folding of shale-sandstone sequence, kings canyon, california folds and thrust which deformation and...

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Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

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Page 1: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folding of Shale-Sandstone sequence, Kings Canyon, California

FOLDS and thrust

Which deformationand stresses

cause theses structures ?

Page 2: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

… Compression…Shortening

Page 3: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

The fold is like a Thrust defined

by its orientation

Parts of a fold:

–axial plane – limbs–“hinge”

Hinge

Page 4: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Types of Folds

• Anticline = arch

• Syncline = trough

• Monocline = stair step

• Dome or Basin

Chevron Fold, Laurel Mt., CA

Page 5: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Syncline

syncline, Israel

Youngest rocks in middle

Page 6: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Anticline

Virgin anticline, southern Utah

Oldest rocks in middle

Page 7: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Domes & Basins

Think of an Egg Carton!

Chernicoff and Whitney

Page 8: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Grenville Dome: Sinclair, WY

Map from Topozone.com

Page 9: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Syncline-AnticlinePairs + Domes: ZagrosMts, Iran

NASA “Earth as Art” web page

Page 10: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Monocline

Page 11: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Fold

Classification

Page 12: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Fold in Glacier, Antarctica

Page 13: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folds axis are perpendicular to the main direction of compression

Page 14: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Little Shuteye, S

ierra Nevada, C

A

David Rogers

Casey Moore, UCSC

Domes are not produced by horizontal but vertical compression

Page 15: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Minor Folds and Foliation Are Clues to Much Larger

Structures

Page 16: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Foliation

Pre

ssur

e

– pressure flattens and/or aligns minerals in a rock

– platy or sheet-like structure reflects the direction in which pressure was applied

– Slate, schist, and gneiss foliated

Microscope Image of Foliated Garnet Schist, VT

1 mm

Page 17: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

FoliationIn every case, the

foliation is:

In the direction of least resistance

at right angles to the direction of greatest compression.

Page 18: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Fold And Foliation

Page 19: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folds and Foliation

Page 20: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

How Geologists Use These Clues

• Here's an outcrop that might be seen in the field.

Page 21: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Minor Folds and foliations can be used to determine the axe of the fold

Page 22: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Pay attentionit migth look like folds

• K = Cretaceous• J = Jurassic• Tr = triassic• At X, we have

younger rocks surrounded by older rock

Page 23: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

But it is produced by differential errosion on a thrust

• Dark green is older rock, thrust over the younger yellow rock

• The Klippe (K)

• W is a Fenster or Window

Page 24: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folds and and Thrust are often associated

The overturned fold in the upper diagram may break, yielding an overthrust fold or thrust fault

Page 25: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folds and thrust have the same

origin

Page 26: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Small thrust fault, Las Vegas, NV,Source: M. Miller, U. of Oregon

ReverseFault

Page 27: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Thrust Faults in Snow

Page 28: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

fold-thrust complex developed in Upper Jurassic limestones in the Haut

Giffre area of the Subalpine thrust belt (Morcles nappe in France)

R.W.H. Butler

Folds and thrust are both responsible for the orogens

Page 29: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folded Appalachians

Near Harrisburg, PA, Source: NASA

Page 30: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?
Page 31: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Folding in Malaspina Glacier, AK, 1969

Page 32: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Oil and Gas Concentrate in Domes

Chernicoff and Whitney

Page 33: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Growth of Minerals

Page 34: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Bohlen et al., 1987

Folded Amphibolite in Marble, Warrensburg(K. Hollocher, NYSGA field photo)

Small Scale Structures Mimic Large Scale Structures!!

Page 35: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Mulwaree fault zone, Australia, Tullis et al.Foliated Gneiss, Nunavut,S. Tella Photo.

Foliated Slate, Shelburne, VT, UVM

Foliation Macroscopic and Microscopic

Feldspar (strong)

Quartz (weak)

Mulwaree fault zone, Australia

Page 36: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Pressure

K. Hamblin

A. Kronenberg

Cararra MarbleDeformationExperiments

Brittle Ductile

Page 37: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Continental Extension

Chernicoff and Whitney

Page 38: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Nevada Bureau of Mines and Geology

Basin and Range

Page 39: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Extension

– Crust Thins Ductile

– Faulting Brittle

Page 40: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Shearing

– lateral slip creates faults

– common at transform boundaries

Page 41: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Faults – result from brittle deformation

– rocks offset across fault

– Sides referred to as “hanging wall” and “footwall”

– 3 types of fault

Hanging Wall

Footwall

Page 42: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Strike & Dip

– Describe fault orientation

– Direction of slip determines kind of fault: “dip-slip” or “strike-slip” Chernicoff and Whitney

Page 43: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Normal Fault, Lamb Canyon, CA

NormalFault

Page 44: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Strike-slip fault near Las Vegas, NV,Source: M. Miller, U. of Oregon

Strike-SlipFault

Page 45: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Strike-slip fault displacement in orchard

Page 46: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Joints

• Brittle “cracks” in rocks

• Form near surface

• Regular spatial distribution

• No offset

Page 47: Folding of Shale-Sandstone sequence, Kings Canyon, California FOLDS and thrust Which deformation and stresses cause theses structures ?

Calcite veins in joints of marble, Laurel Mt., CA

Preferential weathering of joints in Sandstone;