摘要
对河南鹤壁尚峪新生代橄榄霞石岩火山颈中的上地幔橄榄岩捕虏体的流变学进行了研究．结果表明，鹤壁地区新生代辉石地温总体上低于东南沿海及下扬子地区，有两种地温特征．其中全部尖晶石二辉橄榄岩及个别方辉橄榄岩的投影点落在大洋地温曲线上，甚至高于大洋地温，与中国东部新生代辉石地温特征吻合；而多数尖晶石方辉橄榄岩的投影点靠近地盾地温曲线或落在地盾地温曲线上；全部金云母方辉橄榄岩的投影点低于地盾地温．样品的差异应力（２０～３４ＭＰａ）则普遍低于中国东部差异应力平均值（３０ＭＰａ）．应用流动速率及等效粘滞度与深度的数据投影，部分样品落于克拉通区，部分样品靠近大陆拉张带，同样也显示具有双重性特征．鹤壁的资料证实在该地区可能存在有古老克拉通岩石圈的残余。
The mantle peridotitic xenolithes in the volcanic neck of the Cenozoic olivine nephelinites in Hebi area,Henan Province,China,has been investigated.The temperature and pressure calculations indicate that the geotherm in the Hebi area is generally lower than that in the southeastern coastal area and Yangtze area and show two populations of geotherm.All of the spinel lherzolites and the part of the harzburgite projectedly fall on the oceanic geothem curve with a few of them above it.This is coincident with the geotherm of the Cenozoic in the eastem China.Howerer the phlogopite harzburgites and most of the spinel harzburgites are colse to or below the shield geotherm curve.In the diagram for relation between flow rate,equivalent viscosity and tectonic pattern in Hebi area,some points close to the continental extension zone and others fall on craton area showing a dual feature.Hebi area is located on the Daxing'anling-Taihangshan tectonic belt was in influenced prograssively by Pacific plate.In Paleozoic there was a thick,cooler lithosphere root and stablizes at a depth of 200km in North Cnina platform.Detained seismic topography and the study on Cenozoic basalt indicates that the lithosphere in<80km,thinning greatly from Cenozoic to the present.Obviously the lithosphere root has been destroyed.Thus,the question arise:whether any ancient residual lithosphere blocks still remain beneath eastern China?We deduce that there should exist residue of the lithosphere of the ancient craton in this region with low geotherm and enrichment mantle.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
1996年第1期45-52,T001,共9页
Earth Science-Journal of China University of Geosciences
基金
国家自然科学基金
关键词
幔源包体
上地幔流变学
显微构造
河南
mantle xenolith,upper mantle rheology,microstructure,lithosphere root,Hebi area in Henan Province.
