1
|
Harris LB, Bédard JH. Interactions between continent-like ‘drift’, rifting and mantle flow on Venus: gravity interpretations and Earth analogues. ACTA ACUST UNITED AC 2014. [DOI: 10.1144/sp401.9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractRegional shear zones are interpreted from Bouguer gravity data over northern polar to low southern latitudes of Venus. Offset and deflection of horizontal gravity gradient edges (‘worms’) and lineaments interpreted from displacement of Bouguer anomalies portray crustal structures, the geometry of which resembles both regional transcurrent shear zones bounding or cross-cutting cratons and fracture zones in oceanic crust on Earth. High Bouguer anomalies and thinned crust comparable to the Mid-Continent Rift in North America suggest underplating of denser, mantle-derived mafic material beneath extended crust in Sedna and Guinevere planitia on Venus. These rifts are partitioned by transfer faults and flank a zone of mantle upwelling (Eistla Regio) between colinear hot, upwelling mantle plumes. Data support the northward drift and indentation of Lakshmi Planum in western Ishtar Terra and >1000 km of transcurrent displacement between Ovda and Thetis regiones. Large displacements of areas of continent-like crust on Venus are interpreted to result from mantle tractions and pressure acting against their deep lithospheric mantle ‘keels’ commensurate with extension in adjacent rifts. Displacements of Lakshmi Planum and Ovda and Thetis regiones on Venus, a planet without plate tectonics, cannot be attributed to plate boundary forces (i.e. ridge push and slab pull). Results therefore suggest that a similar, subduction-free geodynamic model may explain deformation features in Archaean greenstone terrains on Earth. Continent-like ‘drift’ on Venus also resembles models for the late Cenozoic–Recent Earth, where westward translation of the Americas and northward displacement of India are interpreted as being driven by mantle flow tractions on the keels of their Precambrian cratons.Supplementary material:Bouguer gravity and topographic images over a segment of the Mid-Atlantic ridge and Ross Island and surrounds in Antarctica, principal horizontal stress trajectories about mantle plumes on Earth, map and interactive 3D representations of cratonic keels beneath North America from seismic tomography, and a centrifuge simulation for comparison with Venus in support of our tectonic model are available at http://www.geolsoc.org.uk/SUP18736.
Collapse
Affiliation(s)
- Lyal B. Harris
- Institut national de la recherche scientifique, Centre – Eau Terre Environnement (INRS-ETE), 490 de la Couronne, Québec, Canada QC G1K 9A9
| | - Jean H. Bédard
- Geological Survey of Canada, 490 de la Couronne, Québec, Canada QC G1K 9A9
| |
Collapse
|
2
|
Williams CA, Connors C, Dahlen FA, Price EJ, Suppe J. Effect of the brittle-ductile transition on the topography of compressive mountain belts on Earth and Venus. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/94jb01407] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
3
|
Schultz RA. Localization of bedding plane slip and backthrust faults above blind thrust faults: Keys to wrinkle ridge structure. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999je001212] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
4
|
Ivanov MA, Head JW. Stratigraphic and geographic distribution of steep-sided domes on Venus: Preliminary results from regional geological mapping and implications for their origin. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999je001039] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
5
|
Ivanov MA, Head JW. Tessera terrain on Venus: A survey of the global distribution, characteristics, and relation to surrounding units from Magellan data. ACTA ACUST UNITED AC 1996. [DOI: 10.1029/96je01245] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
6
|
|
7
|
Willett S. The hot, dry mountains of Venus. Nature 1995; 373:285-6. [PMID: 7830760 DOI: 10.1038/373285a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
8
|
Schultz RA, Tanaka KL. Lithospheric-scale buckling and thrust structures on Mars: The Coprates rise and south Tharsis ridge belt. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/94je00277] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
9
|
Schultz RA. Brittle strength of basaltic rock masses with applications to Venus. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/93je00691] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
10
|
Solomon SC, Smrekar SE, Bindschadler DL, Grimm RE, Kaula WM, McGill GE, Phillips RJ, Saunders RS, Schubert G, Squyres SW, Stofan ER. Venus tectonics: An overview of Magellan observations. ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92je01418] [Citation(s) in RCA: 231] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|