盆地岩石圈结构与油气成藏及分布

本文综述了大陆岩石圈研究现状和克拉通盆地、裂谷盆地和前陆盆地的岩石圈结构特征,指出在古裂谷、褶皱带或区域性深断裂等陆壳构造薄弱带上发育起来的多期叠合盆地,具有很好的含油气前景。大型含油气盆地往往存在地幔上隆、地壳减薄和地壳内低速层,盆地基底沉降与盖层沉积厚度较大。适度的后期构造活动改造和岩浆活动有利于沉积盆地内油气生成与保存。     

遥感技术在西北生态脆弱区生态地质勘查中的应用研究

生态地质勘查正在成为煤炭地质勘查工作的主要发展方向。遥感技术作为“非接触式”勘查技术,在生态地质勘查中应有一席之地。通过阐述遥感技术在煤炭、天然气水合物、油页岩等资源勘查中的工作程序及勘查实例,认为在西北生态脆弱区资源勘查领域遥感技术具有独特的优势:通过不同比例尺的遥感煤田地质填图,可快速高效圈定含煤远景区;利用遥感图像的热红外波段数据可以快速获取与水合物相关的温度异常信息,圈定热异常分布区,为天然气水合物进一步勘探指明方向;通过对遥感图像的处理可直接提取与油页岩相关的成矿异常信息,圈定找矿远景区。在西北生态脆弱区应用遥感技术进行资源勘查具有好的经济效益和生态效益。     

西昆仑玛尔坎苏石炭纪大型锰矿带构造背景与成矿条件

西昆仑北段玛尔坎苏地区探明的大型碳酸锰成矿带,是我国近年最重要的找矿成果之一。该锰矿带构造上属北昆仑晚古生代弧后伸展盆地,其构造动力学背景为古特提斯洋向北俯冲于塔里木地块之下形成的弧盆体系。锰矿体主要发育于晚石炭世喀拉阿特河组含炭泥质灰岩夹薄层灰岩中。矿石中主要金属矿物为菱锰矿（75%~95%）,次为软锰矿、硫锰矿及少量黄铁矿等。含锰岩系岩性和岩相学研究表明,玛尔坎苏锰矿带属典型的海相沉积锰矿床,其矿床成因可能与晚古生代半局限盆地沉积和海底热液活动有关。海底热液活动可能为成矿提供了丰富的物质来源。含锰岩系元素和同位素地球化学特征表明,玛尔坎苏锰矿沉淀时的水体环境为常氧条件,而矿层下盘（部分）岩系的岩性及地球化学特征反映其沉积时的水体环境为低氧—贫氧条件。玛尔坎苏锰矿带锰矿石具有负的δ¹³C值（-23.3‰~-10.0‰）,推测有机质导致的还原作用是该锰矿由原生氧化锰在成岩期转化为菱锰矿和形成富锰矿的重要机制。     

山东金青顶金矿床和七宝山金矿床的流体包裹体REE组成

文章运用电感耦合等离子体质谱（ICP-MS）方法，研究了金青顶金矿床和七宝山金矿床的脉石英中流体包裹体REE组成特征，结果表明流体包裹体的REE均为LREE富集型，并显示Eu正异常。成矿流体REE配分模式和REE参数特征表明它们具有相当的来源。与金矿有关的成矿母岩，即昆嵛山花岗岩和七宝山次火山岩的REE特征也极为相似，反映成矿流体的REE组成都有从成岩向成矿过程演化继承的关系。矿床流体包裹体REE组成的相似特征及矿床碳氧同位素等特点表明，金青顶金矿床和七宝山金矿床是华北东部中生代同一构造热事件的产物。     

Surface-deformation monitoring in the permafrost regions over the Tibetan Plateau,using Sentinel-1 data

Differential Interferometric Synthetic Aperture Radar(D-In SAR) has been widely used to measure surface deformation over the Tibetan Plateau. However, the accuracy and applicability of the D-In SAR method are not well estimated due to the lack of in-situ validation. In this paper, we mapped the seasonal and long-term displacement of Tanggula(TGL) and Liangdaohe(LDH) permafrost regions with a stack of Sentinel-1 acquisitions using the Small Baseline Subset In SAR(SBAS-In SAR) method. In the TGL region, with its dry soils and sparse vegetation, the In SAR-derived surface-deformation trend was consistent with ground-based leveling results; long-term changes of the active layer showed a settlement rate of around 1 to 3 mm/a due to the melting of ground ice, indicating a degrading permafrost in this area. Around half of the deformation was picked up on monitoring, in contrast with in-situ measurements in LDH, implying that the D-In SAR method remarkably underestimated the surface-deformation. This phenomenon may be induced by the large soil-water content, high vegetation coverage, or a combination of these two factors in this region. This study demonstrates that surface deformation could be mapped accurately for a specific region with Sentinel-1 C-band data, such as in the TGL region.Moreover, although the D-In SAR technology provides an efficient solution for broad surface-deformation monitoring in permafrost regions, it shows a poor performance in the region with high soil-water content and dense vegetation coverage.     

Investigation on semi-direct and indirect climate effects of fossil fuel black carbon aerosol over China

A Regional Climate Chemistry Modeling System that employed empirical parameterizations of aerosol-cloud microphysics was applied to investigate the spatial distribution, radiative forcing (RF), and climate effects of black carbon (BC) over China. Results showed high levels of BC in Southwest, Central, and East China, with maximum surface concentrations, column burden, and optical depth (AOD) up to 14 μg?m^?3, 8 mg?m^?2, and 0.11, respectively. Black carbon was found to result in a positive RF at the top of the atmosphere (TOA) due to its direct effect while a negative RF due to its indirect effect. The regional-averaged direct and indirect RF of BC in China was about +0.81 and ?0.95 W?m^?2, respectively, leading to a net RF of ?0.15 W?m^?2 at the TOA. The BC indirect RF was larger than its direct RF in South China. Due to BC absorption of solar radiation, cloudiness was decreased by 1.33 %, further resulting in an increase of solar radiation and subsequently a surface warming over most parts of China, which was opposite to BC’s indirect effect. Further, the net effect of BC might cause a decrease of precipitation of ?7.39 % over China. Investigations also suggested large uncertainties and non-linearity in BC’s indirect effect on regional climate. Results suggested that: (a) changes in cloud cover might be more affected by BC’s direct effect, while changes in surface air temperature and precipitation might be influenced by BC’s indirect effect; and (b) BC second indirect effect might have more influence on cloud cover and water content compared to first indirect effect. This study highlighted a substantial role of BC on regional climate changes.     

Variation of earthquake ground motionwith depth

Introduction The 21st century is the time for the exploitation and utilization of underground spaces. It is astrategic way to defeat the severe challenge that human are now confronting with, such as the lackof land, contamination of environment, traffic jam, waste of sources, and so on. The exploitationand utilization of underground space has become a global tendency, and a significant sign inevaluating the speed of modernization of cities. Facing the challenge, it is significantly necess…     

Relationship between garnet skarn and W mineralization: A case study from the Tongshankou Cu-Mo-W deposit,Daye, Hubei.SCIEI北大核心CSCD

石榴子石是矽卡岩型矿床的标志性矿物之一,其结构和成分特征被广泛用来示踪早期成矿流体性质的变化,但其生长过程与金属元素富集过程的关系还不清楚。本文对长江中下游成矿带最西端鄂东矿集区内的铜山口铜钼钨矿床中的石榴子石开展了显微结构和电子探针主量元素、LA-ICP-MS微量元素点分析和面扫描分析。结果显示,铜山口矿床中的石榴子石端元成分以钙铁榴石-钙铝榴石为主,普遍含有一定量的W,特别是在钙铁榴石端元比例高的石榴子石中(可达3898×10-6),且W与Mo、As、Sn存在明显的正相关关系、与Ti存在一定的负相关关系,指示W以类质同象的方式进入石榴子石晶格。石榴子石可包裹结构简单的白钨矿或被具复杂结构的白钨矿交代,指示石榴子石记录了白钨矿形成前和形成过程中流体性质(氧逸度和W含量等)的变化。铜山口矿床中钙铁榴石的大量结晶,导致成矿早期W的大量分散,不利于高品位和大规模钨矿的形成,仅在这些钙铁榴石遭受强烈的退化蚀变时,释放的W在一定程度能够提高矿石的品位,这可能是氧化性矽卡岩型钨矿通常比还原性矽卡岩型钨矿品位低、规模小的重要原因。石榴子石的成分特征(如W、Sn等元素含量和W/Sn、W/Mo和W/As等比值)可以作为判断矽卡岩的氧化还原性和钨矿床的品位及规模的依据,并具有成为W、Mo和Sn等矿床的找矿勘查指示矿物的潜力。     

青海化隆地区拉水峡铜镍矿床地质、地球化学特征及成因

拉水峡铜镍矿床位于化隆基性—超基性岩带中,岩体几乎全岩发生铜、镍硫化物矿化,且已遭受强烈蚀变,以角闪岩为主。岩浆期主要金属硫化物矿物组合为磁黄铁矿、黄铜矿、镍黄铁矿;热液蚀变期主要有紫硫镍矿、黄铁矿、黄铜矿、针镍矿等;氧化表生期主要为含镍高岭石、含镍绿泥石、孔雀石等。矿石轻稀土元素富集和负Eu异常明显,说明岩浆演化过程中发生了大量斜长石等的分离结晶作用。∑PGE含量平均为2460.46×10-9,（Pd＋Pt）/（Os＋Ir＋Ru）值为0.40~2.00,表明铂族元素与岩浆深部熔离作用密切相关;但Pt/Pd（0.01~2.62）、Pd/Ir（0.91~8.77）说明热液作用对铂族元素具有一定的富集作用。S同位素组成变化范围很小,δ34S平均值为2.24‰,硫化物中的S以地幔S为主。拉水峡矿床的形成经历了岩浆融离贯入、热液叠加改造及表生氧化作用3个阶段。     

Characteristics and accumulation mechanisms of the Dongfang 13-1 high temperature and overpressured gas field in the Yinggehai Basin,the South China Sea

The Dongfang 13-1 is located in the diapiric structure belt of the Yinggehai Basin. The formation pressure of its main gas reservoir in the Miocene Huangliu Formation is up to 54.6 MPa(pressure coefficient=1.91) and the temperature is as high as 143°C(geothermal gradient 4.36°C/100 m), indicating that it is a typical high-temperature and overpressured gas reservoir. The natural gas is interpreted to be coal-type gas derived from the Miocene mature source rocks containing type II2-III kerogens as evidenced by high dryness index of up to 0.98 and heavy carbon isotopes, i.e., the δ13C1 ranging from -30.76‰ to -37.52‰ and δ13C2 ranging from -25.02‰ to -25.62‰. The high temperature and overpressured Miocene petroleum system is related mainly to diapir in the Yinggehai Basin and contains more pore water in the overpressured reservoirs due to undercompaction process. The experimental and calculated results show that the solubility of natural gas in formation water is as high as 10.5 m3/m3 under the temperature and pressure conditions of the Sanya Formation, indicating that at least part of the gas may migrate in the form of water-soluble phase. Meanwhile, the abundant gas source in the Basin makes it possible for the rapid saturation of natural gas in formation water and exsolution of soluble gas. Therefore, the main elements controlling formation of the Dongfang 13-1 gas pool include that(1) the diapir activities and accompanying changes in temperature and pressure accelerate the water-soluble gas exsolution and release a lot of free gas;(2) submarine fan fine sandstone in the Huangliu Formation provides good gas-water segregation and accumulation space; and(3) the overlying overpressured mud rocks act as effective caps. The accumulation mechanism reveals that the high temperatural and high pressure structure belt near the diapir structures has a good potential for large and medium-sized gas field exploration.