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Burton Guyot: Hole U1376A

During visual reconnaissance for Hole U1376A, the subsea camera showed no pelagic sediment present in the immediate area. Although no pelagic sediments were recovered, 11 samples were examined from Site U1376. Eight samples collected by scraping material from the indurated sedimentary matrix of a volcanic sandstone and a limestone proved to be barren of nannofossils (Table T1). Three additional samples that contain nannofossils were taken from three chalks within Section 330-U1376A-1R-1. Sample 1R-1, 1 cm, contains a mixed Neogene assemblage that includes S. abies, C. leptoporus, Calcidiscus tropicus, Discoaster neohamatus, and Discoaster deflandrei. Sample 1R-1, 41 cm, contains an assemblage composed of Amaurolithus primus, Amaurolithus delicatus, Amaurolithus tricorniculatus, and Discoaster loeblichii. The LAD of D. loeblichii falls within Subzone CN9a and the first appearance datum of the genus Amaurolithus marks the base of Subzone CN9b, suggesting that the chalk was deposited during the latest Tortonian (late Miocene). Sample 1R-1, 76 cm, contains frequent Sphenolithus heteromorphus, indicating an early to middle Miocene age (Zones CN3–CN4).