博格达山南坡黑沟冰川融水径流     

胡小刚  邓世明 《冰川冻土》1990,12(1):71-82

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大洪山区钾镁煌斑岩的矿物特征及含矿性探讨     

王留海 《矿物岩石》1991,11(4):51-56

本文分析了大洪山区钾镁煌班岩中的矿物特征,利用造岩矿物和副矿物的电子探针分析结果与西溴含金刚石钾镁煌斑岩中相应矿物进行对比。并用特征副矿物镁铝榴石、铬铁矿的化学成分作Cr_2O_3—CaO图,Cr_2O_3-MgO图,利用Cr/(Cr+Al)的比值参数,判别岩体的含矿性。认为该区钾镁煌斑岩目前虽然尚未发现金刚石,但成矿有利因素较多。  相似文献   

陕西北秦岭中段构造应力场的初步研究   总被引：6，自引：0，他引：6  

徐文龙 《地震地质》1991,13(2):161-172

于华北板块南缘的北秦岭中段,在系统测量微断层的位移参数的基础上,通过采用滑动矢量拟合法,获得了该区自新生代以来的三期构造应力场的平均应力张量。三期应力场的方向及性质分别为:(1)以280°—310°方向拉伸为主的松弛期;(2)以305°—336°方向挤压为主的压缩期;(3)以294°—340°方向拉伸为主、辅以21°—68°方向挤压的现代扩张期。研究表明,最新一期即第三期构造应力场的特征与华北板块的区域构造应力场特征是基本一致的  相似文献   

喀喇昆仑山克勒青河谷冰川冰岩界面特征的初步研究   总被引：2，自引：0，他引：2  

唐建成  何元庆 《冰川冻土》1991,13(4):331-336

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西秦岭北缘断裂带新活动特征   总被引：27，自引：2，他引：27       下载免费PDF全文

滕瑞增  金瑶泉  李西候  苏向州 《地震工程学报》1994,16(2):85-90

在本文中，作者在近几年进行的大比例尺活断层地质填图工作的基础上，介绍了西秦岭北缘断裂带晚第四纪以来活动的基本待征，研究了该断裂带的空间展布情况、几何学和运动学特征、断层活动速率、古地震与地震重复周期等。结果表明，该断裂带自第四纪以来由压性逐渐演变为左旋扭动，其水平滑动速率为２．１－２．８ｍｍ／年，垂直滑动速率为０．４－０．７ｍｍ／年，地震复发周期约为５０００年。  相似文献   

安徽大别山北部红刚玉岩石的成因     

孙先如  周作祯 《岩石学报》1994,10(3):275-289

大别山北部红刚玉矿产在太古代大别山群黑云角门外长片麻岩以及超基性岩中。赋存红刚玉的刚玉黑云二长片麻岩的原始岩石为富铝泥质岩，在角门岩相变质条件下，通过两种脱硅方式，即变质分异作用和超基性岩侵位，形成刚玉黑云二长片麻岩。它们形成的温压条件：Ｔ＝５００℃～７００℃，Ｐ＝０．４～０．７ＧＰａ。刚玉形成的可能的化学机制是白云母在缺硅条件下的分解。  相似文献   

Comparison between Pollutant Concentration in the Samples of Fog and Rime Water Collected at Mt. Milešovka     

Fišák  Jaroslav  Řezáčová  Daniela 《Studia Geophysica et Geodaetica》2001,45(3):319-324

The article aims at showing the differences in concentration of pollutants that are contained in the samples of fog and/or low cloud water in comparison with the water from rime. The results follow from the fog and rime measurements made at Mt. Mileovka (eské Stedohoí Mountains). They are compared with the results of other studies that also report the differences in fog and rime chemistry.  相似文献   

Tracing infiltration and recharge using stable isotope in Taihang Mt., North China   总被引：3，自引：0，他引：3  

Fadong Li  Xianfang Song  Changyuan Tang  Changming Liu  Jingjie Yu  Wanjun Zhang 《Environmental Geology》2007,53(3):687-696

The groundwater in headwater region is an important recharge source for the adjacent mountain-front plain. In order to reveal the relationship among precipitation, soil water and groundwater, from June to September in 2004, stable isotopes (deuterium and oxygen-18) in precipitation and soil waters at the depths of 10, 20, 30, 50, 70, 90, and 110 cm were analyzed at two sites covered by black locust (Robinia Pseudoacia L.) (Site A) and grass predominated by Themeda triandra (T. japonica (Willd.) Tanaka) and Bothriochloa ischaemum (B. ischaemum (L.) Keng) (Site B) in an experimental catchment at Taihang Mt., North China, respectively. The δ¹⁸O of precipitation in daily rain events shows large variations (−13.3 to −4.3‰) with a mean of 8.1‰. The δ¹⁸O and δ D of soil waters along profiles in two sites suggest that the influence of canopy cover was just up to 10 cm in top soil water. The soil water moved over the zero flux plane at 70 cm in-depth is expected to escape the evaporative effect at the end of September in both sites. The results show that the stable isotope, instead of tritium as tradition, can be used to trace the soil water behaviors based on the movement of isotopic peak along the vertical profiles in this semi-arid and semi-humid mountainous region. The infiltration depths of soil water in Taihang Mt. are 12 and 10 mm/day from June to September in 2004 in Site A and Site B, respectively. Tracing by stable isotope, recharge fluxes of soil water to local groundwater are of 3.8 and 3.2 mm/day in Site A and Site B, respectively. The results provide desirable information for assessment of local groundwater resources. An erratum to this article can be found at  相似文献   

On Continent-Continent Point-Collision and Ultrahigh-Pressure Metamorphism   总被引：4，自引：0，他引：4  

DONG Shuwen  Chinese Academy of Geological Sciences  Baiwanzhuang Ro  Beijing WU Hongling  LIU Xiaochun  XUE Huaimin Institute of Geomechanics  Chinese Academy of Geological Sciences  Beijing Fei Zhenbi 《《地质学报》英文版》2002,76(1):69-80

Up to now it is known that almost all ultrahigh-pressure (UHP) metamorphism of non-impact origin occurred in continent-continent collisional orogenic belt, as has been evidenced by many outcrops in the eastern hemisphere. UHP metamorphic rocks are represented by coesite- and diamond-bearing eclogites and eclogite facies metamorphic rocks formed at 650-800℃ and 2.6-3.5 GPa, and most of the protoliths of UHP rocks are volcanic-sedimentary sequences of continental crust. From these it may be deduced that deep subduction of continental crust may have occurred. However, UHP rocks are exposed on the surface or occur near the surface now, which implies that they have been exhumed from great depths. The mechanism of deep subduction of continental crust and subsequent exhumation has been a hot topic of the research on continental dynamics, but there are divergent views. The focus of the dispute is how deep continental crust is subducted so that UHP rocks can be formed and what mechanism causes it to be subducte  相似文献   

大别造山带白马尖花岗岩体的钕，锶同位素地球化学研究   总被引：2，自引：1，他引：2       下载免费PDF全文

葛宁洁  柏林等 《地质论评》2001,47(2):184-187

大别造山带白马尖花岗岩体属燕山期侵入岩，为中生代大别山区岩浆活动的产物，为碰撞后花岗岩，锶，钕，同位素数据及稀土元素数据表明，白马尖花岗岩体为壳幔混合型，1．2－1．7Ga的钕模式年龄为其源岩的平均地壳存留年龄，北大别花岗岩类岩石的物质来源并不一致。  相似文献