Posted on Feb 1, 2002

John Garver, professor of geology, and
Mike Bullen '97 published a paper in
Geological Society of America Bulletin (December issue) that details
their work on the evolution of the Tien Shan Mountains in Central
Asia. Their study suggests that the initiation of mountain building
in the Tien Shan occurred about 10 million years ago and
has continued until today. This mountain range has been
created by the collision of India with Asia, and the active growth of the
range has resulted in a number of large earthquakes. Their
evidence includes a study of the time of rock cooling as determined
by fission-track analysis, as well as an analysis of the strata.
This dating of rock cooling, done at the Union fission-track
lab, allowed them to precisely determine when rocks cooled
as they were exhumed from deep levels to the surface.
Bullen, pursuing a master's degree at Penn State, returned to Union
to collaborate with Garver because he was familiar with the
fission-track lab from his undergraduate research. Garver also is
co-author on a paper, “Differential exhumation of an Alpine
microcontinent, Central Anatolia, Turkey: Evaluation of rates and
mechanisms using FT analysis” in
Earth and Planetary Science Letters. The paper details work on the
uplift and evolution of metamorphic rocks in Central Turkey.
These rocks have come up to the surface from great depths as they
have been squeezed between fault zones. The work helps in
understanding how long these fault systems have moved and
the long-term effect of their movement. Some of the dating of
the rocks was done at Union's fission-track lab.