Saturday, June 28, 2008

Day Six/Saturday

Microbialites on log

AM dive:
Deepworker: David Williams, Darlene Lim
CapCom: Allyson Brady

Willow Point – 1 hour bottom time dive
• Large mounds visible from snorkeling distances
• 30 degree steep slope filled with densely populated mircobialites
• New morphology – starting at 37’ there was a field of chimneys, long, thin tubes 25cm-1m tall with wall thickness of 1-2 cm
• Lots of topography to fly through – steep climbs with sheer drops
• Some video problems. Shutting system on/off randomly every 1-10 minutes.
• Sampled from 72’ – didn’t sample at more shallow depths to protect view for divers. Will come back with a smaller footprint than sub to sample.

• Went down 70-75' feet. Little microbialite activity.
• Moved heading and at 75’ found huge (1-2 feet) cauliflower and artichoke shaped microbialites and carbonate flour.
• No microbialites at the top of ridge – algae and chara present.
• At 75' found tree suspended diagonally between wall and bottom – covered with varying sizes of microbialites.
• No samples – but carried down Discovery Channel hand held for shots.

PM dive:
Deepworkers: Bekah Shepard, Greg Slater
CapCom: Bernard

Willow Point – deep mounds
• Linear narrow ridge protruding from the sediment at 150’. New observations
• Sampled sediment profile: very heterogeneous in cross section. Signifies lots of mixing in the upper sediment layers
• Brought up 2 samples from the deep mounds.
• Fingerlike structures are much finer then those seen at shallower depths.

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