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The new thought is that these ocean currents were slowed by blooms of microscopic marine primary producers, which allowed for the settlement of organic-rich sediments at the seafloor, producing many of the economically productive black shale beds that are present today. To this day it remains an intensely researched subject by scholars and ...
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
Sedimentary organic matter includes the organic carbon component of sediments and sedimentary rocks. The organic matter is usually a component of sedimentary material even if it is present in low abundance (usually lower than 1%). Petroleum (or oil) and natural gas are particular examples of sedimentary organic matter.
The term limnology was coined by François-Alphonse Forel (1841–1912) who established the field with his studies of Lake Geneva.Interest in the discipline rapidly expanded, and in 1922 August Thienemann (a German zoologist) and Einar Naumann (a Swedish botanist) co-founded the International Society of Limnology (SIL, from Societas Internationalis Limnologiae).
Organic palynofacies considers all the acid insoluble particulate organic matter (POM), including kerogen and palynomorphs in sediments and palynological preparations of sedimentary rocks. The sieved or unsieved preparations may be examined using strew mounts on microscope slides that may be examined using a transmitted light biological ...
Sedimentary facies are either descriptive or interpretative. Sedimentary facies are bodies of sediment that are recognizably distinct from adjacent sediments that resulted from different depositional environments. Generally, geologists distinguish facies by the aspect of the rock or sediment being studied.
Kerogen is a complex mixture of organic chemical compounds that make up the most abundant fraction of organic matter in sedimentary rocks. [12] As kerogen is a mixture of organic materials, it is not defined by a single chemical formula. Its chemical composition varies substantially between and even within sedimentary formations.
Consequently, decomposition of organic matter in the water column and sediments can cause oxygen concentrations to decline to the point of hypoxia (low oxygen) or anoxia (no oxygen). [5] In dimictic , eutrophic lakes, the hypolimnion is often anoxic throughout a majority of the stratified period. [ 6 ]