塔里木盆地乌什地区上震旦统奇格布拉克组地球化学特征及其地质意义*

塔里木盆地寒武系盐下地层资源量巨大,上震旦统奇格布拉克组是该领域风险勘探的重要层系之一,但当前该层系勘探尚未取得重大突破,其中岩相古地理格局及储集层主控因素认识不深是制约勘探突破的重要因素之一。文中以乌什地区昆盖阔坦剖面为研究对象,通过地层精细描述和104块岩石薄片分析,并优选样品开展常微量元素、稀土元素、碳氧锶同位素、白云石有序度及U-Pb同位素年龄测试,分析了奇格布拉克组沉积环境及白云岩成因。结果表明: (1)塔里木盆地乌什地区昆盖阔坦剖面奇格布拉克组厚约141 m,主要发育叠层石、凝块石、泡沫绵层石3种微生物白云岩和鲕粒、粘结颗粒2种与微生物作用相关的颗粒岩,并根据相序组合可以划分为4个段,自下而上构成碳酸盐缓坡背景下的内缓坡潮坪—微生物丘滩沉积序列;(2)地球化学分析表明,奇格布拉克组沉积时期研究区整体处于温暖、干旱气候条件下的近岸浅水环境,海水具有较高盐度、较高水温和氧化—弱氧化特征,海平面先逐渐上升后快速下降;(3)奇格布拉克组白云岩形成于准同生—浅埋藏期,白云石化流体为具有较高盐度的海水。该研究成果不仅可以为塔里木盆地晚震旦世岩相古地理研究提供依据,还可以为储集层主控因素分析提供依据。     

渭北东部奥陶系岩溶地下水环境同位素特征分

本文通过对渭北东部岩溶地下水环境同位素组成特征的研究，分析了大气降水、地表水、地下水三者之间的转化关系，并对研究区岩溶地下水的形成进行了初步探讨，认为大气降水是研究区岩溶地下水的补给源，地表水与地下水之间存在水力联系，地表水对地下水的补给占补给水源的74.3％。西部岩溶裸露区为岩溶水的直接补给区，其周边浅埋区为岩溶水的间接补给区，东南部的岩溶中-深埋区为岩溶水的径流排泄区。     

Modified state–space procedures for pseudodynamic testing

The existing on‐line numerical integration algorithms are derived from the Newmark method, which is based on an approximation of derivatives in the differential equation. The state–space procedure (SSP), based on an interpolation of the discrete excitation signals for piecewise convolution integral, has been confirmed as more reliable than the Newmark method in terms of numerical accuracy and stability. In an attempt to enhance the pseudodynamic test, this study presents an on‐line integration algorithm (referred to as the OS–SSP method) via an integration of the state–space procedure with Nakashima's operator‐splitting concept. Numerical stability and accuracy assessment of the proposed algorithm in addition to the explicit Newmark method and the OS method were investigated via an eigenvalue, frequency‐domain and time‐domain analysis. Of the on‐line integration algorithms investigated, the OS–SSP method is demonstrated as the most accurate method with an acceptable stability (although not unconditionally stable) characteristic. Therefore, the OS–SSP method is the most desirable method for pseudodynamic testing if the numerical stability criterion (Δt/T⩽0.5) is ensured for every vibration mode involved. Copyright © 2001 John Wiley & Sons, Ltd.     

横观各向同性饱和两相介质动力反应计算分析

针对横观各向同性饱和两相介质的弹性波动方程组,应用基于显式逐步积分计算格式的时域显式有限元方法对其在输入地震波作用下的动力反应进行计算和分析,并将计算结果与完全各向同性饱和两相介质的计算结果进行对比研究。结果显示横观各向同性饱和两相介质与完全各向同性饱和两相介质的动力反应具有较为显著的差异。同时表明时域显式有限元方法是进行横观各向同性饱和两相介质动力反应计算分析的一种有效方法。     

N油田A油组钙质隔夹层地质特征及成因分析

在油田开发过程中,隔夹层控制油气水运动规律,对于寻找剩余油具有重要控制作用。本文以N油田TF组2段A油组为研究对象,通过薄片、岩心测试、测井、碳氧同位素等资料综合分析,研究其钙质隔夹层的分布特征、岩石学特征、物性特征、测井识别特征,并从沉积环境、物质来源、成岩作用相结合的角度分析钙质隔夹层的成因。研究表明,A油组纵向上发育的三套钙质隔夹层主要发育在前滨滩坝沉积微相,顶钙与底钙的岩性以砂质生屑质灰岩为主,中钙为钙质砂岩;三套钙质隔夹层中生物碎屑主要以腕足、腹足、有孔虫为主,含少量棘皮、瓣鳃、红藻、介形虫、苔藓虫等;成岩作用主要为胶结作用,胶结物类型包含早期方解石胶结物、中期铁方解石胶结物、晚期铁白云石胶结物;碳氧同位素分析表明,隔夹层中碳主要来自于沉积过程中的海水,同时有少量来自于大气淡水和有机酸,Ca²⁺主要来源于生物碎屑,其次为钙长石溶解、铝硅酸盐矿物的水化作用。     

一种基于复合金字塔模型的三维模型数据组织方法

针对异构三维模型数据的统一组织和集成管理问题,本文以目前主流金字塔模型、三维场景瓦片的数据组织方法和地图服务规范等相关技术为基础,提出了一种基于复合金字塔模型的三维模型数据组织方法。该方法首先构建覆盖测区的地理格网模型,以此作为异构三维模型数据集成的空间框架。其次,建立三维模型数据与地理格网单元的映射关系,从而构建复合金字塔模型,实现异构三维模型数据的统一管理。最后,在数据结构上对现有数据格式进行扩展,设计了一种面向网络传输的数据格式储存三维模型数据,完成异构三维模型数据的一体化存储。试验结果表明,该方法能够实现异构三维模型数据统一组织与集成管理。     

Quantitative Analysis of Central Asian Countries’ Energy Security and Its Political Influence Factors

Central Asian countries are located in the heartland of the Eurasian Continent. Their geographic location puts their energy flows under tremendous geopolitical pressure from the countries along their limited number of pipelines. With energy trade data from the United Nations Comtrade Statistics Database in the period from 2005 to 2016, this paper evaluates energy security of Kazakhstan and Turkmenistan (exporter) and Kyrgyzstan (importer) using three standards: correlativeness, diversity, and the impact of international relations. It concludes that Kazakhstan and Turkmenistan’s oil markets are balanced in terms of correlation and diversification, and thus less subject to geopolitical pressure. Turkmenistan’s gas markets, on the other hand, still have tremendous exposure to geopolitical risks for lack of diversification. Kyrgyzstan, as an energy importer, could rely on a few neighboring countries for energy supply. We found out that the three Central Asian countries’ energy security is largely determined by four political factors: the relationship with Russia, the new “great game” in Eurasia, the rise of China, and Central Asian regional geopolitical configuration.     

Effects of corridor networks on plant species composition and diversity in an intensive agriculture landscape

The development of modern agriculture has resulted in much homogenization of the landscape consisting of large patches of farmland,so small remnant non-crop habitats especially linear corridors play an important role in the conservation of species and the maintenance of ecosystem functions.However,little attention has been paid to the effects of corridors structural characteristics on the plant species restricted to such habitats.In this study,we selected three types of corridors including ditch,hedgerow and road,and ana-lyzed their structural characteristics.The plant species presented in these corridors were investigated,and the species diversity,abun-dance and frequency were estimated.Moreover,spatial arrangements of corridors were classified into different types to discuss whether there were significant effects of corridor network on plant distribution.The results show that three types of corridors have different ef-fects on plant species composition and diversity.The one-one combined corridor networks and total network associated by three corri-dors have more complex structural features than each single type of corridor.However,there is no strong correlation between the corri-dor networks with their plant species.We suggest that carrying out a pointed vegetation survey at corridor intersections to further test the relationships between structural features of corridor and plants is necessary.     

大数据环境下数字填图数据集成服务技术

应用数字填图技术形成了大量地质填图图幅数据,这些数据空间结构化和非结构化特征并存,如何在网络环境下提供高效的数据服务是急需解决的一个难题。大数据技术的发展为数字填图、数据集成服务提供了一种新的途径。通过对数字填图数据特征的分析,在研究地质调查信息网格大数据处理框架的基础上,提出了结构化和非结构化数据相结合的有序化组织管理、发布与服务方法,并对关键技术进行了研究与试验,取得了良好的效果。     

内蒙古北山地区蓬勃山南石英闪长岩LA-ICPMS锆石U-Pb测年及其意义

对内蒙古北山地区蓬勃山南石英闪长岩进行了岩石地球化学分析,结果表明:SiO2含量55.57%~64.80%,Al2O3含量为14.23%~16.38%,σ值1.02~1.99,K2O/Na2O<1为主,A/CNK为0.82~1,全碱含量K2O+Na2O为3.71%~6.16%,稀土总量ΣREE为(53.77~162.47)×10-6,LREE/HREE为3.55~7.84,轻重稀土分异不明显,(La/Yb)N=2.51~7.99,δEu为0.52~1.06.该岩体的LA-ICPMS锆石U-Pb同位素测年结果表明,其形成时间在310.59±0.88~302±1 Ma之间,相当于晚石炭世晚期.综合分析认为,蓬勃山南石英闪长岩侵位反映了洋壳俯冲的消减熔融岩浆事件.