A. Shemesh et D. Peteet, OXYGEN ISOTOPES IN FRESH-WATER BIOGENIC OPAL - NORTHEASTERN US ALLEROD-YOUNGER DRYAS TEMPERATURE SHIFT, Geophysical research letters, 25(11), 1998, pp. 1935-1938
The first oxygen isotope analysis of biogenic opal from lake sediments
, from the Allerod/Younger Dryas transition in a core from Linsley Pon
d, Connecticut, gives an average estimate of a 6 degrees C drop in tem
perature during the Younger Dryas. This shift represents temperatures
during the bloom season, and may be less than the winter temperature d
rop. The sharp transition itself, with a duration of about 200 years,
suggests that the temperature decrease may have been as large as 12 de
grees C. Previous estimates of the Allerod/Younger Dryas temperature s
hifts are controversial, and range from 3-20 degrees C, suggesting tha
t further interdisciplinary research on the same samples is warranted.