Carbonate Sedimentary Rocks
Carbonate Rocks and Dunham’s Classification
Palkowski, Daniel N.
245-002 General Geology
Dr. Wayne Schlipp
9 December 2007
Abstract The following contains a compendium of research on carbonate rocks. Displayed are a basic description of carbonate rocks, depositional environments, mineralogy, ancient and modern reefs, diagenesis, facies analysis, and classification. Most carbonate rock classification schemes take into account characteristics that may require intensive microscopic study. These classifications are comprehensive, but are only practical if a laboratory is available. Classification based on depositional texture gives a profound insight to the energy of ancient reefs. Dunham’s classification is more descriptive and is much easier to use. Included is a simple concise explanation of Dunham’s classification of carbonate rocks. With a basic understanding of internal structure and texture the Dunham classification can be employed as simply and with as much success as Pettijohn’s classification of clastic sedimentary rocks: saving time, money, and wasted laboratory effort.
Introduction At first glance, an outcrop of carbonate rocks may look very boring, for they are usually drab in color (grey or white) and do not display the typical points of reference that clastic sedimentary structures possess. They are equally unappealing in the scientific jargon given to them, with terms such as fascicular optic calcite and baroque dolomite, to name a few. The interesting aspect of carbonate rocks is not the glossy metallic shine of the sample but the importance of them and the clues they hold into Earth’s ancient past. Covering 7% of the Earth’s land surface carbonates play an important role in the planet’s history and in the future of human existence. Carbonates are vital in the manufacturing of cement, as building stone and aggregates, and they form the reservoirs for about 40% of the world’s oil reserves. In engineering terms they
Palkowski, Daniel N.
245-002 General Geology
Dr. Wayne Schlipp
9 December 2007
Abstract The following contains a compendium of research on carbonate rocks. Displayed are a basic description of carbonate rocks, depositional environments, mineralogy, ancient and modern reefs, diagenesis, facies analysis, and classification. Most carbonate rock classification schemes take into account characteristics that may require intensive microscopic study. These classifications are comprehensive, but are only practical if a laboratory is available. Classification based on depositional texture gives a profound insight to the energy of ancient reefs. Dunham’s classification is more descriptive and is much easier to use. Included is a simple concise explanation of Dunham’s classification of carbonate rocks. With a basic understanding of internal structure and texture the Dunham classification can be employed as simply and with as much success as Pettijohn’s classification of clastic sedimentary rocks: saving time, money, and wasted laboratory effort.
Introduction At first glance, an outcrop of carbonate rocks may look very boring, for they are usually drab in color (grey or white) and do not display the typical points of reference that clastic sedimentary structures possess. They are equally unappealing in the scientific jargon given to them, with terms such as fascicular optic calcite and baroque dolomite, to name a few. The interesting aspect of carbonate rocks is not the glossy metallic shine of the sample but the importance of them and the clues they hold into Earth’s ancient past. Covering 7% of the Earth’s land surface carbonates play an important role in the planet’s history and in the future of human existence. Carbonates are vital in the manufacturing of cement, as building stone and aggregates, and they form the reservoirs for about 40% of the world’s oil reserves. In engineering terms they
References: Akabr, M., Badri, M., Boyd, A., Bruce, C, Delhomme, J.P. (1995) Oil Field, Jan. 95 pp 38-43 Bathurst, R.G.C. (1983) Carbonate Sediments and Their Diagenesis, pp. Elsevier, Amsterdam. Dunham, R.J. (1962) Classification of Carbonate Rocks According to Depositional Texture Earth History scientific website, November 10th, 2007 http://www.earthhistory.org.uk/key-concepts/plate-tectonics-1/ Milwaukee Public Museum public learning website, November 10th, 2007 http://www.mpm.edu/collections/learn/reef envir-petro.html Tucker, M.E., Wright, V.P.(1988) Carbonate Sedimentology,pp. 1-26, 28-36, 314-336, Mass Williams University Educational Website, November 1st, 2007, http://madmonster.williams.edu/geos./L.08.html Wilson, J.L., (1975) Carbonate Facies in Geological History, pp1-46, 257-263