Melting of β-quartz up to 2.0 GPa and thermodynamic optimization of the silica liquidus up to 6.0 GPa     

Pierre Hudon  In-Ho Jung  Don R. Baker 《Physics of the Earth and Planetary Interiors》2002,130(3-4):159-174

Melting relations of β-quartz were experimentally determined at 1.0 GPa (1900±20 °C), 1.5 GPa (2033±20 °C), and 2.0 GPa (2145±20 °C) using a new high-pressure assembly in a piston–cylinder apparatus and substantial differences were found with data previously reported. The new melting data of β-quartz were combined and optimized with all available thermodynamic, volumetric, and phase equilibria data for β-cristobalite, β-quartz and coesite to produce a P–T liquidus diagram for silica valid up to 6.0 GPa. Using the new optimized thermodynamic parameters, the invariant point β-cristobalite+β-quartz+liquid and β-quartz+coesite+liquid were determined to lie at 1687±17 °C and 0.457 GPa, and 2425±25 °C and 5.00 GPa, respectively.  相似文献   

Seismological identification of the 1998 May 28 Pakistan nuclear test     

D. Bowers  A. Douglas  N. D. Selby  P. D. Marshall  D. Porter  N. J. Wallis 《Geophysical Journal International》2002,150(1):153-161

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不对称抽道集共反射面元叠加方法探讨     

邱苏胡旭芝  沈骥千 《中国煤田地质》2003,15(2):49-51,F004,58

总结不对称抽道集共反射面元叠加方法的工作经验，提出自由观测面自由反射界面不对称抽道集共反射面元叠加方法的处理思路和计算方法。在自由观测面的条件下，反射界面可分为简单倾斜平面、规则曲面和自由反射界面三种情况，针对不同情况讨论共反射面元的叠加方法。综合一般情况下的共反射面元叠加方法，提出了“鳞片法”的处理思路。  相似文献   

b值在地震预测中的三类应用及其物理基础与须注意的问题   总被引：1，自引：0，他引：1  

韩渭宾 《四川地震》2003,(1):1-5

将b值在地震预测中的直接应用归为三类：1）根据b值的动态变化预测地震。2）根据G－R律求出各级地震平均复发周期或年均发生率，推测未来一定时段如50年或100年内发生各级地震的危险性。3）根据G－R直线在横轴的截距，预测强余震的震级。讨论了这三种用法的物理基础及现有工作中容易出现的问题。  相似文献   

河北省及邻区地震活动时间间隔的一些特征   总被引：3，自引：1，他引：3  

边庆凯  孙佩卿  支树明  孙华  武有文 《华北地震科学》2003,21(1):22-31,62

介绍了地震活动时间间隔的研究历史和定义，对河北省及邻近地区地震活动时间间隔分布的统计点图、间隔一频次统计图进行了分析，分析时结合不同的震级层次、不同的统计时段（长段不同）、不同的活动水平以及地震活动的丛集与孤立。统计结果显示地震活动时间间隔对数一频次统计结果与G－L关系式的统计结果类似，地震活动时间间对数一频镒也呈指数分布。最后对预测中存在的不足进行了一些简单说明。  相似文献   

粤西河台金矿田糜棱岩XRD特征及其地质意义     

师爽  龚朝阳  焦骞骞  许德如  张胜印  常华诚  胡彬 《地质论评》2021,67(5):67060006-67060006

粤西河台金矿区位于钦州湾—杭州湾（钦—杭）结合带南段的云开地区,是典型的受韧性剪切带控制的金矿。然而,对于剪切带中有利于金成矿的地质环境及其成矿过程仍然存在争议。本文在对河台矿区高村矿床进行详细野外地质调查的基础上,通过X射线衍射（XRD）对含金剪切带中各类糜棱岩系列岩石进行系统研究,建立应力变化—成分变异的对比序列,从而进一步揭示剪切变形与金矿化的关系。结果显示,剪切带中白（绢）云母的含量在9%~40%,并且在初糜棱岩、无矿糜棱岩、含矿糜棱岩、无矿超糜棱岩、含矿超糜棱岩中含量呈现出逐渐递增的趋势。白（绢）云母主要为2M1型,b0值分布在0.55505~0.99002 nm之间,在初糜棱岩、无矿糜棱岩和无矿超糜棱岩中逐渐增高,分别形成在低压、中压和高压环境。可见,从初糜棱岩到超糜棱岩,随着变形强度的增加,热液活动也随之增强,从而新生成了大量白（绢）云母。然而,在含矿的糜棱岩和超糜棱岩中还存在一些低压白云母,推测其可能是在后期脆性裂隙中由于流体活动所新形成的。因此,成矿可能经历了两个阶段,即早期的韧性剪切变形阶段导致金的初步富集,后期叠加的脆性破裂阶段形成具有工业品位的矿体。另外,无矿超糜棱岩的石英含量（29.8%）明显低于糜棱岩（44.2%）,推测在形成石英脉型矿体过程中,部分热液可能来自于其围岩超糜棱岩。因此,相对于初糜棱岩和糜棱岩,超糜棱岩中更有利于金矿的形成。  相似文献   

Application of a Bayesian model to infer the contribution of coalbed natural gas produced water to the Powder River,Wyoming and Montana          下载免费PDF全文

Jason M. Mailloux  Kiona Ogle  Carol D. Frost 《水文研究》2014,28(4):2361-2381

The Powder River Basin (PRB) of Wyoming and Montana contains significant coal and coal bed natural gas (CBNG) resources. CBNG extraction requires the production of large volumes of water, much of which is discharged into existing drainages. Compared to surface waters, the CBNG produced water is high in sodium relative to calcium and magnesium, elevating the sodium adsorption ratio (SAR). To mitigate the possible impact this produced water may have on the quality of surface water used for irrigation, the State of Montana passed water anti‐degradation legislation, which could affect CBNG production in Wyoming. In this study, we sought to determine the proportion of CBNG produced water discharged to tributaries that reaches the Powder River by implementing a four end‐member mixing model within a Bayesian statistical framework. The model accounts for the ⁸⁷Sr/⁸⁶Sr, δ¹³C_DIC, [Sr] and [DIC] of CBNG produced water and surface water interacting with the three primary lithologies exposed in the PRB. The model estimates the relative contribution of the end members to the river water, while incorporating uncertainty associated with measurement and process error. Model results confirm that both of the tributaries associated with high CBNG activity are mostly composed of CBNG produced water (70–100%). The model indicates that up to 50% of the Powder River is composed of CBNG produced water downstream from the CBNG tributaries, decreasing with distance by dilution from non‐CBNG impacted tributaries from the point sources to ~10–20% at the Montana border. This amount of CBNG produced water does not significantly affect the SAR or electrical conductivity of the Powder River in Montana. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Modelling of earthquake rupturing as a stochastic process and estimation of its distribution function from earthquake observations     

Z.-M. Yin  G. Ranalli 《Geophysical Journal International》1995,123(3):838-848

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A hierarchical model for earthquake generation on coupled segments of a transform fault     

John McCloskey 《Geophysical Journal International》1993,115(2):538-551

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Cumulative　frequency　b　value　without　upper　bound　magnitude　and　its　regression　determination     

沈建文 《地震学报(英文版)》1994,(Z1)

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