Abstracts with Programs - Geological Society of America

structures, isolated sink-fills, and faults record the presence of stratigraphic units that are missing
regionally. Upper Ordovician to middle Silurian clasts are incorporated into the Decaturville
breccia (pre-Devonian impact) in lower Ordovician country rock. Middle Devonian marine
sandstone filled a sink in lower Ordovician dolomite near Rolla. Upper Devonian Chattanooga
Shale blanketed the eroded western Ozark platform. Most of this unit was removed below the
sub-Mississippian unconformity in the central Ozarks but was preserved in an embayment that
we informally refer to as the Northwest Arkansas Basin. Clasts of Chattanooga Shale have been
recovered from the Weaubleau breccia (mid-Mississippian impact), a thin interval is preserved
along the Highlandville Fault, along the lower Buffalo River, and in sink-fills in northern Arkansas.
During the Early Mississippian, continued flexure resulted in back-stepping of the shelf margin,
so deep-water facies accumulated on erosional remnants or peritidal lower Paleozoic strata. Major
faults in southern Missouri are associated with some anomalous units of sandstone, limestone, or
olistoliths, providing a record of syn-tectonic sedimentation.
2-3 8:40 AM Pennington, Wayne D. [218074]
THE MENOMINEE CRACK AND CLINTONVILLE BOOMS: SEISMIC EVENTS IN MICHIGAN’S
UPPER PENINSULA AND NORTHEASTERN WISCONSIN
PENNINGTON, Wayne D., Geological and Mining Engineering and Sciences, Michigan
Technological University, 1400 Townsend Dr, Houghton, MI 49931, wayne@mtu.edu
and WAITE, Gregory P., Geological and Mining Engineering and Sciences, Michigan
Technological Univ, 1400 Townsend Dr, Houghton, MI 49931
In spite of its reputation as an aseismic area, there were intriguing occurrences of seismic events
in Upper Michigan and northern Wisconsin in 2010 and 2012. Although these two occurrences
were only about 100 km apart, there is no evidence indicating that they are related or even due to
a similar mechanism.
The Menominee Crack: On October 4, 2010, a loud noise and shaking were observed in an
area north of Menominee. This was associated with the appearance of 110m long crack at the
crest of a ridge, 1.5m in height and up to 9m wide. The crack is apparently a surficial feature,
resulting from stretching of the uppermost soil and clay layers to accommodate the creation of
a ridge at some shallow depth. A reasonable model (first proposed by Dr. Norm Sleep) is that
the limestone underneath the clay experienced a “pop-up” due to high lateral stresses. Usually,
pop-ups occur as a result of recent unloading, as at the base of a quarry or immediately following
glacial retreat; neither of these describes this site, so the cause remains speculative.
Clintonville Booms: Residents of Clintonville began hearing infrequent deep, rumbling sounds
on March 18, 2012; the booms were sometimes accompanied by felt shaking. Following a
relatively large event on March 20 that was clearly a M1.5 earthquake, four seismometers and
eight sound sensors were deployed within and around Clintonville to improve the locations of
subsequent events. Two events were located beneath the southeastern part of Clintonville at less
than 1 km below the surface within the granitic basement. These events were close enough to
the surface so that seismic energy of sufficiently high frequency coupled to the atmosphere and
propagated as sound. The Clintonville booms were indeed due to earthquakes, most of which
were too small to record.
2-4 9:00 AM Tupper, M. Tobias [218762]
IDENTIFICATION OF LOW-LEVEL SEISMICITY IN OHIO
TUPPER, M. Tobias, Geological Sciences, Ohio University, 316 Clippinger Laboratories,
Athens, OH 45701, mt833511@ohio.edu and GREEN, Douglas H., Dept. of Geological
Sciences, Ohio University, 316 Clippinger, Athens, OH 45701
OhioSeis records are examined to identify previously undocumented low-level earthquakes in
Ohio and surrounding regions. Records are scanned at multiple stations (at least four) to identify
peak amplitude arrivals within a time window specified by the lowest likely arrival phase velocity
and the maximum inter-station distance. A potential arrival peak must have an amplitude of
at least 1.5 times the RMS amplitude over an entire hour containing that peak. The location
(epicenter) of the potential earthquake is obtained using a velocity-independent-arrival-orderlocation
(AOL) technique. The event is classified as a probable earthquake if it is similarly
identified and located using a different set of four stations.
Five probable earthquakes in 2011 were each identified using at least five combinations of
stations of four seismic stations. This includes the documented 2011 New Year’s Eve M4.0 event
in Youngstown OH, which was located by this technique within 14 km and 10 seconds of the
epicenter and origin time reported by the USGS. An additional three events were identified using
at least three sets of four stations, and thirteen possible 2011 earthquakes were identified using
two sets of four stations. Most of these locations extend from Lake Erie up the Cuyahoga Valley,
through east-central Ohio towards Marietta OH.
2-5 9:20 AM Malcuit, Robert J. [217936]
A JUPITER ORBIT -- LUNAR ORBIT RESONANCE MODEL: POSSIBLE CAUSE FOR THE
BEGINNING OF THE MODERN STYLE OF PLATE TECTONICS
MALCUIT, Robert J., Geosciences Department, Denison University, Granville, OH 43023,
malcuit@denison.edu
Since the Plate Tectonics Revolution in the earth sciences, there has been this lingering debate
about when plate tectonics began. There are two end-member schools of thought: (1) that plate
tectonics has been operating throughout geologic time (Shervais, 2006, GSA SP-405, p. 173)
and (2) that plate tectonics, as we understand it today, can only occur when the Earth has cooled
sufficiently to permit plates to attain negative buoyancy (Davies, 1992, Geology, 20, p. 963; Stern,
2005, Geology, 33, p. 556). Stern (2005) proposes that the modern style of plate tectonics began
~1.0 Ga ago.
The Late Proterozoic also appears to be a critical time in the history of the lunar orbit. Peale
and Cassen (1978, Icarus, 36, p. 245) identified an orbital resonance state between Jupiter’s
orbit and the lunar orbit when the lunar orbital radius is at 53.4 ER (earth radii). Orbital traceback
calculations suggest that the earth-moon distance would be ~53.4 ER in Late Proterozoic time.
The key element in such an orbital resonance is the perigean cycle of the lunar orbit (the
prograde progression of the perigee position of the lunar orbit). At present the perigean cycle is
8.85 years (60.3 ER). At 53.4 ER the perigean cycle would be ~12 years, the approximate period
of Jupiter’s orbit. Under these conditions the major axis of the lunar orbit would be increased to
the resonant value by a forced ECC (eccentricity) but the orbital angular momentum would remain
near that of a 50 ER orbit and then slowly increase in time to that of a 53.4 ER orbit. As the lunar
orbital ECC reaches a maximum of up to ~0.3, the rock and ocean tidal amplitudes would be
~2.5 times higher than that of a circular orbit of 53.4 ER. Such rock tidal activity could lead to the
development of tidal vorticity induction cells in the upper mantle (Bostrom, 2000, Oxford Univ.
Press) that would aid in the initiation of subduction.
This model can be tested via the tidal rhythmite record of the Late Proterozoic. The two
predictable constants are that the semi-major axis of the lunar orbit should be near 53.4 ER
and the number of sidereal months per year should be about 16 throughout this era. Assuming
that the earth rotation rate at 1.1 Ga (before the forced ECC episode) is ~16.9 hr/d, the number
SESSION NO. 3
of days per year would change from ~519 d/yr at ~1.1 Ga to 466 d/yr at the end of this orbital
resonance era.
SESSION NO. 3, 8:00 AM
Thursday, 2 May 2013
T4. Quaternary Research in the Great Lakes Region I:
The Pleistocene
Fetzer Center, Kirsch Auditorium
3-1 8:00 AM Lepper, Kenneth [218517]
AGE CONSTRAINTS FOR AN UPDATED LAKE AGASSIZ PALEOHYDROGRAPH
LEPPER, Kenneth, Department of Geosciences, North Dakota State University, P.O. Box
6050, Dept. #2745, Fargo, ND 58108-6050, ken.lepper@ndsu.edu, FISHER, Timothy G.,
Environmental Sciences, University of Toledo, MS #604, Toledo, OH 43606, and LOWELL,
Thomas V., Department of Geology, University of Cincinnati, 500 Geology/Physics Building,
University of Cincinnati, Cincinnati, OH 45221
Meltwater releases from Lake Agassiz to the Mississippi, Mackenzie and Great Lakes waterways
have been implicated as triggers of abrupt climate change events during the last deglacial
cycle. To evaluate these assertions a paleohydrograph for Lake Agassiz is needed with robust
chronologic controls. Shorelines represent static water planes and transitions between shoreline
positions represent significant water-level fluctuations. However, geologic ages constraining the
timing of shoreline development, and thereby water-level fluctuations for Lake Agassiz, have
been difficult to obtain, and therefore, sparse. In recent years we have had success in applying
OSL dating techniques to shoreline deposits of Lake Agassiz that are more easily mapped
using LiDAR data. This report will summarize a growing chronologic data set that includes 35
independent OSL ages from five different study areas around the southern basin, but thus far
mostly focused around the southern outlet. The cumulative OSL data set for Lake Agassiz’s
southern basin provides robust age constraints for the Herman, Norcross and Campbell
strandlines with averages and standard deviations of 14.1 ± 0.3 ka, 13.6 ± 0.2 ka, and 10.5 ±
0.3 ka, respectively. In addition, the new age constraints are used to develop an updated
paleohydrograph for Lake Agassiz spanning the time period of approximately 14.5 to 10 ka
which includes rapid climate changes at the end of the last ice age.
3-2 8:20 AM Fisher, Timothy G. [218507]
RECENT STRATIGRAPHIC AND CHRONOLOGIC RESULTS FROM THE HURON-ERIE LAKE
PLAIN OF ANCESTRAL LAKE ERIE, OHIO
FISHER, Timothy G. 1 , BLOCKLAND, Joseph2 , HIGLEY, Melinda3 , ANDERSON, Brad1 ,
GOBLE, Ronald J. 4 , and LEPPER, Kenneth5 , (1) Environmental Sciences, University
of Toledo, MS #604, Toledo, OH 43606, timothy.fisher@utoledo.edu, (2) Department of
Environmental Sciences, University of Toledo, 2801 West Bancroft Street MS604, Toledo,
OH 43606, (3) Illinois State Geological Survey, Champaign, IL 61820, (4) Department of
Earth and Atmospheric Sciences, University of Nebraska - Lincoln, 214 Bessey Hall, Lincoln,
NE 68588, (5) Department of Geosciences, North Dakota State University, P.O. Box 6050,
Dept. #2745, Fargo, ND 58108-6050
An understanding of deglacial events in the Huron-Erie Lake Plain is known in general, but
poorly understood in detail. During east–northeast recession of the Erie and Huron lobes
of the Laurentide Ice Sheet, Ancestral Lake Erie evolved through fluctuating lake levels and
changing outlets. Strandlines are well known, having been mapped ~100 years ago, but detailed
stratigraphic and sedimentologic analyses and age control is left wanting. To increase our
knowledge of this lake, and in the process develop a more four-dimensional understanding of the
surficial geology, we have been dating strandlines and sand dunes using mostly OSL techniques.
To evaluate the Ypsilanti low event, rhythmic lake sediments were analyzed at elevations that
would have experienced subaerial emergence during this low event. Most of the sand dunes are
4000–9000 years younger than the oldest strandlines. Because sand was sourced from older
ice marginal and strandline deposits, dunes either initially formed or were remobilized under
a deteriorating climate during stadials, and post-date disappearance of Ancestral Lake Erie.
Only 507 rhythmites were observed between till and the overlying dune sand and shallow water
sediment, which is fewer than expected. A stratigraphic break within the lacustrine sedimentary
sequence necessary to support the low-water Ypsilanti Phase was not observed. In summary, our
data thus far suggests that stable water levels were short lived and that the lake evolved over a
shorter period of time than is commonly assumed.
3-3 8:40 AM Lowell, Thomas V. [218702]
DO THE ICE MARGIN CHANGES OF THE LAURENTIDE GREAT LAKE LOBES MATCH THE
GREENLAND ISOTOPE RECORD?
LOWELL, Thomas V., Department of Geology, University of Cincinnati, Cincinnati, OH 45221,
thomas.lowell@uc.edu
The Greenland Ice Cores have long been held as a reference for climate change during the
late Pleistocene. The isotopes from multiple cores now provide a detailed record that many
paleoclimate records have been compared to. Glaciers are taken as being most responsive to
temperatures during the summer ablation season. Oerlemans (2005) has show that a global
network of small glaciers can provide a temperature record over the last two hundred years that
matches the global temperature derived from instrumented records. It would be informative to ask
if the margins of ice sheets match the reference for climate change. The lobes of the Laurentide
ice sheet that occupied the Great Lakes are examined here in that context.
For the last glacial maximum records show that the ice sheet was south of the Great Lakes by
27.2 ka cal and continued to reach its maximum at 24.0 ka cal and started to retreat as early as
21.7 ka cal with major retreat underway by 17.0 ka cal. Superposed on this general pattern were
advances at 24.0, 24.0, 22.2 and 21.2 ka cal. With the exception of a warm interstadial at 27.5
and 23.5 ka cal, the ice core is nearly linear during this time. In other words examination of the
ice core alone would not suggest the growth, decay pattern, nor major advances of the ice sheet
margin.
Possible explanations for this disconnect are 1) the ice core record does not represent the
climate of the Great Lakes region; 2) the concept of seasonality, whereby the ice core records
mean annual, not summer temperatures; 3) the dynamics of ice sheets are not driven by climate
changes. Given that the above record was derived from and is consistent with both the Lake
2013 GSA North-Central Section Meeting 3