Lyell Collection
Geological Society, London, Special Publications
Lyell Centre  |   Lyell Collection  |   Subscriptions   |   Geological Society  |   Email alerts  |   Online bookshop  |   Help

Keywords:
Author:
Advanced search>>
This Article
Right arrow Full Text (PDF)
Right arrow References
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Bally, A. W.
Right arrow Search for Related Content
Geological Society, London, Special Publications; 1981; v. 9; p. 13-32;
DOI: 10.1144/GSL.SP.1981.009.01.03
© 1981 Geological Society of London

I. Mechanics of Thrusts and Nappes

Thoughts on the tectonics of folded belts

A. W. Bally

Shell Oil Company, P.O. Box 481, Houston, Texas 77001, U.S.A.

Balanced cross sections and their palinspastic reconstruction in structurally simple external zones of folded belts suggest that a limited amount of continental lithosphere was subducted (Ampferer or A-subduction). This process appears to be associated with preceding or synchronous basement remobilization. Therefore, the rigid or ductile nature and the timing of basement deformation remain as some of the most important orogenic problems. Decoupling and ductility contrasts within the lower continental crust and within the overlying sedimentary sequences are responsible for varying structural styles in mountain ranges.

Gravity gliding as an important factor for mountain building is examined in some detail. Soft sediment gravity tectonics on passive continental margins are dominated by listric normal growth faults. This style contrasts with observed styles of deformation in folded belts. Gravity tectonics induced by stretching of the underlying basement area is commonly observed during the rifting phase of passive continental margins and in episutural basins associated with orogenic systems.