CalPal

ABSTRACT: Based on geomagnetic extrapolations (Laj et al., 1996), quite recently Van Andel (1998) constructed the first continuous glacial radiocarbon calibration curve. The reliability of this calibration curve was challenged by Van der Plicht (1999), who also warned in general against glacial calibration, due to prevailing limitations in the corresponding geophysical data, ice core synchronisms, and terrestrial chronologies. It was suggested that prehistorians should refrain from glacial radiocarbon calibration, until a number of questions concerning the time-scales of the Greenland GRIP and GISP2 ice cores and the Japanese Lake Suigetsu varve chronology (Kitagawa and Van der Plicht, 1998a; 1998b) have been resolved. We argue that the relevant glacial 14C-calibration data have sufficient precision, both on an absolute time-scale and in relation to the ice-core chronologies, to support widespread construction of age-calibrated 14C-chronologies in the Quaternary sciences.

ABSTRACT: ANTIQUITY recently published the first continuous Glacial radiocarbon calibration curve (van Andel 1998), which is based on the geomagnetic extrapolations of Laj et al. (1996), but was already challenged by Van der Plicht (1999) in the immediately succeeding volume of ANTIQUITY. Van der Plicht´s reply urges caution and suggests to prehistorians the unreliability of radiocarbon calibration for the Last Glacial period “for the purposes of prehistoric and environmental calibration” (Van der Plicht 1999, 119) until a number of issues concerning the time-scales of the Greenland GRIP and GISP2 ice-cores and the Japanese Lake Suigetsu varve chronology published by Kitagawa & Van der Plicht (1998a; 1998b) shall have been solved. This response to Van der Plicht (1999) documents that the data sets required for such purposes are already available today and - with possibilities to test each subset of data - do, indeed, allow first approximations of Calendric Age-Conversions of Last Glacial radiocarbon data.