湖北松滋大冶组深水碳酸盐岩沉积     

逄林安  田景  林常梅  柯岭  张超 《海相油气地质》2007,12(4):16-20

湖北松滋下三叠统大冶组主要为一套深水碳酸盐岩,与下伏上二叠统长兴组灰色中厚层状灰岩呈整合接触,它以深水原地沉积为主,夹有深水异地沉积。深水原地沉积以深灰色薄层泥晶灰岩和页岩互层为主,异地沉积以浊流沉积和碎屑流沉积为主。浊流沉积鲍玛层序C、D、E段发育,以粉屑灰岩、泥晶灰岩为主;碎屑流沉积以泥晶砾屑灰岩为主。其岩相类型有泥晶灰岩(M1)、泥晶粉屑灰岩(M2)、泥晶砾屑灰岩(M3)、泥页岩(C1),可组合为盆地—盆地边缘相(M1+C1)、下斜坡亚相、上斜坡亚相(M1或M1+M3)、开阔台地相(M1+C1)四种组合。从早三叠世早期到晚期,水体逐渐变浅,但总体表现为深水沉积环境。  相似文献   

Terrestrial organic matter controlling gas hydrate formation in the Nankai Trough accretionary prism, offshore Shikoku, Japan     

Hiroyuki Saito  Noriyuki Suzuki   《Journal of Geochemical Exploration》2007,95(1-3):88

Sediment core samples from Sites 1175, 1176, and 1178, ODP Leg 190, Nankai Trough were analyzed for sedimentary organic matter and inorganic elemental compositions to clarify geochemical conditions for the formation of gas hydrate. Low chloride concentrations and anomalously low core temperature infer the existence of gas hydrate at Site 1178. Trace amounts of gas hydrate are also suggested for Site 1176. Site 1175 does not have any significant evidence of gas hydrate, although all the three sites are within the gas hydrate stability zone. The sediment from Site 1178 is characterized by abundant terrigenous organic matter, older geologic ages, and comparatively higher maturity levels, suggesting high rates of CO₂ generation during diagenesis. The CO₂ generation potential of sediment may be one of the crucial conditions for the formation of gas hydrate.  相似文献   

如何发挥科研管理在研究型气象业务建设中的作用     

葛蕾 《湖北气象》2007,26(1):92-95

为了提高气象科研工作的效益和效率,促进气象科技事业的繁荣与发展,从当前研究型气象业务建设对科研管理的现实要求出发,结合10多年来国家气象中心科研管理实践,联系从事科研组织管理工作多年的认识与经验,指出了气象部门在科研组织管理工作中存在的若干问题,围绕如何发挥科研管理在研究型气象业务建设中的作用,从7个方面提出了对策。即:切实抓好科研课题的选题与立项;促使科研组织与人才培养紧密结合;制定科学的科研项目实施技术方案;改进和完善科研管理制度;建立健全科研激励资助机制;加强科研档案规范化管理;加强与相关部门或单位的合作。  相似文献   

Distribution of landslides adjacent to the northern side of the Yarlu Tsangpo Grand Canyon in Tibet, China   总被引：2，自引：0，他引：2  

Yanjun Shang  Hyeong-Dong Park  Zhifa Yang  Jie Yang 《Environmental Geology》2005,48(6):721-741

This paper presents results of recent studies on distribution and category of landslides in one section of the Sichuan–Tibet Highway, adjacent to the northern side of the Yarlu Tsangpo Grand Canyon, Tibet, Southwestern China. In the tectonic setting predominated by compression and strike-slipping, active faults are dominant and result in the genesis of the great alpine relief together with fluvial incision and unloading. In this section, with a distance of about 290 km between Ranwu and Lulang, 34 landslides occurred. Among them, the 12 large and super-large landslides comprise the most dangerous part of the highway system to road users over the past 50 years. The landslides usually occurred in slopes comprised of moraine with a large thickness, fluvio-pluvial and lacustrine deposits and fractured rocks. Based on the examination of the physical geography, structural geology, Quaternary geology, stratigraphy and petrography, this paper presents the temporal-spatial distribution of landslides along the section and classification of them into three types with respect to mechanism and composites of landslides.

Type 1.	Landslide initiated at high elevation and transformed into a distal debris flow damming the river with a long reoccurrence interval
Type 2.	Landslide at stream banks, in different ranks of mass movements in dissecting layers of moraines
Type 3.	Landslide of fractured rock mass with quick translation movements.

Each of the three types is presented by distinctive case examples. Type 1 is Yigong Landslide; type 2 includes Dongjiu Landslide group, 102 Landslide group, Suotong Landslide group, Songzong Landslide; and the type 3 is Layue Landslide. A binary landslide, which is seldom seen in nature and which occurred in the outlet of one creek under the integrative function of fluvial incision and road cut, is also presented. These are distributed in different parts of the area with characterized structural geology, topography and composites (gneiss and Quaternary deposits) with accumulative quantity between Suotong and Dongjiu. The most occurred with frequent and rapid translation, shallow shearing planes, various influential factors and unique triggering factors, and a variable period of reoccurrence with a tendency of increasing magnitude. In this region, six influential factors greatly contribute to their occurrence: (a) intensive neotectonic movements, (b) ongoing alpine canyon relief, (c) earthquakes, (d) heavy precipitation, (e) stream erosion, and (f) human activities, to a certain extent. Mostly, the latter four factors play major roles in triggering landslide occurrence. The earthquake causes the rock and soil to fracture and deform, and tends to be unstable, or cause earth-induced landslides. The heavy rainfall in monsoon seasons which saturates the soil and lower the shearing strength is mostly responsible for the occurrence of landslides. The stream erosion disturbs slope toes causing progressive failure. Road construction and deforestation decrease the natural slope stability. Comments and suggestions on the physical measures for remediation of landslides and safety of highways are also made.  相似文献   

Ammonia images near objects with class 0 spectral energy distributions     

Alwyn Wootten 《Astrophysics and Space Science》1995,231(1-2):43-46

The distribution of the sources of the Gamma-Ray Bursts (GRBs) recorded by the CGRO experiment is uniform for all directions in the sky, while the behaviour of the log N-log P suggests a space distribution of the events not homogeneous. The cosmological model can explain this result, but it cannot explain the presence of cyclotron lines in the burst energy spectra that has been observed by many experiments: the soviet KONUS experiment onboard VENERA probes, the Japanese GRBM experiment onboard GINGA satellite and, for only one candidate burst fortuitously observed, by the USA experiment A4 onboard HEAO1 satellite. In order to shed more light on this problem we present a new study of the log N-log P of the Gamma-Ray Bursts of the second BATSE catalogue.  相似文献   

辽西地区中生代火山岩型金矿成矿地质条件与找矿方向     

马建德  刘殿忠 《矿产与地质》2001,15(1):15-19

辽西地区地处我国东部中生代火山活动带，火山岩发育，已恨现二道沟，红石砬子和大青山等火山岩型金矿床（点），研究了该区火山岩型金矿的成矿地质条件，矿床特征和找矿标志，提出了红石砬子，温滴楼，小塔子－马岱沟，大青山－影壁山等找火山岩型金矿有望地区。  相似文献   

物理守恒律保真格式构造与数值预报斜压原始方程传统谱模式改进研究   总被引：8，自引：1，他引：8  

钟青 《气象学报》1997,55(6):641-661

文中构造并证明了一般二次和三次物理守恒律时间差分保真格式两个构造定理，以往一些主要时间离散守恒格式构造方案可作为两个定理特例给出。它们不仅可为解决更加广泛类别的时间离散保真格式构造基本问题提供适用数学基础，而且也为结合已有瞬时空间离散守恒格式，解决更加广泛类别的时－空离散意义下保真格式构造基本问题提供适用的数学基础。此外，文中两个定理还可解决两大类问题的线性和非线性计算不稳定性问题。斜压原始方程传统半隐式全球谱－垂直有限差分模式目前是世界上许多国家的业务预报和大气环流模式。本工作利用文中新构定理，构造并且实现了斜压原始方程全球谱－垂直有限差分模式半隐式高阶全能量守恒方案。以往该项基本问题无论在理论还是实践上长期以来一直都未能得到解决。该项全能量守恒半隐式全球谱模式方案适用于实测资料的长时间数值预报积分。使用ＦＧＧＥ夏季资料进行的１３个个例３０ｄ数值积分实验表明：新型全能量半隐式保真方案可以有效地改进传统预报方案中关于能量质量守恒性质的系统性偏差。值得注意的是，实验统计分析还显示：在本文实验条件下，传统方案中由于时间离散过程中原物理守恒律性质破坏导致的系统误差（简称Ｚ类误差），对于实验总体均方根系统误差的贡献  相似文献   

论中国经济区的类型与组织   总被引：20，自引：5，他引：20  

胡序威 《地理学报》1993,48(3):193-203

根据作者对经济区概念和性质的理解,对我国现实存在的名目繁多的经济区进行了系统的归纳和类型的划分,指出了组织经济区的重要实践意义,并重点论述了如何从组织上加强对不同层次的综合经济区的规划协调和调控管理。  相似文献   

锆石变生特性及其类型划分   总被引：2，自引：0，他引：2  

李秀珍  黄志章 《铀矿地质》1994,10(1):14-19

利用物理测试方法，如Ｘ衍射和红外光谱等方法，测定锆石结构的完整性，进而划分锆石类型。文中指出，随着锆石的结晶程度变差而衍射峰变弱，甚至消失。在红外分析中利用图谱上的６１０ｃｍ（－１）处的吸收峰的变化确定锆石的变生程度是既方便又经济的有效方法，根据该处的吸收峰参数计算出变生系数（Ｈ／Ｍ），从而引出锆石从全结晶形态到强变生状态的变化特征，以达到解决它们有关问题的目的。  相似文献   

鄂东南大沙坪下奥陶统碳酸盐重力流及自发振动成因机理     

郭建华  曾允孚 《岩石学报》1997,13(2):245-253

位于中扬子地台东南缘的大沙坪剖面下奥陶统留咀桥组下段重力流沉积非常发育，重力流沉积类型以富基质的Ａ型碎屑流沉积为主。经区域资料横向对比，这种发育是局部性的。对这种局部性的重力流沉积，本文应用自发振动原理进行了阐述，分析了沉积迁移常数Ｋ、沉积物滑移的最大坡度角αｍａｘ、最小坡度角αｍｉｎ、沉积物输入速率η等参数。αｍａｘ、αｍｉｎ控制了一个自发振动系统，△α（αｍａｘ－αｍｉｎ）、Ｋ、η一起控制了重力流形成的振动周期  相似文献