This file contains 6858 identifications of Chrons 1n through 6n(old) from the Carlsberg Ridge from Merkouriev and DeMets (2006). The magnetic data used for these reversal identifications consist principally of 236,000 km of Russian shipboard data, but are complimented by aeromagnetic and other shipboard data archived at the U.S. National Geophysical Data Center. Readers are referred to Merkouriev and DeMets (2006) for details. Due to large changes in the skewness of the magnetic profiles within the study area, all the magnetic profiles were reduced to the pole using the local ridge azimuth and remanent and ambient field parameters that were calculated for the location where each profile crosses the ridge (or approaches it most closely). Reversal identifications were made on a screen that displayed the phase-shifted digital files and permitted interactive picking from those data. The phase-shifted profiles were compared to a synthetic magnetic profile calculated at 90N with a 0.5-km-thick magnetic source layer. For shipboard profiles, the top of the magnetic layer was modeled to be 2.5 km below the surface. For aeromagnetic profiles, the top of the magnetic layer was modeled to be 2.8 km below the surface since all of the aeroprofiles were flown at a height of 1000 feet (roughly 300 m) above the ocean surface. References: Merkouriev, S., and DeMets, C. (2006). Constraints on Indian plate motion since 20 Ma from dense Russian magnetic data: Implications for Indian plate dynamics, Geochem. Geophys. Geosyst., 7, Q02002, doi:10.1029/2005GC001079.