GEOL 1050 Lecture Notes - Lecture 1: Phanerite, Aphanite, Cross-Bedding
Document Summary
Aphanitic, phaneritic, porphyritic: aphanitic is fine-grained/ rapid cooling. And porphyritic is a mixture of coarse and fine grained crystals. Biochemical limestone- principle compound is caco3, found in warm, tropical, marine waters. Breccia vs conglomerate: breccia is angular rock fragments and conglomerates are rounded rock clasts. Caldera vs crater- craters are bowl shaped depressions on the top of volcanoes and calderas are gigantic volcanic depressions. Cross bedding- created by dune and ripple migration. Decreasing viscosity ---- the lower the viscosity, the lower the sio2 content. Felsic, intermediate, mafic, ultramafic: highest to lowest (sio2): felsic, intermediate, mafic, and. Rhyolite, andesite, basalt: aphanitic (extrusive- quickly cooled/ no crystals) Granite, diorite, gabbro: phaneritic (intrusive- slowly cooled/ has crystals) Definition of a mineral- is: naturally occurring, solid, formed geologically, crystalline structure, definite chemical composition, and is mostly inorganic. Definition of a rock- aggregate of a mineral.
