Triassic-Jurassic sediments and multiple volcanic events in North Victoria Land, Antarctica: A revised stratigraphic model
Triassic-Jurassic sediments and multiple volcanic events in North Victoria Land, Antarctica: A revised stratigraphic model
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南极洲北维多利亚陆地的三叠纪-侏罗纪沉积物和多次火山事件：修订后的地层模型
DOI：
10.3133/ofr20071047srp102
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发表时间：
2007
影响因子：
1.6
通讯作者：
B. Bomfleur
中科院分区：
文献类型：
--
作者：
R. Schöner;L. Viereck;J. Schneider;B. Bomfleur
GANOVEX IX（2005/2006）期间在南极洲北维多利亚地进行了实地调查，对晶体基底和费拉群Kirkpatrick熔岩流之间约300 m厚的大陆沉积物的三叠纪-侏罗纪地层进行了修订。下地层单元（断面峰组）以辫状河型石英砂岩矿床为特征，顶部为页岩和煤夹层。它的上覆层是由细粒硅屑、石英和长石组成的均匀凝灰岩（新名称：“谢弗峰组”）。这些矿床可以与中横越南极山脉的汉森组的部分地层相关联，需要一个远端但未知的大规模硅火山活动来源。基性火山喷发的碎屑产物，以前被描述为一个单独的地层（暴露山组），出现在局部的地层构造中，以及在沉积演替中的不同地层层间穿插。这些主要的水碎屑喷发是费拉尔岩浆活动的第一次陆上表现。最初的柯克帕特里克熔岩/枕状熔岩是由当地的喷发中心产生的，并且可能再次被薄沉积物覆盖，这些沉积物被贯穿南极横贯山脉的厚厚的高原熔岩序列所覆盖。
Field investigations in North Victoria Land, Antarctica during GANOVEX IX (2005/2006) allow the revision of the Triassic-Jurassic stratigraphy of ~300 m thick continental deposits in between the crystalline basement and the Kirkpatrick lava flows of the Ferrar Group. The lower stratigraphic unit (Section Peak Formation) is characterised by braided river-type quartzose sandstone deposits with intercalations of shale and coal occurring at the top. It is overlain by a homogeneous unit of reworked tuffs composed of fine-grained silicic shards, quartz and feldspar (new name: "Shafer Peak Formation"). These deposits can be correlated with parts of the Hanson Formation in the Central Transantarctic Mountains and require a distal yet unknown source of massive silicic volcanism. Clastic products of mafic volcanic eruptions, formerly described as a separate stratigraphic formation (Exposure Hill Formation), occur within local diatreme structures as well as intercalated at various stratigraphic levels within the sedimentary succession. These dominantly hydroclastic eruptions are the first subaerial expression of Ferrar magmatism. The initial Kirkpatrick lavas/pillow lavas were generated from local eruptive centres and again may be overlain by thin sediments, which are covered by the thick plateau lava succession known throughout the Transantarctic Mountain Range.