Geology Test 2 - Chapter 8

The order of events from first (oldest) to last (youngest).

Original horizontality, superposition, lateral continuity, cross-cutting relationships, inclusions, unconformities, and correlation of rock unit fossils.

The age of events or objects, expressed as a number or numbers.

Radiometric dating (determining how much radioactive decay of a specific element has occurred since a rock formed or an event occurred.

Surfaces separating successive rock layers. (seperating different rock ages or types)

Bodies of rock of considerable thickness with recognizable characteristics allowing them to be distinguished from adjacent (next to) rock layers.

Beds of sediment deposited in water are initially formed as horizonatal or nearly horizontal layers.

Within an undisturbed sequence of sedimentary or volcanic rocks, the oldest layers is at the bottom and layers are progressively younger upward in the stack.

Original sedimentary layers extends laterally until it tapers or thins at its edges. this is what we expect at the edges of a despositional environment.

States that a disrupted pattern is older than the cause of disruption. Intrusions and faults are younger than the rocks they cut through.

Contacts between igneous intrusions and surrounding rocks, where surrounding rocks have expierienced contact metamorphism.

State that fragments included in a host rock are older than the host rock.

A surface (or contact) that represents a gap in the geologic record, with the rock unit immediately beneath. most unconformities are buried erosion surfaces.

A surface that represents missing rock strata but beds above and below that surface are parallel to one another.

Is a contact in which younger strata overlie an erosion surface on tilted or folded layered rock. It implies the following sequence of events, from oldest to youngest: (1) deposition and lithication of sedimentary rock. (2) uplift accompanied by folding or tilting of the layers. (3) erosion (4) renewed deposition