GEOS 4350: Sedimentation & Stratigraphy

Homework 5: USGS Bulletin 1291


Our main objectives this semester are to understand: (i) how sedimentary processes produce a record of their actions in the rock record, and (ii) how geologists use this rock record to make inferences about past environments and processes. This homework assignment will provide an opportunity to review a number of sedimentology and stratigraphy concepts that we’ve covered in lecture, and to study an example of how sedimentary geologists deciphered past environments and processes in Unita Mountains.


The goal of this exercise is to (i) become more efficient at reading scientific reports, (ii) review and learn more about basic sedimentation and stratigraphy concepts, and (iii) see how different types of sedimentary data are integrated to create depositional models and investigate earth history.


Study the USGS Bulletin 1291: The Geologic Story of the Uinta Mountains in the Reading Assignments folder on eLearning to answer the following questions

1.     What is the USGS?

2.     What year was this USGS report published?

3.     Where are the Uinta Mountains located?

4.     What is the principle geological structure that characterizes the Uinta Mountains?

5.     How old are the sedimentary rocks that comprise the Uintas?

6.     What is the thickness of the sedimentary rock section in the Uintas?

7.     According to the article, what is a rock formation?

8.     What are the major sedimentary lithologies (rock types) that comprise the Uinta sedimentary rock section?

9.     According to the article, what were the main factors that caused vertical lithologic changes in the Uinta sedimentary rock section?

10.  According to the article, what were some major differences in sedimentation and environmental setting between the Precambrian, Paleozoic, Mesozoic, and Cenozoic?

11.  What are the main geological controls on the modern topography of the Uintas?

12.  Articulate at least three stratigraphy-related questions that you had while you studied the article.