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861.
Risacher et al. (2011) have presented voluminous data on thermal waters of Chile that is quite appreciable; however, their work still falls short on several counts. The most notable shortcoming of the work is the presentation and treatment of data. The interpretations are based on questionable premises (viz., extent of seawater intrusion) and considerations (viz., using average chemical composition of rock types for geochemical modeling, considering volcanic rocks as the only rock type in contact with the geothermal fluids) and assumptions not always substantiated by facts (with proper references) could have been corroborated. Use of Cl/Br ratio for discrimination purpose is unconvincing, considering the uncertainty in the measurement of low (<1 mg/L) Br concentration.  相似文献   
862.
现代泥炭地中蕴藏着巨量的碳,泥炭地生产力的高低会影响全球碳循环及全球气候变化。前人对全新世以来泥炭地生产力做了大量研究,但对前第四纪的“深时”阶段的泥炭地生产力则极少涉及,其主要原因是缺少精确的定年方法。以二连盆地吉尔嘎郎图凹陷早白垩世6号煤为例,利用地球物理测井信号进行频谱分析并获得煤层中米兰科维奇旋回周期参数(123 ka(偏心率):38.1 ka(斜率):22.1 ka(岁差)),将米兰科维奇旋回作为“深时”地层时间的“度量”工具,计算出6号煤层碳的聚集速率为35.1~38.9 g C/(m2·a),进一步推算出其所代表的泥炭地的碳聚集速率为46.2~51.2 g C/(m2·a),净初级生产力(NPP)为231~256 g C/(m2·a)。将该计算结果与全新世同一纬度带泥炭地生产力水平比较,并结合前人研究成果综合分析影响因素,得出早白垩世泥炭地生产力水平主要受温度和大气中二氧化碳含量控制,而这两种因素又与气候相关联,则泥炭地生产力的研究可能对进一步了解古气候提供帮助。  相似文献   
863.
Research on Formation Mechanisms of Hot Dry Rock Resources in China   总被引:3,自引:0,他引:3  
As an important geothermal resource, hot dry rock(HDR) reserves have been studied in many countries. HDR resources in China have huge capacity and have become one of the most important resources for the potential replacement of fossil fuels. However, HDR resources are difficult to develop and utilise. Technologies for use with HDR, such as high–temperature drilling, reservoir characterisation, reservoir fracturing, microseismic monitoring and high–temperature power stations, originate from the field of oil and drilling. Addressing how to take advantage of these developed technologies is a key factor in the development of HDR reserves. Based on the thermal crustal structure in China, HDR resources can be divided into four types: high radioactive heat production, sedimentary basin, modern volcano and the inner–plate active tectonic belt. The prospective regions of HDR resources are located in South Tibet, West Yunnan, the southeast coast of China, Bohai Rim, Songliao Basin and Guanzhong Basin. The related essential technologies are relatively mature, and the prospect of HDR power generation is promising. Therefore, analysing the formation mechanisms of HDR resources and promoting the transformation of technological achievements, large–scale development and the utilisation of HDR resources can be achieved in China.  相似文献   
864.
As a milestone of the entire energy industry, unconventional resources have inevitably swept the world in the last decade, and will certainly dominate the global oil and gas industry in the near future. Eventually, the “unconventional” will become “conventional”. Along with the rapid development, however, some issues have emerged, which are closely related to the viability of unconventional resources development. Under the current circumstances of low crude oil and gas price, coupled with the prominent environmental concerns, the arguments about the development and production of unconventional resources have been recently heated up. This work introduced the full-blown aspects of unconventional resources especially shale reservoirs, by discussing their concepts and definitions, reviewing the shale gas and shale oil development history and necessity, analyzing the shale plays’ geology and petroleum systems with respects to key hydrocarbon accumulation elements and mechanisms, and summarizing the technology resolution. This study also discussed the relevant key issues, including significant estimation uncertainty of technically recoverable resources, the equivocal understanding of complex geology preventing the production and technologies implementation optimization, the difficulties of experiences and technologies global expanding, and the corresponding risks and uncertainties. In addition, based on the latest production and exploration data, the future perspective of the unconventional resources was depicted from global unconventional resources assessments, technology development, and limitations constraining the development.  相似文献   
865.
Outcrop and drill hole data show that the Jurassic coal measures in the northeastern Ordos Basin are composed mainly of the Yan'an Formation and the lowstand system tract of the Zhiluo Formation,and there is a regional unconformity between them. The Dongsheng uranium deposit is associated with the Jurassic coal measures. Research data indicate that the Jurassic coal measures in the study area have a certain hydrocarbon-generating capacity,although the metamorphic grade is low(Ro=0.40%–0.58%). In the Dongsheng region alone,the accumulative amount of generated coalbed methane(CBM) is about 2028.29 × 108 –2218.72 × 108 m~3; the residual amount is about 50.92 × 108 m~3,and the lost amount is about 1977 × 108 m~3. Analysis of the burial history of the host rocks and the evolutionary history of the Dongsheng uranium deposit suggests that the Jurassic coal measures generated hydrocarbon mainly from Middle Jurassic to Early Crataceous,which is the main mineralization phase of the Dongsheng uranium deposit. By the Late Cretaceous,a mass of CBM dissipated due to the strong tectonic uplift,and the Dongsheng uranium deposit stepped into the preservation phase. Therefore,the low-mature hydrocarbon-containing fluid in the Jurassic coal measures not only served as a reducing agent for the formation of sandstone-type uranium deposits,but also rendered the second reduction of paleo-interlayer oxidation zone and become the primary reducing agent for ore conservation. Regional strata correlation reveals that the sandstone-type uranium reservoir at the bottom of the Zhiluo Formation is in contact with the underlying industrial coal seams in the Yan'an Formation through incision or in the form of an unconformity surface. In the Dongsheng region with poorly developed fault systems,the unconformity surface and scour surface served as the main migration pathways for low-mature hydrocarbon-containing fluid migrating to the uranium reservoir.  相似文献   
866.
产于含油(气)盆地中的地浸砂岩型铀矿床与油(气)关系密切,在空间上常与油(气)藏呈共生关系。文章认为其成矿条件和控矿因素相似,并且具有成因联系是二者共生的主要原因。砂岩型铀矿和油(气)藏具有相似的成矿大地构造背景、岩相古地理条件、容矿地层、岩性圈闭、构造控矿条件和有机质基础;在成因上油(气)中的不同组分及其次生矿物对铀有重要的吸附和还原作用,是铀沉淀富集的重要因素之一,铀等放射性元素的存在也有利于油气的生成。由于成矿机理的差异性,砂岩型铀矿与油(气)藏属于异体共生矿床,二者的产出位置并不完全重叠,砂岩型铀矿的产出位置往往更靠近盆缘,且在油(气)储层上方,或以单一矿种产出。  相似文献   
867.
以矿田构造–岩相填图为主要方法,研究确定矿田构造和岩浆-热力构造类型及矿床类型,进行成矿富集中心的圈定及找矿预测,是矿田构造背景复杂地区的有效调研方法之一。东昆仑西段祁漫塔格矿带多期构造–岩浆活动强烈,断裂发育,以印支晚期岩浆侵入成矿与找矿进展较大。本次选择景忍–虎头崖、卡尔却卡B区、乌兰乌珠尔三个矿田区,进行1∶10000构造–岩相填图,填制了三个矿田区岩浆–热力构造类型分布图,认为晚三叠世岩浆侵入作用是该区多金属大规模成矿的主要内因,叠加其上的不同方向断裂控矿作用不同,近东西向和北西西向断裂控矿显著,明确了各矿田构造背景和印支期岩浆侵入形成的花岗斑岩+矽卡岩+断裂带热液成矿的模式,厘定了岩浆–热力构造的识别标志,即主要是印支晚期中酸性侵入岩、花岗斑岩、矽卡岩带、大理岩带、接触交代蚀变带、断裂破碎带叠加热液蚀变带等,圈定了成矿和找矿富集中心。  相似文献   
868.
丰乐铝土矿床位于黔北务正道铝土矿成矿带的南东端,是近年在铝土矿勘查的空白区新探明的中型矿床。勘查发现矿床中含矿岩系顶部拥有不含或偶含炭质岩系的地质特征,与务正道地区其它铝土矿床存在差异性。微量元素Cr/Ni判别显示了含矿岩系的多物源性,V/Zr及Sr/B揭示该区具有海相―陆相或过渡相―海相的沉积特征。结合前人研究成果综合分析认为,该区沉积环境为受海侵影响的近滨海湖泊―沼泽相环境。  相似文献   
869.
白石坝一带花岗岩具高硅低铝、富钾贫钠、非常低Sr(24.9×10~(-6)~82.9×10~(-6))高Yb(2.61×10~(-6)~5.74×10~(-6))的南岭型花岗岩特征,A/CNK介于0.91~0.98之间,σ在1.92~2.22之间。明显富集Rb、Th、K等大离子不相容元素,亏损Ba、Sr、P、Ti等元素,并具有弱Nb亏损,稀土元素分布曲线呈明显的"燕式"型,其形成可能来源于下地壳底部部分熔融与地壳物质发生混合形成的产物,源区深度较浅、水含量低和氧逸度低,处于还原状态下的伸展构造背景,有利于锡矿的萃取和富集,研究其区域构造-岩浆演化,对指导区域矿产预测和评价均具有重要的理论和实际意义。  相似文献   
870.
Large-scale, low frequency modes such as the North Atlantic Oscillation(NAO)and blocking, have an important modulation on the northern hemisphere weather and climate. In this paper, the physical mechanism studies on inter-decadal and decadal variability of NAO and blocking were summarized. The relationship between NAO regime transitions and the interannual variability of NAO in winter during was examined by using a statistical approach. The time-space relationship between NAO and European blocking were discussed. Based on two extreme cold and snowstorm events, the impacts on local weather especially the extreme events within the life cycle (two weeks) of the NAO and blocking were further examined. It was found that the frequently occurrence of the Eurasian extreme snowstorm was closely related to the special combination of NAO and blocking regime. In addition, the development of theoretical modes for NAO and blocking was discussed and issues that remain to be solved were proposed.  相似文献   
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