METAMORPHIC AND IGNEOUS ROCKS OF THE MERRIMAC AREA, PLUMAS NATIONAL FOREST, CALIFORNIA
METAMORPHIC AND IGNEOUS ROCKS OF THE MERRIMAC AREA, PLUMAS NATIONAL FOREST, CALIFORNIA
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加利福尼亚州普拉玛斯国家森林梅里马克地区的变质岩和火成岩
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发表时间：
1951
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通讯作者：
A. Hietanen
中科院分区：
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作者：
A. Hietanen
内华达山脉北部地区的前花岗质岩石由变质沉积和火山系列组成，年龄从石炭纪到侏罗纪不等。同动的超基性侵入岩，现在是蛇形岩，对这些岩石进行了协调或不协调的切割。玄武岩-英安岩、钠流纹岩等岩浆系列与正常的玄武岩-流纹岩系列一起在变质火山岩中发育。内华达山脉系列较年轻的侵入岩，从辉长岩到花岗闪长岩和花岗岩，与变质火山系列具有很大的化学相似性。此外，在前花岗质侵入岩和较年轻的脉岩中，普遍存在富钠段。前花岗质岩石在花岗闪长岩和花岗岩基侵位之前，褶皱变质为绿片岩和绿帘石角闪岩相。后期的接触变质作用影响了靠近岩心岩体接触的区域，导致石榴石、透辉石、绿帘石和红柱石等矿物结晶。深成岩获得了所需的空间，部分原因是将乡村岩石推到一边，部分原因是通过回采和同化作用。
The pre-granitic rocks of an area in the northern Sierra Nevada consist of metamorphosed sedimentary and volcanic series ranging in age from Carboniferous to Jurassic. Synkinematic ultrabasic intrusives, now serpentines, cut these rocks concordantly and discordantly. Magmatic series ranging from basalt to dacite and soda-rhyolite occur together with the normal basalt-rhyolite series among the meta-volcanics. The younger intrusives (Sierra Nevada series), ranging from gabbros to granodiorites and granites, show great chemical similarity to the meta-volcanic series. Furthermore, soda-rich members are common among the pre-granitic intrusives and younger dike rocks. The pre-granitic rocks were folded and metamorphosed to green schist and epidote-amphibolite facies prior to emplacement of granodiorite and granite batholiths. The later contact metamorphism affected the areas next to the contacts of the batholitic intrusions, causing crystallization of such minerals as garnet, diopside, epidote, and andalusite. The plutonic rocks obtained the space needed partly by pushing the country rocks aside and partly by stoping and assimilation.