构造挤压对库车坳陷异常地层压力的影响

库车坳陷异常高压呈东西向带状分布,中部克拉苏-东秋-迪那构造带的地层压力系数在2．0以上,往南北两侧递减。异常高压的分布和古近系的膏盐岩分布密切相关,巨厚的膏盐层盖层是形成异常高压的重要条件。喜马拉雅晚期强烈的构造挤压作用是库车坳陷异常高压形成的主要因素,地层压力和过剩地层压力与最大构造主应力之间具有较好的相关性,构造抬升对该区异常高压形成的影响较小。异常高压对油气藏的形成和保存有十分重要的作用,它是库车坳陷形成大型油气藏的必要条件。     

Formation of Fe-oxyhydroxides from the East Pacific Rise near latitude 13°N: Evidence from mineralogical and geochemical data

The mineralogical and geochemical characteristics of Fe-oxyhydroxide samples from one dredge station (long. 103°54.48′W, lat. 12°42.30′N, water depth 2655 m) on the East Pacific Rise near lat 13°N were analyzed by XRD, ICP-AES, and ICP-MS. Most Fe-oxyhydroxides are amorphous, with a few sphalerite microlites. In comparison with Fe-oxyhydroxides from other fields, the variable ranges in the chemical composition of Fe-oxyhydroxide samples are very narrow; their Fe, Si, and Mn contents were 39.90%, 8.92%, and 1.59%, respectively; they have high Cu (0.88%–1.85%) and Co (65×10⁻⁶−704×10⁻⁶) contents, and contain Co+Cu+Zn+Ni> 1.01%. The trace-element (As, Co, Ni, Cu, Zn, Ba, Sr) and major-element (Fe, Ca, Al, Mg) contents of these samples are in the range of hydrothermal sulfide from the East Pacific Rise near 13°N, reflecting that this type of Fe-oxyhydroxide constitutes a secondary oxidation product of hydrothermal sulfide. The Fe-oxyhydroxide samples from one dredge station on the East Pacific Rise near 13°N are lower in ΣREE (5.44×10⁻⁶–17.01×10⁻⁶), with a distinct negative Ce anomaly (0.12–0.28). The Fe-oxyhydroxide samples have similar chondrite-normalized rare-earth-element (REE) patterns to that of seawater, and they are very different from the REE composition characteristics of hydrothermal plume particles and hydrothermal fluids, showing that the REEs of Fe-oxyhydroxide are a major constituent of seawater and that the Fe-oxyhydroxides can become a sink of REE from seawater. The quick settling of hydrothermal plume particles resulted in the lower REE content and higher Mn content of these Fe-oxyhydroxides, which are captured in part of the V and P from seawater by adsorption. The Fe-oxyhydroxides from one dredge station on the East Pacific Rise near 13°N were formed by secondary oxidation in a low temperature, oxygenated environment. In comparison with the elemental (Zn, Cd, Pb, Fe, Co, Cu) average content of hydrothermal sulfide samples from the East Pacific Rise near 13°N, the Zn, Cd, and Pb contents of the Fe-oxyhydroxides are lower, and their Fe, Co, and Cu contents are higher. Supported in part by the Pilot Project of Knowledge Innovation Project, Chinese Academy of Sciences (Grant No. KZCX3-SW-223), and the Special Foundation for the Tenth Five Plan of COMRA (Grant No. DY105-01-03-1)     

Bacterial community in deep subseafloor sediments from the western Pacific “warm pool”

The bacterial community in deep subseafloor sediments at a depth of 230 cm from the western Pacific “warm pool” is studied by construction of 16S rDNA clone library and PCR-RFLP (Restriction Fragment Length Polymorphism) analysis. The results indicate that the bacterial community in these sediments is mainly composed of five groups: α-Proteobacteria, β-Proteobacteria, CFB group (Cytophaga / Flexibacteria / Bacteroides), Acidobacteria and gram positive bacteria, with a few genera detected in each group. The most abundant bacteria group is α-Proteobacteria, and the next is β-Proteobacteria. The dominant species in α-and β-Proteobacteria are Sphingomonas paucimobilis and Pseudomonas alcaligenes respectively. The CFB group is simply composed of members belonging to Flavobacterium. The gram positive bacteria are rich, and mainly consists of the genus Geobacillus. The analysis of bacterial community indicates that organic matter is still abundant in the subseafloor sediments at the depth of 230 cm in the western Pacific “warm pool”. These bacteria in this deep biosphere may play an important role in the nitrogen cycle of deep sea sediments at “warm pool”. Supported by the National Key Basic Research Support Foundation of China (Grant No. G2000078500) and China Ocean Mineral Resources R&D Association Project (Grant No. DY105-4-2-4)     

Coupling relationships between brachiopods and Girvanella during the Late Devonian F-F transition in Guilin, South China

The abundance curves derived from area proportions of brachiopods and Girvanella in the thin sections from the Yangdi section, South China, exhibits complex relationships during the Late Devonian Frasnian-Famennian transition. The living activity of brachiopods such as grazing and borrowing did great damage to the growth of Girvanella. However, there was more to just a mere a survival competing relationship between them, Girvanella actually improved marine environments by oxygenating the dysoxic ambient sea-water through photosynthesis in the lower Kellwasser Horizon. Profited from this improvement brachiopods’ abundance increased subsequently and suppressed Girvanella again. Nonetheless, without Girvanella’s photosynthesis, brachiopods were wiped out by the farther anoxic environments in the upper Kellwasser Horizon. The complex relationships between Girvanella and brachiopods may be a key to unlocking the relationships between geomicrobes and metazoans in the geological overturn periods. Supported by NSFC Innovation Research Group Program (Grant No. 40621002), MOE Innovative Research Team Program (Grant No. IRT0546), the National Natural Science Foundation of China (Grant Nos. 40472020, 40730209, 40802005 and 40872001) and SINOPEC Project (Grant No. G0800-06-ZS-319)     

闽东南沿海老红砂的分布与沉积地貌特征

本文通过野外调查,阐明了老红砂的分布与地貌形态特征,并根据其沉积的构造特征等提出了老红砂的风成或风－坡积成因及其发育多期性的观点。最后还对进一步研究提出若干建议。     

岩溶矿井煤层底板突水系统的非线性特征初步分析

本文论述了矿井煤层底板突水是一种由缺陷诱导的局域失稳,特别强调存在两种时间尺度的缺陷变化过程。一种是缺陷发育过程,缺陷由小缓慢地扩张变大,是慢变化;另一种是缺陷失稳过程,缺陷的薄弱破坏引起缺陷的瀑涨,是快变化,这后一过程就是矿井煤层底板突水。据此构造了塞子模型并讨论了模型的基本行为,定量地给出失稳判据,用实例检验模型得到准确率为92. 6%。      

特殊的地表岩溶形态及成因探讨

对金沙江溪洛渡电站区二叠系下统( P1 )灰岩岩溶发育规律综合研究后发现: 本区内的岩溶洼地多为“半边岩溶洼地” ;岩溶漏斗四周为玄武岩碎块的“特殊类型岩溶漏斗” ;分布于1100m高程的岩溶湖也多是顺岩层走向发育的岩溶湖。      

矿井音频电透视在任楼煤矿的应用

水文地质条件探查是任楼煤矿矿井防治水工作的首要任务。本文就作者近几年采用矿井物探技术探查水文地质条件的经验予以总结,并重点以实例介绍了应用矿井音频电透视技术探查任楼煤矿水文地质条件的效果,实践证明矿井音频透视技术是该矿探查工作面或盘区内部顶、底板内含、导水构造最有效的物探方法。      

298K时三元体系K^＋／CO3^2—,B4O7^2——H2O和Li^＋／CO3^2—,B4O7^2——H2O相关系

研究了二个三元体系Ｌｉ＋／ＣＯ２－３,Ｂ４Ｏ２－７Ｈ２Ｏ（１）和Ｋ＋／ＣＯ２－３,Ｂ４Ｏ２－７Ｈ２０（２）２９８Ｋ时的相平衡关系和平衡液相的物化性质（密度、折光密、粘度、电导率、ｐＨ值）。研究表明：这二个三元体系均属简单共饱型,无复盐或固溶体形成。体系（１）的两段溶解度曲线对应于无水Ｌｉ２ＣＯ３和Ｌｉ２Ｂ４Ｏ７·３Ｈ２Ｏ结晶区,体系（２）的两段溶解度曲线对应于Ｋ２ＣＯ３·３／２Ｈ２Ｏ和Ｋ２Ｂ４Ｏ７·４Ｈ２Ｏ结晶区。     

滇西昌宁—孟连带硅质岩的阴极发光特征及其意义

阴极发光手段在恢复碳酸盐岩和砂岩的原始结构构造、成岩及孔隙演化等方面已显示出独特作用,而用于地层学研究较少。硅质岩多为自生成因,常由非晶质或隐晶质ＳｉＯ２ 矿物组成,多数在成岩中发生重结晶作用,通常在低能（＜ ２０ ０００ ｅＶ）阴极射线下发光很弱,常被研究者们忽视。通过对滇西昌宁－ 孟连带晚古生代硅质岩的高能（２５ ０００ｅＶ）阴极发光及相关研究表明：自生或重结晶的硅质岩（含放射虫化石）（石英）发光明显,其发光强弱和发光特征与Ｆｅ,Ｃｏ,Ｎｉ和Ｍｎ,Ｃｒ,ＲＥＥ质量分数有直接关系,并受地层的沉积－ 构造背景控制,对造山带地层分区和地层格架研究有重要意义