COSAM » Departments » Geosciences » Colloquium

Colloquium


Geosciences Thesis Proposal - Rahul Bhattacharya

Apr 23, 2018 03:00 PM

“Characterizing Structural Features of the Bellingham Basin by Gravity and Magnetic Modelling”

Thesis Proposal by Rahul Bhattacharya

 

Hosted by Dr. Lorraine Wolf


Geosciences Thesis Proposal - Benjamin Weinmann

Apr 23, 2018 04:00 PM

"Geology of the Alexander City, Alabama 7.5 Minute Quadrangle and Investigations of Eastern Blue Ridge Tectonic Evolution"

Thesis Proposal by Benjamin Weinmann

 

Hosted by Dr. Mark Steltenpohl


Geosciences Thesis Defense - Sara Speetjens

Apr 24, 2018 02:15 PM

"Magma evolution and processes of the Ashi volcano, NW Tibet, China: Sr isotope studies of plagioclase crystals"

Thesis Defense by Sara Speetjens

 

Hosted by Dr. Haibo Zou


Geosciences Thesis Defense - Michael Salisbury

Apr 25, 2018 09:30 AM

"Analysis of the D’Olive Creek Watershed: Identifying the Local Drivers That Have led to Stream Degradation"

Thesis Defense by Michael Salisbury

 

Hosted by Dr. Stephanie Shepherd


Geosciences Thesis Proposal - Elijah Johnson

Apr 25, 2018 05:00 PM

"The Effectiveness of the Augmented Reality Sandbox for Improving Spatial Thinking in Undergraduates"

Thesis Proposal by Elijah Johnson

 

Hosted by Dr. Karen McNeal


Geosciences Colloquium - Rebecca Minzoni

Apr 26, 2018 03:30 PM

"The Past is the Key to Our Future: What Sediments and Fossils can tell us about Antarctic Ice Stability"

By Dr. Rebecca Totten Minzoni

 

Hosted by Dr. Karen McNeal 


Geosciences Thesis Defense - Austin Bush

Apr 18, 2018 02:30 PM

 "Assessing Rainwater Harvesting Potential for Urban Multi-Family Housing Developments in Auburn, Al using a sUAS"

Thesis Defense by Austin Bush

 

Hosted by Dr. Chandana Mitra


Geosciences Thesis Defense - Ted Wilson

Apr 06, 2018 03:30 PM

"Pyrite Biomineralization and Arsenic Sequestration at a Florida Industrial Site: Imaging and Geochemical Analysis"

Thesis Defense by Ted Wilson

 

Hosted by Dr. Ming-Kuo Lee


Geosciences Colloquium - IBA

Mar 29, 2018 03:30 PM

IBA Team 2018 Presentation

 

Hosted by Dr. Ashraf Uddin


GAB Distinguished Lecturer - Robert Gastaldo

Mar 08, 2018 03:30 PM

"Trust but Verify: Do Karoo Basin rocks record the continental expression of the Mother of Mass Extinction?"

By Robert Gastaldo, Colby College

 

Hosted by Dr. Mark Steltenpohl

 

Abstract: 

Do Karoo Basin rocks record the continental expression of the Mother of Mass Extinction?

 

Robert A. Gastaldo, Whipple-Coddington Professor of Geology, Colby College, 5807 Mayflower Hill Drive, Waterville, ME 04901-5807, ragastal@colby.edu

 

Current models of the terrestrial biosphere’s response to the end-Permian crisis are based largely on lithostratigraphic, magnetostratigraphic, and biostratigraphic records obtained from sedimentary successions in the Karoo Basin, South Africa. These successions have been interpreted to represent continuous sedimentation across the upper Daptocephalus (latest Permian) and lower Lystrosaurus (earliest Triassic) vertebrate-assemblage zones, assigned to the Elandsberg Mbr. and lower Palingkloof Mbr., and upper Palingkloof Mbr. and overlying Katberg Fm., respectively. The stratigraphic section at Old (West) Lootsberg Pass, Eastern Cape Province, is used as a cornerstone for the currently accepted model correlated with the marine extinction event, in part, based on a magnetic polarity stratigraphy of limited documentation. A multidisciplinary effort provides a refined stratigraphic framework, encompassing over 740 m of measured section, compiled from twelve, closely spaced and physically correlated localities, across a northwest to southeast distance of less than 2 km. This framework is placed into magnetostratigraphic context and constrained by two U-Pb ID-TIMS age dates.
    The Old Lootsberg Pass succession does not record continuous sedimentation, as previously argued. Rather, the presence of several intraformational pedogenic-nodule conglomerate-lag deposits, a character used by other workers as diagnostic the post-extinction Katberg Formation, occur in the Elandsberg Member 100 m stratigraphically below the Katberg Formation. An interlaminated lithofacies, previously used as a diagnostic feature of the terrestrial event, occurs isolated at several stratigraphic positions, indicating that it is neither unique nor mappable. A dominant signature of normal-polarity magnetozones in the section is interrupted by two, short reverse-polarity interval which are restricted to siltstone beneath erosional contacts with fluvial sandstones, indicating their cryptic nature in the succession. In addition, we recently report a Wuchiapingian maximum-age estimate for a detrital zircon population from a bed stratigraphically above a previously reported Early Changhsingian age estimate for these rocks. A comparison of the sedimentologic features of these deposits reveals that the bed from which the Changhsingian age is derived supports an ashfall interpretation rather than a reworked deposit from which the Wuchiapingian depositional age is derived. A synthesis of our observations from Old (West) Lootsberg Pass with global patterns reported from the marine realm leads to the conclusion that the turnover from the Daptocephalus to Lystrosaurus AZs is not coincident with the end-Permian marine event.

 


Geosciences Colloquium - Stephen Burns

Mar 01, 2018 03:30 PM

"Recent climate and ecosystem change in Madagascar, Why did the megafauna disappear?"

By Stephen Burns, Amherst College

 

Hosted by Dr. Martin Medina


Geosciences Thesis Defense - Jennifer Cartwright

Feb 27, 2018 02:00 PM

"Volatile and Sr Isotope Analysis of Melt Inclusions from the Bandelier Tuff, Valles Caldera, New Mexico: Insights into Pre-Eruptive Magma Conditions"

Thesis Defense by Jennifer Cartwright

 

Hosted by Dr. Haibo Zou



Last Updated: 10/10/2017