山东蒙山侵入岩分布与岩性特征

Distribution and Property Characteristics of Intrusive Rocks in Mengshan Mountain in Shandong Province

以野外地质调查为基础,结合前人的岩石学和年代学成果,根据构造作用和岩浆活动,探讨了蒙山的侵入岩分布与岩性特征。蒙山地区地质构造复杂,岩层表现为韧性变形、剪切、岩浆侵入,岩浆活动具多旋回多期次的特点,侵入岩发育。蒙山的主体是距今2 700~2 500 Ma间三期大规模岩浆侵入活动形成的片麻状英云闪长岩、片麻状花岗闪长岩、二长花岗岩。2 750~2 600 Ma,万山庄序列超铁镁质—镁铁质侵入岩侵入,泰山序列TTG(Trondhjemite,Tonalite,Granodiorite)岩系侵位。大约2 600~2 500 Ma,先后有黄前序列西店子蛇纹岩,峄山序列中粒奥长花岗岩、片麻状粗中粒黑云母花岗闪长岩、中细粒斑状含黑云母花岗闪长岩,傲徕山、红门序列条带状黑云母二长花岗岩、中粒黑云石英闪长岩等侵入。之后,中元古代约1 621Ma牛岚辉绿岩呈脉状侵入,古生代约465Ma常马庄金伯利岩侵入。大规模的岩浆侵入活动和构造作用,使古陆核发生了多次巨变和反复锻造,形成了坚硬的刚性陆壳,塑造了多种地质遗迹和地质地貌景观。

On the basis of field geological survey, combining with petrology and chronology results of predecessors, according to the tectonism and igneous activity, distribution and property characteristics of intrusive rocks of Mengshan Mountain have been discussed. Mengshan Mountain area has complex geolog- ical structures. Magmatic activity has the characteristics of multi- stages and multi- cycles, and intrusive rocks develope well. The main body of Mengshan Mountain is composed of gneissic tonalite, gneissic granodiorite, monzonitic granite which formed by three periods of large scale magma intrusion activities in 2700 ~2500Ma. During 2750~2600Ma, super magnesia - mafic intrusive rock of Wanshanzhuang sequence and TTG （Trondhjemite, Tonalite, Granodiorite） rock series of Taishan sequence have been emplaced. About 2600~2500 Ma, Mengshan Mountain had been invaded by Xidianzi serpentine in Huangqian sequence, grain of trondhjemite, gneissic coarse grain biotite granodiorite, fine grain porphyritic biotite granodiorite in Yishan sequence, and banded biotite monzonitic granite and medium- grained dolomite quartz diorite in Aolaishan and Hongmen sequence successively. In the Mesoproterozoic period, about 1621Ma, Niulan diabase vein intruded in vein type. In the Palaeozoic period, about 465Ma, Changmazhuang kimberlite invaded. Large scale magma intrusion activities and tectonic action made ancient continent nucleus change greatly and forge repeatedly, formed a solid rigid continental crust,geological relics and landscape.