Cook Plant preoperational studies 1970 / John C. Ayers ... [et al.].

consisted of a sandy silt with small black patches of organic material present
on top of the sediment. Several pockets of silt were found. Dive number two
was terminated at a depth of 15 m. No macrophytes were observed on transect
number two.
Date 13 October 1970 Dive No. 3
Location Transect No. 3 - directly off North Range Pole
Depth 16.5 to 5 meters
Team Bob Anderson, Tom Bottrell Dive time 31 minutes
Work Brief/Notes. The MYSIS proceeded north of the Cook Plant and
anchored directly off the North Range Pole at a depth of 16.5 m. The divers
descended the anchor chain of the MYSIS to the bottom and proceeded under tow
of the Zodiac towards shore on transect number three. The bottom type at
16.5 m was a sandy silt. Several pockets of silt 10 to 15 cm in depth were
observed between the depths of 16.5 and 12 m. Small black areas of organic
material 5 to 8 cm in diameter were abundant in these areas of silt. The
bottom type at a depth of 12 m or less consisted of a silty sand exhibiting
bifurcating ripple marks with wave lengths of 30 to 45 cm and heights of 10
to 15 cm. The trend of the ripple marks was in a north-south direction.
Large amounts of detritus had collected in the troughs of the ripple marks.
The detrital material was composed of dead CZadophora with stems, roots, and
leaves of terrestrial plants mixed in. The CZadophora had been washed into
the area, as none was observed in the vicinity of the Cook Plant. A clump
of sedges was also found on the bottom. Sedges being native to swamps, it
had definitely been washed into the area. Several tree branches were found
on the bottom. Chunks of a woody material that were easily broken and resembled peat were also found scattered along transect number three.

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