TY - JOUR
T1 - Structural style, regional distribution, and seismic implications of midcontinent fault-anti-dold zones, United States
AU - Marshak, Stephen
AU - Paulsen, Timothy
N1 - Copyright:
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.
PY - 1997/7
Y1 - 1997/7
N2 - Paleozoic/Mesozoic strata of the United States continental interior contain arrays of steeply dipping faults and associated monoclinal forced folds. Though these Midcontinent fault-and-fold zones clearly were active in pulses during the Phanerozoic, we suggest that they initiated during episodes of Proterozoic extensional tectonism. Based on fault-trace orientation, we divide Midcontinent fault-and-fold zones into two sets - one trending N to NE and the other trending W to NW These sets effectively break the upper crust into blocks that jostle with respect to each other in response to changes in stress state. Notably, many W- to NW-trending fault-and-fold zones link along strike to define semi-continuous NW-trending deformation corridors. One of these, the 200 km-wide Transamerican tectonic zone (TTZ), traces over 2,500 km from Idaho to South Carolina. Seismic events occur in association with fault-and-fold zones, presumably because the zones persist as crustal weaknesses and/or stress risers. Significantly, seismicity most frequently occurs where N- to NE-trending fault-and-fold zones cross the TTZ, suggesting that intracratonic strain in the United States currently concentrates at or near intersecting fault zones within this corridor.
AB - Paleozoic/Mesozoic strata of the United States continental interior contain arrays of steeply dipping faults and associated monoclinal forced folds. Though these Midcontinent fault-and-fold zones clearly were active in pulses during the Phanerozoic, we suggest that they initiated during episodes of Proterozoic extensional tectonism. Based on fault-trace orientation, we divide Midcontinent fault-and-fold zones into two sets - one trending N to NE and the other trending W to NW These sets effectively break the upper crust into blocks that jostle with respect to each other in response to changes in stress state. Notably, many W- to NW-trending fault-and-fold zones link along strike to define semi-continuous NW-trending deformation corridors. One of these, the 200 km-wide Transamerican tectonic zone (TTZ), traces over 2,500 km from Idaho to South Carolina. Seismic events occur in association with fault-and-fold zones, presumably because the zones persist as crustal weaknesses and/or stress risers. Significantly, seismicity most frequently occurs where N- to NE-trending fault-and-fold zones cross the TTZ, suggesting that intracratonic strain in the United States currently concentrates at or near intersecting fault zones within this corridor.
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M3 - Article
AN - SCOPUS:0031472644
SN - 0012-8287
VL - 68
SP - 511
EP - 520
JO - Seismological Research Letters
JF - Seismological Research Letters
IS - 4
ER -