Geology 103 (Sedimentology and Stratigraphy)
California State University, Sacramento
Week 9: Alluvial fans, braided streams |
Objectives:
Upon completion of this unit students should be able to:
Describe longitudinal and lateral profiles (shapes) of an alluvial fan.
Discuss the difference between a debris flow and a stream-dominated alluvial fan.
List common features and deposits of an alluvial fan, including grain size patterns (longitudinal and vertical).
Name the parts of an alluvial fan, and discuss the sedimentary structures in each.
Discuss braiding parameter and meander wavelength as a method of classifying stream types (Rust's classification).
Describe the flow, load, gradient, bar forms, bank material and general architecture of a typical braided stream.
Distinguish between longitudinal, linguoid/transverse and lateral bar forms.
Reading Assignments:
Lecture 13: Alluvial fans- Boggs, 5th edition, pp. 208-209, 211-215
Lecture 14: Braided streams- Boggs, 5th edition, pp. 215-220
Fill out a reading log for each reading assignment. Reading logs are due at the start of class on Wednesday
Class notes:
Graphics from lectures:
Lab this week:
Petrology of evaporites and chemical sedimentary rocks. We will look at hand specimens of coal, chert, ironstone and evaporites. You will fill out a worksheet in class and check your answers. Correct your answers, and then take an open-book quiz before you leave lab.
I will pass out a copy of the lab when we meet. You do not need to print a copy of the lab. This copy is for your reference or to replace lost labs!