CONTACT: GARY GALLUZZO
100 Old Public Library
Iowa City IA 52242
(319) 384-0009; fax (319) 384-0024
Release: April 8, 1999
UI presents April 13 lecture on caves and climate change
IOWA CITY, Iowa -- The University of Iowa Museum of
Natural History will present a free, public lecture, "Stalagmites, Caves and
Climate Change," at 7 p.m. Tuesday, April 13 in Room 112, First Floor, Macbride
Part of the Museum's "Afternoon With a Scientist"
lecture series, the talk will be given by Rhawn Denniston, UI doctoral candidate
who has worked on a new method of reconstructing ancient climates for three
and one-half years under the supervision of Luis Gonzalez, UI associate professor
of geology. Specifically, he and Gonzalez measure the ratio of carbon and
oxygen isotopes in stalagmites and other cave rock formations. According to
Denniston, the annual layers that make up stalagmites can be precisely dated
and offer an alternative to pollen, sometimes preserved in lakes and ponds,
and animal fossils.
Denniston, who has used stalagmites to date the advance
and retreat of Midwest prairies and measure rainfall amounts during Nepal's
monsoon season, will also exhibit stalagmite specimens and show slides highlighting
his work in Iowa, Missouri and Nepal.
For more information, call David Brenzel, program
coordinator, at 335-0482.