Objectives:

Upon completion of this unit students should be able to: List and discuss the main transporting agents and methods of particle transport in a moving fluid. Describe bedforms that occur under different flow conditions. Use the appropriate terms to describe bed thickness and different types of bedding Describe ripple morphology or name ripples in plan view and in cross-section Use cross-bedding to tell flow direction

 

Reading Assignments:

Lecture 4: Density and viscosity, particle transport, Hjulstrom curve- Boggs, 5th edition, pp. 27-31   Lecture 5: Bedform progression, beds and bedding- Boggs, 5th edition, pp. 65-75   Fill out a weekly reading log for these assignments.  The weekly reading log is due Wednesday.   Reading log

 

Class notes:

Lecture 4 notes Lecture 5 notes

 

Lecture graphics:

Lecture 4 graphics Lecture 5 graphics

 

Lab: Sand texture and composition

Lab and homework:   In lab this week we will look at two new sand samples.  You will describe the composition of each unknown sand sample, and interpret the sources or environments.   Your homework is to describe the two unknown sands.  Your description should be word processed, double-spaced and spell-checked.  Use technical writing style.   The assignment will be due at the start of next week's lab.   What to include in your lab writeup:   Observations Start with a sentence or two that summarizes the general features of the sand:  average grain size (Wentworth name) and sorting.  Refer to the table in the text.   Follow the general observations with a detailed analysis of grain composition.  Be concise and accurate!  Use the table to organize your answer.  Longer descriptions are not necessarily better.   Round off estimates to the nearest 10%. The table should have these columns:   Composition Percent Size range Roundness Color Other                                                               Interpretations Finish with a short paragraph of interpretations about the unknown sand.  Identify interpretations with a heading so they stand apart from your observations.  Can you tell anything about the source for the unknown sand?  What types of material were present in the source area? Discuss the textural maturity of the sand.  Use sorting, grain size and grain texture (polish, frosting, etc) to justify your answer.  Discuss the compositional maturity of the sand.  Use the presence of soft or resistant grains to justify your answer.  How far did the grains travel before deposition? Can you identify the environment or agent of deposition?  Support your answer with information about the sorting or texture of the sample. Answer key for unknown #1   Answer key for unknown #2