Petrological Characteristics And Its Tectonic Significance Of Shanxi Zuoyun Jiugaoshan-Inner Mongolia Zhuozi County Early Cretaceous Volcano Rock

The geotectonic location of the Early Cretaceous volcano rock in Jiugaoshan Zhuozixian county is located on the area which is in the west side of the North in The central zone of North China Craton that have been divided by Zhao G C. The discussion of this paper is major in these questions such as the matter source of magma、the structural environment and the earth dynamics of the Early Cretaceous volcano rock in Jiugaoshan Zhuozixian county, these are all based on the field geological work, specifically, by analysing of the field geological features、petrological characteristics and the geochemical characteristics of the Early Cretaceous volcano rock in Jiugaoshan Zhuozixian county.The volcano rock in Jiugaoshan Zhuozixian county is the volcano action which have the same period. The Jiugaoshan volcano rock which is located on the grayish purple and aubergine conglomerate rock of The lower Cretaceous Zuoyun group belong to the time of the Early Cretaceous. The age of the K-Ar isotopes of the volcano rock in Zhuozixian county is126-139Ma, is the same with the Early Cretaceous.Jiugaoshan early Cretaceous volcanic rocks is a suit of dense basaltic andesite and stomata, almond-shaped basaltic andesite, it can be divided into four cycles eruption, volcanic eruption is quiet spillway. Zhuozi County Early Cretaceous Bainvyangpan group volcanic’s volcanism may be divided into three stages:the early are mainly basalt and pores, almond-shaped basalt; the middle stage volcanic rocks is rhyolitic tuff breccia frit, rhyolitic ignimbrite, rhyolitic tuff breccia sintered mainly Central interbedded with rhyolite; late volcanic rocks are rough crystal tuff. Early, volcanic eruption is quiet, middle and late explosive eruption are explosive eruption,but the quiet type is along with the course of explosive eruption.Jiugaoshan early Cretaceous volcanic rocks is a set of high-K calc-alkaline and quasi-alumina based intermediate-basic volcanic rock.Zhuozi County early Cretaceous volcanic rocks is a set of basic-ultrabasic rock and quasi-alumina based alkaline basalt.Chondrite-normalized rare-earth element pattern is right deviation enriched lightrare earth.It don’t have typical crust vee allocation model.Ce anomalies and Eu anomalies are not obvious.It indicates that crystallization differentiation didn’t happen and have congeniality congeniality provenance in magmatic process.The elements of Rb、Ba、Sr、Nd、Zr、Sm、 Yb are more enrichment than primitive mantle and the elements of Ta、Pb、Y、 Lu are deficit to primitive mantle. Magma substance is derived from the highly mixed of material component and crust material component,and the crust material may be more proportion.Controlled by the Late Mesozoic that the subduction of paleo-Pacific Plate to Eurasian Plate,above the Jiugaoshan-ZhuoZi county mantle uplift region, The earth’s crust some intracontinental rifting Led to partial melting of upper mantle and lower crust material mixing Occur in the basic volcanic eruption Formed the volcanic rocks of Early Cretaceous age in Jiugaoshan-ZhuoZiXian. Proved that JiUgaoshan-ZhuoZi county area of Inner Mongolia happened deep intense tectonic-magmatic activity.