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41.
四川盆地中二叠统栖霞组勘探发现系列油气,资源潜力巨大。但广安地区中二叠统栖霞组的岩石学特征及沉积环境研究薄弱。在野外地质调查的基础上,结合室内岩石学、岩相学等综合分析,对广安地区栖霞组碳酸盐岩岩石特征、沉积相类型及其古地理展布特征进行了系统研究。结果表明:广安地区栖霞组主要发育亮晶颗粒灰岩、亮晶生物碎屑灰岩、微晶生物碎屑灰岩、微晶颗粒灰岩、生物碎屑微晶灰岩、含生物碎屑微晶灰岩和泥晶灰岩7种岩石类型;碳酸盐岩颗粒主要以生物碎屑为主,部分层位发育球粒;古生物化石以三叶虫、腕足和有孔虫为主,同时可见棘皮类和藻类;栖霞组沉积期主要为碳酸盐岩台地沉积环境,其中栖霞组晚期(栖二段)台缘滩和台内滩较为发育,为该区油气成藏提供了有利条件。 相似文献
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本文运用了地质力学方法,试图分析新疆某超基性岩的控岩控矿构造。该区可分三个构造带:东西带,北西西带和南北向带,后二者控制岩体。本文讨论了构造运动的型式、断层与铬铁矿成矿关系以及局部应力场特征。 相似文献
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Yan Yan Peng Cui Su-chin Chen Xiao-qing Chen Hua-yong Chen Yi-liang Chien 《山地科学学报》2017,14(2):219-236
Outburst floods caused by breaches of landslide dams may cause serious damages and loss of lives in downstream areas; for this reason the study of the dynamic of the process is of particular interest for hazard and risk assessment. In this paper we report a field-scale landslide dam failure experiment conducted in Nantou County, in the central of Taiwan.The seismic signal generated during the dam failure was monitored using a broadband seismometer and the signal was used to study the dam failure process.We used the short-time Fourier transform(STFT) to obtain the time–frequency characteristics of the signal and analyzed the correlation between the power spectrum density(PSD) of the signal and the water level. The results indicate that the seismic signal generated during the process consisted of three components: a low-frequency band(0–1.5 Hz), an intermediate-frequency band(1.5–10 Hz) and a highfrequency band(10–45 Hz). We obtained the characteristics of each frequency band and the variations of the signal in various stages of the landslide dam failure process. We determined the cause for the signal changes in each frequency band and its relationship with the dam failure process. The PSD sediment flux estimation model was used to interpret the causes of variations in the signal energy before the dam failure and the clockwise hysteresis during the failure. Our results show that the seismic signal reflects the physical characteristics of the landslide dam failure process. The method and equipment used in this study may be used to monitor landslide dams and providing early warnings for dam failures. 相似文献
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The Mahu lake, the third deepest lake in China, is located on the west bank of the Jinsha River in Leibo county, Sichuan Province. It is a dammed lake created by an old landslide on the ancient Huanglang river, a tributary on the west bank of the Jinsha River. Previous studies (Wang and Lu in J Mt Res S1:44–47, 2000) suggested that this landslide was caused by an earthquake approximately 372 ka (Middle Pleistocene), during which a few hundreds of million cubic meters of debris were deposited between 1177 and 900 m a.s.l. (above sea level), covering an area of around 15 km2. Our further investigations, including geodetic survey, borehole drilling, and field reconnaissance, combining with five chronological data, have made some new discoveries at this site. First, the toe of the landslide extends from 900 m a.s.l. down to 320 m a.s.l., i.e., the local bed elevation of the contemporary Jinsha River. Second, the area of the landslide deposits is 17.3 km2 with a volume of 2.38 km3, much larger than the previous estimation. Thus, it should be one of the largest known landslides in China. And the lower elevation of the landslide’s toe also rules out the possibility that it is a hanging valley on the ancient Huanglang river. Our work suggests that this landslide was created by five events according to the overlapping characteristics of the deposits and five chronological data, which are old than 52,600 years, old than 16,000 years, old than 15,500 years, 5800 years, and old than 4200 years, respectively. 相似文献
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一种适合于红藻的总RNA提取方法 总被引:1,自引:0,他引:1
以5种红藻(条斑紫菜(Porphyra yezoensis),日本多管藻(Polysiphonia japonica),长心卡帕藻(Kappaphycus alvarezii),扇形叉枝藻(Gymnogongrus ftabelliformis),带形蜈蚣藻(Grate-loupia turuturu))为实验材料,为了获得高质量的总RNA,比较了Trizol法、试剂盒法、CTAB法和Trizol+纯化柱法。结果显示:Trizol+纯化柱法对5种红藻总RNA的提取均取得了良好的效果。经琼脂糖凝胶电泳检测,所提取的总RNA 28S、18S条带清晰明亮,无降解;A260/A280、A260/A230值均符合要求,表明提取的总RNA质量较好;利用提取的总RNA进行RT-PCR扩增actin基因的保守片段,能够获得约550bp的目的片段,进一步表明Trizol+纯化柱法是适合于红藻总RNA提取的方法。 相似文献