By the latter part of the nineteenth century coarse-grained picrite, and other doloritic rock types were being extracted from William Lawson s estate on the west and north sides of the Hill.
12.
By 1988, 93 examples of these implements had been identified and it should be noted that all of these implements have shaftholes for hafting and there are no examples of picrite being used to produce axes.
13.
The circle is north of Bishop's Castle, north of Corndon Hill over the Welsh border in the small village of White Grit and within a few miles of the Late Neolithic-Early Bronze Age picrite stone axe factory of Cwm-Mawr.
14.
The olivine-rich picrite basalts that occur with the more common tholeiitic basalts of K + lauea and other volcanoes of the Hawaiian Islands are the result of accumulation of olivine crystals either in a portion of the magma chamber or in a caldera lava lake.
15.
The name " picrite " can also be applied to an olivine-rich alkali basalt : such picrite consists largely of phenocrysts of olivine and titanium-rich augite pyroxene with minor plagioclase set in a groundmass of augite and more sodic plagioclase and perhaps analcite and biotite.
16.
The name " picrite " can also be applied to an olivine-rich alkali basalt : such picrite consists largely of phenocrysts of olivine and titanium-rich augite pyroxene with minor plagioclase set in a groundmass of augite and more sodic plagioclase and perhaps analcite and biotite.
