Drilling on the New Jersey continental slope and rise provides an Eocene bathyal to abyssal depth transect and an Oligocene to Miocene bathyal transect that allow the calibration of benthic foraminiferal abundance changes to independent depth estimates through time. New Jersey Transect benthic foraminiferal faunal changes reflect global, regional, and local influences and provide constraints on paleobathymetry and sediment provenance.
  The New Jersey Transect yields cosmopolitan Eocene deep-water benthic foraminiferal faunas. Early to middle Eocene bathyal biofacies are characterized by Lenticulina spp., Alabamina wilcoxensis, and Osangularia spp., whereas coeval abyssal locations contain a deeper Nuttallides truempyi-dominated biofacies. A late middle Eocene shift to a bathyal biofacies dominated by Osangularia spp., Bulimina alazanensis, and Pullenia bulloides reflects a global event that affected bathyal and abyssal sites. However, we lack an abyssal record to evaluate the full regional impact of this global event. Late Eocene bathyal faunas on the New Jersey Transect contain high abundances of Bulimina alazanensis (up to 50%), similar to peak B. alazanensis abundances reported from other Atlantic locations. We speculate that this uniform biofacies indicates that circum-Atlantic and Gulf of Mexico sites were ventilated by similar intermediate to upper deep-water masses in the late Eocene.
  A cosmopolitan Lenticulina spp.-dominated biofacies prevailed in the Oligocene to early Miocene bathyal zone; polymorphinids and A. wilcoxensis were common secondary components of this biofacies. A Uvigerina hispida-B. alazanensis-dominated biofacies characterized the middle Miocene. A coeval increase in Uvigerina spp.-dominated faunas occurred in the Gulf of Mexico, indicating that this increase may be regional in extent. The shift from the Lenticulina spp.-dominated biofacies to the Uvigerina hispida-B. alazanensis-dominated biofacies may be the regional expression of a global late early to early middle Miocene benthic foraminiferal turnover event and associated abundance changes.
  Oligocene to Miocene benthic foraminiferal biofacies changes at the slope sites exhibit sequence stratigraphic variations: (1) downslope-transported shelf taxa above several sequence boundaries (this may represent the slope expression of the shelf lowstand systems tracts) and in the upper parts of several sequences (within the slope equivalent of the shelf highstand systems tracts); (2) a preponderance of U. proboscidea occurs in the lower parts of several sequences (this may represent in situ biofacies within the slope expression of the lowstand systems tracts); (3) higher abundances of Stilostomella spp. occur in the upper parts of several sequences (this may represent the slope equivalent of the highstand systems tracts); and (4) and higher abundances of M. pompilioides span several sequence boundaries. We tentatively interpret the sections immediately above sequence boundaries as correlative to the lowstand systems tracts on the shelf. These sections contain predominantly in situ faunas with minor abundances of transported benthic foraminifers (<10% of the total fauna). Minor abundances of transported benthic foraminifers reappear in the upper parts of several sequences, and may reflect minor shedding of shelf sediments during highstand systems tracts progradation on the shelf.
  Sedimentation in the early middle Miocene and older intervals was dominated by pelagic settling at our slope sites (as it is today), and there is little benthic foraminiferal evidence for widespread downslope transport prior to the middle middle Miocene at our sites. In the Leg 150 region of the New Jersey slope, a dramatic change in the dominant mode of sedimentation occurred between Reflectors m3 (13.5 Ma) and m2 (12.5 Ma). This change is indicated by (1) a major increase in downslope transport of neritic (shelf) species; (2) dramatically increased sedimentation rates (>60 cm/yr); (3) increased terrigenous input; (4) submarine channel cutting; (5) high terrestrial carbon input; and (6) mobilization of biogenic carbonate to form diagenetic nodules. Transported benthic foraminifers dominate the upper middle Miocene to Pleistocene section of the slope cores, reflecting increased sediment supply due to the progradation of clinoforms that progressed from 90 km landward of Site 903 in the early Miocene to ~60 km landward in the middle Miocene to less than 20 km landward in the Pleistocene.

Date of initial receipt: 6 March 1995
Date of acceptance: 26 July 1995

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