Jurassic–Cretaceous rock units along the southern edge of the Wrangellia terrane on Vancouver Island
Jurassic–Cretaceous rock units along the southern edge of the Wrangellia terrane on Vancouver Island
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温哥华岛兰格利亚地体南缘的侏罗纪-白垩纪岩石单元
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
D. Cowan
中科院分区：
文献类型：
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作者：
M. Rusmore;D. Cowan
以前被标绘为利奇河组的岩石可以被细分为两个具有完全不同历史的部分同时代岩石单元。上侏罗纪-下（？）白垩纪潘多拉峰单元可能沉积在大陆边缘的小盆地中，包括黑色泥岩、陆源杂砂岩、放射虫带状硅质岩、绿色凝灰岩、变基性绿岩、少量含砾泥岩和少量石灰岩。局部地层破裂发生在沉积物石化之前。一个静态的，高压，低温变质作用产生的硬铝石组合在变质岩石。潘朵拉峰单元最初与西温哥华岛的环太平洋复合体和华盛顿的圣胡安群岛的宪法形成共同延伸。利奇河杂岩由片理变砂岩、千枚岩和可能为侏罗纪-白垩纪的小型变玄武岩组成。多褶皱，换位，和同运动绿片岩-角闪岩相变质作用的高潮。
Rocks formerly mapped as Leech River Formation can be subdivided into two partly coeval rock units with completely different histories. The Upper Jurassic – Lower(?) Cretaceous Pandora Peak unit, which comprises black mudstone, terrigenous greywacke, radiolarian ribbon chert, green tuff, metabasaltic greenstone, minor pebbly mudstone, and a few blocks of limestone, was probably deposited in small basins on a continental margin. Local stratal disruption occurred before sediments were lithified. A static, high-pressure, low-temperature metamorphism produced lawsonite-bearing assemblages in metaclastic rocks. The Pandora Peak unit was originally coextensive with the Pacific Rim complex on western Vancouver Island and the Constitution formation in the San Juan Islands of Washington. The Leech River complex consists of foliated metasandstone, phyllite, and minor metabasalt of probable Jurassic–Cretaceous age. Multiple folding, transposition, and synkinematic greenschist- to amphibolite-facies metamorphism culm...