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784.
The hydrocarbon migration and accumulation of the Suqiao deep buried-hill zone, in the Jizhong Subbasin, the Bohai Bay Basin, eastern China, was investigated from the perspective of paleo-fluid evidence by using fluid inclusions, quantitative fluorescence techniques (QGF), total scanning fluorescence method (TSF) and organic geochemical analysis. Results show that the current condensate oil-gas reservoirs in the study area once were paleo-oil reservoirs. In addition, the reservoirs have experienced at least two stages of hydrocarbon charge from different sources and/or maturities. During the deposition of the Oligocene Dongying Formation (Ed), the deep Ordovician reservoirs were first charged by mature oils sourced from the lacustrine shale source rocks in the fourth member of Shahejie and Kongdian Formations (Es4+Ek), and then adjusted at the end of Ed period subsequently by virtue of the tectonic movement. Since the deposition of the Neogene Minghuazhen Formation (Nm), the reservoirs were mainly charged by the gas that consisted of moderate to high-maturity condensate and wet gas sourced from the Es4+Ek lacustrine shale source rocks and mature coal-derived gas sourced from the Carboniferous-Permian (C-P) coal-bearing source rocks. Meanwhile, the early charged oil was subjected to gas flushing and deasphalting by the late intrusion of gas. The widely distributed hydrocarbon inclusions, the higher QGF Index, and FOI (the frequency of oil inclusions) values in both gas-oil and water zone, are indicative of early oil charge. In addition, combined with the homogenization temperatures of the fluid inclusions (<160 °C) and the existence of solid-bitumen bearing inclusions, significant loss of the n-alkanes with low carbon numbers, enrichments of heavier components in crude oils, and the precipitation of asphaltene in the residual pores suggest that gas flushing may have played an important role in the reservoir formation. 相似文献
785.
断层电子自旋共振定年中石英信号强度的影响因素分析 总被引:1,自引:0,他引:1
电子自旋共振(ESR)是一种利用矿物在地质环境中的累计辐射能进行测年的技术方法,它采用的测年矿物石英广泛分布,并具有记录断层作用良好的计时零点,是同位素测年的重要补充。ESR信号强度是决定ESR年龄精确度的关键因素,但是各种参数条件对测量结果的影响方式及其程度缺乏系统研究。本文以取自断层带石英的一种顺磁中心——E’心为研究对象,运用单因素重复性实验方法,分析石英ESR定年中5种影响因素与ESR信号强度的相关关系。结果表明,微波功率、调制幅度、扫描宽度是影响ESR信号强度的主控因素,样品管方位及直径对测量结果影响不大。微波功率0.02~0.1 m W、调制幅度0.25~0.4 Gs可作为精确测量断层泥石英E’心普适性的参数区间,过大或过小的扫描宽度均不利于ESR测量,可利用在大扫描宽度条件下先预扫描再精细扫描的方法确定合适的扫描宽度,重复测量后求取平均值可有效降低测量误差。利用本文提出的参数区间及其确定的方法测量断层泥石英的E’心信号强度,能显著提高ESR测量精度。 相似文献
786.
Rare Earth Element Determination in Olivine by Laser Ablation‐Quadrupole‐ICP‐MS: An Analytical Strategy and Applications
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Clare V. Stead Emma L. Tomlinson Balz S. Kamber Michael G. Babechuk Cora A. McKenna 《Geostandards and Geoanalytical Research》2017,41(2):197-212
Olivine offers huge, largely untapped, potential for improving our understanding of magmatic and metasomatic processes. In particular, a wealth of information is contained in rare earth element (REE) mass fractions, which are well studied in other minerals. However, REE data for olivine are scarce, reflecting the difficulty associated with determining mass fractions in the low ng g?1 range and with controlling the effects of LREE contamination. We report an analytical procedure for measuring REEs in olivine using laser ablation quadrupole‐ICP‐MS that achieved limits of determination (LOD) at sub‐ng g?1 levels and biases of ~ 5–10%. Empirical partition coefficients (D values) calculated using the new olivine compositions agree with experimental values, indicating that the measured REEs are structurally bound in the olivine crystal lattice, rather than residing in micro‐inclusions. We conducted an initial survey of REE contents of olivine from mantle, metamorphic, magmatic and meteorite samples. REE mass fractions vary from 0.1 to double‐digit ng g?1 levels. Heavy REEs vary from low mass fractions in meteoritic samples, through variably enriched peridotitic olivine to high mass fractions in magmatic olivines, with fayalitic olivines showing the highest levels. The variable enrichment in HREEs demonstrates that olivine REE patterns have petrological utility. 相似文献
787.
Hafnium Isotope Characteristics of Palaeoarchaean Zircon OG1/OGC from the Owens Gully Diorite,Pilbara Craton,Western Australia
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Anthony I. S. Kemp Jeffrey D. Vervoort Katarina E. Bjorkman Linda M. Iaccheri 《Geostandards and Geoanalytical Research》2017,41(4):659-673
We report Hf isotope data for 3467 Ma igneous zircons from the Owens Gully Diorite of the Pilbara Craton. These zircons, designated OG1 or OGC, have simple, well‐defined U‐Pb age systematics. Measurements obtained by single crystal dissolution yield a moderate range in 176Hf/177Hf (mean 0.280633 ± 34) and 176Lu/177Hf (mean 0.00119) that translate into initial (3467 Ma) 176Hf/177Hf values that are equivalent within measurement uncertainty (mean 0.280554 ± 7, εHf = +0.6 ± 0.2, 2s). Laser ablation analysis yielded clustered initial 176Hf/177Hf ratios (mean 0.280560 ± 20, 2s) indistinguishable from those obtained by solution analysis. The antiquity and moderately high 176Lu/177Hf of these zircons result in significant corrections for radiogenic ingrowth of 176Hf (to 6 εHf units). Depth profiling by concurrent Pb‐Hf isotope determination reveals trends to lower 207Pb/206Pb in several crystals, although these are not accompanied by shifts in 176Hf/177Hf. We conclude that zircons from the Owens Gully Diorite are homogeneous for Hf isotopes at the scale of sampling and within the uncertainty limits of the measurement techniques employed. Zircon OG1/OGC would appear to be an ideal quality monitor for laser ablation Hf isotope determination in ancient zircons, and for laser ablation techniques where Hf isotope and age information are determined concurrently or simultaneously. 相似文献
788.
利用“球面上任意3点确定的平面与球的相交曲线为圆,该截面圆心与球心的连线(球截面圆心法线)垂直于圆平面”的几何关系,提出一种基于球体几何关系的球标靶特征提取算法。通过对球标靶点云构建多组截面圆,对截面圆设定约束条件,构造球心到球截面圆心法线距离平方和的目标函数,以此目标函数最小为条件求解球标靶的球心坐标。通过实验比较本文方法、最小二乘方法、整体最小二乘方法、加权整体最小二乘方法和稳健加权整体最小二乘方法对球标靶的处理效果,结果表明本文方法具有较高的准确性和稳健性。 相似文献
789.
将三维激光扫描技术应用到变形监测中,对三维激光扫描测距、测角、光斑及配准误差进行分析,给出点云误差椭球模型。利用得到的误差椭球半轴长度和点位误差极限值的关系,推导点云变形可监测性指标。最终通过模拟的滑坡实验,验证了该变形可监测性指标的可行性。 相似文献
790.
The precision of height measurements derived from laser scanning a weathered rock surface was analysed. Different registration methods for comparing surfaces to deduce weathering were assessed and the most precise was found to be the method that used registration shapes as control, located in different planes relative to the scanned surface. In addition, the different sources of error in scanning precision were assessed by varying factors such as scan distance, lens configuration, scan angle and the nature of the topography being scanned. From this analysis it was possible to suggest what the optimal scanning conditions were for this particular experimental set‐up. The procedures outlined for assessing errors in the precision of height measurements are transferable to other scanning studies. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献