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191.
192.
本文基于对楚-萨雷苏盆地热兹卡兹甘地区的构造运动、相应动力学机制、沉积地层的研究,对楚-萨雷苏盆地盆地上古生界沉积演化做了阐述,提出了热兹卡兹甘地区晚古生代经历了早中泥盆世火山盆地—晚泥盆世(成盆初期)滨海冲积平原、局限台地—早石炭世(海侵期)台地、台缘斜坡、陆棚—中晚石炭世(海退期)海陆交互相三角洲—早二叠世(干旱气候期)干盐湖—晚二叠世盐湖的沉积演化。 相似文献
193.
晋东北地区燕山期地壳活动剧烈而频繁,经历了3次由伸展→挤压转换→隆升和岩浆活动过程。燕山运动早期形成早侏罗世断陷盆地和中侏罗世挤压坳陷型聚煤构造盆地;中期中晚侏罗世形成被NW、NE向深大断裂围限的火山断陷盆地,中基性—酸性火山喷发和浅成、超浅成中酸性岩浆侵入,晚侏罗世末形成了一系列NNE向褶皱和逆冲推覆构造带;晚期早白垩世再次形成断陷盆地和开阔平缓褶皱,义县组不整合在火山岩之上,晚白垩世处于挤压造山后的山体隆升阶段,左云组不整合在义县组之上,伴随有壳源型花岗岩侵入,NW、NE向断裂复活,形成地堑、地垒式断裂组合,导致山体隆升。 相似文献
194.
编制地壳垂直运动速率等值线图的有限元法 总被引:2,自引:0,他引:2
根据地壳垂直运动研究中的均衡理论,建立描述地壳垂直运动速率空间分布的数学模型,并提出应用有限元法拟合地壳垂直运动速率面的理论和方法。通过计算验证,说明有限元法可实现对地壳垂直运动速率面的精确逼近,是编制地壳垂直运动速率等值图的有效方法。 相似文献
195.
内蒙古耕地重心移动及其驱动因子分析 总被引:27,自引:1,他引:26
简单回顾了内蒙古垦荒历史,并用内蒙古自治区近50年的统计数据计算出1949年~1996年不同年份的全区耕地重心及人口重心,在此基础上得到了内蒙古耕地重心及人口重心均向东北方向移动的结论,分析了耕地重心移动的驱动因子,提出了土地持续利用的几点建议。 相似文献
196.
The multistage concept is explained and illustrated, with particular reference to a bornhardt from the southern Yilgarn Block of southwestern Western Australia. Hyden Rock is a complex inselberg developed on Archaean granite. It probably developed through fracture-controlled differential subsurface weathering in the Cretaceous, followed in the Eocene by erosion of the lateritic regolith and exposure of the massive compartment as an inselberg. But the variations in fracture density to which Hyden Rock owes its origin developed long before the Cretaceous, probably in the latest Archaean or earliest Proterozoic. The relief amplitude of the residual has increased through the Cainozoic.
A rich assemblage of minor forms (basins, runnels, tafoni, pitting, displaced slabs, A-tents) is developed on the bornhardt and, though their mode of development varies, the origin of many can be traced back to magmatic and tectonic events of Late Archaean and earliest Proterozoic times. Others were initiated at the weathering front during the later Mesozoic, and many have developed since exposure, beginning in the Eocene. A few are related to tectonism during the later Quaternary.
The residual is a multistage form. Its development as a major landform can be traced back some 120 million years, and the structures to which the outlines of the bornhardt, and those related to several minor features, originated in later Archaean times. The geomorphological evolution of landforms of the shield lands and cratons extends over vast ages and cannot be regarded as a geologically recent phenomenon. 相似文献
A rich assemblage of minor forms (basins, runnels, tafoni, pitting, displaced slabs, A-tents) is developed on the bornhardt and, though their mode of development varies, the origin of many can be traced back to magmatic and tectonic events of Late Archaean and earliest Proterozoic times. Others were initiated at the weathering front during the later Mesozoic, and many have developed since exposure, beginning in the Eocene. A few are related to tectonism during the later Quaternary.
The residual is a multistage form. Its development as a major landform can be traced back some 120 million years, and the structures to which the outlines of the bornhardt, and those related to several minor features, originated in later Archaean times. The geomorphological evolution of landforms of the shield lands and cratons extends over vast ages and cannot be regarded as a geologically recent phenomenon. 相似文献
197.
以深部地球物理资料为基础,介绍了天山地震带上地幔的基本结构,讨论了天山不同地区上地幔介质的动力学性质和可能的驱动机制。认为水平挤压形变是造成西天山和天山毗邻西昆仑附近区域上地幔岩石圈缩短和增厚的主要原因;而在中天山和东天山靠近准噶尔盆地南缘一带,除了板块运动造成的水平挤压力之外,上地幔热物质有可能上浮甚至侵入到地壳之中。它们与水平运动一样,对壳内脆性介质的构造活动起到非常重要的作用,特别是地壳底部莫霍面附近的低速滑脱层成为震源区深部构造的一个明显标志。此外,自从印度 亚洲大陆碰撞以来,天山部分地区固结冷却的山根有可能在多重挤压变形和小尺度热对流的共同作用下,脱离它们的原有的层位而沉入上地幔 相似文献
198.
Johan G. Borchert 《GeoJournal》1998,45(4):327-336
The retail system is continuously adapting itself to changing demographic conditions, consumer behavior and economic conditions.
Existing retail units, getting larger in order to achieve economics of scale, and new forms of large-scale retailing do not
fit easily in the traditional spatial pattern of retail concentrations. Neverteless the spatial distribution of retailing
in urban areas, as schematized by Berry thirty-five years ago, still has its value. Through an upward hierarchical movement
the retail system has adapted itself to an inflexible spatial system, in which downtown has still a dominant position. Future
developments, however, may weaken the position of central shopping areas in favour of peripheral locations.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
199.
豫北地区地震活动性及其与区域地壳运动的关系 总被引:3,自引:1,他引:2
本根据地震地质和地震分布条带,把豫北地区从西至东分为弱,中,强三个区段。由于区域地壳深部主断裂和大震活动的牵动作用,是造成本地震活动的重要原因,因而从区域地壳块体活动背景上探讨了本区及邻近地区地震活动趋势,中还指出,豫北西部太行山区的林县-薄壁地震带,虽不具有强震构造背景,但小震年月频率多寡和震群活动,却能反映了大区域地壳应力场强弱,亦可作为判断区域性地震活动的指标。 相似文献
200.