GEOL 106 The Earth Through Time Study Guide for Exam 2 The list of topics and questions below is meant to clarify the degree to which you should understand concepts and details for the upcoming exam The list is not exhaustive Instead it includes the main learning objectives for each lecture and reading that will be covered on the exam If you cannot answer one or more of the questions on the list consult your lecture notes and or the reading assignments for more information Topics and Questions 1 Sedimentary Environments What are texture composition and sedimentary structures and how do they help to recognize the environment in which a sedimentary rock was deposited In what types of sedimentary environments do cross bedding graded bedding and ripple marks form In what type of sedimentary environment do mud cracks form and what do they represent Advice study Figures 4 52 and 4 53 to answer the following questions What is a fluvial environment and what types of sediments are deposited there What is a desert environment and what types of sediments are deposited there What is a glacial environment and what types of sediments are deposited there What types of sediments are deposited on a continental shelf What is the role of waves in determining the types of sediments that are deposited on a shelf What types of sediments are deposited on a continental slope and on an abyssal plain deep marine What is the difference between a carbonate reef and a platform What are transitional environments and what types of sediments are deposited there 2 Stratigraphy What is the stratigraphy of the rock record and why does it apply mostly to sedimentary rocks What is conformable bedding in a sedimentary rock or within a sequence of sedimentary rocks What are the three types of unconformities and why are they important in stratigraphy Why is the principle of inclusions important for identifying nonconformities in stratigraphy What are some examples of sediment facies What are transgressions and regressions and how are they represented in a sequence of sedimentary rocks What is Walther s principle and why is it important in stratigraphy 3 Fossils and Fossilization What is the difference between a body fossil and a trace fossil Under what conditions are fossils preserved in sediments How are fossils preserved through permineralization replacement and carbonization 4 Biostratigraphy What is meant by the appearance common interval and extinction of a fossil in the rock record How do fossils and the rocks that host them represent geologic time What is the principle of fossil succession and why is it important What is a stratigraphic column How can it be used to organize the rock record and geologic time What is an index fossil What are the common properties of index fossils What properties of ammonites make them good index fossils for the Cretaceous Period 5 Evolution What is fossil succession and how is it related to evolution What is Darwin s theory of natural selection and how does it apply to a population of individuals of the same species What are differences between Lamarck s and Darwin s hypotheses about how animals adapt and evolve What are some examples of evolution as represented in the rock record How did Mendel s experiments lead to the discovery of genetics