对岩石学,矿物学与材料科学关系的思考

在综观矿物学、岩石学和材料科学的学科发展的基础上，认为它们在对物质成分、结构、性质或性能、形成机制的研究方法和内容等很多方面相通或相似的，并认为其浙趋融合。淡化学科界线，在物理学和化学水平上发展新的边缘交叉学科，是合理、高效地利用矿产资源和发展新材料的需要，也是学科发展的必然。     

西昆仑甜水海黄羊沟闪长玢岩年代学、地球化学特征及构造背景

黄羊沟闪长玢岩岩体侵位于甜水海—喀喇昆仑地块上侏罗统红其拉甫组灰岩地层中,为了厘定其形成时代,揭示岩石成因以及构造背景,对黄羊沟闪长玢岩岩体进行了LA-ICP-MS锆石U-Pb年代学及全岩地球化学分析研究。岩石地球化学研究结果表明,该岩体锆石U-Pb年龄为(159.9±1.4) Ma,形成于碰撞后伸展环境,源区具幔源特征,有地壳物质同化混染参与,形成条件为低压、强氧化环境,经历中等分异作用。该岩体具低硅（w(SiO₂)=56.11%~57.36%）、高钙（w(CaO)=4.29%~6.59%）、富碱（w(Na₂O+K₂O)=6.00%~7.96%）特征,属准铝质（A/NCK=0.79~0.95）岩石,且富集大离子亲石元素K、Rb、Ba、Th、U及亏损高场强元素Nb、Ta、Zr、Hf等,具微弱Eu负异常,δEu均值为0.97。通过区域岩浆活动对比研究,认为黄羊沟岩体与班—怒缝合带革吉地区的帕阿岩体I型花岗岩体具有很强的亲缘性,且与班—怒缝合带内的岩浆岩时限一致,表明甜水海地体南部的黄羊沟闪长玢岩是班—怒缝合带以北区域中、新特提斯洋向南俯冲的岩浆作用响应。     

砂岩储层中原油微生物降解的模拟实验研究

模拟辽河冷东-雷家地区的砂砾岩储层条件，采用该地区的正常原油，在３０℃恒温和充氧下以及有营养元素的水溶液中，进行了原油喜氧微生物降解实验。实验表明，经微生物降解后，原油的化学组成发生了较大变化，饱和烃含量下降，沥青质、非烃含量上升；水溶液的ｐＨ值下降，并在其中检测出了有机酸，可见在微生物的代谢过程中，原油中的烃类分子被部分转化为水溶性含氧酸性产物。降解实验的油样与取自同一地区的两个重质原油饱和烃气相色谱图比较，两者在组成上极其相近，其结果说明辽河油田的重油成因，是原油遭受了喜氧微生物的降解。实验对微生物降解过程的动力学进行了初步研究。微生物对饱和烃馏分中不同化合物的降解序列为:短链正构烷烃、长链正构烷烃、异构烷烃、环状烷烃。但当各组分间的浓度发生较大变化时，降解序列会有所不同。     

Experimental Research on Supercritical Carbon Dioxide Fracturing of Sedimentary Rock: A Critical Review

Supercritical carbon dioxide(ScCO₂) fracturing has great advantages and prospects in both shale gas exploitation and CO₂ storage. This paper reviews current laboratory experimental methods and results for sedimentary rocks fractured by ScCO₂. The breakdown pressure, fracture parameters, mineral composition, bedding plane angle and permeability are discussed. We also compare the differences between sedimentary rock and granite fractured by ScCO₂, ultima...     

Correction factors for the directional response of Gill propeller anemometers

This note briefly summarizes some recent wind-tunnel tests carried out at the Atmospheric Environment Service (AES), Canada, to investigate the directional response of Gill propeller anemometers with two specific models of propeller. Tables of optimum non-cosine-response correction factors are presented for both propeller types and results of some field intercomparisons between the Gill and sonic anemometer measurements of turbulence statistics are summarized. Complete details of this work can be found in two research reports by Bowen and Teunissen (1984) and Teunissen et al. (1985) which may be obtained from either of the authors.On study leave from University of Canterbury, Christchurch, New Zealand.     

准噶尔盆地柴窝堡凹陷中二叠统地层格架与沉积体系特征

柴窝堡凹陷是海西期复杂构造演化形成的具叠合结构的山间坳陷,为准噶尔盆地南部油气勘探开发的热点区域之一。综合利用露头、钻测井、岩心及地震资料,明确柴窝堡凹陷中二叠统层序地层格架、物源、沉积体系构成及展布特征。研究表明,凹陷内可容空间和层序边界受构造升降和古气候变化共同控制,充填地层呈现南厚北薄分布特征;目的层段可划分为4个三级层序SQ1、SQ2、SQ3及SQ4,分别对应乌拉泊组、井井子沟组、芦草沟组及红雁池组;物源由南部时代不同、构造背景相异的伊林黑比尔根山提供;南部斜坡带主要发育冲积扇、扇三角洲沉积相,而在北部凹陷带发育湖泊相;SQ1~SQ4层序沉积时期整体为水退—水进旋回,由早期潮坪—冲积扇沉积环境逐渐演化为晚期冲积扇—扇三角洲—滨浅湖沉积环境,进一步划分为10种亚相和6种微相。相关研究认识可为预测有利油气藏的分布提供一定的理论依据。

     

The Upper Pleistocene deposits at Cassington,near Oxford,England

For much of the Middle and all of the Upper Pleistocene the Upper Thames valley has remained outside the limit of ice advance. The main agents of landform evolution have been the River Thames and its tributaries, which have cut down episodically and in so doing have abandoned a series of river terraces. This study reports the findings of an investigation into exposures in the deposits underlying the Floodplain Terrace at Cassington, near Oxford, England. The sequence exposed reveals a stratigraphy of basal, predominantly fine-grained, lithofacies overlain by coarser gravel lithofacies. The fluvial architecture of these deposits indicates a major change in fluvial style from a low-energy (meandering) to a high energy (braided) channel system. The flora and fauna from the lower fine-grained lithofacies display a marked change from temperate at the base, to colder conditions towards the top, indicating a close association between deteriorating climate and changing fluvial depositional style. Amino acid and luminescence geochronology from the basal fine-grained lithofacies suggest correlation with Oxygen Isotope Stage 5 and hence it is argued that the major environmental change recorded at the site relates to the Oxygen Isotope Stage 5–4 transition. Deposition of much of the overlying gravel sequence probably occurred during Oxygen Isotope Stage 4, suggesting that the latter half of the Devensian may be less significant, in terms of fluvial landscape evolution in the Upper Thames valley, than was believed previously. © 1998 John Wiley & Sons, Ltd.     

湘西北保靖地区志留系小河坝组震积岩的发现及意义

湘西北保靖地区志留系小河坝组主要发育一套砂、泥质沉积。探井岩心观察发现,小河坝组部分层位具有震积岩的典型特征——阶梯状微断层、串珠状构造、球-枕状构造、重荷模和火焰状构造、液化粉砂岩脉、液化卷曲变形构造、震裂缝和角砾状构造等。通过对区内保参1井、保参2井和保参3井纵向震积岩特征的统计,共识别出74层古地震层,根据地震幕的概念,总结出小河坝组地震幕。从3口探井间的横向对比可以看出,大部分地震幕主要集中在小河坝组的2段地层中,从而划分出小河坝期2次地震活跃期和3次平静期。分析了震积岩特征与地震强度和震中距离的关系,结合大地构造背景综合研究发现,该区震积岩的发育受保靖—慈利断裂带构造演化所控制。研究结果对恢复研究区构造背景、地层对比与储层预测具有重要意义。     

Twentieth century eutrophication of the St. Croix River (Minnesota–Wisconsin,USA) reconstructed from the sediments of its natural impoundment

Evaluation of land-use effects on coastal and marine ecosystems requires better understanding of the role of rivers in regulating mass transport from terrestrial to oceanic environments. Here we take advantage of the presence of a riverine lake to use paleoecological techniques to quantify impacts of logging, European-style agriculture, urbanization and continued terrestrial disturbance on mass transport and water quality in the northern drainage of the Mississippi River. Two 2-m sediment-cores recovered in 1999 from Lake St. Croix, a natural impoundment of the St. Croix River, were dated using ²¹⁰Pb and ¹³⁷Cs, and analyzed for historical changes (c. 1840–present) in sediment magnetic susceptibility, inorganic and organic matter content, biogenic silica, fossil pigments, and diatom microfossils. Inorganic sediment accumulation increased threefold between the mid-1800s and present, whereas clear signs of eutrophication were only evident after the mid-twentieth century when biogenic silica accumulation increased sixfold, diatom accumulation rates increased 20- to 50- fold, and the diatom community shifted from predominantly benthic species to assemblages composed mainly of planktonic taxa. Similarly, fossil pigment concentrations increased during the 1960s, and diatom-inferred total phosphorus (DI-TP) increased from ~30 μg TP l⁻¹ c. 1910 to ~60 μg l⁻¹ since 1990, similar to historical records since 1980. Together, these patterns demonstrate that initial land clearance did not result in substantive declines in water quality or nutrient mass transport, instead, substantial degradation of downstream environments was restricted to the latter half of the twentieth century. This is one of eight papers dedicated to the “Recent Environmental History of the Upper Mississippi River” published in this special issue of the Journal of Paleolimnology. D. R. Engstrom served as guest editor of the special issue.