Tow Cam 2
19 March 2010
All times given as GMT
On bottom time: 06:53
Stop time: 09:06:49
Table 1. Wax cores for Tow Cam 2.
Wax
Time
Lat, Long
Geology
Core
1
7:06:59 2°37’ 7.9644”, -94° Jumbled sheet flow
56’ 56.9796”
2
07:11:36 2°37’ 6.4554”, -94° Jumbled sheet flow
56’ 56.6082”
3
07:25:11
2° 30’ 57.5244”, - Pillows
94° 56’ 56.1732”
4
07:31:55
2° 36’ 55.5258”, - Glassy lobes, pillows on north
94° 56’ 55.7695” side of Jellybean Hill
5
07:36:48
2° 36’ 55.5258”, - Pillows on Jellybean Hill
94° 56’ 55.7694”
6
08:07:40
2° 36’ 41.6016”, - Talus
94° 56’ 53.811”
*Balls 2 and 5 didn’t come back. Ball 6 never deployed.
Return?
Yes
No*
Yes
Yes
No*
No*
Objective: traverse graben from north to south across Jellybean Hill. Answer the
following questions.
1) What is the flat-lying terrain?
2) What is Jellybean Hill, and what are the contributions of destruction
(tectonism) and construction (lava)?
3) What are the relative ages between Jellybean Hill and its surroundings?
Summary
Brief log
First images are of heavily sedimented lobate and pillowed flows, with few small
cracks. Contact with ropy to jumbled sheet flows with sedimented pockets occurred
at 07:06:59. Contact to lobes with coalesced pockets at 07:07:49. Jumbled sheets
with pockets of sediment at 7:10:39. Flat surface with some folds observed, heavy
sediment at 07:21:59. Back to jumbled sheets with sediment pockets at 07:23:29.
Lobes with coalesced pockets at 07:25:09; this marks the northern edge of Jellybean
Hill. Jellybean Hill is characterized by glassy lobes and pillows with light sediment
cover. The tow cam went up and over Jellybean Hill and reached the southern edge
at 08:03:59 where the glassy lobate flows overlie lobes with heavy sediment cover.
The lobes transition within one camera frame to flat, featureless sediment with
cracks and fissures. Folded and jumbled flows with sedimented pockets are
observed at 08:12:29. At 08:33:09, contact with flat, heavily sedimented surface; at
08:33:49 we observed heavily sedimented lobes. Contact observed at 08:40:29 with
jumbled and folded sheets with sediment pockets; back to heavily sedimented lobes
at 8:45:29. Fissured jumbled and folded sheets with sediment pockets observed at
8:57:49; this was the last readily observed morphology before the tow cam ended.
Geologic Interpretations
The graben is filled with sedimented lobate and sheet flows; cracks and faults on the
graben floor are rare. Folded and jumbled sheet flows are a recent addition to the
graben floor, and are probably locally channeled, although a broad sheet
morphology appears to be more common. Jellybean Hill is the youngest feature in
the tow camera images; it may have been contemporaneous with the jumbled and
folded sheet flows. We cannot determine whether the exogenic growth of Jellybean
Hill came from a true conduit, or if Jellybean Hill was fed by a tube breakout or some
other “pseudovent.”