ERSC 2P16 Lecture 14: The Classification of Clastic Sedimentary Rocks Part 3
3 Aug 2015
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Document Summary
Classification of rudites: rudites are classified on the basis of particle shape, packing and composition. Conglomerate: a rudite composed predominanty of rounded clasts. Rounded clasts may indicate considerable distance of transport from source. The significance will vary with the lithology of the clast (i. e. , limestone clasts will become round a short distance from their source whereas quartzite will require much greater transport). Breccia: a rudite composed predominantly of angular clasts. Generally indicates that the clasts have not traveled far from their source or were transported by a non-fluid medium (e. g. , gravity or glacial ice). Diamictite: a rudite composed of poorly sorted, mud to gravel-size sediment, commonly with angular clasts. Commonly refers to sediment deposited from glaciers or sediment gravity flows, particularly debris flows. Note: in the following the rock names are given for rudites consisting of rounded clasts (conglomerates) but the term conglomerate may be replaced with the term breccia if the clasts comprising the rock are angular.
