Earth’s Plates.

Apresentação em tema: "Earth’s Plates."— Transcrição da apresentação:

1 Earth’s Plates

2 Stress-Strain Curves Elastic Limit

3 The Donath deformation apparatus
Confining pressure in nature is supplied by the pressure exerted by the weight of interconnected pore fluids (hydrostatic pressure) and the overlying rockmass (lithostatic pressure). Here it is supplied by pumping up fluid pressure.

4 Calculating Axial Stress
What we know is the load or force that is being applied (F) and the cross sectional area of the (A). s = F / A We keep track of a pair of numbers:, e - axial strain and; s - axial stress and plot them in x,y space (respectively).

5 Effect of Temperature on Strength

6 Limestone become progressivley more ductile at higher confining presures

7 rocks, like the fence, will deform in different ways, depending upon
the properties of the rock and the nature of the applied stress Dobras Falhas

8 estudo da “arquitetura da Terra” ….examinação de rochas deformadas
Geologia Estrutural estudo da “arquitetura da Terra” ….examinação de rochas deformadas DEFORMAÇÃO: mudanças em locação, orientação, forma, volume Dúctil brittle (breaks) from: Davis and Reynolds, 1996

9 Conceitos Geológicos TIPOS DE FALHAS

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12 General Nature of Shear Fractures
Shear fractures form from slip parallel to the face of the joint. They are about the same size and scale as joints, occur in parallel sets, with spacings that are a function of the strength of the rock - as in regular joints. The surfaces are actually very small-displacement faults, that are often adorned by slickenlines.

13 The apex of the acute angle points in the direction of shortening
Slickenlines indicate movement direction.

14 Plumose Structure

15 CONCEITOS GEOLÓGICOS TIPOS DE FALHAS

16 TIPOS DE FALHAS Falhas Normais e Inversas
Seção vertical de uma falha normal Zona de omissão indica movimento extensional Seção vertical de uma falha inversa Área de repetição indica movimentos compressivos

17 Falhas Transcorrentes
Movimentos senestral – bloco da esquerda avança Movimentos destral – bloco da direita avança

18 CA Tectonic Elements

19 Offset Ditch, Hollister, CA - 1975

20 Offset Ditch, Hollister, CA - 1992

21 Sistema de falhas normais simétricos e assimétricos
Nonrotational Rotational

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24 Stress-Strain Curves Elastic Limit

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26 Stress-Strain

27 Fold Elements

28 Palmdale, CA Road Cut

29 Shear stress and strain

30 Photo credit: G. Mattioli

31 Steeply Dipping Beds, Pt. Arena, Ca

32 Medidas de campo