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venus - limited extension and volcanism along zones of lithospheric weaknessThree global-scale zones of possible tectonic origin are described as occurring along broad, low rises within the Equatorial Highlands on Venus (lat 50 deg N to 50 deg S, long 60 deg to 310 deg). The two longest of these tectonic zones, the Aphrodite-Beta and Themis-Atla zones, extend for 21,000 and 14,000 km, respectively. Several lines of evidence indicate that Beta and Atla Regiones, located at the only two intersections of the three major tectonic zones, are dynamically supported volcanic terranes associated with currently active volcanism. Rift valleys south of Aphrodite Terra and between Beta and Phoebe Regiones are characterized by 75- to 100-km widths, raised rims, and extensions of only a few tens of kilometers, about the same magnitudes as in continental rifts on the earth. Horizontal extension on Venus was probably restricted by an early choking-off of plate motion by high crustal and upper-mantle temperatures, and the subsequent loss of water and an asthenosphere.
Document ID
19820049516
Document Type
Reprint (Version printed in journal)
Authors
Schaber, G. G.
(U.S. Geological Survey Flagstaff, AZ, United States)
Date Acquired
August 10, 2013
Publication Date
May 1, 1982
Publication Information
Publication: Geophysical Research Letters
Volume: 9
Subject Category
LUNAR AND PLANETARY EXPLORATION
Funding Number(s)
CONTRACT_GRANT: NASA ORDER W-13709
Distribution Limits
Public
Copyright
Other