Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
History
Origin
-
France
Discoverer
Unknown
Alexandre Brongniart
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock