Tessera terrain, Venus: Characterization and models for origin and evolution

Journal Article · Wed Apr 10 04:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JB02742· OSTI ID:5444959

Bindschadler, D L; Head, J W ^[1]

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1. Brown Univ., Providence, RI (USA)

Tessera terrain is the dominant tectonic landform in the northern high latitudes of Venus mapped by the Venera 15 and 16 orbiters and is concentrated in the region between the mountain ranges of western Ishtar Terra and Aphrodite Terra. Tesserae are characterized by regionally high topography, a high degree of small scale surface roughness, and sets of intersecting tectonic features. Available Pioneer Venus line of sight gravity data suggest that tessera terrain is compensated at shallow depths relative to many topographic highs on Venus and may be supported by crustal thickness variations. Three types of tessera terrain can be defined on the basis of structural patterns: subparallel ridged terrains (T{sub sr}), trough and ridge terrain (T{sub tr}), and disrupted terrain (T{sub ds}). Observed characteristics of tessera terrain are compared to predictions of models in order to begin to address the question of its origin and evolution. Formational models, in which high topography is created along with surface deformation, include (1) horizontal convergence, (2) mantle upwelling, (3) crustal underplating, and (4) a seafloor spreading analogy. Modification models, in which deformation occurs as a response to the presence of elevated regions, consist of (1) gravity sliding and (2) gravitational relaxation. The authors find that horizontal convergence and late stage gravitational relaxation are the most consistent with basic observations for subparallel ridged terrain and disrupted terrain. Understanding of the basic structural characteristics of trough and ridge terrain is more tentative, and models involving a spreading process or convergence and relaxation merit further study.

• OSTI ID: 5444959
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:B4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CONTINENTAL CRUST
DEFORMATION
DIMENSIONS
EARTH CRUST
EARTH PLANET
GEOLOGIC FORMATIONS
GEOLOGIC MODELS
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
GRAVITY SURVEYS
NORTHERN HEMISPHERE
ORIGIN
PLANETARY EVOLUTION
PLANETS
SOLAR SYSTEM EVOLUTION
SURFACE PROPERTIES
SURVEYS
TECTONICS
THICKNESS
TOPOGRAPHY
VENUS PLANET