NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Eastern Ishtar Terra: Tectonic evolution derived from recognized featuresPrevious analyses have recognized several styles and orientations of compressional deformation, crustal convergence, and crustal thickening in Eastern Ishtar Terra. An east to west sense of crustal convergence through small scale folding, thrusting, and buckling is reflected in the high topography and ridge-and-valley morphology of Maxwell Montes and the adjacent portion of Fortuna Tessera. This east to west convergence was accompanied by up to 1000 km of lateral motion and large scale strike-slip faulting within two converging shear zones which has resulted in the present morphology of Maxwell Montes. A more northeast to southwest sense of convergence through large scale buckling and imbrication is reflected in large, northwest-trending scarps along the entire northern boundary of Ishtar Terra, with up to 2 km of relief present at many of the scarps. It was previously suggested that both styles of compression have occurred at the expense of pre-existing tessera regions which have then been overprinted by the latest convergence event. The difference in style is attributed mostly to differences in the properties of the crust converging with the tessera blocks. If one, presumably thick, tessera block converges with another tessera region, then the widespread, distributed style of deformation occurs, as observed in western Fortuna Tessera. However, if relatively thin crust (such as suggested for the North Polar Plains converges with thicker tessera regions, then localized deformation occurs, as reflected in the scarps along Northern Ishtar Terra. The purpose is to identify the types of features observed in Eastern Ishtar Terra. Their potential temporal and spatial relationships, is described, possible origins for them is suggested, and how the interpretation of some of these features has led to the multiple-style tectonic evolution model described is shown.
Document ID
19900003135
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Vorderbruegge, R. W.
(Brown Univ. Providence, RI, United States)
Head, James W.
(Brown Univ. Providence, RI, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1989
Publication Information
Publication: Lunar and Planetary Inst., Abstracts for the Venus Geoscience Tutorial and Venus Geologic Mapping Workshop
Subject Category
Lunar And Planetary Exploration
Accession Number
90N12451
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
No Preview Available