,同时也为晚期钨多金属矿化富集提供了储矿空间.