Stratigraphy and fossils Figure 8.2 (page 201) Go to next slide to begin

Sedimentation in lake or sea

Sedimentation in lake or sea Sediments are deposited in horizontal layers and slowly change into rock.

Younger Older

Younger Older If left undisturbed, the youngest layers remain above the oldest.

Stratigraphy and fossils Key Figure 8.3 (page 202) Go to next slide to begin

Outcrop A Outcrop B I II II III

Outcrop A Outcrop B I II II III

Outcrop A Outcrop B I II II III

Some of the fossils found in outcrop A are the same as fossils found in outcrop B, some distance away. Outcrop A Outcrop B I II II III

Some of the fossils found in outcrop A are the same as fossils found in outcrop B, some distance away. Outcrop A Outcrop B I II II Layers with the same fossils are the same age. III

Some of the fossils found in outcrop A are the same as fossils found in outcrop B, some distance away. Outcrop A Outcrop B I II II Layers with the same fossils are the same age. III

Stratigraphic succession Younger rocks I II III Older rocks A composite of the two outcrops.

Stratigraphy and fossils Select the principle of relative dating that is most useful in correlating rock strata among widely separated areas (regionally). A. Superposition B. Faunal succession C. Cross-cutting relationships D. Original horizontality

Stratigraphy and fossils Select the principle of relative dating that is most useful in correlating rock strata among widely separated areas (regionally). A. Superposition B. Faunal succession C. Cross-cutting relationships D. Original horizontality

Stratigraphy and fossils Who established the Principle of Faunal Succession? A. James Hutton B. Nicolaus Steno C. William Smith D. Harry Hess

Stratigraphy and fossils Who established the Principle of Faunal Succession? A. James Hutton B. Nicolaus Steno C. William Smith D. Harry Hess

Stratigraphy and fossils True or False: The Principle of Faunal Succession only applies to a single region, and it cannot be used to correlate stratigraphic sequences on different continents. A. True B. False

Stratigraphy and fossils True or False: The Principle of Faunal Succession only applies to a single region, and it cannot be used to correlate stratigraphic sequences on different continents. A. True B. False

Stratigraphy and fossils Select the kind(s) of geologic data that can be used to globally correlate strata. A. Fossil data B. Paleomagnetic data C. Seismic data D. Radioactive isotope data E. All of the above

Stratigraphy and fossils Select the kind(s) of geologic data that can be used to globally correlate strata. A. Fossil data B. Paleomagnetic data C. Seismic data D. Radioactive isotope data E. All of the above

The radioactive decay of rubidium to strontium Figure 8.11 (page 209) Go to next slide to begin

Rubidium-87 nucleus Neutrons Protons Electron

Rubidium-87 nucleus Neutrons Protons Electron A neutron decays, ejecting an electron…

Rubidium-87 nucleus Strontium-87 nucleus Neutrons Protons Electron A neutron decays, ejecting an electron…

Rubidium-87 nucleus Strontium-87 nucleus Neutrons Protons Electron A neutron decays, ejecting an electron… …and producing a proton, which changes the atom.

The radioactive decay of rubidium to strontium What do all isotopes of any given element have in common? A. Number of protons B. Number of neutrons C. Combined number of protons and neutrons D. All of the above

The radioactive decay of rubidium to strontium What do all isotopes of any given element have in common? A. Number of protons B. Number of neutrons C. Combined number of protons and neutrons D. All of the above

The radioactive decay of rubidium to strontium True or False: The half-life of a radioactive isotope does not vary with changes in temperature and pressure. A. True B. False

The radioactive decay of rubidium to strontium True or False: The half-life of a radioactive isotope does not vary with changes in temperature and pressure. A. True B. False

The radioactive decay of rubidium to strontium A mineral forms and initially incorporates only the parent atoms of a radioactive isotope and no daughter atoms. The parent has a half-life of 5000 years. How long before the parent to daughter ratio is 1:3? A. 5000 years B. 10,000 years C. 15,000 years D. 20,000 years

The radioactive decay of rubidium to strontium A mineral forms and initially incorporates only the parent atoms of a radioactive isotope and no daughter atoms. The parent has a half-life of 5000 years. How long before the parent to daughter ratio is 1:3? A. 5000 years B. 10,000 years C. 15,000 years D. 20,000 years

Original Horizontality The principles of Original Horizontality and Superposition allow for ____________ dates to be determined. A. Absolute B. Numeric C. Relative D. Radiogenic

Original Horizontality The principles of Original Horizontality and Superposition allow for ____________ dates to be determined. A. Absolute B. Numeric C. Relative D. Radiogenic

Original Horizontality In an undisturbed sequence of sedimentary rocks where do the oldest rock strata occur? A. At the top of the sequence B. At the bottom of the sequence C. It depends on the depositional environment

Original Horizontality In an undisturbed sequence of sedimentary rocks where do the oldest rock strata occur? A. At the top of the sequence B. At the bottom of the sequence C. It depends on the depositional environment

Sedimentary bedding True or False: Sediments can remain unlithified for millions of years before becoming lithified sedimentary rocks. A. True B. False

Sedimentary bedding A. True True or False: Sediments can remain unlithified for millions of years before becoming lithified sedimentary rocks. A. True B. False

Sedimentary bedding What kind of unconformity occurs between two horizontal sedimentary beds? A. A disconformity B. A nonconformity C. An angular unconformity

Sedimentary bedding A. A disconformity What kind of unconformity occurs between two horizontal sedimentary beds? A. A disconformity B. A nonconformity C. An angular unconformity

Wasatch Fault What is the approximate maximum age a piece of charcoal can be in order to determine its date using the carbon-14 method of dating? A. 4,000 years B. 70,000 years C. 1,000,000 years D. 50,000,000 years

Wasatch Fault What is the approximate maximum age a piece of charcoal can be in order to determine its date using the carbon-14 method of dating? A. 4,000 years B. 70,000 years C. 1,000,000 years D. 50,000,000 years

Transgression/Regression

Transgression/Regression When sea-levels fall, the sedimentary record of depositions along the coast records this change, which is described as: A. a transgression B. a turbidity current C. global warming D. a regression

Transgression/Regression When sea-levels fall, the sedimentary record of depositions along the coast records this change, which is described as: A. a transgression B. a turbidity current C. global warming D. a regression

Transgression/Regression When a transgression is observed in the sedimentary record, it is interpreted from a shift to off-shore marine facies as a result of: A. decreasing global temperatures B. sea-level rise C. subduction D. sea-level fall

Transgression/Regression When a transgression is observed in the sedimentary record, it is interpreted from a shift to off-shore marine facies as a result of: A. decreasing global temperatures B. sea-level rise C. subduction D. sea-level fall

Transgression/Regression While hiking in the Grand Canyon of northern Arizona, you stop and observe an outcrop that exposes three different sedimentary rock types. On the bottom is a layer of shale, which is overlain by a layer of limestone, which is in turn overlain by a layer of sandstone. This stratigraphy sequence indicates that a _________ or a _________ in sea-level occurred in this location in the past. A. transgression; fall B. transgression; rise C. regression; fall D. regression; rise

Transgression/Regression While hiking in the Grand Canyon of northern Arizona, you stop and observe an outcrop that exposes three different sedimentary rock types. On the bottom is a layer of shale, which is overlain by a layer of limestone, which is in turn overlain by a layer of sandstone. This stratigraphy sequence indicates that a _________ or a _________ in sea-level occurred in this location in the past. A. transgression; fall B. transgression; rise C. regression; fall D. regression; rise

Transgression/Regression What trend would you expect to find in sediments accumulating in any single location along the coast during a sea-level rise? A. the sediment size should decrease as you look up-section B. the sediment should become better sorted as you look up-section C. the sediment should become more rounded as you look up-section D. all of these E. none of these

Transgression/Regression What trend would you expect to find in sediments accumulating in any single location along the coast during a sea-level rise? A. the sediment size should decrease as you look up-section B. the sediment should become better sorted as you look up-section C. the sediment should become more rounded as you look up-section D. all of these E. none of these

Transgression/Regression Changes in global sea-levels are most often caused by shifts in climate. For example, a transgression would be caused by an increase in the melting rate of polar ice caps, which is in turn driven by: A. a reduced greenhouse effect B. an increase in atmospheric dust C. an increase in global temperatures D. a reduction in atmospheric carbon dioxide

Transgression/Regression Changes in global sea-levels are most often caused by shifts in climate. For example, a transgression would be caused by an increase in the melting rate of polar ice caps, which is in turn driven by: A. a reduced greenhouse effect B. an increase in atmospheric dust C. an increase in global temperatures D. a reduction in atmospheric carbon dioxide