论海平面变化与层控矿床成因   总被引：3，自引：0，他引：3       下载免费PDF全文

王剑 《地球科学》1997,22(3):285-292

桂北及桂中大瑶山西侧泥盆纪层控型站矿床成因研究表明，矿床形成赋矿盆地的海平面变化密切相关，它们是“层、系、相、位”四位一体主因素地质场作用的结果，这一新的矿床成因新模式可以概括为：区域赋矿层位与层序边界面关系密切，研究区内共划分出７个 序边界面，其中ＳＢ１（Ｉ），ＳＢ３（Ⅲ）及ＳＢ７（Ｉ）是主要的区域性赋 层位；矿体一般产于Ｉ型层序边界面之上，或产于Ⅱ，Ⅲ层序边界面之下；容矿主岩与一定的沉积体系域  相似文献   

构造因素对半地堑盆地的层序充填的影响   总被引：5，自引：2，他引：5       下载免费PDF全文

漆家福  杨桥 《地球科学》1997,22(6):603-608

运用平衡剖面分析和构造物理模拟实验方法研究了典型铲式正断层模型上盘盆地的发育过程．研究表明，铲式正断层的产状以及断层上盘的变形方式直接影响上盘盆地的形态和沉积层序结构．简单铲式正断层的上盘发育相对简单的半地堑盆地，复杂铲式（坡坪式）正断层的上盘则发育包含有内部次级背斜凸起和向斜凹陷的复式半地堑，而且半地堑盆地的宽度与拆离断层面深度成正比．在沉积物补偿充填的情况下，渐进伸展将使半地堑的宽度也保持不变，从而使半地堑构造斜坡上产生“视水退”的层序结构现象，并且使盆地中“垂向加积”的沉积层序演变为宏观上“侧向加积”的沉积层序．这种由构造因素对半地堑盆地的层序充填的影响在渤海湾盆地的部分老第三纪断陷中得到印证．  相似文献   

Estimation of seismic stress drop from the peak velocity of ground motion     

秦嘉政  刘祖荫  钱晓东  谢庆茵 《地震学报(英文版)》1997,10(5):581-591

ＥｓｔｉｍａｔｉｏｎｏｆｓｅｉｓｍｉｃｓｔｒｅｓｄｒｏｐｆｒｏｍｔｈｅｐｅａｋｖｅｌｏｃｉｔｙｏｆｇｒｏｕｎｄｍｏｔｉｏｎＪＩＡＺＨＥＮＧＱＩＮ（秦嘉政）ＺＵＹＩＮＬＩＵ（刘祖荫）ＸＩＡＯＤＯＮＧＱＩＡＮ（钱晓东）ＱＩＮＧＹＩＮＸＩＥ（谢庆...  相似文献   

逆延华南气温序列方法的探讨   总被引：1，自引：0，他引：1  

林应河  郭英琼 《热带地理》1997,17(3):283-288

本文用香港１８８４－１９８３年逐年１月平均气温代表冬温，把它的年际变化时间序列作为原样本进行了谱分析，从中提取有代表性的周期波，用谱波分析和方差分析法，对选出来的周期波延，迭加，拟合成新的冬温时间序列。用地方志的冻灾史料进行了检验，结果９５％以上的冻灾年与新序列的冷冬年对应；冬季应温多出现连续性冷冬年，史料和新序列也有很好的一致性。  相似文献   

巴里坤盆地现代气候波动及近250年来的冷暖变化   总被引：1，自引：0，他引：1  

罗格平  袁玉江 《冰川冻土》1991,(1)

通过单相关普查找出巴里坤山区年表7的生长限制因子为上年6—7月均温,从而得到了巴里坤近250a来冷暖变化的替代序列。该序列的低通滤波曲线,揭示了近250a来的冷暖变化事实。方差分析指出,巴里坤冷暖变化的主要周期为126a。温度曲线与天山冰川进退时期相吻合。  相似文献   

澜沧—耿马地震发震构造初步研究   总被引：2，自引：0，他引：2  

毛王平  张俊昌 《地震研究》1991,14(1):9-15

本文根据澜沧—耿马地震形变带、极震区及余震序列分布特征,分析了7.6和7.2级地震的发震构造,认为北北西向旱母坝断层是7.2级地震的发震构造,7.6级地震的发震构造不是一条单一的断层,北西向木嘎断裂和北北西向澜沧—勐海断裂均有明显破裂表现,这一特点与震区复杂的地质构造背景有密切联系。  相似文献   

地层柱状模拟新方法及在详细沉积断面综合柱状模拟中的应用   总被引：1，自引：1，他引：1  

金友渔 《地球科学》1991,16(6):697-704

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快速射线追踪及其在地震层析中的应用     

王修琼  姚政生 《内陆地震》1990,4(1):27-32

在地震层析研究中,常常涉及地震波在非均匀介质中的传播路径问题,故快速射线追踪是不可缺少的工具。本文讨论了一种以三点法为基础的逐步逼近的射线追踪方法,其优点是计算速度快、精度高,适合地震层析研究的计算要求。  相似文献   

Sedimentation, distribution and diagenesis of organic matter in a recent carbonate environment, Abu Dhabi, U.A.E.     

Fabien Kenig  Alain Y. Huc  Bruce H. Purser  Jean-Louis Oudin 《Organic Geochemistry》1990,16(4-6)

In the modern hypersaline carbonate lagoon and sabkha sedimentary environments of Abu Dhabi (United Arab Emirates), three types of organic matter originate respectively from microbial mat, Avicennia mangrove, and Halodule lagoonal seagrass. The study of recent sedimentary processes and cross sections through the sabkha sediments lead to the definition of organo-sedimentary facies based on geochemical and sedimentological criteria. This permits the construction of an organo-sedimentary sequence which expresses the Holocene sedimentary record involving a transgressive and a regressive sequence. The various organic facies occur in both sequences.Heterogeneity within the individual organic facies reflects several factors, including sedimentation dynamics, mineral matrix, oxidation and reduction, and selective organic and mineral diagenesis. These parameters are discussed in terms of depositional environment and location within the organo-sedimentary sequence. Changes in distribution, quantity, and preservation potential of the buried organic matter are discussed in terms of sea level changes and sedimentary accretion rates.  相似文献   

Timing of low-temperature metamorphism and cooling of the Paleozoic and Mesozoic formations of the Bükkium,innermost Western Carpathians,Hungary     

P. Árkai  K. Balogh  I. Dunkl 《International Journal of Earth Sciences》1995,84(2):334-344

K-Ar ages of illite-muscovite and fission track ages of zircon and apatite were determined from various lithotypes of the Bükkium, which forms the innermost segment of the Western Carpathians. The stratigraphic ages of these Dinaric type formations cover a wide range from the Late Ordovician up to the Late Jurassic. The grade of the orogenic dynamo-thermal metamorphism varies from the late diagenetic zone through the anchizone up to the epizone (chlorite, maximally biotite isograd of the greenschist facies). The K-Ar system of the illite-muscovite in the < 2 m grain-size fraction approached equilibrium only in epizonal and high-temperature anchizonal conditions. The orogenic metamorphism culminated between the eo-Hellenic (160-120 Ma) phase connected to the beginning of the subduction in the Dinarides, and the Austrian (100-95 Ma) phase characterized by compressional crustal thickening. No isotope geochronological evidence was found for proving any Hercynian recrystallization. The stability field of fission tracks in zircon was approached using the thermal histories of the different tectonic units. A temperature less than 250°C and effective heating time of 20–30 Ma had only negligible effects on the tracks, whereas total annealing was reached between 250 and 300°C. Apatite fission track ages from the Paleozoic and Mesozoic formations show that the uplift of the Bükk Mountains occurred only in the Tertiary (not earlier than ca. 40 Ma ago). Thermal modeling based on apatite fission track length spectra and preserved Paleogene sediment thickness data proved that the Late Neogene burial of the recently exhumed plateau of the Bükk Mountains exceeded 1 km.  相似文献