Paleomagnetic and rock-magnetic measurements are routinely used to provide chronological control for stratigraphic studies of Ocean Drilling Program (ODP) sediments. In addition, rock-magnetic studies of ODP sediments are often used to provide core correlation, resolve glacial-interglacial cycles, and detect other types of paleoenvironmental changes (see reviews in King and Channell, 1991; Reynolds and King, 1995).
Shipboard paleomagnetic studies of Leg 165 sediments were severely hampered by drilling-induced overprints that could not be removed by the available shipboard alternating field (AF) demagnetization capabilities (Sigurdsson et al., 1997). Shore-based paleomagnetic studies with demagnetization equipment capable of AF demagnetization at high peak fields were undertaken to improve the magnetostratigraphy of selected Leg 165 sediments. In addition, rock-magnetic studies of selected Leg 165 sediments were undertaken to detect glacial-interglacial cycles and other types of paleoenvironmental changes.
The results of two separate magnetic investigations are discussed in this paper. The first is a high-resolution paleomagnetic study of the interval adjacent to the K/T boundary in Hole 1001A from the lower Nicaraguan Rise. The second is a low-resolution paleomagnetic and rock-magnetic study of sediments from Hole 1002C from the Cariaco Basin.