Boulder clay is an unsorted agglomeration of clasticsediment that is unstratified and structureless and contains gravel of various sizes, shapes, and compositions distributed at random in a fine-grained matrix. The fine-grained matrix consists of stiff, hard, pulverized clay or rock flour. Boulder clay is also known as drift clay; till; unstratified drift, Geschiebelehm (German); argile á blocaux (French); and keileem (Dutch).[1][2]
The term boulder clay is infrequently used for gravelly sedimentary deposits of nonglacial origin. These deposits include submarine slump and slide deposits along continental margins,[3] lacustrine debris flow deposits consisting of pebbly mudstones,[4] and coarse, poorly sorted, cobbly diamictons associated with the Guangxi karst, China.[5]
^Charlesworth, J. K., 1957. Chap 18, Boulder Clay. In The Quaternary Era, with Special Reference to its Glaciation. v. 1, London, United Kingdom, Edward Arnold, p. 376-388.
^Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) Glossary of Geology (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. ISBN0-922152-76-4
^Reineck, H.E. and Singh, I.B., 1982. Depositional sedimentary environments: with reference to terrigenous clastics. New York, New York, Springer Science & Business Media. 551 pp. ISBN978-3-540-10189-5
^Jiang, X., 2018. Sedimentary Dynamics of Windfield-Source-Basin System New Concept for Interpretation and Prediction. Beijing, China, Science Press, Springer Geology. 341 pp. ISBN978-981-10-7407-3
^Waltham, T., 2010. Guangxi karst: The fenglin and fengcong karst of Guilin and Yangshuo. In: Migoń, P. (Ed.), pp. 293–302. Geomorphological Landscapes of the World. Germany, Dordrecht, Springer. 371 pp. ISBN978-3-540-10189-5