TY - JOUR
T1 - Cenozoic structural evolution of the Catalina metamorphic core complex and reassembly of Laramide reverse faults, southeastern Arizona, USA
AU - Favorito, Daniel A.
AU - Seedorff, Eric
N1 - Funding Information:
Financial support for this project was provided by the Lowell Institute for Mineral Resources at the University of Arizona, a Society of Economic Geologists Graduate Student Research Grant (Hugh E. McKinstry Fund), a Geological Society of America Graduate Student Research Grant, and by the Arizona Geological Society J. Harold Courtright Scholarship. Detailed and constructive reviews by Jon Spencer and John Singleton, as well as comments by associate editor Bob Miller, contributed to a significantly improved manuscript. Petroleum Experts graciously provided an academic license for Midland Valley MoveTM. Chris Clinkscales, Roy Greig, Steve Lingrey, Mark Barton, Roy Johnson, and Amanda Hughes are thanked for their geologic insights. We thank Winston Bardsley, Riley Burkart, Ryan Harris, and Chris Clinkscales for their assistance in field work. This study benefited from conversations about local and regional geology with Carson Richardson, J.D. Mizer, Phil Nickerson, and Sean O’Neal. We appreciate feedback provided to us on related studies by Jon Spencer, Steve Richard, Tim Lawton, Terry Pavlis, Eric Erslev, Richard Tosdal, John Grocott, and Sean Long. We thank George Gehrels, Mark Pecha, and Dominque Giesler for their guidance in carrying out and interpreting U-Pb zircon geochronology. Finally, we thank Kiriaki Xiluri and Amanda Hughes for computer and software licensing support.
Funding Information:
Financial support for this project was provided by the Lowell Institute for Mineral Resources at the University of Arizona, a Society of Economic Geologists Graduate Student Research Grant (Hugh E. McKinstry Fund), a Geological Society of America Graduate Student Research Grant, and by the Arizona Geological Society J. Harold Courtright Scholarship. Detailed and constructive reviews by Jon Spencer and John Singleton, as well as comments by associate editor Bob Miller, contributed to a significantly improved manuscript. Petroleum Experts graciously provided an academic license for Midland Valley MoveTM. Chris Clinkscales, Roy Greig, Steve Lingrey, Mark Barton, Roy Johnson, and Amanda Hughes are thanked for their geologic insights. We thank Winston Bardsley, Riley Burkart, Ryan Harris, and Chris Clinkscales for their assistance in field work. This study benefited from conversations about local and regional geology with Carson Richardson, J.D. Mizer, Phil Nickerson, and Sean O'Neal. We appreciate feedback provided to us on related studies by Jon Spencer, Steve Richard, Tim Lawton, Terry Pavlis, Eric Erslev, Richard Tosdal, John Grocott, and Sean Long. We thank George Gehrels, Mark Pecha, and Dominque Giesler for their guidance in carrying out and interpreting U-Pb zircon geochronology. Finally, we thank Kiriaki Xiluri and Amanda Hughes for computer and software licensing support.
Publisher Copyright:
© 2021. All Rights Reserved.
PY - 2021
Y1 - 2021
N2 - This study investigates the Late Cretaceous through mid-Cenozoic structural evolution of the Catalina core complex and adjacent areas by integrating new geologic mapping, structural analysis, and geochronologic data. Multiple generations of normal faults associated with mid-Cenozoic extensional deformation cut across older reverse faults that formed during the Laramide orogeny. A proposed stepwise, cross-sectional structural reconstruction of mid-Cenozoic extension satisfies surface geologic and reflection seismologic constraints, balances, and indicates that detachment faults played no role in the formation of the core complex and Laramide reverse faults represent major thick-skinned structures. The orientations of the oldest synextensional strata, pre-shortening normal faults, and pre-Cenozoic strata unaffected by Laramide compression indicate that rocks across most of the study area were steeply tilted east since the mid-Cenozoic. Crosscutting relations between faults and synexten-sional strata reveal that sequential generations of primarily down-to-the-west, mid-Cenozoic normal faults produced the net eastward tilting of ~60°. Restorations of the balanced cross section demonstrate that Cenozoic normal faults were originally steeply dipping and resulted in an estimated 59 km or 120% extension across the study area. Representative segments of those gently dipping faults are exposed at shallow, intermediate (~5-10 km), and deep structural levels (~10-20 km), as distinguished by the nature of deformation in the exhumed footwall, and these segments all restore to high angles, which indicates that they were not listric. Offset on major normal faults does not exceed 11 km, as opposed to tens of kilometers of offset commonly ascribed to “detachment” faults in most interpretations of this and other Cordille-ran metamorphic core complexes. Once mid-Cenozoic extension is restored, reverse faults with moderate to steep original dips bound basement-cored uplifts that exhibit significant involvement of basement rocks. Net vertical uplift from all reverse faults is estimated to be 9.4 km, and estimated total shortening was 12 km or 20%. This magnitude of uplift is consistent with the vast exposure of metamorphosed and foliated cover strata in the northeastern
AB - This study investigates the Late Cretaceous through mid-Cenozoic structural evolution of the Catalina core complex and adjacent areas by integrating new geologic mapping, structural analysis, and geochronologic data. Multiple generations of normal faults associated with mid-Cenozoic extensional deformation cut across older reverse faults that formed during the Laramide orogeny. A proposed stepwise, cross-sectional structural reconstruction of mid-Cenozoic extension satisfies surface geologic and reflection seismologic constraints, balances, and indicates that detachment faults played no role in the formation of the core complex and Laramide reverse faults represent major thick-skinned structures. The orientations of the oldest synextensional strata, pre-shortening normal faults, and pre-Cenozoic strata unaffected by Laramide compression indicate that rocks across most of the study area were steeply tilted east since the mid-Cenozoic. Crosscutting relations between faults and synexten-sional strata reveal that sequential generations of primarily down-to-the-west, mid-Cenozoic normal faults produced the net eastward tilting of ~60°. Restorations of the balanced cross section demonstrate that Cenozoic normal faults were originally steeply dipping and resulted in an estimated 59 km or 120% extension across the study area. Representative segments of those gently dipping faults are exposed at shallow, intermediate (~5-10 km), and deep structural levels (~10-20 km), as distinguished by the nature of deformation in the exhumed footwall, and these segments all restore to high angles, which indicates that they were not listric. Offset on major normal faults does not exceed 11 km, as opposed to tens of kilometers of offset commonly ascribed to “detachment” faults in most interpretations of this and other Cordille-ran metamorphic core complexes. Once mid-Cenozoic extension is restored, reverse faults with moderate to steep original dips bound basement-cored uplifts that exhibit significant involvement of basement rocks. Net vertical uplift from all reverse faults is estimated to be 9.4 km, and estimated total shortening was 12 km or 20%. This magnitude of uplift is consistent with the vast exposure of metamorphosed and foliated cover strata in the northeastern
UR - http://www.scopus.com/inward/record.url?scp=85122245235&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85122245235&partnerID=8YFLogxK
U2 - 10.1130/GES02313.1
DO - 10.1130/GES02313.1
M3 - Article
AN - SCOPUS:85122245235
SN - 1553-040X
VL - 17
SP - 1928
EP - 1971
JO - Geosphere
JF - Geosphere
IS - 6
ER -