Photomicrographs of sample 33871 Totally altered feldspar with quartz. The feldspar has been ...

184 Pages·2011·53.53 MB·English

, \
Photomicrographs of sample 33871
Totally altered feldspar with quartz. The feldspar
has been replaced by clay and chalcedony. l6x, crossed
polarizers.
Vug lined by quartz. 40x, crossed polarizers.
, \
Photomicrographs of sample 33871
Totally altered feldspar with quartz. The feldspar
has been replaced by clay and chalcedony. l6x, crossed
polarizers.
Vug lined by quartz. 40x, crossed polarizers.
Photomicrographs of sample 33875
Euhedral phenocryst of quartz with resorbed corners.
16x, crossed polarizers.
Composite phenocryst consisting of sanidine and
plagioclase. 16x, crossed polarizers.
.
,

Photomicrographs of sample 35904
General texture of sample showing the extent
of alteration of the feldspars and biotite.
l6x, crossed polarizers.
Photomicrograph of sample 35905
Porphyry: Subhedral feldspar and quartz
phenocrysts are rimmed by a zeolite. Dark
patches in the groundmass is also the zeolite.
20x, crossed polarizers.
Photomicrograph of sample 35908
Zoned plagioclase with quartz, k-feldspar,
biotite, and hornblende in the granodiorite.
l6x, crossed polarizers.
~
Photomicrograph of sample 35909
Altered coarse grained biotite phenocryst
with subhedral to anhedral plagioclase, quartz,
and K-feldspar in the quartz latite porphyry.
l6x, crossed polarizers.
Photomicrograph of sample 35911
General texture of sample showing the extent
of alteration of the feldspars and the
interstitial occurrence of quartz. l6x, crossed
polarizers.
Photomicrograph of sample 35917
General texture of the quartz monzonite.
l6x, crossed polarizers.
r'
Photomicrographs of sample 35918
Chlorite cluster with intense argillization
and sericitization of adjacent plagioclase
grains. 64x, plane polarized light.
Same, crossed polarizers.