Geology 100 Chapter 10 Study Guide – Flashcards

A radioactive isotope of the element potassium decays to produce argon. If the ratio of argon to potassium is found to be 7:1, how many half-lives have occurred?

An area of slightly dipping sedimentary rock layers has large inclusions and is intruded by an igneous dike. Apply the basic principles for determining relative ages and identify the FALSE statement. A. The dike is older than the sedimentary rock layers is cut across B. The oldest sedimentary layer is the bottom layer. C. The igneous intrusion "baked" (metamorphosed) the sedimentary rock it touched. D. The sedimentary layers started out lying flat.

Choose the proper listing of names that fit the following three descriptions- Age of Mammals, Age of Dinosaurs, and longest geological time period.

Geologists estimate that the age of the Earth is 4.54 billion years old, based on...

If you equate all Earth history to one calendar year, the history of out species (Homo sapiens) would occupy...

IN 1815, William Smith correlated strata from many locations and plotted it on paper to show the spatial distribution of rock units on Earths surface. This document was the first modern:

On the diagram shown, several surfaces between rock layers are identified by letters. Choose the answer that correctly identifies the unconformities. https://d1lexza0zk46za.cloudfront.net/coursepacks/geo/essgeo5/imgs/rq10.2.jpg A. B and E B. A and E C. C and D D. C and E

The boundary surface between the stratigraphic formations is called a...

The four column in this diagram represent fossil-bearing sedimentary rock layers at four different sites. The sedimentary layers are continuous expect at the zigzag lines, which represent unconformities. Compare the sites, determine the relative ages of the fossils, and then identify the FALSE statement. https://d1lexza0zk46za.cloudfront.net/coursepacks/geo/essgeo5/imgs/rq10.3.jpg A. Trilobites are the oldest fossils shown. B. Unconformities are breaks in rock record that indicate missing time. C. The reptile fossils are the second-youngest fossils shown. D. Mammals are the youngest fossils shown.

Uniformitarianism...

What type of unconformity forms when sedimentary rocks overlie either igneous or metamorphic rocks?

Which of the following accurately ranks the subdivisions of geological time in order from largest to smallest? epoch, eon, period, era

Which of the following is NOT a method to determine numerical age? A. Analyzing growth ring patterns in trees B. Carbon-14 dating C. Radioactive decay of uranium to lead D. Cross-cutting relations

Which of the following is TRUE? A. Geologists learned how to determine numerical age long before they could determine relative age. B. Specifying the date on which an event took place is an example of relative age. C. Specifying the age of one feature with respect to another is called its relative age. D. Saying that a fossil is 4 million years old reports its relative age.

Which of the following methods of determining the age of materials is a radiometric dating technique? A. Rhythmic layering of snow layers in glacial ice B. Dendrochronology (tree rings) C. Seasonal changes in growth rings in shelled organisms D. Carbon dating

Which of the following shows the four time divisions listed from oldest to youngest? A. Precambrian. Mesozoic, Archean, Cenozoic B. Precambrian, Paleozoic, Mesozoic, Cenozoic C. Phanerozoic, Precambrian, Mesozoic, Cenozoic D. Hadean, Cenozoic, Mesozoic, Proterozoic

Which of the following statements is FALSE? A. Scientists can date any radioactive material back only three half-lives; after this theres not enough parent material left to measure. B. The "radiometric clock" starts when a radioactive mineral cools below its closure temperature. C. Isotopic dating relies on the parent-daughter ratio. D. Carbon-14 dating is used to date organisms, not minerals.

Which of the following statements is FALSE? A. An unconformity is a break in the rock record that indicates the area was underwater for millions of years. B. Varieties of an element that differ only in the number of neurons are called isotopes. C. The generally accepted age of Earth is 4.54 billion years. D. A formation is the name of a rock layer identified by such factors as rock type and approximate geological age.

Which of the following is FALSE? The principle of... A. inclusions says rock containing inclusions is older than the inclusions. B. cross-cutting relations says the feature of doing the cutting is younger than the feature it cuts. C. original continuity says sedimentary layers began as continuous expenses of sediment. D. superposition says in a sequence of sedimentary beds, the youngest is on top.

You should be able to number the events in the accompanying figure in the proper order of occurrence. If the first (oldest) event is number 1, and the last (most recent) is number 8, which occurred fifth in the sequence? https://d1lexza0zk46za.cloudfront.net/coursepacks/geo/essgeo5/imgs/rq10.1.jpg