Mixed Sedimentary Rock

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Mixed Sedimentary Rock

 

a sedimentary rock consisting of several components differing either in particle size or chemical and mineralogical composition or origin. Mixed clastic rocks include clayey sands, sandy clays, and aleurite clays. Mixed calcareous rocks include dolomitic limestones (10–50 percent dolomite, the rest CaCO3) and limestone dolomites (10–50 percent CaCO3, the rest dolomite). When clastic and calcareous materials are intermixed with pure sands and limestones, intermediate mixed rocks form, such as calcareous sandstones and sandy limestones. When clayey and calcareous materials are intermixed, calcareous clays (10–30 percent CaCO3), marls (30–70 percent CaCO3), clayey limestones (70–90 percent CaCO3), and other rocks form. They are intermediate between clays and pure limestones. Mixed sedimentary rocks are very common.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.