Sample 180-1116A-1R-1, 106-112 cm, contains common, moderately preserved nannofossils. Samples 180-1116A-1R-CC through 18R-CC contain rare to few nannofossils with some almost barren intervals. Preservation ranges from poor to moderate (mostly poor).
Sediment contained in Sample 180-1116A-1R-1, 106-112 cm, is in Zone NN18 or older, based on the presence of Discoaster brouweri. We found rare D. brouweri in Sample 180-1116A-1R-CC, also indicating Zone NN18 or older (Fig. F29).
The occurrence of planktonic foraminifers was highly variable in Hole 1116A and where found, their preservation was moderate to poor. Specimens were abundant to common in Samples 180-1116A-2R-CC, 4R-CC, 9R-CC, 13R-CC, and 15R-CC; they were few to rare in Samples 180-1116A-1R-1, 106-112 cm, 5R-CC, 7R-CC, 10R-CC, 12R-CC, 14R-CC, 16R-CC, and 17R-CC. Samples 180-1116A-1R-CC, 3R-CC, 4R-2, 17-18 cm, and 18R-CC were barren of planktonic foraminifers. No paleontological samples were recovered from Samples 180-1116A-6R-CC and 8R-CC, and Sample 180-1116A-11R-CC was too small for the recovery of foraminifers.
The zonal scheme for planktonic foraminifers at the site is indicated in Figure F29 and the distribution of species is shown on Table T4. Zone N21 was determined for Samples 180-1116A-2R-CC through 13R-CC, based on the occurrence of Globigerinoides fistulosus in Samples 2R-CC and 13R-CC and the absence of Globorotalia truncatulinoides. Sample 180-1116A-14R-CC is in either Zone N21 or Zone N20. It contains questionable G. fistulosus along with Globorotalia crassaformis. Sample 180-1116A-15R-2, 9-10 cm, contains Globorotalia margaritae (last appearance datum [LAD] in Zone N20). Samples 180-1116A-15R-CC and 17R-CC are also placed in Zone N20, based on the occurrence of Globorotalia crassaformis ronda in the absence of G. fistulosus and Globorotalia tosaensis.
Hole 1116A, in 1851 m water depth, had a benthic foraminiferal assemblage indicative of a middle bathyal (500-2000 m) depth throughout, characterized by Cibicidoides rugosus, Hoeglundina elegans, and Oridorsalis umbonatus, as well as Ceratobulimina pacifica (in Sample 180-1116A-2R-CC), Osangularia culter (in Sample 180-1116A-13R-CC), and Pullenia bulloides as well as Sphaeroidina bulloides (in Sample 180-1116A-15R-CC). Globobulimina sp. is found with relatively high frequency in Samples 180-1116A-2R-CC, 7R-CC, 13R-CC, 15R-CC, and 16R-CC, suggesting a substrate rich in organic matter at the time of deposition. The presence of inner neritic (<50 m water depth) benthic species of Amphistegina, Calcarina, and Elphidium in Samples 180-1116A-5R-CC, 9R-CC, and 17R-CC indicates turbiditic horizons.
At Site 1116 we estimated sedimentation rate on the basis of nannofossil and foraminifer datum events (Fig. F30). The average sedimentation rate for the horizon 1.06 to 104.12 mbsf is calculated to be at least 70 m/m.y.