8. basement contraction & vert

7/30/2019 8. Basement Contraction & Vert

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8. BASEMENT8. BASEMENT--INVOLVEDINVOLVED

CONTRACTION ANDCONTRACTION AND

VERTICAL DISPLACEMENTVERTICAL DISPLACEMENT

Basement-Involved Contraction and Vertical

Topics

• Plate-Tectonic Habitat

• Boundary Conditions

• Brittle Basement-Involved Contraction

– Planar low-angle basement faults

– Planar high-angle basement faults

– Antilistric master faults

– Listric masterfaults

• Brittle Basement-Involved Vertical• Low-T Ductile Basement-Involved Contraction

Plate-Tectonic Habitat

from back-arc thrust belt to the craton

and in front of collision zones

basement wedges

block

uplift

Low-angle subduction favors basement involvementBoundary Conditions



Basement types

Brittle

crystalline

Low-T ductile sedimentary Low-T ductile crystalline

Fault Curvature

listric: HW dips away

from master fault

antilistric, upthrust: HW

dips toward master fault

Brittle Basement-Involved Contraction

• Planar low-angle master fault

– Homogeneous cover

– Stiff and soft layer cover

• Planar high-angle master fault

• Antilistric master fault

• Listric master fault

Planar, low-angle master thrust

homogeneous cover sequence

steep forelimb, gentle backlimb

Planar, low-angle master thrust

stiff layer in cover sequence



Major

basement

uplifts,

U.S. Rocky

Mts.

Structures are:

asymmetric

elongate-blocky

parallel

Typical Structure

Derby Dome, Wyoming

Dallas

Dome

2.4 million barrels oil

1.2 tcf gas

Dallas dome, Wyoming


Planar, high-angle master fault

High-angle thrust with stiff layer



Location of

Hamilton

Dome

U.S. Rocky

Mts.

Hamilton dome, Wyoming 263 million barrels oil, 1.9 tcf gas

Hamilton dome, Wyoming

well-based interpretation seismic and well-based interpretation

Hamilton Dome

Dollarhide field, west Texas


Dollarhide

field



same-sense reactivation

ms

W E

sub-Penn uncf

D

Subunconformity trapDollarhide field compartmental faults

seismic time slice

Dollarhide field

Rhourde el Baguel field, Algeria Rhourde el

Baguel field,

Algeria

top Cambrian ss

looking ENE

~3 billion barrels

oil in place

Rhourde el Baguel field

Antilistric master fault



East Grass Creek uplift, Wyoming

steep limb not well imaged

East Grass Creek uplift, Wyoming

steep limb not well imaged

South Coyanosa anticline, west Texas: anti-listric fault structure

antilistric fault structure

South Coyanosa field

Listric master fault



Location of

Wind River

uplift, U.S.

Rocky Mts. Structures are:

asymmetric

elongate-blocky

parallel

Typical Structure

Wind River Mts., Wyoming

Typical Structure: Wind River Mts.

Rotated Block Model

r = W / tan θ0 R = (W2 + r2)1/2

Length balance by area uplift at trailing edge



Location of

Rattlesnake Mt.

U.S. Rocky Mts.

short, steep forelimb

l o ng , s t r ai g ht b ac k l i mb p ar al l e l b e d d e d

drape fold

block

rotationx l i n e b a s e m e n t

Rattlesnake Mtn., Wyoming

Rattlesnake Mtn., Wyoming

uplifted, unrotated

r o t a t e d b l o c k

Rotated block modelRotated block model

55 billion barrels oil produced, 5 million/day production

5 bcf gas production /day



Rotated block modelRotated block model

r = 10.6 km, R = 23.4 km,

D = 2.8 km, H = R-r = 12.8 km

Z = H + ‘th. seds below C’ = 18.6 km

R r

Z

D = 2.8 km

Wrench (strike-slip) folds?Wrench (strike-slip) folds?

Depth Structure Map

Vertical Master Fault

Pryor Mts.

Clay model of vertical block uplift

Sand model of vertical block uplift

Location of

Rattlesnake Mt.

U.S. Rocky Mts.



Colorado National Monument

basement boundary faults

Colorado National Monument

c r o s s s e c t i o n s

cross sections across northern boundary of

Colorado National Monument drape fold

Colorado

National

Monument

Saybrook field, Ohio



Saybrook fieldfractured and dolomitized reservoir

up to 8% porosity

reserves of 0.1-10 million barrels

Saybrook field

time-structure maps

Low-T Ductile Basement-Involved

Contraction

Marsh Creek anticline

ANWR

pre Missippian

north flank of Sadlerochit Mts.



north flank of Sadlerochit Mts.

low-t metamorphic basement with vertical fold axes

Fourth Range

cross section of frontal Brooks Range structureInterpret the profile

ST 8-1

8. basement contraction & vert

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