Exam 8: Geologic Time

Benthic foraminifera are useful for correlation and dating of Paleozoic through Recent marine sedimentary rocks.

Which English engineer and amateur geologist (his first name was William)is generally credited with first demonstrating the principle of faunal succession from his observations in building canals?

On the blank provided beside each geologic cross section below, write the name of the specific type of unconformity that is labeled with an arrow.The v-pattern indicates igneous rocks.All other patterns are different types of sedimentary rocks. a)______________________________ b)______________________________ c)______________________________

Paleophrenology is the study of fossils and ancient life forms.

The radioactive decay of U-238 to Pb-206 is slightly faster in hot magmas than in cool, solidified rock.

The amount of time required for half of the radioactive parent isotopes in a sample to decay is called its ________.

Numeric age dates based on radioactivity are very important for studying Proterozoic geologic history because fossils are rare or absent.

Pieces of one rock contained within another are called ________ and give evidence that that smaller rock is ________ the main body.

Which of the following denotes remains of particular organisms that were widely distributed, but lived for only a relatively brief interval of geologic time?

Of an original amount of radioactive parent isotope, 25% remains and 75% has decayed.How many half-lives have elapsed?

Strata above an angular unconformity were tilted before the older strata were eroded.

Acritarchs, conodonts, graptolites and trilobites would all be useful as index fossils, environmental indicators, or relative dating tools for ________.

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. -Choose the option that does not fit the pattern.

What age range can cosmogenic dating determine for exposed surfaces?

In terms of age, a fault is ________ that a rock it cuts.

Which rocks are most useful in unraveling Earth's geologic history?

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. -Choose the option that does not fit the pattern.

Give an example of a fossil type and inferences about its original environment.

The radioactive isotope, potassium-40, has argon-40 as a daughter product.

The rare element iridium has been implicated in which "ancient health" crisis?