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Formation of fold and thrust belts on Venus due to horizontal shortening of a laterally heterogeneous lithosphereAn outstanding question relevant to understanding the tectonics of Venus is the mechanism of formation of fold and thrust belts, such as the mountain belts that surround Lakshmi Planum in western Ishtar Terra. These structures are typically long (hundreds of km) and narrow (many tens of km), and are often located at the margins of relatively high (km-scale) topographic rises. Previous studies have attempted to explain fold and thrust belts in various areas of Venus in the context of viscous and brittle wedge theory. However, while wedge theory can explain the change in elevation from the rise to the adjacent lowland, it fails to account for a fundamental aspect of the deformation, i.e., the topographic high at the edge of the rise. In this study we quantitatively explore the hypothesis that fold and thrust belt morphology on Venus can alternatively be explained by horizontal shortening of a lithosphere that is laterally heterogeneous, due either to a change in thickness of the lithosphere or the crust. Lateral heterogeneities in lithosphere structure may arise in response to thermal thinning or extensive faulting, while variations in crustal thickness may arise due to either spatially variable melting of mantle material or by horizontal shortening of the crust. In a variable thickness lithosphere or crust that is horizontally shortened, deformation will tend to localize in the vicinity of thickness heterogeneity, resulting in a higher component of dynamic topography there as compared to elsewhere in the shortening lithosphere. This mechanism may thus provide a simple explanation for the topographic high at the edge of the rise.
Document ID
19940030974
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Zuber, M. T.
(Johns Hopkins Univ. Baltimore, MD., United States)
Parmentier, E. M.
(Brown Univ. Providence, RI., United States)
Neumann, G. A.
(Johns Hopkins Univ. Baltimore, MD., United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1994
Publication Information
Publication: Lunar and Planetary Inst., The Twenty-Fifth Lunar and Planetary Science Conference. Part 3: P-Z
Subject Category
Lunar And Planetary Exploration
Accession Number
94N35480
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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