Spatial Characteristics and Controlling Factors of the Strike‐slip Fault Zones in the Northern Slope of Tazhong Uplift,Tarim Basin: Insight from 3D Seismic Data

The detailed characteristics of the Paleozoic strike-slip fault zones developed in the northern slope of Tazhong uplift are closely related to hydrocarbon explorations. In this study, five major strike-slip fault zones that cut through the Cambrian-Middle Devonian units are identified, by using 3D seismic data. Each of the strike-slip fault zones is characterized by two styles of deformation, namely deeper strike-slip faults and shallower en-echelon faults. By counting the reverse separation of the horizon along the deeper faults, activity intensity on the deeper strike-slip faults in the south is stronger than that on the northern ones. The angle between the strike of the shallower en-echelon normal faults and the principal displacement zone(PDZ) below them is likely to have a tendency to decrease slightly from the south to the north, which may indicate that activity intensity on the shallower southern en-echelon faults is stronger than that on the northern ones. Comparing the reverse separation along the deeper faults and the fault throw of the shallower faults, activity intensity of the Fault zone S1 is similar across different layers, while the activity intensity of the southern faults is larger than that of the northern ones. It is obvious that both the activity intensity of the same layer in different fault zones and different layers in the same fault zone have a macro characteristic in that the southern faults show stronger activity intensity than the northern ones. The Late Ordovician décollement layer developed in the Tazhong area and the peripheral tectonic events of the Tarim Basin have been considered two main factors in the differential deformation characteristics of the strike-slip fault zones in the northern slope of Tazhong uplift. They controlled the differences in the multi-level and multi-stage deformations of the strike-slip faults, respectively. In particular, peripheral tectonic events of the Tarim Basin were the dynamic source of the formatting and evolution of the strike-slip fault zones, and good candidates to accommodate the differential activity intensity of these faults.     

中国海域区古近纪含煤盆地与煤系分布研究

新近纪和古近纪是全球重要的聚煤期。中国古近纪聚煤盆地分布在东部沿海省区,是全球性环太平洋聚煤带的组成部分。中国海域区含煤沉积盆地虽然也属于断陷盆地和坳陷盆地类型,且成群出现,但总体构造背景有利于含煤沉积的持续发展,盆地群连续性好,含煤沉积厚度大,如琼东南盆地、东海海域西湖凹陷,含煤沉积厚度达1km以上,这是陆上区古近纪含煤盆地所不能相比的。研究表明,海域区的聚煤盆地内大多由若干凹陷组成,为聚煤凹陷,可分为两大类,即半地堑凹陷和地堑凹陷。根据成煤盆地的水体深浅又可分为深水半地堑凹陷和浅水半地堑凹陷,地堑凹陷均为深水凹陷。盆地内表现为明显的两个聚煤带：缓坡聚煤带和陡坡聚煤带,缓坡聚煤带占绝对优势。在潮坪体系的潮上带和潮间带沼泽,利于聚煤作用的广泛发生。泥炭的堆积可能存在两种形式：原地堆积和异地堆积。由于盆地构造的频繁活动异地堆积可能是海域区聚煤盆地成煤作用的重要形式。海域区巨厚的含煤沉积为海域区煤成气成藏提供了丰厚的物质基础。又由于含煤地层埋深大,煤的变质作用程度相对较高,成为良好的烃源岩。     

Archaean high-K granitoids produced by remelting of earlier Tonalite–Trondhjemite–Granodiorite (TTG) in the Sangmelima region of the Ntem complex of the Congo craton,southern Cameroon

We present a geochemical and isotopic study that, consistent with observed field relations, suggest Sangmelima late Archaean high-K granite was derived by partial melting of older Archaean TTG. The TTG formations are sodic-trondhjemitic, showing calcic and calc-alkalic trends and are metaluminous to peraluminous. High-K granites in contrast show a potassic calc-alkaline affinity that spans the calcic, calc-alkalic, alkali-calcic and alkalic compositions. The two rock groups (TTG and high-K granites) on the other hand are both ferroan and magnesian. They have a similar degree of fractionation for LREE but a different one for HREE. Nd model ages and Sr/Y ratios define Mesoarchaean and slab-mantle derived magma compositions respectively, with Nb and Ti anomalies indicating a subduction setting for the TTG. Major and trace element in addition to Sr and Nd isotopic compositions support field observations that indicate the derivation of the high-K granitic group from the partial melting of the older TTG equivalent at depth. Geochemical characteristics of the high-K granitic group are therefore inherited features from the TTG protolith and cannot be used for determining their tectonic setting. The heat budget required for TTG partial melting is ascribed to the upwelling of the mantle marked by a doleritic event of identical age as the generated high-K granite melts. The cause of this upwelling is related to linear delamination along mega-shear zones in an intracontinental setting.     

基于“3N”理念的德化县旅游资源开发思路

现代社会的都市化及人工化,引发人类种种生理、心理问题,生活在钢筋水泥森林中的都市人逃出“现代围城”的欲望日益强烈,让身心回归真正的自然,于是“3N”旅游应运而生。本文结合德化县的实例,探讨“3N”旅游及其产品的开发问题。     

从原生晕、原生叠加晕到构造叠加晕:化探找盲矿法的发展与创新

构造叠加晕找盲矿法是在原生晕找盲矿法理论基础上发展的新技术方法。根据热液矿床成矿成晕具多期多阶段叠加特点提出的原生晕叠加理论,将原生晕找盲矿法发展为原生叠加晕找盲矿法;根据热液矿床成矿成晕严格受构造控制而提出的构造叠加晕理论,将原生叠加晕找盲矿法发展为构造叠加晕找盲矿法。文章介绍了从原生晕到原生叠加晕又到构造叠加晕找盲矿法在理论、研究思路、工作方法等方面的发展与创新。     

SharpMap在青海省气象信息网络数据库中的应用

在 .NET环境下开发了基于B/S结构的青海省气象信息网络数据库。该数据库系统由气象信息基础数据库、数据库管理网站及一个空间信息平台构成。气象数据能够实时入库,并具有底图制作、基于地图的数据检索、数据统计和图形绘制等功能,将查询结果叠加在电子地图上显示,直观方便。系统于2009年在青海省气象台投入使用,提高了青海省气象台气象数据共享能力和服务水平,并为青海省气象台的各项业务工作提供了有力的支持。系统采用SharpMap技术实现了空间信息平台,并应用Ajax等技术提高了系统效率,本文对其在网络数据库中的应用     

内蒙古阿钦楚鲁二长花岗岩锆石SHRIMP U-Pb年龄及地球化学特征

阿钦楚鲁二长花岗岩体位于西伯利亚板块东南缘查干敖包奥尤特朝不楞早古生代构造-岩浆岩带中段, 主要岩石类型为中细粒二长花岗岩和中粗粒二长花岗岩。SHRIMP锆石U-Pb同位素定年结果表明, 阿钦楚鲁二长花岗岩的成岩年龄为(296.3±3.8) Ma, 为华力西晚期。岩石地球化学分析结果表明:阿钦楚鲁二长花岗岩富硅, w(SiO₂)为73.48%~74.22%, 过铝质, w(Al₂O₃)为13.63%~14.01%, A/CNK值为1.04~1.10, 碱质含量较高, w(K₂O)+w(Na₂O)为8.08%~8.54%, 里特曼指数(σ)为2.13~2.46, 相对富钾, K₂O/Na₂O值为1.31~1.54, 属高钾钙碱性系列。该岩石富集大离子亲石元素Rb、Sr、Ba和轻稀土元素(LREE), 相对亏损Ta、Nb、Ti等高场强元素, 稀土元素总量为(112.05~130.16)×10^-6, 中等Eu负异常(δEu=0.52~0.65), 稀土元素配分曲线呈现出略微右倾型, 轻稀土较陡, 重稀土较缓, 具有向A型花岗岩过渡的后碰撞高钾花岗岩特征;岩石具有较低的⁸⁷Sr/⁸⁶Sr初始值(0.703 849~0.704 236)和正的ε_Nd(t)值(4.2~4.3), 反映其物质来源可能主要为幔源岩浆底侵作用形成的新生大陆地壳。基于上述分析研究和构造环境判别, 结合区域对比, 推测阿钦楚鲁二长花岗岩为在岩石圈由挤压增厚向伸展体制转换的动力学背景下, 由于俯冲板片的断离, 造成软流圈上涌和岩石圈地幔的部分熔融, 而部分幔源岩浆底侵到地壳的下部或者呈基性侵入体的形式侵入地壳, 引起上部地壳的熔融而形成后碰撞高钾钙碱性花岗岩。     

The influence of turbulent mixing on the subsurface chlorophyll maximum layer in the northern South China Sea

Journal of Oceanology and Limnology - We present observations from deployments of turbulent microstructure instrument and CTD package in the northern South China Sea from April to May 2010. From...     

Seasonal variation and principle of cyanobacterial biomass and forms in the water source area of Chaohu City,China

We investigated seasonal variations in cyanobacterial biomass and the forms of its dominant population(M. aeruginosa) and their correlation with environmental factors in the water source area of Chaohu City,China from December 2011 to October 2012. The results show that species belonging to the phylum Cyanophyta occupied the maximum proportion of phytoplankton biomass,and that the dominant population in the water source area of Chaohu City was M. aeruginosa. The variation in cyanobacterial biomass from March to August 2012 was well fitted to the logistic growth model. The growth rate of cyanobacteria was the highest in June,and the biomass of cyanobacteria reached a maximum in August. From February to March 2012,the main form of M.aeruginosa was the single-cell form; M.aeruginosa colonies began to appear from April,and blooms appeared on the water surface in May. The maximum diameter of the colonies was recorded in July,and then gradually decreased from August. The diameter range of M. aeruginosa colonies was 18.37–237.77 μm,and most of the colonies were distributed in the range 20–200 μm,comprising 95.5% of the total number of samples. Temperature and photosynthetically active radiation may be the most important factors that influenced the annual variation in M. aeruginosa biomass and forms. The suitable temperature for cyanobacterial growth was in the range of 15–30°C. In natural water bodies,photosynthetically active radiation had a significant positive influence on the colonial diameter of M.aeruginosa(P0.01).