The veins occupy northwest-striking fractures that cut volcanic rocks, microdiorite and felsite
porphyry of the Cretaceous-age Tip Top Hill Formation.
Carbonate-Rich Albitite and Albitite Felsite
. The carbonate-rich albitite consists of fine to medium grains of near end-member albite ([Ab.sub.97-100]), calcite, and dolomite (Figure 4(d)).
The Braithwaites though-they've gotten wind of the outing and are planning to join with their little semihellions, Felsite
Age of the Tinto felsite
, Lanarkshire: a possible [sup.39]Ar-40Ar monitor.
Potassium feldspar is also scarce in felsite
clasts in this part of the section.
The 16 papers here discuss such matters as the felsite
quarry complex of Northmaven in Scotland, new discoveries at the Mynydd Rhiw axehead production site, seamer axeheads in southern England, obsidian in the Near East during the Halaf period as a case study on why people use exotic raw material, interpreting evidence for prehistoric conflict, and ideology and context within the European flint-mining tradition.
Rare earth element deposits in inferred felsite
(1968) The Rooiberg Felsite
north of Middelburg and its relation to the layered sequence of the Bushveld Complex.
Perhaps we should associate the appearance of the felsite
bar whetstone in Period sub-III with this development of polished slate.
The seams are virtually flat throughout the area, but are locally intruded by felsite
domes, which reduce the overall reserve.
These intermediate-felsic hypabyssal rocks are mainly composed of quartz porphyry, granite porphyry, granite, felsite
, granodiorite, quartz monzonite, and diorite porphyry.
Fletcher (1881, 1884) divided the mountain into a "central slate series" surrounded by "syenite" and "felsite
", unconformably overlain by Devonian sedimentary rocks.