Earth Science Unit 3 Review Worksheet Name Block Circle the letter that corresponds to the correct answer 1. Which geologic principle is used when a geologist observes an outcrop or rocks and determines that the bottom layer is the oldest? d. Inclusion 2. Which term does not describe a gap in geologic time? a. Unconformity b. Nonconformity c. Disconformity d. Key bed 3. Which of the following is not a characteristic of an index fossil? a. Was commonplace while alive b. Existed for a long period of time c. Is geographically widespread d. Is easily recognizable 4. Based on radioactive elements, what is the calculated age of Earth? a. 4.6 billion years b. 5 million years c. 15 billion years d. 1 million years 5. Which type of fossil forms when an organism s hard parts dissolve and leave a cavity that later fills with sediment? a. Mold b. Coprolite c. Cast d. Gastrolith 6. The geologic principle that states that sedimentary rocks are deposited in horizontal layers is the principle of 7. You can tell that a fault is younger than the rock it cuts across by applying the principle of
8. The principle that states that the processes occurring today have occurred since Earth formed is known as the principle of 9. What is the matching of outcrops from one geographic region to another? a. Correlation b. Unconformity d. Uniformitarianism 10. In an undisturbed rock sequence, the youngest rock layer is located a. At the bottom of the sequence b. At the top of the sequence c. Below the sedimentary rock layer d. Below the unconformity 11. What are the particles eroded from a layer of rock that become incorporated in an overlying rock layer? a. Fossils b. Unconformities c. Sills d. Inclusions 12. The relative age of a rock layer that contains inclusions is a. Older than the source of the inclusions b. Older than the layer below it c. Younger than the source of the inclusions d. The same as the intrusion that cuts across it 13. Which of the following was not a source of heat for the early Earth? a. Meteor bombardment b. Gravitational contraction c. Radioactivity d. Hydrothermal energy 14. What is the process by which a planet becomes internally zoned when heavy materials sink toward its center and lighter materials accumulate near its surface? a. Photosynthesis b. Dewatering c. Accretion d. Differentiation 15. Where is most of the North American Precambrian shield exposed at the surface? a. Canada b. Minnesota c. Wisconsin d. Michigan
16. What mineral can be used to radiometrically date Earth s age? a. Zircon b. Quartz c. Hematite d. Feldspar 17. What is the name of the first supercontinent, which formed near the end of the Proterozoic? a. Laurentia b. Grenville c. Rodinia d. Pangaea 18. What volcanic process most likely formed Earth s atmosphere? a. Differentiation b. Outgassing c. Crystallization d. Photosynthesis 19. To what does orogeny refer? a. The drifting of microcontinents b. The building mountain ranges c. The formation of volcanic islands d. The breaking apart of the supercontinents 20. Which of the following was not a source of information about the early presence of oxygen on Earth? a. Red beds b. Banded iron formations c. Stromatolites d. Meteorites 21. An organism composed of a single cell, which does not contain a nucleus, and is the simplest kind of cell, is a. A eukaryotes b. A prokaryote c. An acritarch d. Amino acid 22. An organism composed of cells that contain nuclei is a(n) a. Eukaryotes b. Prokaryote c. Animo d. Acritarch 23. Eukaryotes differ form prokaryotes in the most eukaryotes are a. Smaller b. Simpler c. Larger d. Found only in stromatolites 24. The oldest known fossil eukaryotes are a. Related to cyanobacteria b. Smaller than modern single-celled eukaryotes c. Similar to jellyfish d. About 2.1 billion years old
25. The Ediacaran fauna are generally believed to be a. Animals composed of eukaryotic cells b. Animals composed of prokaryotic cells c. Algae d. Cyanobacteria 26. The absence of tracks and trails leads scientists to speculate that the Ediacaran fauna were a. Already extinct by the late Proterozoic b. Plants c. Relatively immobile d. prokaryotes 28. During what period was Laurentia completely surrounded by passive margins? a. The Cambrian b. The Ordovician c. The Devonian d. The Permian 29. What term describes a drop in sea level and the resulting seaward movement of the shoreline? a. Regression b. Excursion c. Explosion d. Transgression 30. What are the most common fossils of the Cambrian fauna? a. Sharks b. Trilobites c. Crinoids d. Rugose corals 31. What is the calm area behind a reef called? a. A clastic wedge b. A passive margin c. A lagoon d. A continental shelf 32. Which of the following is not an evaporite mineral? a. Anhydrite b. Quartz c. Halite d. Gypsum 33. What is the triangular shaped sedimentary rock deposit that was deposited adjacent to an uplifted area called? a. A passive margin b. An active margin c. A clastic wedge d. An orogeny 34. What landmass collided with Laurentia and caused the Acadian Orogeny? a. Gondwana b. Avalonia c. Baltica d. Siberia
37. Which term describes down-dropped blocks of crust bounded by steeply dipping normal faults? a. Volcanic arcs b. Basins c. Red beds d. Batholiths 38. What are tiny organisms that float in the oceans and make their own food through the process of photosynthesis called? a. Echinoids b. Gastropods c. Phytoplankton d. Teleosts 39. What makes a dinosaur different from other reptiles? a. Dinosaurs were very large b. Dinosaurs laid eggs c. Dinosaurs were carnivorous d. Dinosaurs had upright postures 40. What seed-bearing, flowering plants first appeared during the Cretaceous? a. Angiosperms b. Phytoplankton c. Prosimians d. Cycads 41. What is radiometric dating and how is it used? 42. What was the name of the first supercontinent and when did it form? 43. What occurs during the process of outgassing, and what role did this process play in the formation of the atmosphere? 44. What important function do phytoplankton perform?