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:
The five bases are adenine, guanine, cytosine, thymine, and uracil, which have the symbols A, G, C, T, and U, respectively. The name of the base is generally used as the name of the nucleotide, although this is technically incorrect.
Explanation:
E. Weathering - Sometimes the Earth's crust is forced to pull apart into smaller sections or pushed back together. Because of the constant movement, rocks underneath are brought up on the surface. This movement of rocks is referred to as uplift. When a metamorphic rock undergoes this process, it may be subjected to constant wear and tear. The rock will weather and may crumble into smaller pieces.
Not sure what you're asking so I'll list the places in order of least amount of change in time to the most1.Terrestrial equator2. tropic of Capricorn and Cancer3. North and South Pole
