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1.
Koike Katsuaki 《地球科学》2011,36(2):209-226
Sample data in the Earth and environmental sciences are limited in quantity and sampling location and therefore, sophisticated spatial modeling techniques are indispensable for accurate imaging of complicated structures and properties of geomaterials. This paper presents several effective methods that are grouped into two categories depending on the nature of regionalized data used. Type I data originate from plural populations and type II data satisfy the prerequisite of stationarity and have distinct spatial correlations. For the type I data, three methods are shown to be effective and demonstrated to produce plausible results: (1) a spline-based method, (2) a combination of a spline-based method with a stochastic simulation, and (3) a neural network method. Geostatistics proves to be a powerful tool for type II data. Three new approaches of geostatistics are presented with case studies: an application to directional data such as fracture, multi-scale modeling that incorporates a scaling law, and space-time joint analysis for multivariate data. Methods for improving the contribution of such spatial modeling to Earth and environmental sciences are also discussed and future important problems to be solved are summarized. 相似文献
2.
《煤田地质与勘探》2021,49(5):190-199
The Cretaceous is a typical period for studying the greenhouse climate and the earth system interactions, and the world's most extensive terrestrial strata are mainly in East Asia, especially in China. Continental sediments can effectively reflect the paleo-climate change, but the previous studies of the Late Cretaceous paleo-climate, based on the combined characteristics of continental climate-sensitive sediments, were barely found in China. To obtain the Late Cretaceous paleo-climate characteristics of China, the distribution characteristics of different continental climate-sensitive sediment types in the early, middle and Late Cretaceous in China were studied in detail. According to the distribution and combination characteristics and types of continental climate-sensitive sediments, seven climate types can be divided: 1) warm-humid and warm-dry climate; 2) hot and dry climate; 3) hot-dry and arid climate; 4) hot-dry and semiarid climate; 5) hot-dry and hot-wet climate; 6) hot-dry and warm-humid climate; 7) hot-dry and warm-dry climate. The results show that in the early Late Cretaceous, the hot and dry climate was the most widespread, followed by warm-humid and warm-dry climate, but the climate was drier than the paleo-climate of the previous study of Early Cretaceous. Hot and dry climate zone became wider in the Coniacian and Maastrichtian; furthermore, it covered Xinjiang to the east of China from east to west after the Santonian Period. The hot-dry and semiarid climate zone was nearly latitudinally distributed from the northwest to the southeast and it shows a further increase in aridification. Global geological events, paleogeographic features and regional tectonic evolution had significant impacts on the paleoclimate of China in the Late Cretaceous, such as global eruptive events of volcanoes led to the temperature increase in China in the early Late Cretaceous; coastal mountain ranges in southeastern China led to the drying of the Late Cretaceous climate in southern China; Xuefeng Mountains, Wuling Mountains, Nanling Mountains and Tai-hang Mountains were the dividing line between the hot and dry climate zone and hot-dry and arid climate zone in the early Late Cretaceous, and Altun Mountains were the dividing line between the southeastern section of the hot and dry climate zone in western China in the middle Late Cretaceous. 相似文献
3.
西藏金沙江缝合带西段晚三叠世碰撞作用与沉积响应 总被引：17，自引：4，他引：17
青藏高原是由若干条缝合带和其间所夹的沉积盆地构成,其中晚三叠世北羌塘盆地位于金沙江缝合带南缘,盆地的充填实体显示为南薄北厚,为楔形沉积体;在垂向上,以不整合面为界可将该套充填地层划分为两个构造层序,下部构造层序以复理石建造为特征,上部构造层序以磨拉石建造为特征,具有典型的前陆盆地充填序列;盆地具双物源和双古流向体制,沉降中心和沉积中心具有不一致,显示其为金沙江缝合带南侧的周缘前陆盆地,从而确定了晚三叠世北羌塘前陆盆地与金沙江缝合带的成因关系。在此基础上,结合在金沙江缝合带西段新发现和确定的蛇绿岩的最小年龄和碰撞型花岗岩的年龄,本文根据下部构造层序复理石的年龄、前缘隆起的形成年龄、冲断带隆升成为地貌高地的年龄、下部不整合面的时代和前缘隆起型碳酸岩缓坡的形成时间标定了金沙江缝合带碰撞事件的时代下限,根据上部构造层序磨拉石的年龄、上部不整合面的年龄、花岗岩和构造碎裂岩成为物源的年龄标定了金沙江缝合带碰撞事件的时代上限,表明金沙江缝合带初始碰撞事件为卡尼克期与诺利克期之间,最终碰撞事件介于诺利克期与瑞替克期之间. 相似文献
4.
利用测井信息评价盐湖相烃源岩 总被引：1，自引：0，他引：1
盐湖相烃源岩富含膏、盐质成分,使其测井响应特征发生极大改变,给测井评价烃源岩带来困难。基于实测数据,分析了盐湖相烃源岩中普遍发育的纯泥岩、含膏(盐)泥岩和膏(盐)质泥岩有机碳含量的测井响应模式,发现纯泥岩和含膏(盐)泥岩TOC与AC和LogRt呈正比,与DEN呈反比,膏(盐)质泥岩TOC与DEN呈正比,与LogRt呈反比,并基于此建立了盐湖相烃源岩测井评价方法,即首先利用ΔGR区分岩性,再针对不同岩性建立TOC评价模型,最后根据实测S1+S2和TOC建立相关关系,就可以求取烃源岩的TOC和S1+S2。利用该方法对东营凹陷沙四下亚段烃源岩性质和展布进行分析,发现预测TOC与实测TOC吻合程度高,具有一定推广价值。 相似文献
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中国昆明地区岩溶洞穴洞口带苔藓植物研究 总被引：2，自引：1，他引：1
为了研究中国西南岩溶洞穴植物区系与生物多样性特征, 作者曾两次对云南昆明地区12个岩溶洞穴进行了野外考察和苔藓植物标本采集工作。其中含昆明市石灰岩洞穴1个, 石林县石灰岩洞穴5个和宜良县白云岩洞穴6个。根据采自12个岩溶洞穴洞口带的164件苔藓植物标本研究, 本文首次报道昆明地区洞穴苔藓植物10科18属25种。昆明地区洞穴中分布较多的苔藓植物科有丛藓科( Po ttiaceae) 5属8种,凤尾藓科( Fi ssidentaceae ) 1属4种,柳叶藓科( Amblystegiaceae ) 3 属3 种和青藓(Brachytheciaceae ) 2属3种。溶洞中较常见的4种苔藓植物种类是萤光苔类植物光苔Cyathodiumcavernarum Kunze ( 见于6个溶洞中) , 小凤尾藓Fissidens bryoides Hedw ( 见于4个溶洞中) , 橙色净口藓Gymnostonum calcareum Nees et Ho rsch (见于3 个溶洞中)和长叶扭口藓Tortella tortuosa( Hedw ) Limp ( 见于3个溶洞中)。野外观察表明,受洞穴弱光环境生态因子的限制, 昆明地区洞穴苔藓植物主要生长于洞穴洞口0～ 26m带范围内; 2种丛集型藓类植物, 橙色净口藓Gymnostonumcalcareum Nees et Horsch, 和钩喙净口藓G.recurvirost re Hedw 参与洞口带钟乳石或石笋钙华沉积。 相似文献
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Shi-zhen Li Zhi Zhou Hai-kuan Nie Lei-fu Zhang Teng Song Wei-bin Liu Hao-han Li Qiu-chen Xu Si-yu Wei Shu Tao 《China Geology》2022,5(1):110-135
The shale gas resources in China have great potential and the geological resources of shale gas is over 100×1012m3,which includes about 20×1012m3 of recoverable resources.Organic-rich shales can be divided into three types according to their sedimentary environments,namely marine,marine-continental transitional,and continental shales,which are distributed in 13 stratigraphic systems from the Mesoproterozoic to the Cenozoic.The Sichuan Basin and its surrounding areas have the highest geological resources of shale gas,and the commercial development of shale gas has been achieved in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in these areas,with a shale gas production of up to 20×109m3 in 2020.China has seen rapid shale gas exploration and development over the last five years,successively achieving breakthroughs and important findings in many areas and strata.The details are as follows.(1)Large-scale development of middle-shallow shale gas(burial depth:less than 3500 m)has been realized,with the productivity having rapidly increased;(2)breakthroughs have been constantly made in the development of deep shale gas(burial depth:3500-4500 m),and the ultradeep shale gas(burial depth:greater than 4500 m)is under testing;(3)breakthroughs have been made in the development of normal-pressure shale gas,and the assessment of the shale gas in complex tectonic areas is being accelerated;(4)shale gas has been frequently discovered in new areas and new strata,exhibiting a great prospect.Based on the exploration and development practice,three aspects of consensus have been gradually reached on the research progress in the geological theories of shale gas achieved in China.(1)in terms of deep-water fine-grained sediments,organic-rich shales are the base for the formation of shale gas;(2)in terms of high-quality reservoirs,the development of micro-nano organic matter-hosted pores serves as the core of shale gas accumulation;(3)in terms of preservation conditions,weak structural transformation,a moderate degree of thermal evolution,and a high pressure coefficient are the key to shale gas enrichment.As a type of important low-carbon fossil energy,shale gas will play an increasingly important role in achieving the strategic goals of peak carbon dioxide emissions and carbon neutrality.Based on the in-depth study of shale gas geological conditions and current exploration progress,three important directions for shale gas exploration in China in the next five years are put forward. 相似文献
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A method is proposed for the prospecting prediction of subsurface mineral deposits based on soil geochemistry data and a deep convolutional neural network model.This method uses three techniques(window offset,scaling,and rotation)to enhance the number of training data for the model.A window area is used to extract the spatial distribution characteristics of soil geochemistry and measure their correspondence with the occurrence of known subsurface deposits.Prospecting prediction is achieved by matching the characteristics of the window area of an unknown area with the relationships established in the known area.This method can efficiently predict mineral prospective areas where there are few ore deposits used for generating the training dataset,meaning that the deep-learning method can be effectively used for deposit prospecting prediction.Using soil active geochemical measurement data,this method was applied in the Daqiao area,Gansu Province,for which seven favorable gold prospecting target areas were predicted.The Daqiao orogenic gold deposit of latest Jurassic and Early Jurassic age in the southern domain has more than 105 t of gold resources at an average grade of 3-4 g/t.In 2020,the project team drilled and verified the K prediction area,and found 66 m gold mineralized bodies.The new method should be applicable to prospecting prediction using conventional geochemical data in other areas. 相似文献
8.
《煤田地质与勘探》2021,49(3):1-7
The Deep Resources Exploration and Mining(DREAM) grant program, within the framework of The National Key Research and Development Program grants, is a pillar to implement China's science and technology strategy in the area of deep resources exploitation. To tackle the insufficient of theories and technologies for the 1000-meter-deep mining, a section of mining, covering the research of basic theories, general technologies and application demonstration, was arranged in the layout of DREAM under the principle of "whole chain design, integrated implementation". In the aspect of basic research, DREAM mainly focused on the deep rock mechanics and mining theory, such as the in-situ mechanical behavior of deep rock, deep high stress induction and energy regulation theory. For the general and key technologies, DREAM supported the research on the mine construction and hoisting, excavation, rock breaking, mining methods and mining safety according to the characteristics of coal and metal mines. For the demonstration application, taking green, safe and efficient as the starting point, DREAM aimed at the green, safe and high efficiency mining, and the demonstration and leading role projects such as the low-waste and high-efficiency back fill mining. Since 2016, 10 RD projects have been funded, and 122 institutional participants with a total budget of RMB 235 million from the central government and RMB 480 million from enterprises as well as local governments have been involved. It is expected that the mining section of DREAM would contribute to establishing the theory and technology system in the area of deep mining and promoting the ability of deep resource exploitation in China. 相似文献
9.
Wei Xiong Xi Mei Bei-bei Mi Hao Yang Zong-zhu Han Yong Zhang Wen-chao Lu 《China Geology》2022,5(1):160-170
As a new type of pollutants in the marine environment,microplastics have attracted increasing attention from scientific researchers and environmental protection workers in China and abroad.However,for the microplastic pollution in sea areas in China,there are a very limited number of studies on its current status and few reviews of research on the microplastics.This paper reviews the surveys and researches of microplastics in the Bohai Sea,the Yellow Sea,the East China Sea,the South China Sea,and main estuaries in China carried out in recent years and proposes an outlook for future work,aiming to provide research suggestions and solutions for ecological protection against microplastic pollution in sea areas in China.Previous studies have shown that microplastics are widely distributed in water bodies and sediments in sea areas and major estuaries in China.The Pearl River Estuary,in the South China Sea suffers the most serious microplastic pollution,followed by the Bohai Sea.In contrast,the microplastic pollution in the Yellow Sea and the East China Sea is comparatively slight.Microplastics in sea areas in China are mainly fibrous and are concentrated in offshore areas with developed industry and a dense population(especially around estuaries and bays).In addition,they are widely affected by human activities,such as shipping,aquaculture,industry,and sewage discharge.Here the authors suggest unifying measurement units and research methods and developing related standard systems to carry out researches related to microplastics.Furthermore,this paper also suggests further deepening researches on both the source-sink process of microplastics and nanoscale microplastics while enhancing the development and implementation of related policies,aiming to promote researches and control of microplastics in sea areas in China. 相似文献
10.
Xiongqi Pang Chengzao Jia Junqing Chen Maowen Li Wenyang Wang Qinhong Hu Yingchun Guo Zhangxin Chen Junwen Peng Keyu Liu Keliu Wu 《地学前缘(英文版)》2021,12(2):695-711
The discovery and large-scale exploration of unconventional oil/gas resources since 1980s have been considered as the most important advancement in the history of petroleum geology;that has not only changed the balance of supply and demand in the global energy market,but also improved our understanding of the formation mechanisms and distribution characteristics of oil/gas reservoirs.However,what is the difference of conventional and unconventional resources and why they always related to each other in petroliferous basins is not clear.As the differences and correlations between unconventional and conventional resources are complex challenging issues and very critical for resources assessment and hydrocarbon exploration,this paper focused on studying the relationship of formations and distributions among different oil/gas reservoirs.Drilling results of 12,237 exploratory wells in 6 representative petroliferous basins of China and distribution characteristics for 52,926 oil/gas accumulations over the world were applied to clarify the formation conditions and genetic relations of different oil/gas reservoirs in a petroliferous basin,and then to establish a unified model to address the differences and correlations of conventional and unconventional reservoirs.In this model,conventional reservoirs formed in free hydrocarbon dynamic field with high porosity and permeability located above the boundary of hydrocarbon buoyancy-driven accumulation depth limit.Unconventional tight reservoirs formed in confined hydrocarbon dynamic field with low porosity and permeability located between hydrocarbon buoyancy-driven accumulation depth limit and hydrocarbon accumulation depth limit.Shale oil/gas reservoirs formed in the bound hydrocarbon dynamic field with low porosity and ultra-low permeability within the source rock layers.More than 75%of proved reserves around the world are discovered in the free hydrocarbon dynamic field,which is estimated to contain only 10%of originally generated hydrocarbons.Most of undiscovered resources distributed in the confined hydrocarbon dynamic field and the bound hydrocarbon dynamic field,which contains 90%of original generated hydrocarbons,implying a reasonable and promising area for future hydrocarbon explorations.The buried depths of hydrocarbon dynamic fields become shallow with the increase of heat flow,and the remaining oil/gas resources mainly exist in the deep area of“cold basin”with low geothermal gradient.Lithology changing in the hydrocarbon dynamic field causes local anomalies in the oil/gas dynamic mechanism,leading to the local formation of unconventional hydrocarbon reservoirs in the free hydrocarbon dynamic field or the occurrence of oil/gas enrichment sweet points with high porosity and permeability in the confined hydrocarbon dynamic field.The tectonic movements destroy the medium conditions and oil/gas components,which leads to the transformation of conventional oil/gas reservoirs formed in free hydrocarbon dynamic field to unconventional ones or unconventional ones formed in confined and bound hydrocarbon dynamic fields to conventional ones. 相似文献
11.
基于RS和GIS的石羊河流域近50年土地覆被类型变化研究 总被引：1，自引：0，他引：1
选取石羊河流域为研究区，采用1970～2017年18期Landsat系列卫星遥感数据，通过数据处理、面向对象信息提取，获取了石羊河流域近50年土地覆被类型基础数据；运用转移矩阵、GIS分析手段，对石羊河流域不同土地类型时空变化特征进行了研究.结果表明：1）近50年来，石羊河流域自然绿洲面积总体呈逐年减少趋势，由1970年的35 717.53 km2减少到2017年的33 865.47 km2；人工绿洲面积相应增加，由5 355.79 km2增至7 208.70 km2.2）耕地、天然林地、天然草地、建设用地总体呈增加趋势，耕地的增加主要由天然草地、未利用地及水域湿地转化而来，天然林地的增加主要由天然草地、未利用地转化而来，天然草地面积的增加主要由未利用地转化而来，建设用地的扩张以占用周围草地、耕地及未利用地为主.3）石羊河流域土地类型的演变，总体反映了石羊河流域生态环境趋好，绿洲区域逐渐增加. 相似文献
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成矿区（带）是区域成矿学的核心内容,成矿区（带）的划分和研究是成矿规律认识的深化和科学表达,同时是具有矿产资源潜力的成矿单元,是服务于勘查决策的主要载体。文章根据全国成矿区（带）划分意见,对甘肃涉及的4个成矿域、8个成矿省及12个Ⅲ级成矿区带进行分析和研究,依据省内区域矿产空间分布的集中性和区域成矿作用的统一性原则,重点讨论矿床所处的大地构造环境、成矿作用与区域地质演化过程、容矿围岩时空分布一致性或相似性;参考区域地球化学场、地球物理场特征,划分Ⅳ级成矿区（带）26个,Ⅴ级成矿区（带）94个。明确各级成矿区带地质意义及显著特征。文章指出本次对甘肃省成矿区带的划分具有探索性,随着认识不断深化,成矿区带的研究和厘定将更加科学。 相似文献
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测定岩石类样品中的Zr含量,酸溶经常结果偏低,碱溶通常较难获得较低的检出限。本文选取了不同岩性的岩石类国家标准物质GBW07104、GBW07106、GBW07107、GBW07114、GBW07835、GBW07836、GBW07837作为实验样品,分别采用酸溶后复溶、Na2O2碱熔、赶硅后Na2CO3和Na2B4O7三种前处理方法,对电感耦合等离子体质谱仪进行参数优化后上机测定,结果表明:对样品赶硅后加入少量Na2CO3和Na2B4O7混合试剂高温熔融处理岩石样品后,锆的测量值准确度高,而且获得了最低的检出限,同时缩短了方法流程,操作快捷。该方法更适用于各类岩石样品锆的测定。 相似文献
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保存良好的Autunia conferta.和Dichophyllum flabellifera近来在新疆塔里木盆地西北缘下二叠统上部的发现,是在塔里木盆地的首次记录.这两个种以前曾被归于Callipteris属内,后来Kerp指出该属的属名有问题,便与Haubold提出了形态属Callipteris的重新划分方案,这一方案笔者表示完全同意.A.conferta是欧美植物群中早二叠世常见分子,在中欧的少数地点亦见于上石炭统上部,在中国则极少发现,仅见报道于河北开平赵各庄群上部和山西太原下石盒子组.D.flabellifera是欧美植物群中的另一早二叠分子,在西欧和北美的上石炭统上部亦见少数先驱分子,在华夏植物群中从未发现过.本文记载为其在国内首次记录.上述发现在古植物地理上具有一定意义. 相似文献
18.
时间谱电阻率法中的剩余电磁效应研究 总被引：2，自引：0，他引：2
根据频谱激电（SIP）法或复电阻率（CR）法中研究剩余电磁（REM）效应的思想，通过分析时间谱电阻率（TSR）法中场的基本特征，在TSR法中建立了与SIP（或CR）法中参数Φmax/Φ0max相类似的参数－Emax/E0，用来描述了TSR法中的REM效应。通过对一维可极化大地模型的REM效应的理论计算，验证了用Emax/E0表示的REM异常可用来形象地反映地电断面电阻率的高低。 相似文献
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耕作措施对陕西耕作土壤碳储量的影响模拟* 总被引：6，自引：0，他引：6
鉴于农业生态系统土壤有机碳(SOC)平衡对中国农业可持续发展的重要性,文章以陕西农业生态系统为对象,整合农业生物地球化学模型(DNDC)与陕西农业地理信息系统数据库,利用陕西地区气象和作物资料,对陕西省2000年作物生长发育和土壤碳循环进行了模型模拟,实例探讨了耕作管理对土壤碳储量的影响,并由此评价生物地球化学模型在气候变化、土壤性质及农业耕作管理措施对土壤碳含量影响方面的预测能力。敏感性分析表明土壤性状,尤其是初始有机碳含量是影响模型区域尺度模拟的最主要敏感因素。区域模拟使用灵敏系数分析法,分别采用敏感因子的最大、最小值驱动模型在每一模拟单元内的运算,以产生一个土壤有机碳变化的范围值,土壤有机碳变化的真实值应以较大机率包含在这一范围内。分析模拟结果可以得出3点结论: 1)2000年陕西耕作土壤总有机碳储量约为103TgC,是一个大气CO2源,向大气释放碳0.5TgC; 2)提高作物秸秆还田率是提高陕西农田碳库储量的有效可行措施,将作物秸秆还田率从当前的15 ％ 提高到50 ％ 或90 ％ 会使陕西农田土壤从大气CO2源转变为汇,每年分别增加土壤有机碳库储量0.7TgC或2.1TgC; 3)施用有机农肥(500kg/hm2)也会增加土壤碳输入,从而提高土壤碳储量,使陕西农田系统转变为较弱的碳(C)源,每年可多固定0.2TgC。 相似文献
20.
火山活动与气候变化研究进展 总被引：12，自引：1，他引：12
综述了火山活动对气候影响的研究进展。不同岩浆成分及喷发类型的火山活动对气候的影响不同：中酸性普林尼（Pl inian）式火山喷发主要造成气候变冷和臭氧层破坏，它导致气候变化的时间较短，但空间范围较大；大火成岩省造成气候变化的时空范围及程度均较大，它能够导致地表温度、海平面大幅度变化，最终引起生物灭绝；中小规模玄武质裂隙式喷发主要造成火山盆地内气候较大幅度变化，但对气候影响的持续时间较短，主要气候效应是导致附近地区温度快速下降和形成酸雨。简要阐述了第四纪火山活动的特点。 相似文献