ISSN:
1365-246X
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
Notes:
Numerous short features in the ocean magnetic anomaly patterns (25–100 nT amplitude, 8–25 km wavelength: tiny wiggles) have been identified in several independent magnetic profiles, and have been modelled either as short polarity intervals (‘cryptochrons’) or as palaeointensity fluctuations (Cande & Kent 1992). In the last few years, several authors (e.g. Tauxe et al. 1994; Lowrie & Lanci 1994; Hartl, Tauxe & Constable 1993) have identified, on high-resolution magnetostratigraphic sections, short polarity intervals, correlated with cryptochrons deriving from the ocean floor. The record of a previously undetected short normal-polarity event, lasting about 11 kyr, from an upper Tortonian-lower Messinian sedimentary sequence (e.g. Compagnoni et al. 1992) in central Italy (42.0°N, 13.0°E), is reported here. The north virtual geomagnetic polar (VGP) path of the R-N transition appears to be strongly confined to a meridian band passing over the Americas about 90° away from the site longitude, as reported in recent years for a large number of reversals. This short feature is lacking in the corresponding ocean-floor magnetic anomaly patterns, probably because of the difficulties of resolving polarity intervals as short as this one in ocean magnetic profiles.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-246X.1996.tb05262.x
