alteration type
TRANSCRIPT
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DI SUSUN OLEH :KURNIA SETIAWAN WIDANA
NIM : 22010002
MAGISTER TEKNIK GEOLOGIINSTITUT TEKNOLOGI BANDUNG
2010
TUGASALTERASI BATUAN
TIPE-TIPE ALTERASI DAN KENAMPAKAN SAYATAN TIPIS
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ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPH
ARGILLIC Kaolin, Montmorillonite, Quartz, Cristobalite, Pyrite,
Calcite, Chalcedony, Zeolite, Adularia
Cristobalite
Zeolite
The oval feature in this photomicrograph is an amygdule: a formerly open vesicle which has been filled with a secondary
mineral(s) precipitated from low-T ground waters which have penetrated into the
rock. In this case, the amygdule is probably filled with a zeolite mineral.
Clay Mineral
Plagioclase altered to clay mineral (kaoline/montmorillonite)
Cristobalite
Opal
Opal
Cristobalite
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ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPHS
ADVANCE ARGILLIC
Kaolin, Pyrophyllite, Dickite, Alunite,
Quartz, Topaz, Tourmaline
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ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPHS
POTASSIC K-Feldspar, Biotite, Sericite, Chlorite,
Quartz, Magnetite, Hematite, Anhydrite,
Albite, Epidote, Actinolite
Biotite
In this photomicrograph, euhedral to subhedral biotite and plagioclase crystals are
surrounded by optically-continuous, gray-colored K-
feldspar.
Chlorite replacing Biotite
In this photo, a large "book" of
red-brown biotite is partially replaced by green chlorite.
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ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPHS
PHYLLIC/SERICITIC
Sericite, Quartz, Chlorite, Pyrite
Pyrite (reflected light microsope)
PyPy
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ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPHS
PROPYLITIC Chlorite, Epidote, Prehnite, Actinolite, Clinozoisite, Calcite,
Zoisite, Albite.
Actinolite
Low to medium grade amphibolite consisting essentailly of actinolite-tremolite. The large grain in the centre of the image displays two cleavages
which intersect at 56 - 124°.Field of view 2.7 mm, plane light