Unlike at Petit Anse, however, at Alderney Point the unconformity is between arkosic sandstone
of the upper part of the Glenkeen Formation, overlain by angular boulder conglomerate of the Horton Group containing abundant clasts of the Glenkeen sandstone, both containing potassium feldspar.
The member was composed predominantly of coarse-grained, light-colored, cross-bedded arkosic sandstone
and minor boulder beds.
The reservoir consists of arkosic sandstone
including interbeds of siltstone and shale (claystone).
1) with the conglomeratic arkosic sandstone
of the Chalky Buttes Member (CBM) of the Chadron Formation (White River Group), which is exposed at numerous buttes in the North Dakota-South Dakota-Montana tri-state area (2).
King (1990) described the stone as a medium- to thick-bedded, red, arkosic sandstone
having thin to medium interbeds of siltstone, mudstone, intraformational breccia, red conglomerate and green sandstone.
The rock units are the same Triassic black shales and arkosic sandstone
, overlain by shale fragment breccias and tertiary tuffs, and there is extensive silification and argillic alteration.
The study site is underlain by carbon-rich shale and arkosic sandstone
of the Late Mississippian Horton Bluff Formation and the arenaceous sandstone of the Triassic Wolfville Formation.
Coarse red arkosic sandstone
a few metres thick at Miller Pond Road rests on a basement of Late Ediacaran rocks east of the basin.
The uranium mineralization can be divided into two types: (1) carbon and pyrite-related quartz sandstone type and (2) hematite arkosic sandstone
Although they originally had a high feldspar content, some of the arkosic sandstones
underwent diagenetic alteration that removed the feldspars, resulting in an elevated quartz content (Kyle and McBride, 2014).
The formation can range in thickness from ten to fifty meters of interbedded shale and arkosic sandstones
The Indicator Group is composed of sub-arkosic to arkosic sandstones