6. PASS-THROUGH CORE MEASUREMENTS OF MAGNETIC SUSCEPTIBILITY AND NATURAL GAMMA RAY, NEW JERSEY COASTAL PLAIN¹

John M. Metzger,^2,4 Steven C. Remer,² Kenneth G. Miller,^2,3 Dennis V. Kent,³
Mickey C. Van Fossen,^2,3 James V. Browning,² and Dave S. Goldberg³

ABSTRACT

We measured magnetic susceptibility (MS) and core gamma radiation (CGR) on 3162 ft (963.9 m) of core recovered by the New Jersey Coastal Plain Drilling Project (Ocean Drilling Program Leg 150X) at Island Beach, Atlantic City, and Cape May, New Jersey. Integration of core lithology, core/log (MS and CGR), and downhole gamma-ray (DGR) log studies have (1) documented the core/log expression of previously determined unconformities; (2) shown that MS is a proxy for glauconite percent in the New Jersey Coastal Plain; (3) illustrated a major change in sedimentation from shelfal glauconite evidenced by very high MS values to deltaic deposition with low MS values in the earliest Miocene (ca. 22 Ma); (4) shown that comparison of MS and CGR with DGR can be used to resolve discrepancies in depth between downhole logs and cores; and (5) shown that the CGR detects some zones noted in the lithology (e.g., phosphate rich zones) that are not resolved in the DGR.

¹Miller, K.G., and Snyder, S.W. (Eds.), 1997. Proc. ODP, Sci. Results, 150X: College Station, TX (Ocean Drilling Program).
²Department of Geological Sciences, Rutgers University, Piscataway, NJ 08855, U.S.A.
³Lamont Doherty Earth Observatory of Columbia University, Palisades, NY 10964, U.S.A.
⁴Correspondence author: jmm@essc.psu.edu