Volcaniclastic rocks and volcaniclastic facies in the Middle Precambrian (Aphebian) Belcher Group, Northwest Territories, Canada
Volcaniclastic rocks and volcaniclastic facies in the Middle Precambrian (Aphebian) Belcher Group, Northwest Territories, Canada
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加拿大西北地区中前寒武纪（Aphebian）贝尔彻群的火山碎屑岩和火山碎屑相
DOI：
10.1139/e82-109
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发表时间：
1982
影响因子：
1.4
通讯作者：
J. Donaldson
中科院分区：
文献类型：
--
作者：
B. Ricketts;M. Ware;J. Donaldson
中前寒武纪弗莱厄蒂组由一层厚的喷发和喷发火山岩组成，起源于贝尔彻群岛以西的一个源区。喷涌火山相由厚的块状熔岩流组成，其中一些是复合熔岩流，它们与厚的透镜状枕状熔岩单元互插。火山碎屑岩为爆发相，是潜水和潜水岩浆喷发的产物。根据地层的几何形状、沉积结构和结构特征，可以识别出多种火山碎屑相，包括：由垂直火山灰柱的沉降物沉积而成的薄层凝灰岩和凤头石（有些凝灰岩含有增生凤头石，因此起源于地面喷发柱）；枕状石（透明质碎屑岩）是由熔岩在水中迅速淬火形成的；火山碎屑浊积岩代表相对较深的再沉积层；一股巨大的火山碎屑流…
The Middle Precambrian Flaherty Formation consists of a thick sequence of volcanic rocks of both effusive and explosive origin, derived from a source area west of the Belcher Islands. The effusive volcanic facies are made up of thick, massive lava flows, some of which are compound, that are intercalated with thick lenticular units of pillowed lava. Facies of explosive origin, the volcaniclastic rocks, are a product of phreatic and phreatomagmatic eruptions. A variety of volcaniclastic facies are recognized on the basis of bed geometry, sedimentary structures, and textural characteristics, and include: thinly bedded tuffs and lapillistones that were deposited by fallout from vertical ash columns (some tuffs contain accretionary lapilli and hence originated from subaerial eruption columns); pillow talus deposits (hyaloclastites) resulting from the rapid quenching of lava in water; volcaniclastic turbidites representing relatively deep-water resedimented tephra; and a single massive pyroclastic flow that was...