Rf. Denniston et al., Speleothem evidence for changes in Indian summer monsoon precipitation over the last similar to 2300 years, QUATERN RES, 53(2), 2000, pp. 196-202
Speleothems from a web-ventilated dolomitic cave in the Pokhara Valley, cen
tral Nepal, preserve a mineralogic record of Indian summer monsoon variabil
ity over the past 2300 yr, Annually deposited aragonite layers formed betwe
en 2300 and 1500 yr B,P,, indicating reduced monsoon precipitation and incr
eased cave aridity, whereas alternating calcite/aragonite laminae deposit e
d after 1500 yr B,P. record elevated summer monsoon precipitation and incre
ased cave humidity. Dense, optically clear calcite layers deposited from 45
0 +/- 5 to 360 +/- 20 yr B.P. (1550 to 1640 A.D,) indicate a less-evaporati
ve cave environment and suggest moister and/or cooler conditions, possibly
related to climatic change associated with the onset of the Little Ice Age.
(C) 2000 University of Washington.