are the remains. imprints, or traces of prehistoric organisms.
PERMINERALIZED REMAINS:
are fossils in wich the spaces inside are filled with minerals from groundwater.
CARBON FILM: thin film of carbon residue preserved as a fossil.
MOLD: a type of body fossil thet forms in rock when an organism with hard parts is burid, decays or dissolves, and leaves a cavaty in the rock.
CAST: a type of bode fossil that forms when crystals fill a mold or sediments wash into a mold and harden into rock.
INDEX FOSSIL: remains of species that existed on earth for a relatively short period of time, were abundant and widespread geographically.
PRINCIPLE OF SUPERPOSITION: states that in undisturbed rock leayer, the oldest rocks are on the bottom and the rocks become progressively younger toward the top.
RELATIVE AGE: is it age in comparison to other things.
UNCONFORMITY: gap in the rock leayer that is due to erosion or period without any deposition.
No hay comentarios:
Publicar un comentario