排序方式: 共有17条查询结果,搜索用时 640 毫秒
11.
New evidence of tectonic uplift and transform of movement style along Ailao Shan-Red River shear zone 总被引:3,自引:1,他引:3
Using cooling curves of K-feldspars obtained by specific40Ar/39Ar step heating procedure and multiple diffusion domain modeling (MDD model), together with results of dating hornblende,
biotite, muscovite, and apatite, this research relates the cooling history of 3 areas, from Ejia in NWto Jinping in SE of
Ailao Shan-Red River shear zone, and near Hekou (distance about 390 km). The results indicate that the slip distance of Ailao
Shan-Red River shear zone is more than 350 km (at least based on the study done within China). And between the end of the
left-lateral slip movement and the beginning of the right-lateral slip movement, the uplift of shear zone from SE to NW was
homogeneously extended. 相似文献
12.
Olujide Omotosho 《Geotechnical and Geological Engineering》2004,22(3):351-359
This paper uses a deltaic lateritic soil sample to study the combined influence of total gravel composition and gravelly exclusion
on compaction parameters MDD (or maximum dry density) and OMC (or optimum moisture content) derived from standard laboratory
compaction tests. In the end, MDD was found to vary polynomially with percentage of gravelly exclusion with improved or higher
values as total gravel composition increases. OMC on the other hand was found to decrease continually with increasing gravelly
exclusion but independent of the total gravel composition. Also, a model was presented in form of a family of curves to predict
actual or field compaction parameters (which is devoid of gravelly exclusion) and their laboratory counterparts.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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14.
西秦岭北缘中生代构造活动的^40Ar/^39Ar、FT热年代学证据 总被引:7,自引:3,他引:7
钾长石MDD和磷灰石裂变径迹研究表明,西秦岭北缘地区存在2次区域性快速冷却事件,分别为约230~210MaB.P.和约140~120Ma B.P.。约230~210Ma B.P.的快速冷却事件可能反映西秦岭秦岭洋于印支期闭合,发生了大规模的岩浆侵入活动,以及随后造山带迅速褶皱、隆升事件;140~120Ma B.P.的快速冷却事件与西秦岭北缘断裂以北的白垩纪盆地发育的时间一致,可能与西秦岭北缘隆升,同时其以北地区形成巨大的盆地有直接关系。同时,该事件与燕山运动主幕发生的时间一致,说明中燕山期我国东西部广大区域普遍存在一次构造运动。 相似文献
15.
青藏高原北缘中生代伸展构造^40Ar/^39Ar测年和MDD模拟 总被引:15,自引:1,他引:15
陈宣华 尹安 George E. Gehrels 王小凤 Eric S. Cowgill Marty Grove T. Mark Harrison 陈正乐 《地球学报》2002,23(4):305-310
沿着青藏高原北缘的阿尔金山脉东段 ,发育了长度大于 30 0km、EW走向的拉配泉断裂。中美合作阿尔金课题组的地质填图结果表明 ,该断层实际上是一条南倾的正断层 ,局部倾角可以低至 30°以下。沉积学和热年代学研究控制了拉配泉断裂的活动时代 :早—中侏罗统地层可以解释为断裂上盘的伸展盆地沉积 ;下盘岩石中钾长石40 Ar/ 3 9Ar测年和MDD模拟给出 2个阶段的冷却事件 ,早期事件出现在约 2 2 0~ 187Ma之间 ,晚期事件出现在早白垩世晚期 (约 10 0Ma)。早期事件代表了拉配泉断裂正断作 相似文献
16.
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
17.
George GEHRELS 《《地质学报》英文版》2004,78(2)
This paper discusses the relationships between granitic magmatism and gold mineralization and the exhumation history of the Dapinggou gold deposit in northern Altun, NW China based on the geochronological data, including zircon U-Pb ages, Rb-Sr isochron age and 40Ar-39Ar dating and MDD modeling data. The main granitic magmatism age in this area is attained from the ID TIMS U-Pb geochronology of zircons from the Kuoshibulak granite, the biggest granite in the northern Altun area, which gives a concordant age of 443±5 Ma in the Late Ordovician. Zircon ID TIMS U-Pb geochronology of the West Dapinggou biotite granite west of the Dapinggou gold deposit gives concordant ages around 485±10 Ma, representing the early stage of Ordovician magmatism. The Rb-Sr isochron age (487±21 Ma) of 6 quartz inclusion samples from quartz veins in this gold deposit is very close to that of the West Dapinggou granite. MDD modeling of step heating 40Ar-39Ar data of K-feldspar from the same West Dapinggou biotite granite gives 相似文献