1 / 24

Lab # 5 Review

Learn how to build, restore, and balance cross sections through terminology, examples, and exercises. Dive into faulting theories, fold and thrust belt concepts, and practical restoration techniques. Master key principles and methods for structural analysis.

kerrymartinez
Download Presentation

Lab # 5 Review

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. Lab # 5 Review Fractures, Faults, & Friction

  2. Coulomb Failure Law

  3. Byerlee’s Law

  4. Envelope of Frictional Sliding

  5. Importance of Differential Sress

  6. Sandbox Experiment

  7. Anderson’s Theory of Faulting

  8. Principal Stresses and Faulting

  9. Lab #7 Balancing & Restoring Cross Sections

  10. Structure of the Lab • Go through terminology and example • Build a simple cross section (Problem 1) • Restore a simple cross section (Problem 2) • Start working on assignment, Problem 3

  11. Cross Sections • Deformed Cross Section: subsurface geology as it is now • Restored Cross Section: what subsurface looked like before deformation • Balanced Cross Section: deformed cross section capable of being restored

  12. Fold and Thrust Belt • result of crustal shortening Older Younger Foreland Hinterland   blind thrust  ramp flat

  13. Assumptions • Conservation of Area • Consistency of Bed Length • Plane Strain • Break-Forward Sequencing • Forward Ramping Faults • Kink-Style Folds

  14. Kink Folds

  15. Kink Method Example • We first find the line L12 that bisects the angle between dips 1 and 2 • Extend the dips out to L12. When you cross the line, continue with the dip on the opposite side

  16. Continue Plotting Axial Traces (Steven Dutch)

  17. Completed Beds (Steven Dutch)

  18. Fill in the Lithologic Units (Steven Dutch)

  19. Restoring a Cross Section • Identify the foreland & hinterland • Identify the transport direction • Choose a pin line • Label each point where the trace of the axial plane of a fold crosses a contact - these will be your line segment end-points • restore youngest fault first • restore line segments • evaluate your loose line

  20. Bed Length Conservation • If you encounter a folded layer in the deformed cross section that does not intersect a fault, simply reproduce it as a horizontal line in the restored section.

  21. Restoring a Cross Section - Faults • Follow the fault in the direction opposite the Transport Direction until you hit the ramp. Draw a horizontal line segment at the top of the ramp with the same length as you measured above for the line segment. • Faults should be reproduced as they are (without making lines horizontal) unless they show signs of being folded by younger stage faulting. This is part of why we restore youngest faults first!

  22. Chevron Fold

  23. Kink bands

More Related