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2 hits

  • Thumbnail for KBR16

    This thin section is noticeably layered with alternating lenticular zones of compositionally similar quartzofeldspathic layers of differing grain size. Plagioclase, k-feldspar, quartz and glass or clay are the identifiable mineral phases. This is described by Western Minerals Inc. as 'adinole, potassium-rich, with ?hercynite. From same type of situation as KRB15...Occurs above a conspicuous dolerite pegmatite.'

  • Thumbnail for KBR15

    According to Western Minerals Inc., this sample is a 'contact rock from sediment immediately above dolerite,…rock with quartz 'spots'–probably inverted from tridymite spherulites–in a matrix of devitrified glass with mullite and cordierite.' Due to the fine-grained nature of the sample, it is difficult to distinguish individual mineral phases in the allotriomorphic, equigranular, microcrystalline groundmass. The only noteworthy features in this thin section are the spherical, slightly coarser grained nodules with orange-brown rims.