金刚石矿物学、包裹体及碳稳定同位素研究综述          下载免费PDF全文

杨献忠  袁学银  王军  蔡逸涛  康丛轩 《中国地质调查》2014,6(6):12-18

金刚石是地球上最坚硬、对形成环境要求最苛刻的矿物之一。金刚石的矿物学特征、包裹体特征及碳稳定同位素组成记录了金刚石生长、熔蚀、搬运等地质过程中的温度、压力及物质成分等信息,是探索金刚石物质来源、形成过程和地球深部物理化学环境的重要研究对象。总结了国内外金刚石矿物学特征、包裹体特征和碳稳定同位素组成的相关研究成果,发现金刚石晶形和组合及其颜色可大致区分金刚石来源; 金刚石表面特征是区分原生金刚石与砂矿金刚石的重要鉴别特征; 金刚石包裹体类型及组合、包裹体年代学及金刚石碳稳定同位素研究,可分析金刚石物质来源和地球深部物理化学环境,确定金刚石形成时代,为研究金刚石成因、地幔岩石圈深部作用过程以及壳幔相互作用提供重要依据。  相似文献   

Climate change and groundwater resources in China          下载免费PDF全文

BAI Bing  CHENG Yan-pei  JIANG Zhong-cheng  ZHANG Cheng 《地下水科学与工程》2017,5(1):44-52

Water resources play an important role in supporting the economic and social development of China. The impact of climate change on water resources has become a bottleneck in this process, especially for major projects, with surface water and groundwater systems experiencing considerable impacts. The annual natural recharge of fresh groundwater is 8 840×10~8 m~3, which accounts for approximately 31% of the water resources. Groundwater is the most significant water source for many cities and energy bases, and it is also the main source acting as a buffer against extreme climate events caused by climate change. However, most of the groundwater in China buried deeply and unevenly, which increases the difficulty of investigating and exploiting this resource.This paper illustrates the general conditions of China water resources and hydrogeological hazards, such as karst sinkholes, surface subsidence, and soil salinization, caused by climate change, El Nino, La Nina, other climate events and human activities and presents the regulatory measures enacted to mitigate these issues in China.The China Geological Survey(CGS) has organized professional teams to investigate and evaluate groundwater resources and the environment since 1999. Based on these investigations, the total quantity, expected exploitable quantity and current exploited quantity of groundwater in whole China have been evaluated. In addition, an evaluation of the groundwater pollution caused by climate change throughout China and key areas has been conducted. At present, the CGS is conducting national groundwater monitoring projects and establishing regional engineering and technical measures for water resource exploitation and utilization.  相似文献   

Assessment of thermal evolution of Paleozoic successions of the Holy Cross Mountains (Poland)     

《Marine and Petroleum Geology》2017

Poland is considered the most prospective country for shale gas production in Europe. Hydrocarbon generation/expulsion scenarios, drawn in the latest intensive exploration phases, tend to overestimate maturation levels when compared with brand new data acquired after recent drillings. We tested an integrated workflow to correlate published and original thermal maturity datasets for the Paleozoic to Jurassic successions cropping out in the Holy Cross Mountains. These successions, when preserved in subsurface, host the major source rocks in the area. The application of the workflow allowed us to highlight the burial and thermal evolutionary scenarios of the two tectono-stratigraphic blocks of the Holy Cross Mountains (Łysogòry and Kielce blocks) and to propose this approach as a tool for reducing levels of uncertainty in thermal maturity assessment of Paleozoic successions worldwide. In particular, published datasets including colour alteration indexes of Paleozoic microfossils (conodont, acritarchs) and vitrinite and graptolite reflectance data, show differences in levels of thermal maturity for the Łysogòry (mid mature to overmature) and Kielce (immature to late mature) blocks. Original data, derived from optical analysis, pyrolysis, and Raman spectroscopy on kerogen, and X-Ray diffraction on fine-grained sediments, mostly confirm and integrate published data distribution. 1D thermal models, constrained by these data, show burial and exhumation events of different magnitude, during the Late Cretaceous, for the Łysogòry (maximum burial depths of 9 km) and Kielce (burial depths of 6 km) blocks that have been related to the Holy Cross Fault polyphase activity. In the end, Palynomorph Darkness Index and Raman spectroscopy on kerogen, for Llandoverian and Cambrian rocks, turned out to be promising tools for assessing thermal maturity of Paleozoic organic facies devoid of vitrinite macerals.  相似文献   

Ground penetrating radar for facies architecture and high-resolution stratigraphy: Examples from the Mesoproterozoic in the Chapada Diamantina Basin,Brazil     

《Marine and Petroleum Geology》2017

Ground Penetrating Radar (GPR) surveys were conducted on Mesoproterozoic eolian, fluvial, deltaic, estuarine, and shallow marine successions in the Chapada Diamantina Basin. The subsurface continuation of facies and facies architecture exposed on road cuts was imaged using the GPR signal of a 400-MHz antenna penetrating 8 m in depth, even with mudstone intervals. Reflection patterns in the GPR profiles that were compared with photo mosaics of outcrops and supporting data from vertical sections and gamma ray logs, reveal sedimentary, stratigraphic, and structural features, such as sedimentary structures, the external geometry of architectural elements, stratigraphic surfaces, folds and tension gashes. The patterns most likely reflect the response from low-weathered, non-porous muscovite-illite-rich mudstone and quartzarenite sandstone in which authigenic and detrital illite and sericite are prevalent clay minerals.Measured vertical sections and radar stratigraphy indicate high-frequency cyclic successions of estuarine and shoreface intervals are present at the base of the Tombador Formation. The shoreface intervals are composed of heterolithic strata and offshore tidal bars deposits. The heterolithic shoreface strata exhibit tabular geometry that can be easily identified throughout the outcrop and in the subsurface. Such intervals represent the end of high-frequency transgressive cycles, and hence they are potential candidates for including the maximum flooding surfaces and for defining genetic sequences. Therefore, GPR proved to be an independent method for studying facies architecture and the establishment of a high-resolution stratigraphic framework even in the Precambrian.  相似文献   

月球冷海玄武岩矿物成分研究     

张小梦  张迅与  陈媛  蔡伟  卢瑜  吴昀昭 《地学前缘》2018,25(1):314-324

月海玄武岩的矿物组成反映了岩浆源区的化学成分以及岩石形成时的物理和化学环境,对月球热演化研究以及月球资源的开发利用都具有重要意义。本文选择延展范围长的冷海为研究区,基于月球矿物成像光谱仪(Moon Mineralogy Mapper,简称M3)数据研究其矿物的空间变化特征。综合利用光谱、地形、元素等多源遥感数据将冷海划分为25个地质单元。提取169条新鲜坑光谱曲线,获取吸收中心波长、波段面积比等光谱参数。通过光谱吸收特征分析,获得冷海玄武岩铁镁质矿物变化特征。东部冷海地层较老,铁镁质矿物主要为单斜辉石,辉石钙含量较月球样品单斜辉石钙偏低,与澄海以及雨海老的地层矿物组成类似。西部冷海和露湾的地质单元较为年轻,富含橄榄石。风暴洋和雨海年轻玄武岩的矿物也富含橄榄石。这种富含橄榄石、大面积分布的玄武岩反映了月球晚期热演化的独特性。尽管地理上冷海为一个独立的月海,其东西部玄武岩矿物组成的差异以及与其同位置周围月海矿物组成的类似性反映了冷海玄武岩源区与周围月海具有联系。  相似文献   

河北宽城蛇纹石玉的宝石矿物学特征研究          下载免费PDF全文

徐子维  孙佳乐  郝森  刘云贵  王礼胜  宋彦军 《岩石矿物学杂志》2023,42(3):442-450

河北宽城蛇纹石玉结构细腻,颜色可呈肉红色、绿色,当地市场称之为"热河玉"。本文通过常规宝石学测试结合激光拉曼光谱、电子探针、X射线粉晶衍射、激光剥蚀等离子质谱以及可见光吸收光谱等手段对其进行了系统分析,并采用伽玛能谱仪对其放射安全性进行了检测。结果表明,肉红色样品折射率及相对密度值均较低,折射率为1.54~1.55,相对密度为2.33~2.43,主要组成矿物为斜纤蛇纹石,主要具纤维交织结构、纤维柱粒交织结构,局部可见变余生物骨架结构,次要矿物有方解石和透辉石,Fe和Mn元素含量相对较高,Fe元素含量范围在184.9×10^-6~951.7×10^-6,Mn元素含量为106.4×10^-6~287.3×10^-6;绿色样品折射率为1.55~1.56,相对密度为2.58~2.62,主要组成矿物为叶蛇纹石,具更加细腻的纤维交织结构,次要矿物为滑石及四方硫铁矿,Fe元素含量极高,可达5 979×10^-6~6 359×10^-6。结合可见光吸收光谱分析结果认为Fe³⁺、Fe²⁺以及Mn³⁺的综合作用是导致样品呈现肉红色的主要原因,而Fe²⁺和Fe³⁺则是导致绿色的主要原因。放射性检测结果显示样品的内、外照射指数及放射性比活度值均低于标准要求,对人体无放射性危害。  相似文献   

Effects of grain size distribution on mineralogical and chemical compositions: a case study from size‐fractional sediments of the Huanghe (Yellow River) and Changjiang (Yangtze River)     

Xiaojing Zhou  Anchun Li  Fuqing Jiang  Jian Lu 《Geological Journal》2015,50(4):414-433

The influence of hydrodynamics on the chemical composition of sediments is based on the uneven distribution of element abundances in different size fractions. In this study, 72 size‐fractional sediments from the Huanghe (Yellow River) and Changjiang (Yangtze River) riverbeds were measured with XRD, SEM, ICP‐AES and ICP‐MS. The analysis results show that the mineral and chemical characteristics change with grain size in the Huanghe and Changjiang sediments. According to the principal components analysis, three independent geochemical factors were found. The first factor elements, Zr, Hf, Th, U, Y, La and TiO₂ are influenced by the existence of heavy minerals. The second factor elements, Al₂O₃, alkalis, alkaline earth (excluding Ca and Sr) and most of the transitional metals are dominated by clay minerals. The third factor group includes Ca and Sr, which were controlled by calcium‐bearing mineral contents and chemical weathering intensities. The various grain size distributions greatly affect the mineralogical and chemical compositions of bulk sediments. Compared to other size fractions, the 5–6PHI size fractions of the Huanghe and Changjiang sediments have special mineralogical and chemical compositions, and intermediate volume percentages. Weight or volume percentage of each size fraction may be more suitable than mean grain‐size of the bulk sediment to elucidate the grain size effects. Chemical Index of Alteration (CIA) values increase steeply with decreasing grain size, while Weathering Index of Parker (WIP) values are relatively stable. Because of the big influence of the abundance of clay minerals on CIA values, it is questionable to use CIA as a proxy of weathering intensity. Considering the clay mineral effects, stability in values and heterogeneous material properties, WIP has the potential to indicate the chemical weathering intensity of sediments. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

四川盐源混合铜矿的工艺矿物学研究     

杨虎  罗红莹  陆宽伟  张英 《岩石矿物学杂志》2021,40(4):757-763

利用扫描电镜、X射线能谱分析、XRD、MLA矿物检测软件对四川盐源混合铜矿的物质组成、赋存状态、嵌布特性、粒度特征、解离特征进行了研究.结果表明,该矿石中的主要有价金属是铜,含量为1.05％,主要赋存于黄铜矿、斑铜矿、辉铜矿、孔雀石中,脉石矿物主要有石英和长石,其次为方解石、绿泥石;主要矿物的粒度均小于20 μm,其中...  相似文献   

关于江苏地热勘查工作的思考   总被引：1，自引：0，他引：1  

赵剑畏 《江苏地质》2004,28(2):76-81

地下热水是一种多功能矿产资源，市场前景广阔。提出省内地热异常的讨论标准，总结了全省地热异常分布规律和成热条件等，对江苏今后地热勘查工作思路和技术路线提出了见解。  相似文献   

层硅铈钛矿的矿物学研究          下载免费PDF全文

楼凤升  张荣英  刘汉儒 《岩石矿物学杂志》1988,7(1):58-65

层硅铈钛矿是一种罕见又多变的矿物,因而至今未见详细报导。笔者在赛马碱性岩体的铀、钍、铌、稀土巨型综合矿床中获得了各种成因的新鲜矿样,作了系统的研究,指出该矿物为单斜晶系、具类似2M型白云母结构的层状钛硅酸盐。  相似文献