Finite strain and strain variation analysis in the Sheeprock Thrust Sheet: an internal thrust sheet in the Provo salient of the Sevier Fold-and- Thrust belt, Central Utah
IR@C-MMACS: CSIR-Centre for Mathematical Modelling and Computer Simulation, Bangalore
View Archive Info| Field | Value | |
| Title |
Finite strain and strain variation analysis in the Sheeprock Thrust Sheet:
an internal thrust sheet in the Provo salient of the Sevier Fold-and-
Thrust belt, Central Utah
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| Creator |
Mukul, Malay
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| Subject |
Geosciences
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| Description |
The Sheeprock thrust sheet in west-central Utah is an internal thrust sheet in the Provo salient of
the Sevier fold-and-thrust belt. We have measured finite strain in quartzites (the dominant lithology), sampled
along a square grid within the thrust sheet, using the modified normalized Fry method (McNaught, M. A.
(1994) Modifying the normalized Fry method for aggregates of non-elliptical grains. Journal qf Struc.turrrl
Geology 16 4933503). The X/Y and X/Z axial ratios from unsampled locations within the sample area were
estimated using the spatial statistics approach. The strain ellipsoids exhibit a variable three-dimensional orientation
pattern resulting from modification of the initial layer parallel shortening (LPS) strain ellipsoid by fault
parallel shear in conjunction with vertical flattening and/or horizontal stretching indicating that the thrust
sheet did not undergo plane strain deformation in the transport plane. This suggests that the plane strain
assumption used in drawing restorable balanced cross-sections breaks down for internal thrust sheets with
more than one penetrative-strain producing deformation event. The X!Z strain axial ratios decrease away
from the thrust towards the middle of the sheet. The X/Y strain axial rattos from interpolated image diagrams
indicate transport-parallel stretching at the front end of the sheet and strike-parallel stretching at the back end
of the sheet. The footwall and hanging wall finite strain patterns are similar indicating that most of the strain
in the Sheeprock thrust sheet developed early in the deformation history of the thrust sheet before and perhaps
during the growth of a large fault propagation fold pair.
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| Publisher |
Elsevier Science Ltd
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| Date |
1998
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://cir.cmmacs.ernet.in/288/1/MukulMitra1998.pdf
Mukul, Malay (1998) Finite strain and strain variation analysis in the Sheeprock Thrust Sheet: an internal thrust sheet in the Provo salient of the Sevier Fold-and- Thrust belt, Central Utah. Journal of Structural Geology, 20 (4). pp. 385-405. |
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| Relation |
http://www.elsevier.com
http://cir.cmmacs.ernet.in/288/ |
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