The finest (< 5 [micro]m) groundmass
serves as a matrix for scattered grains > 5 [micro]m in size.
39]Ar analysis of groundmass
plagioclase sample D1-1 was carried out at the Vrije Universiteit (VU) in Amsterdam using the VULKAAN [sup.
Many of the river cobbles collected often had very irregular surfaces, where the phenocrysts jut out from the eroded groundmass
In addition, powder x-ray diffraction analysis of a coprolite sample indicates that the groundmass
consists of calcium phosphate.
This breccia consists of a groundmass
of chrysotile [+ o -] antigorite [+ o -] chlorite within which irregular millimetric--to decametric-sized bodies of serpentinized harzburgite appear here and there.
The respective values for the groundmass
of the inside-crater crystalline-derived breccia matrix range from -27.
It is characterized by a wide range of very low-grade, low-grade, and rare medium-grade metamorphic rock fragments, set in a groundmass
rich in mica laths and quartz grains.
Despite the inclusion of statements such as 'all contain sanidine in the groundmass
as well as significant amounts of plagioclase .
Anil points out that "Webster's 2nd defines pilandite as 'a leucocratic porphyry with phenocrysts, a groundmass
of anorthoclase, and a little amphibole" and adds "Well at least I know what 'a', 'with', 'of', 'and', and 'little' mean.
They have a speckled, densely granular appearance due to a combination of colorless lipid droplets, <6 [micro]m diameter, set in a magenta-stained yolk groundmass
often contains plagioclase phenocrysts, several millimetres, sometimes up to 1 cm in size.
The most common groundmass
texture is intergranular, with seriate, very fine- to coarse-grained, finely albite twinned and tapered labradorite laths, stubby augite prisms, subequant olivine grains and platy to equant opaque grains.