Venus tectonics: another Earth or another Mars

Journal Article · Sat Sep 01 04:00:00 EDT 1979 · Geophys. Res. Lett.; (United States)

DOI:https://doi.org/10.1029/GL006i009p00739· OSTI ID:5773458

McGill, G E

The presence of presumably primordial large craters has led to the suggestion that Venus may have a thick lithosphere like that of Mars despite its similarities to Earth in size and density. However, crust and upper mantle temperatures on Venus are very likely higher than on Earth so that a dry Venus could have a lithosphere with a thickness similar to that of Earth. If a trace of volatiles is present in the mantle, the lithosphere of Venus could be thinner. Due to the absence of liquid water, erosion and deposition will be much slower on Venus than on Earth, favoring retention of primordial cratered surfaces on portions of the crust that have not been destroyed or buried by tectonic and volcanic activity. Geochemical models of solar system origin and petrological considerations suggest that K is about as abundant in Venus as in Earth. The abundance of /sup 40/Ar in the atmosphere of Venus lies somewhere between the Earth value and one-tenth of the Earth value. Because erosional liberation of /sup 40/Ar on Venus will be relatively inefficient, this range for /sup 40/Ar abundance at least permits an active tectonic history, and if the /sup 40/Ar abundance is towards the high end of the range, it may well require an active tectonic history. Thus we are not constrained to a Mars-like model of Venus tectonics by craters and possible mantle dryness; an Earth-like model is equally probable.

• Research Organization: Department of Geology and Geography, University of Massachusetts, Amherst, Massachusetts 01003
• OSTI ID: 5773458
• Journal Information: Geophys. Res. Lett.; (United States), Journal Name: Geophys. Res. Lett.; (United States) Vol. 6:9; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
ARGON 40
ARGON ISOTOPES
CAVITIES
CHEMISTRY
CRATERS
ELEMENTS
EVEN-EVEN NUCLEI
GEOCHEMISTRY
GEOLOGIC HISTORY
ISOTOPES
LIGHT NUCLEI
METALS
NUCLEI
PLANETS
PLATE TECTONICS
POTASSIUM
STABLE ISOTOPES
TECTONICS
VENUS PLANET
VOLCANISM