Sapropel

Sapropel

Sapropel (a contraction of ancient Greek words sapros and pelos, meaning putrefaction and mud, respectively) is a term used in marine geology to describe dark-coloured sediments that are rich in organic matter. Organic carbon concentrations in sapropels commonly exceed 2% in weight.

Contents

Formation

Sapropels are thought to develop during episodes of reduced oxygen availability in bottom waters, such as an Oceanic Anoxic event (OAE). Most studies of sapropel formation mechanisms infer some degree of reduced deep-water circulation. Oxygen can only reach the deep-sea by new deep-water formation and consequent "ventilation" of deep basins. There are two main causes of OAE: A reduction in deep-water circulation or a raised upper level oxygen demand.

A reduction in deep-water circulation will eventually lead to a serious decrease in deep-water oxygen concentrations due to biochemical oxygen demand associated with the decay of organic matter that sinks into the deep-sea as a result of export production from surface waters. Oxygen depletion in bottom waters then favours the enhanced preservation of the sinking organic matter during burial in the sediments. Organic-rich sediments may also form in well-ventilated settings that have highly productive surface waters; here the high surface demand simply extracts the oxygen before it can enter the deep circulation currents so depriving the bottom waters of oxygen.

Significance

Sapropelic deposits from global Ocean Anoxic Events form important oil source rocks. Detailed process studies of sapropel formation have concentrated on the fairly recent eastern Mediterranean sapropels, the last of which was deposited between 9.5 and 5.5 thousand years ago.

The Mediterranean sapropels of the Pleistocene reflect increased density stratification in the isolated Mediterranean basin. They record a higher organic carbon concentration than non-sapropel times; an increase in the δ15N and corresponding decrease in δ13C tells of rising productivity as a result of nitrogen fixation.[1] This effect is more pronounced further east in the basin, suggesting that increased precipitation was most pronounced at that end of the sea.[1]

Uses

According to Romanian tycoon Dinu Patriciu, the sapropel has a huge potential of being developed into a wide array of products, including a new form of alternative energy[2]. Currently Dinu Patriciu has a marine exploration project in the Black Sea, that examines the sapropel sediments in that region, with sediment cores collected and investigated by several universities and research institutes across the world[2].

References

  1. ^ a b Philip A. Meyers and Michela Arnaboldia (2008). "Paleoceanographic implications of nitrogen and organic carbon isotopic excursions in mid-Pleistocene sapropels from the Tyrrhenian and Levantine Basins, Mediterranean Sea". Palaeogeography Palaeoclimatology Palaeoecology 266: 112. doi:10.1016/j.palaeo.2008.03.018. 
  2. ^ a b Patriciu: Examination of sapropelic mud in Black Sea could last 2-3 years, 19 June 2009, wall-street.ro, retrieved at 30 July 2010

Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • sapropel — SAPROPÉL, sapropeluri, s.n. Mâl bogat în substanţe organice aflate în diferite stadii de descompunere, format în ape sărace în oxigen (mări, lagune, lacuri), şi care are efecte terapeutice. – Din fr. sapropel. Trimis de IoanSoleriu, 13.09.2007.… …   Dicționar Român

  • Sapropel — oder Faulschlamm (altgriechisch σαπρός sapros „faul“, „verfault“) entsteht unter natürlichen Bedingungen in nährstoffreichen Gewässern und Sümpfen, wenn organisches Material bei Abwesenheit von Sauerstoff biochemisch umgewandelt wird. Es… …   Deutsch Wikipedia

  • sapropel — ou sapropèle [sapʀɔpɛl] n. m. ÉTYM. 1953, sapropel, Quillet, mais antérieur (1905, Potomé, d après P. George); sapropèle, 1975; de sapropélique. ❖ ♦ Géol., géogr. Boue noire, riche en matières organiques en décomposition. || Le sapropel serait à… …   Encyclopédie Universelle

  • Sapropel — oder Faulschlamm entsteht nach H. Potonié in stagnierendem oder halbstagnierendem Wasser aus den in ihm lebenden echten Wasserorganismen pflanzlicher und tierischer Natur. Die schwimmend oder am Grund des Wassers lebenden Tiere und Pflanzen… …   Lexikon der gesamten Technik

  • sapropel — m. Depósito de restos orgánicos en el fondo de lagos y mares, que se descompone sin tener contacto con el aire. Se le considera el paso previo a la formación del petróleo. * * * ► masculino PETROGRAFÍA Materia orgánica en proceso de putrefacción …   Enciclopedia Universal

  • sapropel — sàpropel m DEFINICIJA ekol. bitumenozni mulj, nastaje taloženjem organskih tvari podvrgnutih truljenju u lužnatoj sredini; nataložen u sedimentnim stijenama vremenom daje gorivo, ugljen, naftu ETIMOLOGIJA grč. saprós: truo + pēlós: blato …   Hrvatski jezični portal

  • sapropel — [sap′rə pel΄] n. [< SAPRO + Gr pēlos, mud, slime] black, decaying, organic bottom deposits in some lakes, rivers, etc. that lack oxygen and are rich in hydrogen sulfide sapropelic adj …   English World dictionary

  • sapropel — {{#}}{{LM S35058}}{{〓}} {{[}}sapropel{{]}} ‹sa·pro·pel› {{《}}▍ s.m.{{》}} Depósito de materia orgánica, acumulada en el fondo del agua y fuera del contacto con el aire, que sufre una transformación por fermentación: • El sapropel es un paso previo …   Diccionario de uso del español actual con sinónimos y antónimos

  • Sapropel — sapropelis statusas T sritis ekologija ir aplinkotyra apibrėžtis Bestruktūrė gėlųjų vandenų ir pelkių nuosėdinė organinė uoliena, susidariusi daugiausia iš žemesniųjų augalų ir gyvūnų liekanų. atitikmenys: angl. decay ooze; sapropel vok.… …   Ekologijos terminų aiškinamasis žodynas

  • sapropel — sapropelis statusas T sritis ekologija ir aplinkotyra apibrėžtis Bestruktūrė gėlųjų vandenų ir pelkių nuosėdinė organinė uoliena, susidariusi daugiausia iš žemesniųjų augalų ir gyvūnų liekanų. atitikmenys: angl. decay ooze; sapropel vok.… …   Ekologijos terminų aiškinamasis žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”