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| Titel |
Geologic interpretation of the near-infrared images of area SW of Beta Regio taken by the Venus Monitoring Camera |
| VerfasserIn |
E. V. Shalygin, A. T. Basilevsky, D. V. Titov, W. J. Markiewicz, F. Scholten, Th. Roatsch, M. A. Kreslavsky, L. V. Moroz, N. I. Ignatiev |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250064196
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| Zusammenfassung |
| We analyze night-time near-infrared (NIR) images of Beta-Phoebe region obtained with the
1-µm channel of the Venus Monitoring Camera (VMC) onboard Venus Express. Comparisons
with the results of the Magellan radar survey and the model NIR images show that the
night-time VMC images provide reliable information on spatial variations of the NIR surface
emission.
Here we consider if tessera terrain has the different NIR emissivity (and thus
mineralogical composition) in comparison to the surrounding basaltic plains. This is done
through the study of an area SW of Beta Regio where there is a massif of tessera terrain,
Chimon-mana Tessera, surrounded by supposedly basaltic plains. Our analysis showed that
1-µm emissivity of tessera surface material is by 15 – 35 % lower than that of relatively
fresh supposedly basaltic lavas of plains and volcanic edifices. This is consistent
with hypothesis that the tessera material is not basaltic, maybe felsic, that is in
agreement with the results of analyses of VEX VIRTIS and Galileo NIMS data.
If the felsic nature of venusian tesserae will be confirmed in further studies this
may have important implications on geochemical environments in early history of
Venus.
We have found that the surface materials of plains in the study area are very variegated in
their 1-µm emissivity, which probably reflects variability of degree of their chemical
weathering.
We have also found a possible decrease of the calculated emissivity at the top of Tuulikki
Mons volcano which, if real, may be due to different (more felsic?) composition of volcanic
products on the volcano summit. |
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