Earth Science Chp 7 and 8

interior

ordering of objects or features from oldest to most recent

actual date of event

states that when rocks form at Earth's surface in layers, the lowest layer formed first and each successibely higher layer is younger than the one below.

states that sedimentary layer are horizontal, or nearly so, when they are deposited. Non-horizontal layering indicates disruption of the beds at some time after deposition.

states that geologic features, such as dieks and faults, that cut across otherwise continous rocks formed after the rocks that they cut across.

fractures across which rocks are displaced as a result of tectonic forces

states that objects enclosed by rock formed prior to inclusions within the rock.

states that sedimentary beds are continously deposited over large areas until some sort of barrier limits deposition.

states that fossils found in rocks change through the time as some species become extinct and new ones appear.

by different fossil associations and the names of periods derive from places where the rocks of that age, based on their fossil, were first described.

eons > era > period > epoch

unconformities are former land or seafloor surfaces between rock layers that represent intervals not recorded in the rock layer. They are gaps in the rock record, when erosion rather than deposition happened.

separate sedimentary or volcanic rocks that are inclined at different angles. when an angular unconformity is present, the time required for tilting the lower rocks and eroding them to produce a new surface of deposition for the upper rocks is not represented in the geologic record.

separate sedimentary or volcanic rocks that are inclined at the same angle but are separated by an irregular erosion surface.

separate sedimentary or volcanic rocks from underlying plutonic-igneous or metamorphic rocks.

eighteenth-century geologist who applied scientific observations and principle to conclude that the earth is very very old.

refers to energy and subatomic particles released when atoms of one element tranform into atoms of another element by proceses that change the number of protons and neutrons and in the nucleus.

same element that have the same number of protons but a different number of neutrons

instability that causes a transformation of an unstable isotope to a stable one by changing the number of protons, neutrons, or both.

time interal during which the parent-isotope atom decreases by half.

1) measuring the abundances of parent and daughter isotopes. 2) knowing the half-life value for the rate of decay of parent to daughter.

4.03 billion years old.

no