HR: 16:00h
AN: T14C-01 INVITED [Abstracts]
TI: Relationships Between Incremental and Cumulative Fold Growth With Neotectonic Examples From the
Southern Tianshan, China
AU: * Suppe, J
EM: suppe@princeton.edu
AF: Department of Geosciences, Princeton University, Princeton, NJ 08544
United States
AU: Hubert-Ferrari, A
EM: Aurelia.Ferrari@unine.ch
AF: Institut de Gologie, Universit de Neuchtel, rue Emile Argand 11, Neuchtel, CH-2007
Switzerland
AU: Wang, X
EM: xinwang0080@sina.com
AF: Department of Geosciences, Zhejiang University, Hangzhao, na
China
AB:
Some mechanisms of upper crustal fault-related folding display profiles of incremental fold growth that are collocated with
the distribution of finite fold uplift, whereas others do not. For example instantaneous uplift in fault-bend folding is not
coincident with cumulative uplift because fault bends are velocity discontinuities through which rock moves progressively.
This causes uplifted rock to move away from the instantaneous locus of uplift. In contrast, some models of detachment
folding assume that instantaneous uplift rate is coincident with and proportional to cumulative uplift. We show how these
concepts play out quantitatively in two well imaged actively forming anticlines in the southern Tianshan. The Yakeng
detachment fold shows collocated growth in which incremental uplift is linearly proportional to cumulative uplift with a high
statistical significance. This has the practical result of allowing one to measure fractional uplift quite accurately. In
contrast Quilitak anticline is a complex fault bend fold that shows non-collocated fold growth at several scales, which we
illustrate with [1] a detailed analysis of progressive motion of young strata through a fold hinge and [2] large-scale
folding of the land surface producing giant fold scarps as high as 800 m.
DE: 8005 Folds and folding
DE: 8010 Fractures and faults
DE: 8102 Continental contractional orogenic belts
DE: 8107 Continental neotectonics
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting