Definition
Boninite is a mafic extrusive rock which is high in magnesium and silica content, formed in fore-arc environments, typically during the early stages of subduction
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
History
Origin
Japan
Pennines, England
Discoverer
Unknown
J.J. Ferber
Etymology
From its occurrence in the Izu-Bonin arc south of Japan
From Grit + Stone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock