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I thought I posted this yesterday. Apologies if this is the second time around. -NM -> In collecting for pollen I,ve seen that burrowed boundry between the -> maestricht ian and the Hornerstown. Never thought of it as a good -> boundary for k/t studies in N.J. because the top of the Cretaceous is -> an erosion interval. So what am I overlooking? -> Gil Brenner The boundary between the Navesink and the Hornerstown is not necessarily an unconformity. Studies of formanifera by Olsson and Wise (1987) indicate that the basal Hornerstown represents a condensed section which spans the K/T boundary. Gallagher (1993) also states "In sum, micropaleontological evidence places the K/T boundary within the lower part of the Hornerstown Formations, with no long-term, major break in deposition and no evidence for an angular unconformity." Articulated crocodile and turtle specimens are not uncommon in this interval, and fragile complete ammonite steinkerns have also been found, making it appear unlikely that this layer is reworked. As for the burrowed zone below the Hornerstown, there are outcrops much further north of Sewell, the best known site, that show no sign of being burrowed. Yet the same Maestrictian fauna is present. Steve Kurth Literature cited: Gallagher, W. B. 1993. The Cretacous/Tertiary Mass Extinction Event in the Northern Atlantic Coastal Plain. The Mosasaur, 3:75-152. Olsson, R. K., and Wise. 1987. Upper Maestrichtian to Middle Eocene stratigraphy of the New Jersey slope and coastal plain. In: J. E. van Hinte, S. W. Wise, et al. (eds), Initial reports of the Deep Sea Drilling Project, Vol. XCII, PP. 1343-1365. Olsson, R. K. 1989. Depositional sequences in the Cretaceous post rift sediments on the New Jersey Atlantic margin. Marine Geology, 90: 113-118.
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