Mathematics – Logic
Scientific paper
Dec 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agufm.p52b..03k&link_type=abstract
American Geophysical Union, Fall Meeting 2008, abstract #P52B-03
Mathematics
Logic
5417 Gravitational Fields (1221), 5480 Volcanism (6063, 8148, 8450), 6225 Mars
Scientific paper
Previous work has suggested that extension at many graben systems on Mars may be due to stresses associated with the emplacement of volcanic dikes. If the magma filling a dike is denser than the surrounding country rock, as is true in Hawaii, the dike will produce a positive gravity anomaly. For example, dike material may be less degassed than its surroundings, and thus less vesicular, resulting in a greater density. Although individual dikes can not be detected in orbital gravity data, the aggregate effect of dike swarms is detectable. In this work, I consider gravity evidence for dike swarms in the Thaumasia region of Mars. Thaumasia is the southeast portion of the Tharsis volcanic province and contains some of the earliest evidence for geologic activity in Tharsis. The Claritas Fossae graben system in western Thaumasia has a residual gravity anomaly (after removing the effects of both the surface topography and the compensating root) of up to 100 mGal, implying the presence of dense subsurface material. Detailed modeling shows that plausible combinations of dike height, density contrast, and filling factor (the fractional amount of dike material) can reproduce the observed anomaly. Thus, subsurface dike swarms may be present along much of this 1500 km long graben system. Maps of the residual gravity anomaly in the remainder of Thaumasia reveal the existence of a series of elongated, positive anomalies that radiate from a common center point in southeastern Tharsis. The common center point suggests a common origin. Their elongated planform, anomaly amplitudes, and origin within the Tharsis volcanic province are all consistent with formation as dike swarms. In the Solis Planum region of Thaumasia, there is no surface expression of these dikes, suggesting that the dikes pre-date the youngest surface lavas. This implies that the dike swarms were emplaced in the late Noachian or earliest Hesperian. On-going work is focused on assessing the physical volcanology conditions required to emplace these dikes, which in some cases exceed 2000 km in length. Possible analog structures in the Tempe Terra region are also being assessed.
No associations
LandOfFree
Gravity Evidence for Radiating Dike Swarms in the Thaumasia Region of Mars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gravity Evidence for Radiating Dike Swarms in the Thaumasia Region of Mars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravity Evidence for Radiating Dike Swarms in the Thaumasia Region of Mars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1239299