Geology 1001 Chapter 9.pdf

Geology 1001 Chapter 9 Study online at https://quizlet.com/_8cg7fp 1. Dating using radioactive isotopes that decay over time is called ________ dat- ing. isotopic 2. Which are principles of rel- ative dating? Original horizontality Cross-cutting relations Superposition 3. Match each geologic era with its meaning in the fos- sil record. Cenozoic - Recent life. Mesozoic - Middle life. Paleozoic - Ancient life. 4. Match the resulting fossil with its method of preser- vation. Petrified wood - Organic matter replaced by silica or pyrite. Insect in amber - Organic matter trapped in tree sap. Dinosaur bones - Hard parts buried and pre- served. Fish with fins and scales - Impressions on a lake bed. Fossil fern - Thin films of carbon on a rock surface. 5. Buried erosion surfaces that represent large inter- vals of time are called ____________. uncomformities 6. Indicate the typical se- quence of formation for sedimentary rock land- scapes, beginning with the first even at the top and the last event at the bottom. Deposition of sediments in layers (first) Lithification into sedimentary rocks Erosion of rocks into a landscape 1 / 23

Geology 1001 Chapter 9 Study online at https://quizlet.com/_8cg7fp 7. Which statements are true regarding the geologic timescale. It was first created using relative dating and correlation. It is based on data from fossils. 8. Preserved trackways and worm burrows in rock are examples of __________. trace fossils 9. Uniformitarianism can be stated as __________. "the present is the key to the past" 10. How did Earth's oxy- gen-rich atmosphere de- velop from a carbon diox- ide-rich atmosphere? Through photosynthesis by cyanobacteria. 11. Both _________ dating and ______ dating can be used for correlation of the rock units shown in the dia- gram. relative isotopic 12. Which are important about fossils in the rock record? They are evidence of ancient life. They document evolution of life. They can be used to date rocks. 13. Match the age-dating term on the left with its correct definition on the right. Relative dating Uses geologic principles and common sense. Isotopic dating Uses analytical methods and assigns num- bers. 14. The oldest rocks and min- erals on Earth's surface have been found in Cana- da, Greenland, and Aus- Precambrian 2 / 23

Geology 1001 Chapter 9 Study online at https://quizlet.com/_8cg7fp tralia and are from the _________. 15. Fossils of species that lived on Earth for a long time period are often found in _________, whereas fos- sils of species that lived for a shorter time are often found _________. many rock layers; in a layer or two 16. A _________ fossil is a very short-lived, geographically widespread fossil species known to exist during a specific period of geologic time. index 17. Use the mnemonic to place in order some of the peri- ods of the Paleozoic, Meso- zoic, and Cenozoic Eras. Neogene (most recent) Cretaceous Jurassic Triassic Devonian Cambrian (oldest) 18. When a geologist attempts to match up two different sections of rock accord- ing to time, he or she is __________ the rocks. correlating 19. Isotopic dating is accom- plished by assigning ages in years to rocks using __________ dating meth- ods. analytical 20. The principle of ______________ tells geol- ogists that the oldest rock superposition 3 / 23

Geology 1001 Chapter 9 Study online at https://quizlet.com/_8cg7fp layer in the diagram is on the bottom; therefore, it was deposited first. 21. Match the principle of rel- ative dating with its defini- tion. Superposition - The oldest rock is at the bot- tom. Cross-cutting relations - The fault is younger than the rocks is cuts across. Original horizontality - Sediments and volcanic units are usually deposited in flat-lying layers. Inclusions - Rocks may incorporate older pieces of rock. Contact effects - A baked zone forms next to a dike during intrusion. 22. Place the events that formed the landscape shown in the correct se- quence, from the first event at the top to the last event at the bottom. Sedimentary layers are deposited horizontally. Sedimentary layers are lithified. The river cuts through the rock layers. The canyons widen and tributaries form. 23. Which principle can be used to determine the rel- ative age of an igneous in- trusion called a dike? Cross-cutting relations. 24. Which materials can be dated with carbon-14 tech- nology at archeology sites? Charcoal Bones Wood 25. Place the isotopes in order, from the system best for dating the youngest materi- Carbon-14 (best for young materials) K-Ar Rb-Sr (best for old materials) 4 / 23

Geology 1001 Chapter 9 Study online at https://quizlet.com/_8cg7fp als on the top to the system best for dating oldest mate- rials on the bottom. 26. Match the description of a group of dinosaurs with the correct examples. Diverse group of carni- vores and herbivores with hip structures similar to lizards. Tyrannosaurus rex and Apatosaurus. 27. Match the description of a group of dinosaurs with the correct examples. Had birdlike hip structures and were herbivores. Stegosaurus and Triceratops. 28. An isotope refers to any el- ement that has the same number of protons but a different number of ________. neutrons 29. Trilobites first appeared on Earth during the _________. Cambrian Period 30. What geologic features could cut across sedimen- tary rocks and therefore than the rocks they cut across? Fractures Dikes Veins 31. Groundwater can be dated using _________. isotopes 32. 5 / 23

Geology 1001 Chapter 9 Study online at https://quizlet.com/_8cg7fp Observed changes (evolu- tion) Development of stronger front fins in Paleozoic fish occurred, as compared to fish fossils found in older rock layers. 33. Evolutionary theory Favorable genetic mutations occurring in a species are more successful in small, isolated populations than in large populations. 34. Determine the sequence of events that created the rocks shown by putting the following in order, with the oldest (and first) event on the bottom and the most re- cent event on the top. Deposition of tan fossil-bearing layer. Land surface eroded, forming igneous peb- bles. Cross-cutting dike intruded. Green shale and gray limestone deposited horizontally. 35. Archaeology uses this spe- cific isotope to determine the age of bones, wood, and charcoal, preserved at a site. Carbon-14 36. Which of the following types of data could be used by geologists to esti- mate the age of past Earth events? Tree rings Ice cores Lake varves 37. You can use both super- position and contact ef- fects to determine that the light-colored volcanic rock is younger than the under- lying unit. True 38. Choose the rock types that might exist immediately be- low a nonconformity. Granite Nonlayered metamorphic rocks 6 / 23

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