Polar constituents of organic matter rich marls from evaporitic series of the Mulhouse basin     

P. Schaeffer  F. Fache-Dany  J.M. Trendel  P. Albrecht 《Organic Geochemistry》1993,20(8)

A suite of marl samples from the evaporitic series of the Mulhouse basin (France; Lower Oligocene) was studied for its biomarker content, in particular its polar constituents. Novel series of 3-carboxyalkyl steranes and 15-oxo triaromatic ketones were identified by synthesis. The 3-carboxyalkyl steranes probably originate from highly polar precursors yet unreported in living organisms. Our data suggest that micro-algae could be the major source of these compounds which seem to be indicators of high algal input rather than characteristic of evaporitic environments. The 15-oxo triaromatic ketones could be oxidation products of triaromatic steroid hydrocarbons formed during diagenesis, although their formation during work-up procedure could not be excluded.  相似文献   

Total nitrogen content of deep sea basalts     

Thomas L. Norris  Oliver A. Schaeffer 《Geochimica et cosmochimica acta》1982,46(3):371-379

Various models have been suggested concerning the origin and evolution of the earth's atmosphere. An estimate of the nitrogen content of the mantle could further constrain atmospheric models. Total nitrogen content was determined by thermal neutron activation analysis via ¹⁴N(n,p)¹⁴C. The ¹⁴C was converted to carbon dioxide and counted in miniature low level proportional counters. The total nitrogen content of U.S.G.S. standards BCR-1 and G-2 as determined by different laboratories is variable, probably due to atmospheric adsorption by the finely ground samples. Total nitrogen content was determined in deep sea basalt glasses from three regions: East Pacific Rise ($\text{15 ± 4, 18 ± 4}$, and $\text{7 ±}\text{ppm}\text{2 N}$), Mid-Atlantic Rift (FAMOUS Region:$\text{22 ± 5, 18 ± 3}$, and $\text{10 ± 2}\text{ppm}\text{N}$) and the Juan de Fuca Ridge ($\text{17 ± 4}\text{ppm}\text{N}$). Matrix material from the same samples as the glasses was available from the East Pacific Rise ($\text{37 ± 6, 26 ± 4}$, and $\text{34 ± 6}\text{ppm}\text{N}$) and the Mid-Atlantic Rift ($\text{39 ± 4}\text{ppm}\text{N}$) which are about 50 to 100% greater than the associated glasses. The increased matrix abundance may be due to incorporation of chemically bound nitrogen from sea water rather than dissolved molecular nitrogen. The nitrogen content of the FAMOUS samples are inconsistent with the model of Langmuir et al. (1977) for petrogenesis based on trace element data. Factors which can affect the observed nitrogen content in the basalts and the interpretation in terms of the mantle nitrogen abundance are discussed (e.g. partial melting and degassing of the basalts). A lower limit of about 2 ppm N in the mantle can be estimated.  相似文献   

压力及流体对岩石孔隙结构与黏弹性的影响规律研究:理论模型及实验观测          下载免费PDF全文

程卫  巴晶  马汝鹏  张琳 《地球物理学报》1954,63(12):4517-4527

地质成因和构造/热应力导致地壳岩石中的孔隙结构（裂隙和粒间孔）的变化.影响岩石黏弹性的因素包括压力、孔隙度、孔隙中包含的流体和孔隙几何形状等.相对于岩石中的硬孔隙,岩石黏弹性（衰减和频散）受软孔隙（裂隙）的影响更大.本文选取三块白云岩样本,进行了不同围压和流体条件下的超声波实验测量.利用CPEM（Cracks and Pores Effective Medium,裂隙和孔隙有效介质）模型获得了岩石高、低频极限的弹性模量,并通过Zener体（标准线性体）模型将CPEM模型拓展到全频带而得到CPEM-Zener模型,用该模型拟合岩石松弛和非松弛状态下的实验数据,本文得到平均裂隙纵横比和裂隙孔隙度以及纵波速度和品质因子随频率的变化关系.结果表明,饱水岩石的平均裂隙纵横比和裂隙孔隙度均高于饱油岩石,随着压差（围压和孔隙压力的差值）的增加,饱油岩石中的裂隙首先闭合.并且压差在70 MPa以内时,随着压差增大,岩石的平均裂隙纵横比和裂隙孔隙度在饱水和饱油时的差值增大,此时流体类型对于岩石裂隙的影响越来越显著,此外,对饱水岩石,平均裂隙纵横比随压差增加而增大,这可能是由于岩石中纵横比较小的裂隙会随压差增大而逐渐趋于闭合.在饱水和饱油岩石中,裂隙孔隙度和裂隙密度都随着压差增加而减小.通过对裂隙密度和压差的关系进行指数拟合,本文获得压差趋于0时的裂隙密度,且裂隙密度随孔隙度增大而增大,增大速率随压差增加而降低.针对饱水和饱油的白云岩样本,CPEM-Zener模型预测的纵波频散随压差增大而减小,此变化趋势和实验测得的逆品质因子随压差的变化关系基本一致,由此进一步验证了模型的实用性.本研究对岩石的孔隙结构和黏弹性分析以及声波测井、地震勘探的现场应用有指导意义.  相似文献   

GasBench-IRMS在碳酸盐岩δ^13C和δ^18O在线连续分析中的应用   总被引：1，自引：0，他引：1  

陶成把立强  李广友杨华敏 《岩矿测试》2006,25(4):334-336

采用GasBench-IRMS气体质谱分析技术，实现了碳酸盐岩中碳氧同位素的在线连续分析。优化了色谱柱温、离子源参数等工作条件，排除了空气中N2O的干扰。结果表明，色谱柱柱温为40℃、65℃时，方法线性范围较宽，结果准确可靠。方法用于碳酸盐岩国家一级标准物质中δ^13C和δ^18O的测定，结果与标准值一致。  相似文献   

Tropical instability wave interactions within the Galápagos Archipelago     

W.V. Sweet  J.M. Morrison  Y. Liu  D. Kamykowski  B.A. Schaeffer  L. Xie  S. Banks 《Deep Sea Research Part I: Oceanographic Research Papers》2009,56(8):1217-1229

The effects of tropical instability waves (TIW) within the eastern equatorial Pacific during the boreal fall of 2005 were observed in multiple data sets. The TIW cause oscillations of the sea surface temperature (SST), meridional currents (V), and 20 °C isotherm (thermocline). A particularly strong 3-wave packet of ～15-day period TIW passed through the Galápagos Archipelago in Sep and Oct 2005 and their effects were recorded by moored near-surface sensors. Repeat Argo profiles in the archipelago showed that the large temperature (>5 °C) oscillations that occurred were associated with a vertical adjustment within the water column. Numerical simulations report strong oscillations and upwelling magnitudes of ～5.0 m d^?1 near the Tropical Atmosphere Ocean (TAO) buoy at 0°, 95°W and in the Archipelago at 92°W and 90°W. A significant biological response to the TIW passage was observed within the archipelago. Chlorophyll a measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) increased by >30% above 1998–2007 mean concentrations within the central archipelago. The increases coincide with coldest temperatures and the much larger increases within the archipelago as compared to those of 95°W indicate that TIW induced upwelling over the island platform itself brought more iron-enriched upwelling waters into the euphotic zone.  相似文献   

东营市胜利油田工矿废弃地调查与整治潜力分析          下载免费PDF全文

王霖琳  巴玉柱  段存国  刘新艳  巴文庄  张艳秀  李岩 《山东国土资源》2014,30(10)

当前,城市的快速扩张导致建设用地供需矛盾日益突出,油田工矿废弃地整治作为土地综合整治规划的重要组成部分,在建设用地指标转移、有效耕地面积增加、生态环境改善等方面可以起到积极的作用。因此,为查清东营市胜利油田工矿废弃地的复垦利用潜力,首先对石油开采对土地利用的影响进行了综述,在此基础上确定了胜利油田工矿废弃地的基本类型,进而对工矿废弃地的现状进行了调查,依据废弃地所在区域的规划用途、灌溉条件、排水条件,盐碱程度、区位条件进行了潜力分区和测算,最终获得了东营市胜利油田工矿废弃地潜力测算的相关数据,可以为该区域工矿废弃地的整治及建设用地、耕地指标的流转与保护提供参考依据。  相似文献   

On the feasibility of using a lake water balance model to infer rainfall: an example from Lake Victoria     

SHARON E. NICHOLSON  XUNGANG YIN  MAMOUDOU B. BA 《水文科学杂志》2013,58(1):75-95

Abstract

A water balance model of Lake Victoria that can be used to assess rainfall from lake level, is derived. The model utilizes satellite estimates of rainfall directly over the lake. The model, initially derived and calibrated for the period 1956–1978, is reformulated here in such a way that all water balance terms except evaporation can be calculated from a combination of catchment rainfall and level of the lake. The reformulated model is validated and used to predict lake level fluctuations during the period 1931–1994. An error analysis is also performed. The model is then “inverted” to solve for mean rainfall conditions during various intervals of changing lake levels. For modern periods with known rainfall conditions, the error in model estimates is of the order of 1%.  相似文献   

华北克拉通奥陶纪岩浆活动——来自河南安阳岭头地区白垩纪闪长岩中继承锆石U- Pb年龄的证据     

杨长青  巴燕  王艳慧  何凯  白国典 《地质论评》2023,69(3):1150-1160

通过高精度的LA-ICP-MS锆石U-Pb同位素测年,在太行山南段河南安阳县岭头一带白垩纪闪长质侵入岩中获得一批443.6±6.1 Ma(MSWD=6.3)的年龄数据,相当于晚奥陶世晚期,这是在华北克拉通内部发现的首例反映加里东期岩浆侵入活动的高精度锆石U-Pb定年数据,为揭示华北克拉通早古生代构造岩浆演化提供了依据。结合区域上同期构造岩浆事件的特点,认为443.6±6.1Ma的锆石可能为华北克拉通板内裂解拉张作用的产物,它是奥陶纪晚期(440 Ma前后)古劳亚大陆分裂,华北克拉通漂离加拿大地盾和北美内陆地台,同时形成北太平洋——这一影响全球的构造地质事件在华北克拉通内部的响应。鉴于稳定克拉通地区奥陶纪岩浆侵入活动与金刚石原生矿存在极高的关联度,本次发现也为在鹤壁地区寻找金刚石原生矿提供了重要参考。  相似文献   

西藏厅宫斑岩铜矿床地质、蚀变及矿化特征研究     

杜等虎  杨志明  刘云飞  曲焕春  李秋耘  许博  巴登珠 《岩石矿物学杂志》2015,34(4):447-474

本文对西藏厅宫大型铜矿进行了详细研究,矿床详细的地质岩相学-蚀变以及典型剖面填图表明,矿区存在2个岩浆事件高峰,即始新世的钾长花岗岩(~50 Ma)和中新世的斑状二长花岗岩、英云闪长斑岩及闪长玢岩(约13~17 Ma)。野外和室内研究发现,厅宫矿区存在2期重要的矿化事件,即始新世(~50 Ma)铜矿化及中新世(~15Ma)的铜钼矿化。始新世含矿岩体为钾长花岗岩,其最主要的特点是其成矿岩体结构的特殊性,表现在该矿床的成矿岩体没有典型的斑状结构,而是独特的细晶-似伟晶结构,说明含矿岩浆发生过骤冷,可能是流体突然逃逸,矿物结晶的固相点发生漂移所致。同时,该岩体还发育大量显微文象结构、显微晶洞构造等,均说明岩浆曾经富水,并且曾经流体饱和;中新世含矿岩体为具有埃达克岩特征的斑状二长花岗岩,主要以脉状的铜、钼矿化为主。该矿床蚀变分带类似于冈底斯带其他斑岩矿床。时间上,分别为早期的钾硅酸盐化、转换阶段的青磐岩化、随后的绢英岩化及最晚期的泥化蚀变;空间上,以含矿岩体为中心向外依次为钾硅酸盐化、绢英岩化、青磐岩化,最晚期的泥化呈补丁状或条带状叠加早期各类蚀变。铜矿化主要发生在始新世的黑云母化阶段和中新世的绢英岩化阶段,而钼矿化主要发生在中新世的钾硅酸盐化和绢英岩化的转换阶段。  相似文献   

Diamond Discovered in Dangqiong Ophiolite, Western Yarlung-Zangbu Suture Zone, Tibet     

XIONG Fahui  YANG Jingsui  Robinson T.PAUL  XU Xiangzhen  BA Dengzhu  LI Yuan  LIJinyang  ZHANG Zhongming  RONG He 《《地质学报》英文版》2015,89(Z2):99-100

<正>The first diamonds from ophiolite were found in peridotite of Luobusa ophiolite along Yarlung Zangbu suture zone in Tibet,China(IGCAGS,1981),and then more and more diamonds found in harzgurgite(Bai et al.,1993;Yang et al.,2007a;Robinson et al.,2014;Xu et al.,  相似文献