Simple Lithology


definition A generally soft, white, very fine-grained, extremely pure, porous limestone. It forms under marine conditions from the gradual accumulation of skeletal elements from minute planktonic green algae (cocoliths), associated with varying proportions of larger microscopic fragments of bivalves, foraminifera and ostracods. It is common to find flint and chert nodules embedded in chalk. more like this
source; C.S. Harris, 2009, unpublished web page, more like this
broader limestone
narrower chalk
in scheme simplelithology
is primary topic of chalk