Normal Faults Extensional Tectonics - PowerPoint PPT Presentation

1 / 40
About This Presentation
Title:

Normal Faults Extensional Tectonics

Description:

Bounded by normal faults. Back Arc extension. Extension of the lithosphere 1 ... Sand above plasticine. Block Rotation. Domino block rotation in the Basin and Range ... – PowerPoint PPT presentation

Number of Views:510
Avg rating:3.0/5.0
Slides: 41
Provided by: jaime97
Category:

less

Transcript and Presenter's Notes

Title: Normal Faults Extensional Tectonics


1
Normal FaultsExtensional Tectonics
2
Tectonic Settings for Extension
  • Divergent plate motions
  • Gravitational collapse
  • Over-thickened crust
  • Continental margins
  • Salt Domes

3
Extensional Tectonics
4
Divergent BoundaryNormal Faults, rifts
5
(No Transcript)
6
Continental Extension
7
(No Transcript)
8
Divergent Boundaries Continental Plate Separation
Parallel valleys volcanoes and earthquakes.
East African Rift Valley
Somali Subplate
African Plate
9
Rifts
Rifts Bounded by normal faults
10
Back Arc extension
11
(No Transcript)
12
Extension of the lithosphere 1
13
Extension of the lithosphere 2
14
Lithospheric Extension
  • Thinning of the lithosphere
  • Normal faulting at the surface
  • High heat flow (rinsing of the isotherms)
  • Thermal subsidence - gt sedimentary basins

15
(No Transcript)
16
North Sea Extensional Basin
17
Pure shear vs. simple shear systems
18
Gravitational Collapse of Mt. Belts
19
Basin and Range Province
20
(No Transcript)
21
New Mountains-Active Fault Basin and Range
Province

22
Two modes of extension
23
Out crop- domino blocks
24
Sandbox- Block rotation
Sand above plasticine
25
Block Rotation
26
Domino block rotation in the Basin and Range
27
Listric (curved) Faults- roll over anticlines
28
(No Transcript)
29
Small roll-overs
30
Sedimentation during faultingGrowth faulting
Animation by R. Allmendinger http//www.geo.cornel
l.edu/geology/faculty/RWA/movies/
31
Curved faults Block rotationGrowth Strata
0
3 km
32
Gulf of Mexico
33
Passive Margin
34
Gulf of MexicoSalt
35
Extension Above Salt Diapir
36
Transfer zone in a rift
37
(No Transcript)
38
(No Transcript)
39
Successive generations of normal faults
  • Older faults rotate and become inactive
  • New faults cross-cut them
  • Result large magnitude extension

40
(No Transcript)
Write a Comment
User Comments (0)
About PowerShow.com