Download - Alteration Type
DI SUSUN OLEH :KURNIA SETIAWAN WIDANA
NIM : 22010002
MAGISTER TEKNIK GEOLOGIINSTITUT TEKNOLOGI BANDUNG
2010
TUGASALTERASI BATUAN
TIPE-TIPE ALTERASI DAN KENAMPAKAN SAYATAN TIPIS
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
ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPHS
ADVANCE ARGILLIC
Kaolin, Pyrophyllite, Dickite, Alunite,
Quartz, Topaz, Tourmaline
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.
ALTERATION TYPE
MINERAL TYPES THIN SECTION PHOTOMICROGRAPHS
PHYLLIC/SERICITIC
Sericite, Quartz, Chlorite, Pyrite
Pyrite (reflected light microsope)
PyPy
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