T314 Large Igneous Provinces (LIPs) in the Solar System

Wednesday, 28 September 2016
1:30 PM - 5:30 PM
Room 201

GEOLOGIC PROCESSES AND STRATIGRAPHIES RECORDED WITHIN VENUSIAN SHIELD FIELDS

Paper number: T314-5
Program: Technical Sessions
Time: 2:30 PM – 2:45 PM

Authors

Abstract

Small shield volcanoes are the dominant manifestation of volcanism on the surface of Venus. They are >>106 in number (Crumpler et al, 1997), and often occur in tight clusters known as shield fields. This study intends to examine six Venusian shield fields with the intent of identifying recent geologic processes on the surface of Venus and establishing local stratigraphies within each of the shield fields. These shield fields include Chernava Colles, Ran Colles, Nordenflycht Patera, Urutonga Colles, Monoshi Tholus, and Asherat Colles.

Lat/Long

Area (km²)

Mean Diameter (km)

Chernava Colles

10°S 24°W

~164,000

~1.5

Ran Colles

0°N 162°E

~643,000

~3

Nordenflycht Patera

36°S 92°W

~25,000

~2.2

Urutonga Colles

13°N 150°E

~10,000

~1.3

Monoshi Tholus

37°S 106°W

~45,000

~2.3

Asherat Colles

12°N 160°E

~95,000

~4.2

All shield fields are mapped in ArcGIS 10.3 utilizing Magellan mission SAR imagery (~100m/pixel). Classification of shield edifices and shield fields is based on the criteria of Guest et al (1992), and Crumpler et al (1997). All shield fields in question postdate surrounding units. Shield flow units consist of volcanic material which is the product of individual shield edifices; they are identifiable by definitive flow boundaries. Nordenflycht Patera, Monoshi Tholus, Urutonga Colles, and Asherat Colles all contain a single decipherable shield flow unit. Chernava Colles contains two decipherable shield flow units, and Ran Colles contains three decipherable shield flow units. Monoshi Tholus displays only extensional stress features, while all other fields display some combination of compressional and extensional stress features. The dominant edifice in the examined fields in question is the shield with the exception of Monoshi Tholus, which has a dominance of cones. To aid in the method of identifying recent geologic processes, a recent volcanic edifice alignment detection software is utilized (Thomson and Lang, 2016).Relative timing is decipherable within all fields, indicating that volcanic activity is not uniform across the field. Implications of this study will facilitate the understanding of local stratigraphic relationships on Venus, and by elucidating intra-field stratigraphies, further light could be shed on more regional stratigraphic relations.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-285503

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