Guadalupian （Middle Permian） Conodont Faunas at Shangsi Section, Northeast Sichuan Province

This study recovered the Guadalupian conodont faunas from Shangsi (上寺) Section in Northeast Sichuan (四川). Four genera and nine species were identified, and three conodont zones were recognized and established; they include Jinogondolella nankingensis Zone, J. aserrata Zone, and J. postserrata Zone. The Roadian and Wordian boundary is set in the interval 5 m from the top of Bed 86 by the first appearance of the conodont J. aserrata. The Wordian and Capitanian boundary is set in the interval 2.3 m from the top of the Bed 95 by the first appearance of J. postserrata. Most of the specimens demonstrated low color alteration index (CAI) as 1.5-3, indicating that most part of the Maokou (茅口) Formation may have the suitable thermal conditions for the formation of oil source rocks.     

Fault Characteristics in Longmen Mountain Thrust Belt,Western Sichuan Foreland Basin,China

Through field geological survey,the authors found that abundant thrust faults developed in the Longmen (龙门) Mountain thrust belt.These faults can be divided into thrust faults and strike-slip faults according to their formation mechanisms and characteristics.Furthermore,these faults can be graded into primary fault,secondary fault,third-level fault,and fourth-level fault according to their scale and role in the tectonic evolution of Longmen Mountain thrust belt.Each thrust fault is composed of several secondary faults,such as Qingchuan (青川)-Maowen (茂汶) fault zone is composed of Qiaozhuang (乔庄) fault,Qingxi (青溪) fault,Maowen fault,Ganyanggou (赶羊沟) fault,etc..The Longmen Mountain thrust belt experienced early Indosinian movement,Anxian (安县) movement,Yanshan (燕山)movement,and Himalayan movement,and the faults formed gradually from north to south.     

Main Controlling Factors on Hydrocarbon Accumulation and Distribution in Marine Sedimentary Sequences in South China

Multiple source rock assemblages were deposited in the sedimentary provinces in South China in geologic history,and some of them were destructed by and some survived against multiple tectonic movements.Therefore,multiple sources,mixed sources,and uneven distribution of sources occurred in the marine sedimentary basins in South China during the late stage of hydrocarbon pooling.Epidiagenesis of the marine carbonate reservoirs and its modification to reservoir poroperm characteristics determined the formation and the scale of natural gas pools.The exploration practices show that the large to medium gas fields mainly occur in areas with high-quality reservoirs.Detailed study of the paleo-oil accumulations and typical oil and gas reservoirs reveals that the basins experienced multiphase superimposition and modification,leading to the distribution of the Paleozoic paleo-oil accumulations and bitumen in the peripheral areas.The phenomenon that oil and gas production concentrates in the Sichuan basin indicates that the overall sealing conditions of a basin determine the oil/gas potentials and the scale of oil and gas production.This is a critical factor controlling the accumulation and distribution of gas in the marine sequences in South China.The early oil and gas pools in the Yangtze platform left billions of bitumen in the peripheral areas due to the destruction of seals.Since the Himalayan,"late-generation and late-accumulation" gas pools represented by the gas pools in the Sichuan (四川) basin were formed in the marine sedimentary sequences in South China as a result of the change of the sealing conditions.Current gas discoveries appear to be "paleo-generation and paleo-accumulation" gas pools but actually are "late-generation and late-accumulation" gas pools.These patterns of hydrocarbon pooling clearly depict themselves in western Sichuan basin and Weiyuan (威远)gas field.It is revealed that the gas pools in the Sichuan basin were mainly formed as a result of hydrocarbon phase change (thermal cracking of oil to gas),miscible migration,and dynamic equilibration since the Himalayan.A large number of gas pools were formed in the Himalayan and the gas pools in the marine sequences are characterized by late pooling; this kind of gas fields/pools are controlled by:(1) effectiveness of modification and superimposition of the marine basins,(2) effectiveness of the source rocks,(3) effectiveness of the overall preservation conditions,and (4) effectiveness of plays.     

GPS技术遥感南极大气水汽含量的研究

随着各地GPS基准站网的逐步建立与完善,地基GPS气象学的应用在各地已逐渐普及,但在南极还很少涉及。南极的天气变化直接影响着全球的气候变化,对南极大气水汽含量的研究,可为全球气候研究提供参考。文中根据最佳组网方案解算出南极长城站的对流层天顶总延迟,利用改进的Hopfield模型及局部加权平均温度模型计算的转换系数计算了该站上空绝对可降水分,并与南极实际可降水分进行了对比分析,二者差异很小,说明了利用GPS数据解算南极高精度可降水分的方法是正确的。     

近50年来中国六大流域径流年内分配变化趋势

基于1950年以来的全国六大流域19个重点控制水文站实测月径流量观测资料,以1980年为界,分析各站实测径流量年内分配不均匀系数、集中度以及集中期的变化;采用Mann-Kendall非参数统计检验方法,诊断了各月径流量的变化趋势。结果表明,自1980年以来,全国六大流域的月径流发生了时空变化,除海河的石匣里、响水堡站和黄河花园口站年内径流不均匀性和相对集中度较小以外,其它站的年内径流不均匀性和相对集中度较大,以松辽流域为最大;此外,南方流域各站冬春季(12~3月)的径流均呈现增加的趋势,5月份呈现减少的趋势,7月份呈现增加的趋势;北方流域各站冬春季(1~5月)径流呈现减少的趋势,以海河流域各站、松辽的铁岭、黄河利津站和淮河的吴家渡站减少趋势最为严重。     

基于空间信息技术的堰塞湖库容分析方法研究

快速准确计算堰塞湖库容,对了解地震堰塞湖险情具有重要的意义.利用遥感和地理信息系统等空间信息技术,提出了一种基于像素的三维水面的计算动库容的方法,能准确计算水面为曲面,包括动库容在内的总库容.该方法利用遥感影像提取水体边界线,与DEM求交后可得到带高程的边界点,利用空间插值技术获得三维水面,然后利用库容计算模型求解.同时,在分析该算法计算效率的基础上,提出了基于河流分段的库容计算优化算法,最后通过实验对比分析了该方法的合理性和优越性.     

基于语义的地理信息分类体系对比分析

地理信息分类体系之间的语义不一致性,被认为是影响地理信息系统实现在语义层次上信息共享的最大障碍.首先,本文在阐述中国地理信息分类体系之间参照模式的基础上,提出了一种基于语义的地理信息分类体系对比分析方法.其次,对中国现行的几种地理信息标准分类体系进行了详细的对比分析.最后,为中国地理信息分类体系的编制和修订提出了一些建议.     

2008年度海洋与极地科学领域项目受理与评审

12008年度面上项目受理和同行通讯评议情况1.1项目受理情况2008年地球科学四处共受理申请项目708项,其中包括面上项目440项、青年基金259项和地区基金9项,申请项数比2007年增加12.2%。面上项目比2007年增加27项,增长6.5%;青年基金增加45项,增长21%;地区基金与2007年度相比增加5     

基于矿物学方法评价浙江省土壤中Pb污染状况

利用土壤重金属元素环境质量矿物学评价方法,对淅江省全境土壤中不同土壤类型(或亚类)表层、不同母质表层和剖面中的Pb进行环境质量评价的结果表明,土壤中Pb的实测量和土壤对Pb的固持量决定了土壤中Pb的环境质量,浙江省土壤中Pb的污染度有正负值,说明土壤中的Pb对有些地区产生了污染,而对有些地区则没有产生污染.研究结果揭示,土壤矿物对Pb具有一定的固定与容纳能力,超过其固定与容纳能力,土壤中的Pb会对环境造成污染.这一旨在揭示土壤中重金属元素与各种矿物之间环境平衡关系的方法,可为评价土壤环境质量提供科学依据和技术支撑.     

山东三山岛金矿床流体包裹体特征及其地质意义

三山岛金矿床位于莱州市三山岛—仓上断裂带内,矿石主要为蚀变岩和含金石英脉2种类型。随着胶东金矿床研究的深入和三山岛金矿资源的不断减少,对三山岛金矿床的成矿作用及深部开发前景问题研究具有更重要的意义。针对上述问题,对三山岛金矿床2种类型矿石的成矿流体特征进行对比研究,认为代表成矿早—中期的蚀变岩型矿石形成于中温(均一温度为325～240℃)、低盐度(2.07%～6.88%)、低密度(0.720～0.868g/cm3)、酸碱性不均匀(pH=3.27～10.43)、以氟化物和氯化物为成矿物质载体的还原性流体;代表成矿中—晚期的含金石英脉型矿石形成于中—低温(均一温度为306～160℃)、低盐度(1.05%～9.73%)、低密度(0.739～0.962g/cm3)、碱性(pH=9.25～9.85)、以氯化物和硫化物为成矿物质载体的还原性流体。成矿流体性质的转变反映了成矿流体处于由比较封闭到比较开放的构造环境的转变期,且成矿流体早期以原生岩浆水为主,后期有变质水、大气降水以及海水的参与作用。三山岛金矿成矿深度为2.5～5km,根据目前的开采深度推算其深部还有一定的资源量可供开发。