FIELD PROBLEMS IN SEDIMENTARY GEOLOGY


Dept. #0423, Course #C19-0 Date & time: 3 week summer field trip + Fall Quarter TBA; (alternate years). Average enrollment: 6 (this is minumum enrollment for field course to run) COURSE DESCRIPTION: Field methods in stratigraphy and sedimentology; interpretation of depositional systems and paleoenviroments; methods of observations, data recording and analysis, and presentation of geological information (maps, cross sections). Course involves 2.5-week field trip to Colorado/Utah in late August - mid September (returning to Evanston in time for regular classes) and meets through the Fall quarter. Prerequisite - C13 Sedimentary Geology. PREREQUISITES: GEOL C13 TEACHING METHODS: Two days of lecture followed by 3.5 week field trip METHOD OF EVALUATION: Lecture participation/preparation C13 term paper review/rewrite Field trip participation Field notes and final field report READING: 1) Chap 1-4, 10-12 in Compton, R., 1962, Manual of Field Geology, Wiley & Sons, NY, 378 pp. 2) Chap. 10-13 in Boggs,1995, Principles of Sedimentology and Stratigraphy, Freeman and Co., N.Y., 410 pp. 3) Chap. 1-4, 7-10, 12, 14 in Walker, R.G. & James, N.P. (eds.), 1992, Facies Models, Response to Sea Level Change, Geological Assoc. of Canada, 409 pp. 4) Ager, D., 1973, The Nature of the Stratigraphical Record 3rd ed., Wiley & Sons, NY, 151 pp. COURSE OUTLINE: C19 is students will preregister for C19 in the Spring quarter. The course will be scheduled for the Fall quarter, but the field trip will actually take place in early September just prior to beginning of the Fall quarter. Final reports will be due at the end of the Fall quarter (12/2). The course has four components: a) Preparatory phase (Spring quarter; June-August): Background for the course is introduced in GEOL C13 during the Spring quarter. Students in C13 who will take C19 in the Fall will complete a C13 term paper on a field trip site. The term paper will be included in the C19 guidebook and these students will present a field lecture on their site during the field trip. In addition, background reading for the field trip will be assigned at the end of Spring quarter to all students who preregister for C19. b) Lecture phase (2-days in early September): After arrival in Colorado, there will be 8 hrs of lecture and workshop to review concepts (depositional systems, facies models, and field methods), evaluate retention of background reading, and provide instructions for the format of field notebooks and field exercises. c) Field trip/field exercise phase (approx. 20 days in the field): A series of sites have been chosen with specific field exercises to be performed at each. Students will record measurements and observations. Each day will end with a summary discussion. See below for sites/ exercises. d) Write-up phase: Fall Quarter lab sessions will be scheduled upon return. The lab sessions will be devoted to discussion of field notes, interpretations of data, and format for the final report. Evaluation of student performance will be based on the quality of the field notebook, participation in the field exercises, quality of field lecture, mastery of the reading material, and quality of the final report (including completed maps and charts and interpretative write-up).

SYLLABUS

Lecture Topics

(4 two-hour lectures + workshops) 1) Review - Depositional environments/facies models 2) Nonmarine environments/facies models 3) Marine siliciclastic environments/facies models 4) Marine carbonate environments/facies models 5) Pennsylvanian through Cretaceous History of Colorado 6) Sedimentologic field methods 7) Stratigraphic field methods 8) Field trip itinerary and exercises

Field Trip Exercises

1) General descriptions of stratigraphic units - (All formations seen on field trip) 2) Detailed measured sections (using jacob staff, tape measures, etc.) a) Lee Hill Rd. - Fountain Fm. to base of Cretaceous b) Lykins Gulch Section - Carlile Shale to Ft. Hayes Limestone c) 6-mile Fold - Carlile Shale to Ft. Hayes Limestone d) Alameda Rd. and Turkey Creek outcrops - Dakota Fm. e) Rock Canyon Anticline - Dakota SS; Greenhorn LS to Ft. Hayes LS f) Wahweap Wash, Utah - Dakota SS and Mancos Shale 3) Detailed descriptions of sedimentary and biogenic structures a) Fountain Fm. (Pennsylvanian), Lee Hill Rd. b) Lyons SS (Permian), Lyons Quarry c) Dakota SS (Cretaceous), North Boulder, Alameda Parkway, Turkey Creek, Rock Canyon, Wahweap Wash. d) Greenhorn Formation, Rock Canyon e) Codell SS to Ft Hayes LS, Rock Canyon 4) Descriptions of modern sedimentary processes Eolian Processes - GSD Natl. Park

Field Trip Itinerary - Exercise areas

5 days - Boulder-Denver, CO area - Fountain through Greenhorn 3 days - Rock Canyon, CO area - Greenhorn and Niobrara cyclothems 3 days - CO to UT traverse - trace Greenhorn west 3 days - Wahweap Wash, UT area - Dakota SS and Tropic Shale 2 days - Castle Dale, UT - Ferrron SS

Final Report must include:

1) Measured Sections a) Generalized measured section for Front Range succession (Pennsylvanian - Cretaceous). b) Detailed measured section of Fountain-Lyons transition. c) Detailed measured sections for Dakota Group (CO and UT). d) Detailed measured section for Greenhorn Formation. d) Detailed measured section for Blue Hill SH through Ft. Hays LS. e) Detailed measured section for Dakota-Mancos Formations. 2) Correlation diagram Correlation of Dakota interval Correlation of Greenhorn interval 3) Interpretive reports Write up of each section with a) interpretation of depositional environment for each unit; b) interpretation of sequence stratigraphy and sea level history; summary of geologic history. Reports must cite field observations (from field notebooks - also handed in) in support of all interpretations.