普朗斑岩型铜矿区矿化蚀变特征矿物填图及找矿潜力分析：来自资源一号02D遥感卫星的证据          下载免费PDF全文

赵志芳  张新乐  陈琪  张瑞丝  李文昌  曹晓民 《沉积与特提斯地质》2022,42(1):17-29

随着近年来取得重要找矿突破的普朗斑岩型铜矿的规模化开采，进一步摸清首采区外围资源潜力任务紧迫。遥感技术尤其是国产卫星资源一号02D星等高光谱卫星成功发射，为我国高海拔艰苦地区快速精准识别与矿化相关的蚀变矿物提供了可能。针对以往对植被覆盖区高光谱矿物识别有效性方法探索不足，本文选取普朗铜矿区为研究，采用资源一号02D高光谱遥感数据，使用比值植被指数划分植被覆盖区及非植被覆盖区。基于实测波谱，分层次构建了植被覆盖区及非植被覆盖区与普朗铜矿矿化密切相关的绢云母、绿泥石、绿帘石蚀变特征矿物波谱曲线，并采用匹配滤波方法开展了蚀变矿物填图示范应用。野外验证表明：该方法可有效探测普朗斑岩型铜矿外围尤其是首采区东侧植被覆盖区绢云母等蚀变特征矿物分布信息，结果显示普朗首采区东侧具有较大找矿潜力。  相似文献   

藏东昌都觉学红层滑坡的地质成因分析          下载免费PDF全文

李洪梁  陈龙  杨栋  张佳佳  田尤  蔡佳君  王灵  李宝幸 《沉积与特提斯地质》2022,42(4):684-695

觉学红层滑坡发育于向斜北东翼形成的反向坡，是近年来依托川藏交通廊道沿线灾害地质调查在新厘定的“藏东昌都红层区”发现的典型红层滑坡。为厘定其成因，以基础地质为切入点，进行了详实的地质调查与分析。结果表明，滑坡区地层岩性主要为中侏罗统东大桥组(J₂d)紫红色、灰色薄层泥岩、粉砂质泥岩夹中-厚层砂岩。地层内发育与区域构造活动配套的轴面劈理(S₁)、“X”型共轭剪节理(S₂、S₃)和层间剪切劈理(S₄)。文章从沉积环境控制地层岩性及物理力学性质、区域构造演化制约斜坡结构与岩体结构面组合特征和地下水及重力作用加剧斜坡失稳等角度，提出觉学红层滑坡形成于内外地质营力耦合的失稳机理，对区域红层滑坡防治和川藏交通建设具有一定参考价值。  相似文献   

关于相的命名及其分类的建议          下载免费PDF全文

牟传龙 《沉积与特提斯地质》2022,42(3):331-339

岩相古地理研究与编图是能源资源调查与勘探非常重要的基础工作。要开展岩相古地理研究，必须要准确理解和定义与岩相古地理研究相关的基本概念。现在涉及到相的研究成果，无论国外还是国内，对相的含义、使用及其分类不尽一致。通过系统回顾“相”一词诞生到发展演化过程，结合多数学者的意见和使用习惯，本文建议采用“相”是“沉积环境的物质表现，包含了物理特征、化学特征和生物特征”的含义。对于相的命名，可以使用代表物质的如灰岩相；代表环境的，如河流相；代表成因的，如浊流相；代表生物综合特征的，如笔石相；以及代表构造背景如磨拉石相等。对侧重环境的相命名与分类，按照“环境+相”原则来使用。根据研究程度，按照相(facies)—亚相(subfacies)—次相(suborder facies)来描述和分类。即相是沉积环境的物质表现，亚相是相的次一级环境的物质表现，次相是亚相的次一级环境的物质表现，而微相(microfacies)则是岩石薄片、揭片和磨光面中的生物学和沉积学的全部特征。  相似文献   

自然资源定义、分类，观测监测及其在国土规划治理中的应用          下载免费PDF全文

付宇佳  谭昌海  刘晓煌  孙兴丽  袁泽民  郑艺文 《中国地质》2022,49(4):1048-1063

【研究目的】为摸清中国资源家底、认清资源变化规律、管好国土用途，解决现有自然资源内涵不一、分类上存在差异、在数据获取上不统一、资源管理分属不同部门导致的资源在空间管理上交叉重叠等问题。【研究方法】本文采用文献综述法对自然资源的定义、分类及有关资源观测监测指标的相关文献进行梳理。【研究结果】（1）明确了观测监测体系下的自然资源是自然状态或未被加工的状态下通过生产能够产生价值的资源，可将其分为气候资源、地表覆盖资源及地下水资源3类开展研究；（2）总结得到自然资源综合观测与监测的对象、内容及观测方法；（3）分析自然资源观测监测在资源间及资源与环境间、资源资产管理、生态环境修复上的具体作用。【结论】文章最后指出自然资源观测监测是研究资源间、资源与环境间作用，资源资产管理以及生态环境修复中不可缺少的技术手段。创新点：（1）明确了自然资源的定义，解决自然资源在部门管理上、分类上以及数据获取上不统一的问题；（2）分析自然资源观测与监测的内容和指标，结合系统调查、观测实验、预测模拟、监测评价“四位一体”的探测技术，有效掌握自然资源家底、进行资源资产管理，研究资源间、资源与环境的相互关系，在国土规划治理中发挥作用。  相似文献   

Fluid evolution and ore genesis of the A'gui Cu deposit in southern Great Xing'an Range,Northeast China: Evidence from fluid inclusion and C–H–O–S–Pb isotopes     

《Chemie der Erde / Geochemistry》2023,83(2):125953

The A'gui Cu deposit is located in the eastern slope of the southern Great Xing'an Range (SGXR), and it is a vein-type Cu deposit spatially and temporally related to the Cretaceous monzogranite which intruded Pingshan Formation. Vein-type Cu orebodies are mainly hosted in the NE and nearly EW faults. Previous studies on the A'gui deposit mainly focused on geological exploration, and there was no study on its fluid evolution and genesis. Therefore, we carried out conducted fluid inclusion and stable isotope (C–H–O–S–Pb) analysis to study the fluid evolution, fluid and ore-forming material sources and genesis of the A'gui deposit. According to the field investigations and mineral crosscutting relationships, four paragenetic stages were identified: quartz–pyrite–chalcopyrite–pyrrhotite–arsenopyrite ± magnetite (Stage I), quartz–pyrite–chalcopyrite (Stage II), quartz–chalcopyrite ± pyrite–sphalerite–galena (Stage III) and carbonate ± quartz (Stage IV). From Stage I to Stage II, the assemblage of fluid inclusions (FIs) in quartz is characterized by the development of daughter mineral–bearing three–phase FIs (SL–type), vapour FIs (V–type), vapour–rich two–phase aqueous FIs (LV–type) and liquid–rich two–phase aqueous FIs (VL–type). Only VL–type FIs appeared in the Stage III quartz and Stage IV calcite. The homogenization temperatures of FIs in stages I, II, III and IV are 329–390 °C, 255–336 °C, 166–244 °C and 120–157 °C, with salinities of 3.37–45.33 wt%, 3.53–39.76 wt%, 4.17–7.86 wt% and 3.37–7.15 wt% NaCl eqv., respectively. The fluid inclusion type assemblage suggested that obvious fluid boiling occurred in the Stage I and Stage II. Fluid boiling may be the reason for the precipitation of useful minerals. According to the HO isotope analysis of stages I–II quartz (δ¹⁸O_H2O = −2.1 to 3.2 ‰, δD_V–SMOW = −128.4 ‰ to −110.6 ‰), the fluid was originally magmatic water. From Stage III to Stage IV (δ¹⁸O_H2O = −12.3 to −2.3 ‰, δD_V–SMOW = −129.6 ‰ to −104.2 ‰), the HO isotope value is obviously close to the meteoric water line, indicating that meteoric water is mixed with evolved magmatic solutions. The ore–forming fluid of the A'gui deposit represents a medium–high temperature NaCl-H₂O magmatic hydrothermal system. The C isotope compositions (δC_V–PDB = −5.74 ‰ to −4.76 ‰) in stage IV indicate that the C in the fluid was derived from a magmatic source and was affected by meteoric water. In addition, the measured S isotope compositions in stages I–III of the hydrothermal fluids (δ³⁴S_V–CDT = 2.2 to 3.7 ‰) indicate that S mainly comes from granitic magma. Further, the Pb isotope (²⁰⁶Pb/²⁰⁴Pb = 18.276–18.367, ²⁰⁷Pb/²⁰⁴Pb = 15.52–15.556, ²⁰⁸Pb/²⁰⁴Pb = 38.157–38.193) in stages I–III indicate that the ore-forming materials are derived from the mixture of mantle and orogenic material. In summary, this study showed the A'gui is a typical magmatic hydrothermal vein-type Cu deposit that related to Cretaceous monzogranite formed under the joint constraints of Mongolia-Okhotsk Ocean and Paleo-Pacific Ocean tectonic system. Fluid boiling and mixing are the main ore-forming mechanism.  相似文献   

Geochronology,Geochemistry, and Implications of Aplite Dyke in the Giant Jiama Porphyry Copper System,Tibet          下载免费PDF全文

QI Jing  TANG Juxing  LIN Bin  YANG Hairui  TANG Xiaoqian  TANG Pan  FANG Xiang  ZHANG Tingting  LI Faqiao  SUN Miao  WANG Mengdie  CUI Hao  XIE Jinling 《《地质学报》英文版》2023,97(5):1406-1421

Jiama is a giant, high-grade porphyry copper system in the Gangdese metallogenic belt, Tibet. Multistage intermediate–felsic porphyries intruded in this deposit, some of which are strongly associated with copper-polymetallic mineralization. These ore-bearing porphyries include monzogranite, granodiorite, and quartz diorite porphyries. A new granite aplite dyke was found in the south of Jiama. Its age, genesis, and relationship with ore-related magmatism are obscure. Here, its emplacement age and...  相似文献   

铀成矿机理的统一性探讨     

伍皓  熊树银  夏彧  周恳恳  梁薇  李炼鹏  雷星 《沉积与特提斯地质》2023,43(1):59-76

为探讨不同类型铀矿床是否可能本质上都是地幔柱作用的产物，在“全球热液铀矿成因理论”和“热点铀成矿理论”等前人研究基础之上，结合岩浆岩锆石铀、钍含量研究初步揭示了：（1）铀、钍主要富集于外地核；（2）洋岛玄武岩、板内玄武岩、高分异花岗岩及伟晶岩型铀矿可能为地幔柱产物。对比国内多种类型铀矿床科研成果，总结发现有一定数量的铀矿床与洋岛玄武岩、板内玄武岩、A型花岗岩以及高分异花岗岩紧密伴生，成矿与成岩时空基本耦合。如四川攀枝花大田混合岩型铀矿和松辽盆地钱家店–白兴吐砂岩型铀矿伴生两类玄武岩；甘肃芨岭钠交代型铀矿和陕西商丹伟晶岩型铀矿区伴生两类花岗岩；粤北诸广–贵东花岗岩型铀矿区、赣南多类型铀矿区和江西相山、新疆白杨河火山岩型铀矿区伴生以上四类岩石类型。分析认为上述岩石类型可能是由地幔柱生成并起着导矿或导矿兼储矿的关键作用，据此提出铀矿“核源–地幔柱”成因认识，即：外地核是铀元素的主要发源地，地幔柱是铀运移的统一通道，铀成矿过程可能是外地核中的金属铀呈铀氢化物或铀合金氢化物等形式沿地幔柱上升迁移，直至在浅部地质体氧化聚集成固态铀矿物的过程。  相似文献   

米仓山—大巴山地区赫兰特期岩相古地理及其页岩气地质意义          下载免费PDF全文

熊国庆  周小琳  李小刚 《沉积与特提斯地质》2022,42(3):368-384

上扬子地区赫兰特期发育一套含赫兰特贝和达尔曼虫化石的独特的沉积单元，其沉积环境长期以来存在争议，还缺乏更为精细的沉积相时空变化研究。本文以米仓山—大巴山地区赫兰特期地层为研究目标，通过系统资料收集，野外详细观测和室内镜下分析等手段，采用“点-线-面”的岩相古地理分析方法，重建了研究区赫兰特期岩相古地理。剖面沉积相分析表明，观音桥段发育于不同沉积环境之中，因而具有不同的岩相特征，总体上为赫兰特期海平面下降的产物，但经历了不只一次的海平面升降变化，海退过程的沉积记录相对明显，海侵记录仅在盆地边缘或水下高地边缘有所响应。复原的岩相古地理显示，该时期呈现北西高、北东和南西低，中间多个水下高地的沉积古地理格局，这种格局有利于扬子克拉通盆地内形成优质的富有机质页岩；研究区内观音桥段沉积相主要以浅海陆棚相（浅水陆棚亚相）为主，局部发育孤立台地和碳酸盐缓坡，滨海相局限于盆地西北古陆边缘。页岩气勘探开发中，区内粉砂质泥岩、碳质泥岩发育的浅海陆棚相区为页岩气优质储集层和勘探有利区，但应尽量远离物源区和水下隆起区；白云岩、泥质灰岩发育的孤立台地和碳酸盐缓坡区，压裂过程中，应选择合适层位，尽可能压穿白云岩、泥质灰岩，连通五峰组—龙马溪组含气页岩段，提高页岩气产量。  相似文献   

糜棱岩化过程中锆石的稳定性 ——以西南三江高黎贡、西盟地区花岗质糜棱岩为例          下载免费PDF全文

王冬兵  唐渊  王保弟  罗亮  廖世勇 《沉积与特提斯地质》2021,41(1):15-23

自然条件下锆石的稳定性对于合理解释锆石年龄及深入理解锆石同位素年代学有重要意义.本文对西南三江造山带高黎贡山和西盟地区的花岗质糜棱岩进行了显微构造和锆石U-Pb年代学研究.高黎贡山和西盟糜棱岩中主要造岩矿物长石、石英、云母发生了明显的变形和重结晶,而锆石则以独立晶体或以残留核的形式保存了原始的岩浆结构.高黎贡山和西盟糜...  相似文献   

Millennial- to centennial-scale anti-phase relationship between the Westerlies and the East Asian summer monsoon and its cultural response along the Silk Roads after a great earthquake in southern Altay ~ 3500 cal a BP     

Jiawei Fan  Hongyan Xu  Hanchao Jiang  Xiaotong Wei  Wei Shi  Qiaoqiao Guo  Siqi Zhang  Xianzhou Bai  Xingqi Liu  Jule Xiao 《第四纪科学杂志》2023,38(1):123-137

It is strongly debated whether the Westerlies and the East Asian summer monsoon (EASM) are in-phase, anti-phase or out-of-phase, and how hydroclimatic changes in the above two climate systems affected trans-Eurasian cultural exchanges during the late Holocene. In this study, we establish a 3500-a-long paleoclimatic sequence based on high-resolution analyses of sedimentological and geochemical data of a well-dated sediment core from Yileimu Lake in southern Altay. High percentages of the >63-µm fraction and high values of Zr/Rb and Rb/Sr ratios indicate strong transport of weakly weathered, coarse sediments into the depocenter of the lake caused by enhanced surface runoff and catchment erosion associated with a wet climate, and vice versa. High values of Ca and total inorganic carbon (TIC) contents imply increased precipitation of endogenic carbonates in the lake water under intense evaporation associated with a dry climate, and vice versa. This new record indicates two wet intervals at 3500–2300 and 600–100 cal a bp , interrupted by a severe and prolonged dry interval from 2300 to 1000 cal a bp , and a mild dry interval with occasionally wet conditions from 1000 to 600 cal a bp. These results are broadly consistent with other paleoclimatic records in Westerlies-dominated Asia and are generally anti-phase with those in the EASM region. We suggest that a strengthening/weakening and southward/northward migration of the Westerlies during a negative/positive phase of the North Atlantic Oscillation (NAO) transported more/less water vapor into arid Asia. Meanwhile, a decreasing/increasing El Niño-Southern Oscillation (ENSO) superimposed on a southward/northward shift of the Intertropical Convergence Zone (ITCZ) triggered a weakening/strengthening and southward/northward movement of the West-Pacific subtropical high (WPSH), resulting in decreasing/increasing EASM intensity. In addition, the wet climate from 3500 to 2300 cal a bp may have contributed to the development of nomadic herding in the eastern Eurasian Steppe and Altay region, and to the opening of the proto-Silk Roads. Potentially, intense seismic activities in the Altay Mountains ~3500 cal a bp may have also promoted the opening of the proto-Silk Roads by forcing the herdsmen to move to the inter-mountainous basins. The strong EASM intensity from 2300 to 1000 cal a bp in eastern China may have contributed to the creation of the ancient Silk Roads by the Han Dynasty.  相似文献