1 / 25

Class Outline

Learn basic techniques and principles in structural geology, deformation mechanisms, continuum mechanics, and earthquake focal mechanisms in this course. Includes hands-on field measurements and mapping using stereographic projections.

vsnodgrass
Télécharger la présentation

Class Outline

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. Class Outline • Deformation of the lithosphere, an overview • Basic Techniques in Structural Geology and Tectonics • Basic of Continuum mechanics- strain • Basic of Continuum mechanics- stress • Deformation Mechanism…

  2. II. Basic Techniques in Structural Geology • Fundamental principles • Field measurements and mapping • Stereographic projections • …

  3. Representations of lines and planes.. Line as a pole.. Plane as great circle..

  4. Stereographic equal-angle projection (Wulff’s Stereonet) Lambert’s equal area projection (Schmidt;s stereonet)

  5. Spherical coordinate frame… Polar Net (N is the pole of the coordinate net)

  6. Stereographic nets (equal-angle nets or Wulff)’s stereonets) NB: Only half of the sphere is generally plotted Polar Net (polar axis vertical) Meridional Net (polar axis horizontal)

  7. Equal-area nets- Schmidt Polar Net (polar axis vertical) Meridional Net (polar axis horizontal)

  8. Projecting data… B(B’): 72,0 (252,0) C:72,45

  9. B (B’): 72,0 (252,0) C:72,45 Q: 227, 43 (e.g., dip direction of a bed S: 47, 47 (pole to bedding defined by Q)

  10. Paper & pencil..

  11. Measuring angles on a sterographic projection… P: 272,45

  12. Fold axis of (Cylindrical) fold might be determined from the intersection of bedding planes.

  13. Folded beddingas poles &as great circles.. β diagram n(n-1)/2 intersections Π diagram

  14. Elastic Rebound Theory Interseismic strain (locked fault gets stressed) Co-seismic strain (fault failure during Earthquake Posterior to Last earthquake

  15. First Motions

  16. P-wave Radiation Pattern

  17. Earthquake focal mechanisms will always have variations in polarity. Some stations will have first motion up, others first motion down.

  18. First Motions: Denali Earthquake

  19. Earthquake Focal Mechanisms

  20. Earthquake Focal Mechanisms

More Related