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141.
使用氧同位素方法 ,测试了西太平洋马里亚纳岛弧、马里亚纳海槽、冲绳海槽和东太平洋加拉帕戈斯裂谷的海底热液烟囱和硫化物全岩样品。结果表明 :马里亚纳岛弧上的埃斯梅拉尔达破火山口的热液硫化物的形成温度最高 (达 2 75℃ ) ,而成为高温产物的代表 ;冲绳海槽和加拉帕戈斯裂谷烟囱 ,表现为中高温类型 ,其氧同位素温度在 1 5 0℃左右 ;马里亚纳海槽以蛋白石为主要矿物的烟囱物 ,则显示出典型的低温热液类型 ,少量黄铁矿砂试样则表现出中温类型特征。但上述区域大都不同程度地存在有闪锌矿、黄铁矿、黄铜矿等中高温热液矿物 ,说明研究区除马里亚纳海槽明显有中低温热液活动类型外 ,其它区域皆具备中高温热液活动特征 相似文献
142.
Geochemistry of Ore Fluids and Rb-Sr Isotopic Dating for the Wulong Gold Deposit in Liaoning, China 总被引:3,自引:0,他引:3
WEI Junhao QIU Xiaoping GUO Dazhao TAN Wenjuan Faculty of Earth Resources Chinese University of Geosciences Wuhan Hubei Institute of Geology Chinese Academy of Geological Sciences Beijing 《《地质学报》英文版》2004,78(6):1267-1274
On the basis of detailed geological studies of the Wulong gold deposit, three metallogenic stages can be identified. With quartz fluid inclusions as an object of study, the authors investigated phase characteristics, compositional variations, temperature and pressure changes, fluid evolution, Pb isotope tracing and Rb-Sr isotopic dating of fluid inclusions entrapped in the above three metallogenic stages. The results show that Na+ is decreased obviously with metallogenic evolution, while K+ and other cations and gas compositions (H2, CO, CH4 and CO2) are increased slightly, and that the temperature and salinity vary in a pulsating manner along with the metallogenic evolution. Inverse calculation of hydrogen and oxygen isotopes indicate that at the first metallogenic stage the fluids were magmatic water, at the second stage they were dominated by magmatic water with a minor amount of meteoric water involved, and at the third stage, i.e., the final stage of metallogenesis, the fluids were composed complete 相似文献
143.
中国东部中生代火山岩区不仅拥有丰富而类型多样的地质遗迹资源,同时也是我国人口和城镇、乡村最密集的地区,且交通便利、产业齐全、经济发达,是利用地质遗迹资源推动经济发展,支撑乡村振兴的先行区和示范区。本文以福建省大田县杞溪村为例,通过开展地质遗迹资源和社会人文资源综合调查和分析融合,将其规划、设计并建设成为一个以火山文化为特色的地质文化村。基于杞溪地质文化村的建设经验,通过对比分析,提出我国在建设地质文化村时普遍存在单村资源和承载能力有限等问题,认为地质文化村建设方向应遵循以点带面,发挥区域联动作用,使业态趋于完善的发展路径,最终实现该模式的可持续发展。 相似文献
144.
文章探讨了广西沉积矿床的成矿地质背景;划分了沉积矿床成矿系列;建立了海相沉积矿床和陆相沉积矿床两种成矿模式;新提出台沟相沉积和海沟相沉积矿床;呼吁重视对台沟相和海沟相沉积矿床的研究和找矿。 相似文献
145.
By examining the absolute magnitude (H) distributions (hereafter HD) of the cold and hot populations in the Kuiper belt and of the Trojans of Jupiter, we find evidence that the Trojans have been captured from the outer part of the primordial trans-neptunian planetesimal disk. We develop a sketch model of the HDs in the inner and outer parts of the disk that is consistent with the observed distributions and with the dynamical evolution scenario known as the ‘Nice model’. This leads us to predict that the HD of the hot population should have the same slope of the HD of the cold population for 6.5<H<9, both as steep as the slope of the Trojans' HD. Current data partially support this prediction, but future observations are needed to clarify this issue. Because the HD of the Trojans rolls over at H∼9 to a collisional equilibrium slope that should have been acquired when the Trojans were still embedded in the primordial trans-neptunian disk, our model implies that the same roll-over should characterize the HDs of the Kuiper belt populations, in agreement with the results of Bernstein et al. [Bernstein, G.M., and 5 colleagues, 2004. Astron. J. 128, 1364-1390] and Fuentes and Holman [Fuentes, C.I., Holman, M.J., 2008. Astron. J. 136, 83-97]. Finally, we show that the constraint on the total mass of the primordial trans-neptunian disk imposed by the Nice model implies that it is unlikely that the cold population formed beyond 35 AU. 相似文献
146.
本文综合了以往有关勘查和研究成果,总结浙江省江山—绍兴深断裂以南中生代火山岩区火山银矿床、点的时空分布、中型银矿床定位、成矿物质来源、成矿温度、矿石有用组分的垂直分带、矿物垂直分带、近矿围岩蚀变分带、矿体原生晕、稳定同位素、火山岩下的基本底物质组成差异与银矿的成矿关系等统计规律与成矿系列,认为浙东南火山岩区仍有良好的火山银(金、铅锌)矿找矿远景。 相似文献
147.
焦家断裂带位于龙(口)-莱(州)断裂带的南段,为胶西北地区三大著名的金成矿带之一。焦家断裂带南段因第四系覆盖至寺庄以南去向不明。根据近几年的研究成果,认为焦家断裂带应为龙(口)-莱(州)断裂带南段的高家庄子-紫罗姬家段,特别是南部的徐村院-紫罗姬家段所揭露断裂带应为焦家断裂带在该区的南延并具有较好的找矿前景。 相似文献
148.
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150.
The Trans Indus-Salt Range, located in northern Pakistan, is one of the most tectonically active fold-and-thrust belts and comprises three main regions: the Potwar-Salt Range, the Kohat-Surghar Range and the Bannu Basin-Khisor Range. Of these, the Bannu Basin is the least studied and only a handful of publically accessible datasets and publications are available. Recently made public 2D seismic profiles and well data from the Bannu Basin indicate the presence of salt as well as evidence for a main detachment surface which is Neoproterozoic in age. Our findings suggest that the Salt Range Formation could be the main detachment for the entire basin.Interpretation also shows a Miocene-Eocene basin-wide unconformity that marks the Himalayan orogenic event which separates the pre-Himalayan from the syn-Himalayan sedimentary units. On the basis of seismic reflection data, we conclude that the basin experienced three main tectonic settings. An early stage of pre-Himalayan passive tectonic environment is followed by the compressional Himalayan tectonics which resulted in uplifted areas sourcing the fluviatile fill of the subsided basin. During this time, sedimentation from the northern margin of the basin may have influenced the southward flow of salt. This is followed by a more recent stage of thrusting that produced folds and thrusts deforming all of the sedimentary units.Structural geometries suggest that prospective traps are developed mainly in the anticlines outlining the eastern and western boundaries of the Bannu Basin, as well as the southern zone of the basin. Furthermore, the presence of salt diapirism and transpression zones together with numerous oil seeps in and around the basin increase the probability of hydrocarbon accumulation and indicate great potential for future exploration. 相似文献