1 / 37

Field Trip #3: Paleozoic Rocks II

Field Trip #3: Paleozoic Rocks II. Cretaceous Stratigraphy of Central Texas. Field Trip #3: Paleozoic Rocks II. Location Geology Assignment / Methods Reminders. Text: Manual, p. 267-278; Compton, p. 166-171; 182-184; 242-243. . Location. Hamilton Creek. Stop 1. (E. McBride).

Rita
Download Presentation

Field Trip #3: Paleozoic Rocks II

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Field Trip #3: Paleozoic Rocks II Cretaceous Stratigraphy of Central Texas

  2. Field Trip #3: Paleozoic Rocks II • Location • Geology • Assignment / Methods • Reminders Text: Manual, p. 267-278; Compton, p. 166-171; 182-184; 242-243.

  3. Location Hamilton Creek Stop 1 (E. McBride) Stop 2 road cut near Max Starke Dam (E. McBride)

  4. Location Creek near Stop 2 (Luis Garcia)

  5. Geology

  6. Geology Paleozoic Sedimentary Rocks Pennsylvanian – Smithwick Shale Ordovician – Honeycut Formation of Ellenburger Group Bastrop N 5 miles

  7. (Manual, p. 272)

  8. Geology Paleozoic Events • Flooding by Shallow Seas • Uplift Ouachita Mts (Penn) • Faulting (Penn) • Erosion of Ouachitas (P-J)

  9. Geology Ellenburger Group • sabkha • evaporites • karst • natural gas - subsurface (nps.gov)

  10. Geology Guidebook of the Geology of Travis County

  11. Geology Smithwick Shale • marine • high sediment supply • turbidites (E. McBride)

  12. Field Trip #3: Paleozoic Rocks II • Location • Geology • Assignment / Methods • Reminders Text: Manual, p. 267-278; Compton, p. 166-171; 182-184; 242-243.

  13. Assignment / Methods 1) Smithwick Shale Paleocurrent and Deformation Features • measure and plot the orientation of: • 1) joints • 2) faults • 3) sandstone dikes • 4) fossil wood fragments • 5) current ripples and solemarks

  14. sandstone feeder bed sandstone dike (416M) Assignment / Methods • water-saturated sediment • excess pore pressure

  15. Assignment / Methods clastic dikes and joints (E. McBride) (E. McBride)

  16. groove casts Assignment / Methods flute casts (416M) solemarks (416M) 416M

  17. Assignment / Methods • plot features in 4 rings • show # of measurements • show bi-directional trends

  18. Assignment / Methods 2) Honeycut Formation Checklist road cut near Max Starke Dam (E. McBride)

  19. Assignment / Methods limestone vs dolomite Dolomite - Thin Section Dolomite - SEM (Soil Science Society of America) (Soil Science Society of America)

  20. (Earth and Ocean Sciences at UBC) (Luis Garcia) Assignment / Methods stylolites vs stromatolites

  21. (Compton, p. 183) Assignment / Methods fault breccia vs solution collapse breccia • solution collapse breccia – filled cave • fault breccia – repeated crushing / cementation

  22. Assignment / Methods soft-sediment deformation vs brittle deformation (Compton, p. 243) • faults break more resistant layers only • mottled textures in shear zone

  23. Assignment / Methods teepee structure and geopetal structure Geopetal – Thin Section (Matt Campbell)

  24. Field Trip #3: Paleozoic Rocks II • Location • Geology • Assignment / Methods • Reminders Text: Manual, p. 267-278; Compton, p. 166-171; 182-184; 242-243.

  25. Reminders • Brunton • Rock Hammer • HCl Acid • Hand Lens • Field Notebook • Lab Manual • Water • Lunch • Clipboard • Colored Pencils • Ruler & Protractor • Extra Paper

  26. Field Trip #3: Paleozoic Rocks II Cretaceous Stratigraphy of Central Texas

  27. Cretaceous Stratigraphy of Central Texas • Paleogeography and Sea Level • Stratigraphy

  28. Paleogeography and Sea Level Late Cretaceous Paleogeography http://www4.nau.edu/geology/master.html?http://www4.nau.edu/geology/

  29. Cretaceous Stratigraphy of Central Texas • Paleogeography and Sea Level • Stratigraphy

  30. (Manual, p. 272)

  31. Stratigraphy (Duex and Lock, Univ. LA) • relatively flat-lying • retreating escarpment

  32. Stratigraphy • resistant and non-resistant limestone

  33. (www.cretaceousfossils.com)

  34. Stratigraphy • hard (pure) and soft (clay-rich) • shallow subtidal and supratidal (www.cretaceousfossils.com) Hensell Sand Badlands • sand, conglomerate, paleosols • terrestrial environment Glen Rose Limestone Stairsteps

  35. Stratigraphy Edwards Limestone “Swiss Cheese” • pure limestone and dolomite • chert-rich Oyster-rich Del Rio Clay • carbonaceous clay • pyrite – anoxic lagoon

More Related