Special Session OS-3: "Middle to Late Miocene Perturbations of the
Earth Ocean and Climate Systems: An Integrated Approach."
at AGU 2001 Spring Meeting
John B. Hynes Convention Center
Boston, Massachusetts
May 29-June 2, 2001
Thursday, March 1, was the deadline for receipt of the Postal/Express
Mail 2001 Spring Meeting Abstract Submission Form.
Thursday, March 8 at 1400 UTC, is the deadline for receipt of the
2001 Spring Meeting Interactive Web Abstract Submission Form.
Monday, April 30 is the Preregistration and Housing deadline.
Co-Conveners:
Andre W. Droxler
Rice University, Dept. of Geology and Geophysics, MS-126, PO Box 1892,
Houston, TX 77251-1892, Phone: 713/348-4885, Fax: 713/348-5214
Email: andre [at] rice.edu
Liselotte Diester-Haass,
Zentrum fur Umweltforschung, Universitat des Saarlandes, 66041
Saarbrucken, Germany, Fax +49/6841-171774
Email: A.L.Haass [at] t-online.de
James Wright,
Rutgers University, Department of Geology, Wright Chemistry Building,
Piscataway, NJ 08854, Phone: 732/445-5722, Fax: 732/445-3374,
Email: jdwright [at] rci.rutgers.edu
John Anderson,
Rice University, Dept. of Geology and Geophysics, MS-126, PO Box 1892,
Houston, TX 77251-1892, Phone: 713/348-4884, Fax: 713/348-5214,
Email: johna [at] rice.edu
It is well established that the middle and late Miocene corresponds to a
transition in the Cenozoic evolution of the Earth Ocean and climate
systems. The interval at the end of the early Miocene and the very
beginning of the middle Miocene was characterized by unusual warmth and
high sea level. Subsequent to the "Mid-Miocene Climate Optimum", the
East Antarctic ice sheet expanded. In addition to a contemporaneous
establishment of the West Antarctic ice sheet, several lines of evidence
point out that the first small northern hemisphere ice sheets were also
initiated at this time. The middle Miocene climatic deterioration is
well recorded in benthic oxygen isotope records, which integrate a
stepwise ice volume increase and an overall cooling of the deep and
intermediate water masses. A series of high amplitude sea level
fluctuations, observed in low latitude planktic oxygen isotope records
and in the stacking pattern of sedimentary sequences along carbonate and
siliciclastic margins, culminated by a major sea level fall at the
middle-to-late Miocene boundary followed by a significant sea level
transgression at the very beginning of the late Miocene. During the
middle and late Miocene, the ocean carbonate system suffered dramatic
modifications illustrated in a series of intervals when the carbonate
sediments were poorly preserved and "crashed". In addition, the middle
and late Miocene witnesses some very high amplitude fluctuations in
biogenic productivity, characterized by a series of unusually high
biogenic productivity intervals, often referred to as "biogenic blooms
or bursts." Moreover, during the middle and late Miocene, the North
Atlantic became a source for deepwater formation and a modern-like
deepwater conveyor became firmly established.
The proposed session (half or full day) will bring together scientists
who have recently or are currently focusing their research on the middle
and late Miocene in terms of (1) the expansion and establishment of ice
sheets in Antarctica and in the northern hemisphere, (2) the
high-resolution benthic and planktic oxygen and carbon isotope records,
(3) the sequence stratigraphy framework along carbonate and
siliciclastic margins, (4) the carbonate "crash" or "crashes", (5) the
biogenic "blooms and bursts", (6) the global surface, deep and
intermediate ocean circulation, and (7) the continental climate changes
associated with some major vegetation modifications. This proposed
session will offer a unique opportunity to compare and integrate the
results of these different research focuses and ultimately help the
establishment of a more coherent model to better understand the timing,
amplitudes, causes, and effects of the observed Earth ocean and climate
perturbations during the middle and late Miocene.
If you are interested in participating at this session, please send your
abstract to AGU before the deadlines:
Thursday, March 8 at 1400 UTC, is the deadline for receipt of the 2001
Spring Meeting Interactive Web Abstract Submission Form which can be
found on the AGU web site at: http://www.agu.org
If you need any extra information, do not hesitate to contact one of
the four conveners of the session.
Best regards from Houston,
Andre W. Droxler