GEOL 222 Final, Fall 2005

1 AMERICAN UNIVERSITY OF BEIRUT DEPARTMENT OF GEOLOGY FINAL EXAMINATION Sedimentology (Geol 222) February 2, 2006 Dr. Fadi Nader 8:00 am Exam rules apply Time: 2 hours PART I: PRACTICAL QUESTIONS 1. Rock classification (20 points): Name the rocks represented by the photomicrographs (A to F) shown on Plate I (page 5), according to the rock texture and the nature of constituents. • • For limestones, giv classification s classification table on page 6). Name also the porosity type(s) and amount(s) where appropriate. * The percentage estimation chart is on page 6. PART II: DEFINITIONS & SHORT ANSWERS 2. Define seven out of the ten following terms (20 points): Bounding surface [dunes] Accumulation surface [dunes] Alluvial fan Sorting Dissipative shorelines Cheniers Eustatic sea-level change Hummocky cross-stratification (HSC) Turbidites Sabkha 3. Short answers (20 points): a. List the various laboratory steps followed during a sieving experiment: b. Once channels are initiated in an alluvial setting, they may expand and shift position through a combination of: c. List the FOUR mechanisms of transport/deposition in an alluvial environment: 2 d. Name four different types of paleosols (usually, paleosols are recognized on the basis of organic, textural and stratigraphic features): e. The anatomy of a dune (in section) consists of the following features (you may draw a small sketch): f. Dune development could be inhibited by (factors): g. Where rivers flow into a basin, the effluent behavior and consequent depositional patterns (sediment delivery to the basin) depend upon: h. Define the three distinct zones of a delta-profile: i. List the major components of carbonate sediments: j. What are the three most common marine evaporite minerals and their respective seawater concentration thresholds required for precipitation? BONUS QUESTION ☺ ☺ : k. Speleothems (cave formations) were grouped into three main categories (White, 1976). These categories are: 3 PART III: DIAGRAMS/ FIGURES QUESTIONS 4. Add a figure-caption/title to the following diagram and discuss it briefly in less than 10 lines (10 points): 5. Add a figure-caption/title to the following composite figure including (5A; right) and (5B; below) and discuss it briefly in less than 10 lines (10 points): 5A � 5B 4 PART IV: DISCUSSION QUESTIONS 6. Answer one of the two following questions (20p): a. Discuss special sedimentological environment. To answer this question you need to: 1) d e ; 2) describe the different zones within an estuary; and 3) explain the classification of estuaries based on the dominant processes. *** Make use of the figures (6A) and (6B). 6A 6B b. Discuss the relationship between sea-level changes and carbonate production/ accumulation (i)? Define the different types of carbonate platforms (ii). Do these platforms behave similarly during sea-level changes (justify your answer; iii) ***Make use of the following figures (6C and 6D). 6C 6D GOOD LUCK 5 6