Vicki L. Hansen

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Understanding the nature and timing of tessera formation Tessera terrain, known originally as parquet terrain, on is fundamental to Venus tectonic and geodynamic models. Venus is characterized by at least two intersecting sets of Tesserae are commonly considered to exhibit complex deformation histories, to represent the oldest global stratigraphic(More)
Geological analysis of planets typically begins with the construction of a geologic map of the planets' surfaces using remote data sets. Geologic maps provide the basis for interpretations of geologic histories, which in turn provide critical relations for understanding the range of processes that contributed to the evolution. Because geologic mapping(More)
near-surface transitional-tensile failure conditions or due to The term tessera has been used to describe regions of dereactivation of steeply oriented preexisting fractures resulting formed venusian crust exhibiting two or more intersecting sets in steep-sided graben. Formation of tensile-fracture ribbons of structural elements; however, tessera includes(More)
Crustal plateaus on Venus constitute one of that planet’s most intriguing tectonic features. They host so-called “tessera” terrain, or deformed crust exhibiting two or more sets of intersecting tectonic lineaments, which comprises ∼8% of Venus’ surface. Major questions surrounding crustal plateaus and tessera terrain include: (1) What is the nature of(More)
Eastern Aphrodite Terra, a deformed region with high topographic relief on Venus, has been interpreted as analogous to a terrestrial extensional or convergent plate boundary. However, analysis of geological and structural relations indicates that the tectonics of eastern Aphrodite Terra is dominated by blistering of the crust by magma diapirs. The findings(More)
The Venus surface exhibits quasi-circular structures with a bimodal size distribution; there are at least 17 large (;1300–2600-km diameter) crustal plateaus and volcanic rises, which form major geomorphic features, and ;515 smaller (200-km median diameter) coronae. All of these features—plateaus, rises, and coronae—are interpreted to be the surface(More)
Plains, planitiae, or lowlands—expanses of gentle, long-wavelength (~1000 km) basins— cover ~80% of Venus's surface. These regions are widely accepted as covered by volcanic fl ows, although the mechanism(s) responsible for resurfacing remains elusive; in addition, a volcanic origin for the lowland surface may be open to question. Lowland resurfacing is(More)