Answer:
O.
Explanation:
There are different types of soils and it is made up of different layers or horizon such as A, B, C, O, R and E. Together all the horizons forming soil profile. Each horizon containing different soil types.
O horizon: Known as top layer of the soil which contains layer of organic matter which is about two inches thick, and made up of humus such as decomposing leaves, dark-colored, carbon rich matter, twigs and microbial biomass which is mixed with small grained minerals for the formation of aggregate structures.
Adenosine Diphosphate (ADP)
Potassium-Argon dating has the advantage that the argon is an inert gas that does not react chemically and would not be expected to be included in the solidification of a rock, so any found inside a rock is very likely the result of radioactive decay of potassium. Since the argon will escape if the rock is melted, the dates obtained are to the last molten time for the rock. Since potassium is a constituent of many common minerals and occurs with a tiny fraction of radioactive potassium-40, it finds wide application in the dating of mineral deposits. The feldspars are the most abundant minerals on the Earth, and potassium is a constituent of orthoclase, one common form of feldspar.
