Exam 8: Time and Geology

Fossils are common in __.

The half-life of the carbon 14 isotope is 5730 years. If there were 4 billion atoms of C-14 in a particular organism at the time it died, how many atoms of C-14 would there be in the remains of that organism 11,460 years after it died?

Under some circumstances, correlation between two regions can be made by assuming that similar rock types in the two regions formed at the same time.

In an unconformity the contact represents a gap in the geologic record.

The ___ Era began with the appearance of complex life, as indicated by fossils like trilobites.

The principle of crosscutting relationships states that a disrupted pattern is older than the cause of disruption.

In the radioactive decay process of __ decay, an electron is emitted from the nucleus of the parent isotope.

The Mesozoic Era precedes (is older than) the Paleozoic Era.

The proportional amount of atoms that decay with time _____ by the high pressures and temperature of Earth's interior.

The principle of original horizontality states that beds of sediment are nearly always deposited as nearly horizontal layers.

Radon is an intermediate product of uranium-238 decay.

When marine geologists collects a core of undeformed ocean-floor sediment, they know that the youngest layer is on the top of the core and the oldest is at the bottom because of the principle of __.

By the principle of __, the surface feature known as the Grand Canyon is ___ than the sedimentary formations that are exposed in the side walls of the Grand Canyon.

The ____ is based upon the observation that fossil species succeed one another through layers in a predictable order.

The _____ is the principle says that the same processes and natural laws that operated in the past are those we can actually observe or infer from observation as operating at present.

Another term for cosmogenic isotope dating is surface exposure dating.

The principle of ______ states that fragments included in a host rock must be _______ than the host rock.

Radiocarbon dating is useful in dating an event that occurred in the past ________ years.

Relative time refers to the time sequence in which events take place rather than the number of years involved.

Alvarez and others proposed a hypothesis that dinosaur extinction occurred because __.