This chapter is the site report for Medford corehole, the twelfth continuously cored and logged onshore site drilled as part of the NJCPDP. The NJCPDP began with drilling at Island Beach (March–April 1993), Atlantic City (June–August 1993), and Cape May (March–April 1994) as part of Ocean Drilling Program (ODP) Leg 150X (Miller et al., 1994a, 1994b, 1996; Miller and Snyder, 1997). These three sites targeted Oligocene–Miocene sequences and tried to unravel icehouse sea level changes tied to continental slope drilling by the JOIDES Resolution on ODP Leg 150 (Miller and Mountain, 1994; Miller et al., 1996, 1998).

ODP Leg 174AX continued onshore drilling at the following locations with specific objectives:

  1. Bass River, New Jersey (October–November 1996) (Miller et al., 1998), targeting Upper Cretaceous to Paleocene strata unsampled during Leg 150X.

  2. Ancora, New Jersey (July–August 1998) (Miller et al., 1999), an updip, less deeply buried Cretaceous–Paleocene section complimentary to the Bass River site.

  3. Ocean View, New Jersey (September–October 1999) (Miller et al., 2001), focusing on middle Eocene–upper Miocene sequences.

  4. Bethany Beach, Delaware (May–June 2000) (Miller et al., 2003), concentrating on thick Miocene sequences in the depocenter of the Salisbury Embayment.

  5. Fort Mott, New Jersey (October 2001) (Sugarman et al., 2004), targeting the largely nonmarine Cretaceous Potomac Group and its contained aquifers.

  6. Millville, New Jersey (May–June 2002) (Sugarman et al., 2005), targeting upper Cretaceous sequences from southern New Jersey.

  7. Sea Girt (September–November 2003) (Miller et al., 2006), targeting upper Cretaceous sequences from northern New Jersey.

  8. Cape May Zoo (September–October 2004) (Sugarman, et al., 2007), targeting middle Miocene through Pleistocene sequences to better define the distribution of Miocene sequences and aquifers in the Cape May peninsula.

The Medford site was located to focus on improved correlations of Cretaceous sequences and aquifers. One particular goal for Medford drilling is the nonmarine aquifers of the Potomac, Raritan, and Magothy Formations (Zapecza, 1989). As the deepest unit in the coastal plain above metamorphic basement, information on the Potomac Formation (Neocomian–earliest Cenomanian; Doyle and Robbins, 1977) is largely limited to discontinuously sampled wells in New Jersey and Delaware. Exceptions to this include the continuous corehole at Leg 174AX Fort Mott (Sugarman et al., 2004) and New Castle, Delaware (Benson and McLaughlin, 2006). Both sites provided reasonably complete coring of the Potomac Formation and new insights into this unit, but both were drilled in an updip position and in a restricted geographic area (the southern New Jersey and Delaware coastal plains; the sites are ~6.5 km apart). The Medford corehole provides a more basinal view from the central part of the New Jersey coastal plain and provides an updip location to extend our strike line landward from Sea Girt to Ancora to Medford, as well as a central tie point for correlation of aquifers between the southern (e.g., Fort Mott site) and northern New Jersey coastal plain.