Speaker: Dr. Brad Sageman (Northwestern University)

Abstract: In 1917, Joseph Barrell published a paper titled "Rhythms and the Measurements of Geologic Time" in which he proposed that the sedimentary record was made up of more surfaces representing missing time than rock representing recorded time.  This insight has been appreciated for generations since, and eventually led to the development of an...

Speaker: Dr. Catherine Badgley (University of Michigan)

Speaker: Dr. Clara Blattler (Princeton University)

Abstract: It is surprising that we cannot robustly answer the question: “Why is the sea salty?” The major-element composition of seawater acts as an important boundary condition that...

Speaker: Mark Pagani (Yale University)

Speaker: Andrew Whitehill (MIT)

Abstract: Sulfur isotope mass-independent fractionation (S-MIF) is ubiquitous in Archean and Paleoproterozoic sedimentary rocks and provides the most convincing evidence for a low-oxygen early (pre-2.4...

Speaker: Dr. Mark Leckie (UMass-Amherst)

Abstract:

Global tectonics had a profound influence on climate, weathering, sea level, and seawater chemistry during Mesozoic time. The linkages between tectonic activity, planktic foraminiferal evolution and environmental perturbations, including the so-called Mesozoic ‘Oceanic Anoxic Events’ (OAEs) are compelling. Diversification and extinction are closely tied with the major OAEs...

Speaker: Dr. Mick Follows (MIT)

Speaker: Daniel Stolper (Caltech)

Abstract:

The abundance of multiply substituted (‘clumped’) isotopologues (e.g., ¹³C¹⁶O₂¹⁸O^2-) in carbonates is a thermodynamically controlled function of temperature for equilibrated systems. Measurement of clumped isotope abundances can thus be used under certain circumstances to measure carbonate formation...

Speaker: Daniel Stolper (Caltech)

Abstract:

Methane is a critical greenhouse gas, energy resource, and product of microbial metabolisms. Despite its importance in the carbon cycle, distinguishing the sources of methane in natural systems is challenging due to gas migration and potentially overlapping chemical and isotopic characteristics of biogenic and thermogenic sources. Knowledge of the formation...

Speaker: Dr. Wolfgang Kiessling (Erlangen, Germany)

Speaker: Dr. Ines Pereira (ITQB, Portugal)

Abstract:

A key reaction in microbial sulfur metabolism is the reduction of sulfite by the dissimilatory sulfite reductase, DsrAB. This enzyme is present in sulfate, thiosulfate and sulfite reducing organisms, and also in sulfur-oxidizers where it is thought to operate in reverse. The mechanism of sulfite reduction by DsrAB has long been the subject of controversy due to the in vitro formation of...