Three-dimensional geometry of piggyback thrusting
1987 (English)In: Geology, ISSN 0091-7613, E-ISSN 1943-2682, Vol. 15, no 11, 1052-1056 p.Article in journal (Refereed) Published
The three-dimensional geometry and kinematics of piggyback stacks of imbricate thrust sheets are illustrated and discussed using a single model shortened in a squeeze box. Strike-parallel geometric elements simulated include lateral ramps, eyed sheath folds, splays, and thrust/thrust interference. Fine details of these structures were exposed by eroding a shortened wedge of sand using a newly developed vacuum-eroding technique. A kinematic analysis of the model shows a stepwise increase in imbricate thrust spacing and/or a decrease in rate of nucleation of imbricate thrusts in the direction of thrust transport. Despite the steady forward advance of a rear wall, the piggyback wedge accreted episodically, recording different strain domains in longitudinal cross sections. Strain partitioning in single layers by bed-length balancing showed an increase in layer shortening with volume loss and a corresponding decrease in imbricate thrusting and ramp folding with depth.
Place, publisher, year, edition, pages
Geological Society of America , 1987. Vol. 15, no 11, 1052-1056 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-11373DOI: 10.1130/0091-7613(1987)15<1052:TGAKOE>2.0.CO;2OAI: oai:DiVA.org:uu-11373DiVA: diva2:39141