Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Trachyandesite is an extrusive igneous rock.
History
Origin
USA
Indonesia
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock