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Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Jan 02, 2016

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Nathan Park
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Page 1: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 2: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 3: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 4: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 5: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 6: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Problem imaging the forelimb… critical for evaluating the structural style

Page 7: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Problem imaging fore-limb from seismic… interpretations are commonly strongly model-driven

Page 8: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

First-pass interp - steep faults..…not in vogue

Page 9: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Low-angle thrust (detachment at depth??)

Page 10: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 11: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Simple fault-bend fold

Suppe model

Page 12: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 13: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 14: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 15: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 16: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 17: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Suppe fault bend folding…..

But is this too simplistic a style?

Page 18: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 19: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 20: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 21: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 22: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 23: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Fault-bend foldingFault-propagation folding

Panels of constant-dip strata, folds grow by hinge migration

Page 24: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Test kinematic models using growth strata

Growth triangles

Page 25: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

“growth fans” ratherthan “growth trianglesare the usual style….

So are the fault-bendmodels applicable?

Page 26: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 27: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 28: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 29: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Detachment fold

Page 30: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 31: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

From Sherkati et al. 2004 (Mar. Pet. Geol. )

Page 32: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

McQuarrie 2004 J. Struct. Geol.

Page 33: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 34: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Structural styles in the Zagros…..Geomorphologic evolution suggests buckle sheet“detached” on Hormuz salt+ minor internal detachments

Page 35: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Geomorphological studies of developing folds using Landsat imagesfrom the Zagros Mountains, Iran. (Henry Lickorish)

Page 36: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 37: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 38: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Fold collision

Page 39: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Fold interactions:• Long cylindrical • Abrupt plunges• Collided folds• Merged folds

Page 40: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 41: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Fold train initiatesIf one fold amplifies slightly faster…it will weakenSo strain transferred onto that fold - other folds slow down/stop.System experiences stress drop.

Page 42: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

CONTROLS ON BUCKLE FOLD EVOLUTION?

Page 43: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 44: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Quantify through modellingby Martin Casey….

Page 45: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Buckle fold development

Finite element modelling by Martin Casey

Page 46: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Viscosity ratio 10:1

Differential stress

Page 47: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 48: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 49: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 50: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Stress concentratedin hinge area

Differential stress

Stress dropon limbs

Page 51: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Example….

Page 52: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Chevron fold (Hartland Quay)

• Bed-parallel slip• Strain in hinge

Page 53: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Structures on limbs

shear fibres on beddingfractures in beds

More models…..

Page 54: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Contrast with higher viscosity ratio...

Page 55: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 56: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 57: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 58: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 59: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Stress dropthroughout

Page 60: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Viscosity ratio 10:1

Viscosity ratio 40:1

Longer wavelength (and lower diff stress) for higherviscosity contrast

Page 61: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Unloading limbs - can promote fracture here

Stress history is complex

But can be modelled…..

Page 62: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Modelling fracture potential

and evolution

Timing might be crucial….Diagenetic “events”Fluid migration “events”

Page 63: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Buckling is important

Stress history is complex

Model in 3D… and….Fold-thrust complexes

Page 64: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 65: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Multilayers?

Page 66: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Examples from Champsaur

Page 67: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 68: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 69: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

WNW ESE

Page 70: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 71: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

WNW ESE

Page 72: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 73: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Thrust cuts through Ramp area folds Thrust breaks back

? continuum - localised slipplus distributed deformation

Page 74: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

WNW ESE

Page 75: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 76: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 77: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

Different predictionsfor sand connectivity

Precursor buckling important….

Page 78: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear

Page 79: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 80: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 81: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 82: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

• Strat YES

• Complex localisation orogenic interiors?

Page 83: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 84: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 85: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 86: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 87: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 88: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 89: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.
Page 90: Introduction Fault-bend folding Fault-propagation folding Detachment folding Buckles Fold-thrust complexes in multilayers Trishear.

IntroductionFault-bend foldingFault-propagation foldingDetachment foldingBucklesFold-thrust complexes in multilayersTrishear