Week 7: Palaeontology and stratigraphy

(1) Which of the following would NOT be considered a fossil? (a) a dinosaur bone (b) a dinosaur footprint (c) the impression of a fern leaf (d) a basalt dyke (2) In which of the following rocks would you be most likely to find fossils? (a) gneiss (b) limestone (c) granite (d) basalt (3) What type of fossil is shown in the picture? (a) body fossil (b) trace fossil (c) permineralized fossil (d) cast fossil (4) Why are feathers rarely found in the fossil record? (a) because birds usually die in dry environments (b) because feathers do not contain hard parts (c) because feathers are very small and thus are not well preserved (d) because birds die in forests, areas with high oxygen levels (5) Why do plants generally become carbonized impressions if they are preserved as fossils? (a) because chemical reactions leave behind only the carbon (b) because they often begin to decay before fossilization (c) because they are easily moved by wind and water (d) because they are generally scavenged by animals (6) Which of the following circumstances is likely to preserve a fossil? (a) Leaves from an ancient oak tree fall to the ground in a forest (b) A mammoth dies of starvation in the middle of a vast dry plain (c) A jellyfish is buried by a submarine landslide (d) Bacteria living in the ocean die near the shoreline and sink to the bottom (7) What type of fossil forms when a buried organism decays or is dissolved, but the original shape is preserved in the sediment? (a) body fossil (b) trace fossil (c) mold fossil (d) cast fossil (8) Which of the following is a brachiopod? (a) Figure 1 (b) Figure 2 (c) Figure 3 (d) Figure 4 (9) Fossils are most often identified based on changes in their ________, which is easily recognizable, even in the field (a) morphology (b) DNA (c) domain (d) lifestyle (10) Imagine that a layer of leaves is scattered along a forest floor; what must happen in order to preserve these leaves as fossils? (a) The leaves must be picked up by wind or animals and carried to a desert. (b) The leaves must be buried slowly so that the leaves can begin to rot. (c) The leaves must be buried rapidly in order to keep out oxygen (d) The leaves will never be preserved as they do not contain hard parts (11) Explain why the fossil record is incomplete. (12) What is a fossil? In what type(s) of rock are fossils most likely to be found? Why? Page 2 of 36 Relative dating and Stratigraphy (1) If the relative ages of two formations are known, what else about them can be inferred? (a) their absolute ages (b) their fossil assemblages (c) their lithologies (d) their relative position in the geologic column (2) Based on the figure below, what is the age of Layer 7 relative to Layer 3 (a) Layer 7 is younger than Layer 3 (b) Layer 7 is older than Layer 3 (c) Layer 7 and Layer 3 are the same rock type, so they are the same age (d) Their relative ages cannot be determined (3) Based on the figure above, which principle of stratigraphy could be used to determine the relative ages of Layer 7 and Layer 3? (a) the principle of fossil succession (b) the principle of original horizontality (c) the principle of lateral continuity (d) the principle of inclusions Page 3 of 36 (4) Uniformitarianism is succinctly summarized by which phrase? (a) The future is the key to the present (b) The present is the key to the past (c) The past is the key to the present (d) The present is the key to the future (5) As understood by modern geologists, the principle of uniformitarianism implies that (a) the Earth has always had the same basic appearance that it has today (b) igneous, metamorphic, and sedimentary rocks are uniformly mixed throughout the crust (c) physical processes observed today (such as erosion and volcanic eruptions) have been active in the past at roughly the same rates (d) physical processes observed today (such as erosion and volcanic eruption) occurred much more rapidly in the past, quickly sculpting the Earth’s surface (6) In the area immediately surrounding an igneous intrusion, a host limestone is locally metamorphosed to produce marble. Which of the following statements is correct? (a) The intrusive igneous rock must be older than the limestone (b) The limestone must be older than the marble (c) The limestone must be you