In geology, a key bed (syn marker bed) is a relatively thin layer of sedimentary
rock that is readily recognized on the basis of either its distinct
physical characteristics or fossil content and can be mapped over a very
large geographic area.[1]
As a result, a key bed is useful for correlating sequences of
sedimentary rocks over a large area. Typically, key beds were created as
the result of either instantaneous events or (geologically speaking)
very short episodes of the widespread deposition of a specific types of sediment. As the result, key beds often can be used for both mapping and correlating sedimentary rocks and dating them. Volcanic ash beds ( and bentonite beds) and impact spherule beds, and specific megaturbidites
are types of key beds created by instantaneous events. The widespread
accumulation of distinctive sediments over a geologically short period
of time have created key beds in the form of peat beds, coal beds, shell beds, marine bands, black in cyclothems, and oil shales. A well-known example of a key bed is the global layer of iridium-rich impact ejecta that marks the Cretaceous–Paleogene boundary (K–T boundary). Please let me know if it works.
Answer:
Option B is correct.
Explanation:
There are <u>thousands</u> of proteins and only 20 amino acids.
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Answer:
It could be halogens for example things like fluorine
Answer:
B. Osmosis
Explanation:
Osmosis is the process in which oxygen and carbon dioxide exchanged occur between the alveoli and the capillaries because the oxygen enters the body and the carbondioxide gas leaves the cell through a semi-permeable membrane and we know that Osmosis is a process in which smaller molecules moves from higher concentration to lower concentration through semi-permeable membrane of the cell.
