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91.
本区构造发展存在三个不同阶段,印支期为初始褶皱阶段;燕山期为逆冲推覆定型阶段;喜马拉雅期为改造与破坏阶段。其地质结构明显具有双重构造,构造反转和推覆滑税三大特征。区内地震反射特征与岩性组合有一定对应关系,本文首次尝试利用地震反射信息特征对沉积环境进行分析。 相似文献
92.
Within the Central European Zechstein Basin the Permian Kupferschiefer has been deposited under anoxic conditions. In most parts of the basin, the metal content does not exceed values commonly observed in black shales. However, in areas near to the Zechstein sea-shore which are simultaneously related to rift zones a significant base metal enrichment is observed. Organic geochemical analyses of the copper-mineralized sections in the Kupferschiefer from Southwest Poland show that significant changes in the composition of organic matter are associated with the metal enrichment processes. Porphyrins, commonly abundant constituents of the shale, have been decomposed by oxidizing fluids. Additionally, aliphatic hydrocarbons have been largely removed from the bitumen and alkylated aromatic systems were affected by side-chain degradation. This particular type of alteration is explained by ascending oxidizing solutions which transported high amounts of base metals from Lower Permian red beds into the Kupferschiefer horizon acting as a geochemical trap. The metal precipitation is suggested to be a result of thermochemical sulphide production with organic matter acting as hydrogen source. In areas such as the Lower Rhine Basin in the bottom section of the Kupferschiefer the base metals lead and zinc as well as barium have been accumulated from basinal Carboniferous formation waters. Copper enrichment is not observed because potential source rocks are missing in this area. However, the observed compositional changes of the organic matter do not point towards thermochemical redox processes. 相似文献
93.
94.
塔里木盆地两种重要的圈闭型式及其与喜山期油气关系 总被引:1,自引:0,他引:1
在塔里木盆地众多的圈闭类型中,中生界披覆背斜圈闭和以下古生界为主的断块潜山(或潜山)圈闭是最重要的两种高产圈闭型式,此两种圈闭均主要形成于中生代,它们所富集的油气均主要是喜山期以来生成的油气。披覆背斜圈闭封闭样多为单封闭层整合型,而断块潜山(或潜山)圈闭封闭样成式为不整合型(其中许多尚属多封闭层圈闭),故从理论上看,中生界披覆背斜圈闭封闭和储聚油气能力要优于古生界断块潜山(或潜山)圈闭,塔北勘探实 相似文献
95.
96.
以大庆地区地质资料为基础,应用弹性力学问题的有限单元法.计算大庆地区东西剖面的应力场,分析多个指标的分布特点及其所指示的应力圈闭和流体活动特点,为今后油田的勘探和开发提供新依据。 相似文献
97.
Hidetaka Takeoka 《Journal of Oceanography》2002,58(1):93-107
The Seto Inland Sea is a representative coastal sea in Japan with a complicated geometry and thus a variety of marine environments.
This sea is, at the same time, one of the most industrialized areas in Japan, and its marine environment has been significantly
affected by the anthropogenic impacts over the last four decades. The wide range of marine environments in this sea and the
serious environmental issues resulting from these impacts have attracted the attention of Japanese coastal oceanographers.
It is believed that the nature and scope of these studies might be an example of the progress of Japanese coastal oceanography.
The historical changes in the Seto Inland Sea environment in the last four decades are briefly summarized, and the progress
in the studies of the Seto Inland Sea is reviewed with reference to historical changes. Some recent research topics and activities
are also mentioned.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
98.
A time-series sediment trap was deployed from December 1994 to February 2002 at the mouth of Tokyo Bay (35°03′ N, 139°40′
E; water depth, 850 m). Sinking particles were obtained with a time interval of one week at a depth of approximately 100 m
above the sea floor. Observed total mass fluxes varied from 3.3 to 226.7 g/m2/day with an average of 28.0 g/m2/day. Concentrations of rare earth elements, Al, Ca and Si in particulate materials were measured. The combustible fraction
at 450°C is assumed to be equivalent to the organic matter content. Contents of biogenic materials, namely organic matter,
opal and calcium carbonate, were about 30% and the content of lithogenic material was about 70%. Using La/Yb ratios of particles
from the sediment trap and Tama-gawa River and surface sediment of Tokyo Bay, it was estimated that about 50% of the lithogenic
particles collected in the sediment trap at the mouth of Tokyo Bay originated from resuspended surface sediment in Tokyo Bay.
An increasing trend of Opal/CaCO3 ratio in the sinking particles was found in the spring season. It is suggested that the relative increase of diatoms is due
to the decreasing dissolved inorganic nitrogen input into Tokyo Bay. 相似文献
99.
北戴河海滩泥沙捕获实验及其初步结果分析 总被引:2,自引:1,他引:2
介绍了利用泥沙捕获器观测破波带泥沙垂直分布结构的现场实验方法和基本程序,以及利用实验结果计算泥沙通量的方法。研究表明,近岸带泥沙运移通量及其在垂向上的分布受破波带相对位置和海滩地形变化的影响。在破波点附近,波浪的搅动和流场作用强,泥沙运移通量增大,泥沙在波浪的作用下可以大量进入垂直水体以悬移和跃移的方式运移。在本实验中,破波点附近的泥沙在距海底100cm的垂直水体中运移,通量垂向向上逐渐减小。远离破波点,泥沙运移通量和进入垂直水体的高度明显下降。在地形变化复杂的有坝海滩,沙坝顶部的泥沙运移通量最大,泥沙进入垂直水体运移的机率增加,而在沙坝问的沟槽内,波浪和海流作用减弱,泥沙通量和垂向进入水体运移的比例下降。 相似文献
100.