Anatomy of a large-scale braid-plain quartzarenite from the Neoproterozoic Shaler Group, Victoria Island, Northwest Territories, Canada
Anatomy of a large-scale braid-plain quartzarenite from the Neoproterozoic Shaler Group, Victoria Island, Northwest Territories, Canada
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加拿大西北地区维多利亚岛新元古代页岩群大型辫状平原石英岩的解剖
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发表时间：
1992
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通讯作者：
R. Rainbird
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作者：
R. Rainbird
新元古代Kuujjua组是一个厚达120 m的结构未成熟石英砂岩，其典型特征为简单和复合平面交错层理的横向持久板状平面陪衬，夹有数十公里宽的稀有薄硅质粉砂岩透镜体。 它被解释为一条大河的存款，占据了一个辫状平原，至少150公里宽，从东南流入阿蒙森盆地。 该存款的主要元素是堆叠板状和横向连续的复合交错层，解释为非常大的通道形式，主要通过叠加的小型到中型的二维沙丘的侧向加积迁移。简单的平面交错层理代表了沉积在河道中的中等至大型的二维周期性底形。罕见的槽状交错层理代表三维沙丘，可能是在切割较大床型的狭窄低级斜槽中沉积的。白云质粉砂岩透镜体被解释为大流量的沉积物。
The Neoproterozoic Kuujjua Formation is an up to 120 m thick, texturally submature quartzarenite typified by laterally persistent tabular planar cosets of simple and compound planar crossbedding, intercalated with rare, thin dolomitic siltstone lenses up to tens of kilometres wide. It is interpreted as the deposit of a big river, occupying a braid plain, at least 150 km wide, which flowed into the Amundsen Basin from the southeast. The dominant elements of this deposit are stacked tabular and laterally continuous compound crossbeds, interpreted as very large channel forms, which migrated mainly by lateral accretion of superposed small- to moderate-scale two-dimensional dunes. Simple planar crossbedding represents moderate to large two-dimensional periodic bedforms deposited in channels. Rare trough crossbedding represents three-dimensional dunes, which probably were deposited in narrow low-stage chutes that cut across the larger bedforms. Dolomitic siltstone lenses are interpreted as deposits of large flo...