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Thrombolites have a clotted structure without the laminae of stromatolites.Each clot within a thrombolite mound is a separate cyanobacterial colony.The clots are on the scale of millimetres to centimetres and may be interspersed with sand, mud or sparry carbonate. [1]
Thrombolites are poorly laminated or non-laminated clotted structures formed by cyanobacteria, common in the fossil record and in modern sediments. [18] There is evidence that thrombolites form in preference to stromatolites when foraminifera are part of the biological community. [33]
Oncolites are very similar to stromatolites, but, instead of forming columns, they form approximately spherical structures. [3] The oncoids often form around a central nucleus, such as a shell fragment, [ 4 ] and a calcium carbonate structure is deposited by encrusting microbes .
"Spongiostromata" is an antiquated form taxon that refers primarily to fossil cyanobacteria. "Spongiostromate" is also used to describe stromatolites and oncolites that do not preserve clear tubules or other cellular microstructure.
The stromatolites found today are almost all carbonate rocks (made of limestone), but these structures are mostly composed of the minerals gypsum and halite (rock salt), Hynek said.
The human brain is the central organ of the human nervous system, and with the spinal cord, comprises the central nervous system. It consists of the cerebrum, the brainstem and the cerebellum. The brain controls most of the activities of the body, processing, integrating, and coordinating the information it receives from the sensory nervous ...
Cerebral infarction, also known as an ischemic stroke, is the pathologic process that results in an area of necrotic tissue in the brain (cerebral infarct). [1] In mid to high income countries, a stroke is the main reason for disability among people and the 2nd cause of death. [2]
Brain cells make up the functional tissue of the brain. The rest of the brain tissue is the structural stroma that includes connective tissue such as the meninges, blood vessels, and ducts. The two main types of cells in the brain are neurons, also known as nerve cells, and glial cells, also known as neuroglia. [1]