共查询到19条相似文献，搜索用时 296 毫秒
1.
MDD模式与快速冷却事件 总被引：6，自引：0，他引：6
ＭＤＤ 模式（Ｍｕｌｔｉｐｌｅ Ｄｉｆｆｕｓｉｏｎ Ｄｏｍａｉｎ ｍｏｄｅｌ） 是Ｄｏｄｓｏｎ 模式的扩展,它可以从一个钾长石样品分析中,得到温度在≤３５０ ～１５０ ℃之间的一条连续的冷却曲线,因此,ＭＤＤ 模式的一个突出贡献是对快速冷却事件的定量制约。冈底斯岩带与哀牢山－ 红河剪切带中新世的快速冷却事件与构造含义是利用这一模式进行研究的成功实例,它不仅定量厘定了快速冷却事件的时间,证实了其存在的普遍性,而且明确指出了中新世印度和欧亚板块碰撞后岩石圈质量转移过程的时间序列,定量地指出了冈底斯岩带逆冲抬升导致的地壳增厚与沿哀牢山－ 红河剪切带地壳块体的侧向挤出在时间上的同步性和差异性 相似文献
2.
文中概述了江西九瑞武山铜金矿床（体）地质特征，建立了块状硫化物型、矽卡岩型，斑岩型铜金矿床（体）综合信息找矿模式；运用数学地质方法着重分析研究了武山铜金矿床不同类型矿体的空间变化规律，介绍了矿床（体）立体定量预测及靶区优选的找矿预测效果 相似文献
3.
4.
滇西澜沧变质带变质作用和变形作用的关系 总被引：18，自引：3，他引：18
滇西澜沧变质带经历了两期变质变形事件，其时代分别为５１９Ｍａ和２８０～１９０Ｍａ。早期变质变形事件（Ｍ１Ｄ１）可由销长石和石榴石变斑晶的包裹体痕迹确定，形成近Ｅ－Ｗ向的变形构造格局。晚期变质变形作用（Ｍ２Ｄ２）以形成蓝片岩相矿物组合，如以蓝门石（青铝门石）＋多硅白云母＋绿泥石＋石英等为特征，并形成近Ｎ－Ｓ向的变形构造格局．钠质问石以青铝闪石和蓝闪石为主，白云母多为３Ｔ＋２Ｍ；型多硅白云母，其ｂｏ均值在９．０４０Ａ以上；蓝片岩相变质作用的Ｐ、Ｔ条件估计分别为０．６～０．７ＧＰａ和３００℃。晚期变质变形事件经历了二个主要阶段（Ｍ２ａＤ２ａ和Ｍ２ｂＤ２ｂ），分别伴随透入性面理（Ｓ２）和褶劈理（Ｓ３）的形成，蓝门石的４０Ａｒ－３９Ａｒ定年分别为２７９Ｍａ和２１４Ｍａ；Ｍ２ｃＤ２ｃ期局部受到热的扰动，以及出现大量的膝折带或宽缓褶皱。上述变质变形演化历史代表了澜沧变质带的隆升及剥蚀过程。 相似文献
5.
华北晚太古代－早元古代高级变质区的变质PTt轨迹及其地壳热动力学演化模式 总被引：4，自引：1，他引：4
华北高级变质区是早前寒武纪下地壳的组成部分，经历复杂的地质演化。根据变质ＰＴｔ轨迹和变质矿物冷却年龄研究，确定高级变质区ＰＴｔ演化具有两种基本形式：（１）逆时针ＩＢＣ型轨迹和（２）顺时针ＩＴＤ型轨迹。前者属晚太古代末期变质事件，反映在相对稳定环境中地壳的缓慢冷却过程，下地壳冷却速率较小（＜０．３℃／Ｍａ）。后者代表早元古代变质事件，形成于地壳的构造隆升过程，下地壳冷却速率明显加快（２．４～３．７℃／Ｍａ）。高级变质区地壳热动力学状态由晚太古代末期重力均衡条件下的稳定状态转变为早元古代增厚地壳的构造隆升状态。这种转变起因于早元古代大陆增厚（造山）作用 相似文献
6.
沉积学研究中的地层倾角测井资料解释 总被引：5，自引：1，他引：5
地层倾角测井资料中包含着丰富的地质信息，它不仅可以反映地层的岩性界面，而且对于地层的时间当量层理面也有所响应，即当地层的沉积构造发生变化时，与之相应的地层倾角和侧向也将随之发生变化。在地展倾角矢量图上，根据倾角矢量随深度的变化关系可以将其划分为五种颜色模式:蓝模式、红模式、绿模式、黄模式和白模式，这五种颜色模式分别反映不同的沉积构造。砂岩体在倾角矢量图上主要表现为三种矢量图模式:ａ.古水流模式-水流层理、顺流加积和进积；ｂ.底线模式-侧向加积和冲蚀接触；ｃ.地层形状模式-压实模式、古水流模式和底线模式可以指示以水流为其搬运介质的沉积砂体，如河道沉积和三角洲沉积，压实模式可以指示岩礁或砂坝。综合分析地层倾角矢量图、地层倾斜方位频率图和画有横向对比线的地层倾角极板曲线图可以研究如下所述的地层沉积学问题:１）地层的形状特征，如地层的厚度、地层的延伸方向和延伸范围、地层面形状。２）地层界面特征，即相邻地层的接触关系，是渐变接触还是突变接触。３）层理特征，如块状层理、纹层状层理和非均质层理。４）沉积旋回和韵律。５）古水流方向和砂体加厚方向。６）砂体微相，即当大的沉积环境（如三角洲沉积环境）已知的条件下，可以识别（如分流河道砂体、河口坝砂体等)砂体微相。 相似文献
7.
荷载微粒闪长质包体是全球范围内Ⅰ型花岗岩的普遍特征，本文对中国东部不同构造域内印支期以来的典型岩体及其荷载微粒闪长质包体进行了对比研究，提出两种岩浆并存的地质、岩石学标志。根据岩石∈Ｎｄ＿０和Ｔ＿（ＤＭ），模式年龄的大小将花岗岩及其荷载闪长质包体划分为三种组合类型：①花岗岩Ｔ＿（ＤＭ）明显大于或∈Ｎｄ＿０明显小于荷栽微粒闪长质包体；②花岗岩Ｔ＿（ＤＭ）明显小于或∈Ｎｄ＿０明显大于微粒闪长质包体；③二者相近。指出三种组合类型分别受①古老地壳区（早元古－太古宙），②较新造山带（古生代以来），③较老地壳区（中、晚元古代）所制约。提出花岗岩及其荷载微粒闪长质包体是分别来自深部地壳不同成分层部分熔融的成因观点。 相似文献
8.
沉积型（贡溪式）重晶石矿床模式 总被引：5，自引：0，他引：5
车勤建 《大地构造与成矿学》1995,19(3):288-289
沉积型（贡溪式）重晶石矿床模式车勤建（湖南省地质研究所，长沙４１０００７）ＡＭＥＴＡＬＬＯＧＥＮＩＣＭＯＤＥＬＦＯＲＳＥＤＩＭＥＮＴＡＲＹＧＯＮＧＸＩ－ＴＹＰＥＢＡＲＩＴＥＤＥＰＯＳＩＴＳ￥ＣＨＥＱｉｎｊｉａｎ（ＨｕｎａｎＩｎｓｔｉｔｕｔｅｏｆＧｅｏ... 相似文献
9.
大别山东部含柯石英榴辉岩锆石U—Pb测年—多期超高压变质作用证据 总被引：6，自引：0，他引：6
大别造山带东段南，北大别两类不同产关的柯石英榴辉岩同位素地质年代学对比研究表明：１．石马辉岩超高压变质事件发生于４７１±２Ｍａ前，并受到海西期热事件；（２）碧溪岭与超镁铁质岩共生的榴辉岩是晚元古代北大别古岛岛弧超高压变质作用的产物，镁铁－超镁铁质堆晶岩系可能形成于９１±５６Ｍａ；（３）大别地区东部加里东期和印支期超高夺变质带并置，反映了造山带形成多期“开”“合”的复杂演化史。 相似文献
10.
11.
L. Y. Hu Y. Liu C. Scheepens A. W. Shultz R. D. Thompson 《Mathematical Geosciences》2014,46(2):227-240
The multiple-point simulation (MPS) method has been increasingly used to describe the complex geologic features of petroleum reservoirs. The MPS method is based on multiple-point statistics from training images that represent geologic patterns of the reservoir heterogeneity. The traditional MPS algorithm, however, requires the training images to be stationary in space, although the spatial distribution of geologic patterns/features is usually nonstationary. Building geologically realistic but statistically stationary training images is somehow contradictory for reservoir modelers. In recent research on MPS, the concept of a training image has been widely extended. The MPS approach is no longer restricted by the size or the stationarity of training images; a training image can be a small geometrical element or a full-field reservoir model. In this paper, the different types of training images and their corresponding MPS algorithms are first reviewed. Then focus is placed on a case where a reservoir model exists, but needs to be conditioned to well data. The existing model can be built by process-based, object-based, or any other type of reservoir modeling approach. In general, the geologic patterns in a reservoir model are constrained by depositional environment, seismic data, or other trend maps. Thus, they are nonstationary, in the sense that they are location dependent. A new MPS algorithm is proposed that can use any existing model as training image and condition it to well data. In particular, this algorithm is a practical solution for conditioning geologic-process-based reservoir models to well data. 相似文献
12.
深层重力流水道砂体储层预测方法及效果分析 总被引：2，自引：0，他引：2
由寻找单纯构造圈闭发展到岩性圈闭，及识别隐蔽非背斜岩性圈闭，如何准确对该圈闭进行定量化储层预测描述，以及储层预测的精度、可靠性合理评价，一直是地质研究人员关注的问题。依靠高品质地震、地质、测井、钻井、分析化验等资料，结合地球物理新技术、新方法，围绕深层重力流水道砂体如何从定性分析到定量预测这一核心问题，各种技术方法相互配合，成功地进行了多方法的砂体厚度预测、渗透砂体预测、物性参数预测。经钻井资料验证，均见到较好地质效果，为深层重力流水道砂体发育区的储层定量化预测摸索了一套行之有效的方法。 相似文献
13.
Emmanuel Chapron Fabien Arnaud HERVÉ Noël Marie Revel Marc Desmet Laurent Perdereau 《Boreas: An International Journal of Quaternary Research》2005,34(4):404-416
The Holocene evolution of Rhone River clastic sediment supply in Lake Le Bourget is documented by sub-bottom seismic profiling and multidisciplinary analysis of well-dated sediment cores. Six high-amplitude reflectors within the lacustrine drape can be correlated to periods of enhanced inter- and underflow deposition in sediment cores. Based on the synthesis of major environmental changes in the NW Alps and on the age-depth model covering the past 7500 years in Lake Le Bourget, periods of enhanced Rhone River flood events in the lake can be related to abrupt climate changes and/or to increasing land use since c. 2700 cal. yr BP. For example, significant land use under rather stable climate conditions during the Roman Empire may be responsible for large flood deposits in the northern part of Lake Le Bourget between AD 966 and 1093. However, during the Little Ice Age (LIA), well-documented major environmental changes in the catchment area essentially resulted from climate change and formed basin-wide major flood deposits in Lake Le Bourget. Up to five 'LIA-like' Holocene cold periods developing enhanced Rhone River flooding activity in Lake Le Bourget are documented at c. 7200, 5200, 2800, 1600 and 200 cal. yr BP. These abrupt climate changes were associated in the NW Alps with Mont Blanc glacier advances, enhanced glaciofluvial regimes and high lake levels. Correlations with European lake level fluctuations and winter precipitation regimes inferred from glacier fluctuations in western Norway suggest that these five Holocene cooling events at 45°N were associated with enhanced westerlies, possibly resulting from a persistent negative mode of the North Atlantic Oscillation. 相似文献
14.
15.
秦岭造山带中段中新生代构造抬升的热年代学证据 总被引：3，自引：0，他引：3
秦岭造山带中段沙沟街韧性剪切南北两侧岩体的Ar Ar、MDD模式计算及磷灰石裂变径迹测量结果表明 ,秦岭造山带中新生代期间南北两侧表现出不同的冷却过程 ,北侧在 140Ma期间发生快速冷却 ,而南侧除 30 0～ 2 0 0Ma期间发生过快速冷却外 ,在 130～ 90Ma期间发生过快速冷却。反映了秦岭造山带碰撞之后陆内造山的不一致性 ,这与区内的构造作用过程相一致。 相似文献
16.
地学模拟技术的一个发展方向是与地学过程分析密切结合,另一个发展方向是与数据可视化技术相结合。前者试图通过使用各种数学方法模拟地学随机现象,并对这些不良结构化或半结构化的地学问题进行定量化描述;后者运用计算机的三维可视化功能,在三维环境下将空间信息管理、地学解译、空间分析、地学统计与预测、三维图形可视化等技术相结合,实现计算可视化、分析可视化、过程可视化、结果可视化和决策可视化,并用于地学分析。回顾了地学中计算机三维地学建模技术、地质统计学和地学非线性现象模拟方法,并对该领域的发展进行了展望,认为加强地学模拟的理论体系、方法体系、技术体系的研究和实践既有着重要的理论意义,又有着重要的现实意义。 相似文献
17.
18.
19.
Identification of sharp and discontinuous lithological boundaries from well log signal stemming from heterogeneous subsurface structures assumes a special significance in geo-exploration studies. Well log data acquired from various geological settings generally display nonstationary/nonlinear characteristics with varying wavelengths and frequencies. Modelling of such complex well-log signals using the conventional signal processing techniques either fails to catch-up abrupt boundaries or at the best, do not provide precise information on insidious lithological discontinuities. In this paper, we have proposed a new wavelet transform-based algorithm to model the abrupt discontinuous changes from well log data by taking care of nonstationary characteristics of the signal. Prior to applying the algorithm on the geophysical well data, we analyzed the distribution of wavelet coefficients using synthetic signal generated by the first order nonstationary auto-regressive model and then applied the method on actual well log dataset obtained from the KTB bore hole, Germany. Besides identifying the formation of layered boundaries, the underlying method also maps some additional formation boundaries, which were hitherto undetected at the KTB site. The results match well with known geological lithostratigraphy and will be useful for constraining the future model of KTB bore hole data. 相似文献