Magnetostratigraphic correlations in two cores from the late Triassic Lunde Formation, Beryl Field, northern North Sea, UK

Hounslow, Mark W. and Maher, Barbara A. and Thistlewood, Laurence and Dean, Kevin (1995) Magnetostratigraphic correlations in two cores from the late Triassic Lunde Formation, Beryl Field, northern North Sea, UK. Geological Society Special Publication, 98. pp. 163-172. ISSN 0305-8719

Abstract

The magnetostratigraphy of two cores from the late Triassic Lunde Formation of the northern North Sea are compatible with the calibrated magnetostratigraphy for the Norian stage determined by Gallet et al. (1993) from Tethyan carbonates. The polarities of the cores indicate a lower to upper Norian age for core 9/13A-36 and lower to middle Norian age for core 9/13A-A45. The isolated characteristic magnetizations are due to a Triassic detrital remanent magnetization, which is partially overprinted with a drilling-induced remanence of two origins. The drilling-induced remanences are associated with (1) the main coring procedure, producing an overprint which is oriented downcore and (2) the subsample coring procedure, which produces an overprint parallel to the subsample core axis and directed outwards from the main core axis. The elimination of those specimens with a significant drilling-induced remanence is important for the determination of the magnetostratigraphy in these cores.