Triangular diagrams showing framework proportions of quartz, the two feldspars, polycrystalline quartzose lithics, and unstable lithics of volcanic and sedimentary parentage successfully distinguish the key provenance types ."
22.
Another group is rich in quartz ( quartzites, quartz schists and quartzose gneisses ), with variable amounts of white and black mica, garnet, feldspar, zoisite and hornblende.
23.
Cornish miners originally coined this term for hard, chemically and physically inert silica-cemented quartzose sandstones, commonly, but not always found as seatearths within English Carboniferous coal measures.
24.
The Goudini formation is more feldspathic and finer grained than the Skurweberg Formation, which is characterised by fairly thick bedded medium to coarse grained, light grey, slightly feldspathic quartzose sandstone.
25.
Between, the lower part of the North Col Formation consists of biotite-quartz schist intercalated with epidote-quartz schist, biotite-calcite-quartz schist, and thin layers of quartzose marble.
26.
This term is now used for similar quartzose sandstones found typically as seatearths in the Carboniferous coal measures of Nova Scotia, the United States, and the Triassic coal-bearing strata of the Sydney Basin in Australia.
27.
Erected in the early fourteenth century B . C . as guardians of the Mortuary Temple, the two 50-foot monoliths consist of a quartzose sandstone rock ( quartzite ) formed by quartz particles cemented with iron oxide.
28.
The Mahnomen Formation has a lower member, which lacks iron oxide components, and an upper member dominated by beds of iron oxide argillite and lean iron-formation interlayered with non-iron oxide argillite, siltstone and quartzose sandstone.
29.
The geological formations are categorized under four heads namely, the ( 1 ) Archeans ( the gneisses ), ( 2 ) the Eparchean unconformity ( Quartzose sandstones Overlying the granite with a distinct unconformity ), ( 3 ) Puranas ( formation of Cuddapah group well developed in the valley ) and ( 4 ) Quaternary deposits.
30.
They are commonly hollow and / or branching assemblages of glassy, protocrystalline, and heterogeneously microcrystalline tubes, crusts, slags, vesicular masses, and clusters of refractory materials that often form during the discharge phase of lightning strikes propagating into silica-rich quartzose sand, mixed soil, clay, caliche and other carbonate-rich sediments.
