Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water. Crystallization, erosion, sedimentation, and metamorphism transform one rock type into another or change sediments into rock. The rock cycle describes the transformations of one type of rock to another. The process by which a rock changes form or mineral content as a result of environmental changes such as heat and pressure. a rock that was altered by metamorphism.
Decline in the global population of amphibians is due to multiple reasons which include:
A moist ecosystem is necessary for amphibians especially for the purpose of their reproduction. The drainage of the wetlands deprives them of their habitat.
Pollutants adversely affects the survival of the gametes, tadpoles or the adult amphibians by acting as toxic agents and inhibiting their normal metabolic function.
Infectious diseases often cause their death resulting their population to decline.
Global climate warming affects their normal metabolic growth and development and hence causes their population to decline.