Marcellus shale
What is Marcellus shale?Marcellus shale is a sedimentary rock which has exposure in eastern North America. It is found in the...
الأحد، 22 مارس 2015
Shale
ShaleShale is a sedimentary rock composed of fine grained sediments mainly silt and clay particles ranges at size of 1/256 millimetre....
السبت، 21 مارس 2015
Scoria
What is Scoria?Scoria is a highly vesicular, dark coloured volcanic rock that may or may not contain crystals (phenocrysts). It is...
Rhyolite
What is Rhyolite?Rhyolite is an extrusive igneous rock with a very high silica content. It is usually pink or gray in...
Pumice
What is Pumice?Pumice is a light coloured, extremely porous igneous rock that forms during explosive volcanic eruptions. It is used as...
Obsidian
What is Obsidian?Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava...
Basalt
What is basalt?Basalt is a fine grained volcanic igneous rock formed of plagioclase and pyroxene minerals. It is most commonly formed...
الخميس، 19 مارس 2015
Andesite
What is andesite?Andesite is an extrusive igneous volcanic rock which is in between rhyolite and basalt. Texture of andesite is between...
