Planktonic foraminifers recovered from Leg 166 drilling showed a progression from well-preserved to poorly preserved specimens with increasing depth. The high carbonate production and shedding from the Great Bahama Bank diluted the pelagic components to the extent that planktonic foraminifers had scattered occurrences, particularly in the lower Pliocene and/or uppermost Miocene sections in Sites 1003-1005 and Site 1007. A reasonable planktonic foraminiferal biostratigraphic framework was possible for these sites because samples from thin, clay-rich layers contained moderately to well-preserved specimens throughout the lower Pliocene to Miocene interval. Better preservation of the specimens occurred in these layers because they were dominated by terrigenous sedimentation. The planktonic foraminiferal zonation shows that Neogene sediments with a basal age of earliest Miocene were recovered from Holes 1003A-1003C. Four unconformities were identified on the basis of planktonic foraminiferal taxa. Upper Pliocene to Holocene sediments were recovered from Hole 1004. Sediment diagenesis prevented placement of the Pliocene/Pleistocene boundary. Middle Miocene to Pleistocene sediments were recovered from Holes 1005A-1005C. A large unconformity separates the lowermost upper Miocene and lower Pliocene sediments. At Site 1006, a complete middle Miocene to Pleistocene section was recovered, in contrast to the sites more proximal to the Bahamian platform. The lower Pliocene recorded high sedimentation rates. Holes 1007A-1007C recovered Neogene and uppermost Oligocene sediments. Three prominent unconformities were identified at the Pliocene/Pleistocene boundary, upper/lower Pliocene boundary and the Miocene/Pliocene boundary. The lower upper Miocene to uppermost Oligocene section appears to be complete at this site.
|Original language||English (US)|
|Number of pages||10|
|Journal||Proceedings of the Ocean Drilling Program: Scientific Results|
|State||Published - 2000|
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