foliation and types

IN THE NAME OF ALLAH IN THE NAME OF ALLAH THE MOST BENEFICIENT THE MOST BENEFICIENT

ANDAND THE MOST MERCIFUL.THE MOST MERCIFUL.

Presented To:Presented To:Prof. Dr. Mirza Shahid BaigProf. Dr. Mirza Shahid Baig

Presented By:Presented By:

FAZAL ELAHI

Roll # 179

BS. Applied Geology

5th Semester

Evening “B”

2008-2012

Presentation TopicPresentation Topic

FOLIATION

FoliationFoliation

The layered structure common to metamorphic rocks. Planar arrangement of structural or textural

features in any rock type, but particularly that resulting from the alignment of constituent mineral grains of a metamorphic rock along straight or wavy planes. Foliation commonly occurs parallel to original bedding, but it may not be obviously related to any other structural direction. Foliation is exhibited most prominently by sheety minerals, such as mica or chlorite

Formation MechanismsFormation Mechanisms• Foliation is usually formed by the preferred

orientation of minerals within a rock • Alignment of tabular minerals in

metamorphic rocks, igneous rocks and intrusive rocks may form a foliation. Typical examples of metamorphic rocks include porphyroblastic schists

• Foliation may be formed by realignment of micas and clays via physical rotation of the minerals within the rock

orthogneiss, orthogneiss,

Schematic showing foliation development by pure and Schematic showing foliation development by pure and simple shear. simple shear.

THANKSTHANKS