приклади
The siltstones contain poorly sorted angular fragments of quartz, and angular clasts and cleavage fragments of plagioclase and alkali feldspar.
This is substantiated by the presence of eroded Permian carbonate clasts .
The clasts in volcaniclastic rocks may range from fine ash to bombs and enormous blocks.
The conglomerates contain a mixture of basement-derived clasts and large Upper Permian limestone clasts .
Geochemical analyses of these clasts show that the eruption tapped two chemically distinct rhyolitic magmas.
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