Kinematic models of fluvial terraces over active detachment folds: Constraints on the growth mechanism of the Kashi-Atushi fold system, Chinese Tian Shan

Abstract

Research Article| July 01, 2006 Kinematic models of fluvial terraces over active detachment folds: Constraints on the growth mechanism of the Kashi-Atushi fold system, Chinese Tian Shan K.M. Scharer; K.M. Scharer 1Department of Geological Sciences, 1272 University of Oregon, Eugene, Oregon 97403, USA Search for other works by this author on: GSW Google Scholar D.W. Burbank; D.W. Burbank 2Department of Earth Science, University of California, Santa Barbara, California 93106-9630, USA Search for other works by this author on: GSW Google Scholar J. Chen; J. Chen 3State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Seismological Bureau, P.O. Box 9803, Beijing 100029, People's Republic of China Search for other works by this author on: GSW Google Scholar R.J. Weldon, II R.J. Weldon, II 4Department of Geological Sciences, 1272 University of Oregon, Eugene, Oregon 97403, USA Search for other works by this author on: GSW Google Scholar Author and Article Information K.M. Scharer 1Department of Geological Sciences, 1272 University of Oregon, Eugene, Oregon 97403, USA D.W. Burbank 2Department of Earth Science, University of California, Santa Barbara, California 93106-9630, USA J. Chen 3State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Seismological Bureau, P.O. Box 9803, Beijing 100029, People's Republic of China R.J. Weldon, II 4Department of Geological Sciences, 1272 University of Oregon, Eugene, Oregon 97403, USA Publisher: Geological Society of America Received: 19 Apr 2005 Revision Received: 02 Mar 2006 Accepted: 24 Mar 2006 First Online: 08 Mar 2017 Online Issn: 1943-2674 Print Issn: 0016-7606 Geological Society of America GSA Bulletin (2006) 118 (7-8): 1006–1021. https://doi.org/10.1130/B25835.1 Article history Received: 19 Apr 2005 Revision Received: 02 Mar 2006 Accepted: 24 Mar 2006 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation K.M. Scharer, D.W. Burbank, J. Chen, R.J. Weldon; Kinematic models of fluvial terraces over active detachment folds: Constraints on the growth mechanism of the Kashi-Atushi fold system, Chinese Tian Shan. GSA Bulletin 2006;; 118 (7-8): 1006–1021. doi: https://doi.org/10.1130/B25835.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract During detachment folding, the relationship between differential uplift and shortening depends on the mechanism of fold growth, such as limb rotation or hinge migration, and may vary over the lifetime of a fold. Thus, neither long-term shortening rates nor the present fold geometry unambiguously constrain the kinematics of fold growth. Where rivers cut through growing anticlines, flights of abandoned fluvial terraces act as passive kinematic markers. As shortening progresses, the terraces become deformed and thereby preserve critical information about the kinematics and evolution of active fold growth. To constrain recent fold growth across three detachment folds in the Kashi-Atushi fold system in the SW Tian Shan, China, we surveyed flights of deformed terraces and compared them with geometric models of successively emplaced horizontal unconformities (terraces) across pregrowth strata deformed by hinge migration, limb rotation, and a combination of the two. Migration of angular hinges and curved hinge zones were also compared. Each kinematic model predicts both a distinct geometry for the deformed terraces and contrasting angular relationships between the terraces and the pregrowth strata. Notably, limb rotation and migration of curved hinge zones result in progressively rotated terraces that cut across pregrowth strata, whereas all limb-lengthening models result in parallelism between pregrowth strata and terrace straths across much of the fold. The Kashi-Atushi terraces show clear evidence of abandoned axial surfaces, concentrated deformation near the core of the folds, and progressive tilting with age. When compared to the model predictions, the folds are likely growing by a combination of limb rotation in the tight cores of the folds and hinge-zone migration of pregrowth strata across the flanks of the folds. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.