Science: New
Discovery:Geology: Paleomagnetism: Central Asia: Glaciations: Climate
Change
Paleomagnetism
of Neoproterozoic through to Lower Paleozoic rocks on microcontinents
of Central
Asia: implications for the Precambrian glacial Paradox and amalgamation
of
Eurasia
Tillite at the Base of
the Tsagaan
Oloom Fm (Gobi-Altai area)
Supported by the National Science Foundation EAR05-08597
Project Summary
The latest Neoproterozoic through
the Cambrian is one of the most
remarkable intervals in geologic time. It marks the onset
of biodiversity at the Vendian-Cambrian boundary, major transitions in
seawater
chemistry, major plate reorganization, the breakup of the Rodinia
supercontinent
and Gondwana assembly
and a possible change
from
severe climate with low-latitude glaciations to Phanerozoic circumpolar
pattern.
Existing paleomagnetic data
suggest that at
least some of the
Neoproterozoic
glaciogenic sediments were deposited at low paleolatitudes in sharp
contrast to
their Pleistocene counterparts. Several competing models vie for
explanation of
this unusual paleoclimatic record
(e.g. Snowball, Slushball and High Obliquity models).
The extant paleomagnetic database does not allow a clear
distinction
amongst these models.
The
Ural-Mongol fold belt, which separates the Baltica, Siberia, North
China and
Tarim blocks, is the largest in Eurasia. Its central part comprises a
number of
microcontinents with
Intellectual Merit
The
Broader
Impacts
The University of Florida is
committed to
enhancing geologic education in the USA through the active recruitment
of
under-represented groups. We will also
involve undergraduate
students
in this research in order to train future generations of geologists and
have
requested funds to support undergraduate research projects within the
current
proposal. Our work also involves the
substantial
collaboration of Russian colleagues
and students. These
types of collaborative efforts allow the
Russian scientists access to western scientists and their laboratories
and
vice-versa.
We
would like to emphasize the training that this grant will provide to
undergraduate, graduate and postdoctoral scholars. Also, our
international
collaboration with scientists in Russia fosters integration of the
latter into
the international scientific community. Results
from this project will be shared via the published literature (i.e.
with other
scientists); with undergraduate and graduate students (via formal and
informal
departmental seminars) and with the general public.
Project
Participants
Dr.
Joseph G. Meert (Project
Director and downright ugly)
Dr. Natasha
Levashova
(Co-Project Director)
Vimal Pradhan
(Ph.D.
student and Inspirational Leader)
Shawn Malone
(M.S.
student and field guide)
Laura Gregory
(M.S.
student and finder of lost souls)
Jessica Yff
(undergraduate
researcher and moral compass)
Major Findings: (Publications)
1.
Levashova,
N., Kalugin, V., Gibsher,
A.S., Yff, J., Rybanin, A.B.,
Meert, J.G. and
Malone, S.J., 2010. The Origin
of the Baydaric
Microcontinent, Mongolia: Constraints from Paleomagnetism and
Geochronology, Tectonophysics,
in press. pdf of
submission.
2. Gibsher, A.S., Meert, J.G., Levashova, N.M., Grice, W.C. and Kamenov, G.D., Ediacaran fossils predating the Snowball Earth episodes? New Evidence from the Lesser Karatau microcontinent, Kazakhstan, Geology, in review
3.
Levashova,
N., Gibsher, A.S.,
Meert, J.G. and Grice, W.C., The
Origin
of the Central Asian orogenic belt
Microcontinents: Constraints from Paleomagnetism and Geochronology,
Precambrian Research, accepted
pending revisions.
4.
Meert, J.G,,
Gibsher, A.S., Levashova, N.M., Grice, W.C. and Kamenov, G.D., 2009.
Paleomagnetism,
geochronology, glaciation and Ediacaran(?) fossils from the
Lesser Karatau microcontinent, Kazakhstan, Geological Soc. Am.
abstracts, 41:7.
5.
Pradhan,
V.R., Meert, J.G., Levashova, N.M. and Gibsher, A.S., 2009. Preliminary
paleomagnetic data on Late Cambrian to Ordovician carbonate beds of
Tamdy
Series from the Lesser Karatau microcontinent, South Kazakhstan,
Geological
Soc. Am. abstracts, 41:7.
7.
Levashova,
N., Meert, J.G., Gibsher, A., Grice, W., Rybanin, A., 2007. Preliminary ages
and paleomagnetic data on the Neoproterozoic Kurgan Fm. From the lesser
Karatau
range in south
8.
Gregory,
L.C., Meert, J.G., Levashova, N., Grice, W.C., Gibsher, A., Rybanin,
A.,
2007. Paleomagnetic and geochronologic
data from
10.
Gregory,
L.C., Levashova, N., Meert, J.G. and Malone, S.J., 2006. Paleomagnetic
constraints from Neoproterozoic to early Cambrian rocks in
11. Levashova, N., Gibsher, A.S. and Meert, J.G., 2010. Precambrian microcontinents of the Ural-Mongol Belt: new paleomagnetic and geochronological data, Geotectonics, 44, in press (in Russian).
Shawn Malone (M.S. Student) and Munkh-Erdene
(Mongolian
Survey) orient limestone samples
from the Bayan Gol Formation along the Zavkhan river.
Mongolian Airways Super Luxury Liner (a Soviet
Antonov-24
prop) that took us from Ulaan Bataar
to Gobi Altai in western Mongolia. The runway was dirt and the
parking
space was the only paved
section of the airport.
Field Crew in front of a ovoo. Front
(relaxed)
driver Uri (Novosibirsk), back (from right) Alexander Rybanin
(aka Sasha- Novosibirsk), Natasha Levashova (Moscow), Roman Shelepaev
(Novosibirsk), Munkh-
Erdene (Mongolian Survey), Valery Kalugin (Novosibirsk) and Shawn
Malone
(Florida).
Shawn Malone standing in front of red and grey
shales in
the Bayan Gol formation.