Chap 14 terms Crossword

a basic law of geochronology, stating that in any undisturbed sequence of rocks deposited in layers, the youngest layer is on top and the oldest on bottom, each layer being younger than the one beneath it and older than the one above it.
determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age, (i.e. estimated age).
system of chronological dating that relates geological strata (stratigraphy) to time. It is used by geologists, paleontologists, and other Earth scientists
a long and distinct period of history with a particular feature or characteristic.
the point in between the Cretaceous and Tertiary periods. Geologists have dated this period to about 65.5 million years ago.
a method of dating geological or archeological specimens by determining the relative proportions of particular radioactive isotopes present in a sample
the time taken for the radioactivity of a specified isotope to fall to half its original value.
a scientist who studies fossils
the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.
a period of time in history or a person's life, typically one marked by notable events or particular characteristics.
an indefinite and very long period of time, often a period exaggerated for humorous or rhetorical effect.
a length or portion of time