PALEO SEA-LEVEL AND GIA

Meters of subsidence or uplift from glacial isostatic adjustment (GIA) complicate the interpretation of paleo sea-level data. I work on combining photogrammetry, differential GPS, and stratigraphy of exposed coastal sedimentary rocks to constrain the predictive GIA models and provide greater certainty on paleo sea-level.

sea level

 

STRATIGRAPHIC CYCLES

Periodic environmental change can result in apparent cyclicity in a sedimentary succession. However, the sedimentary system is sensitive to internal thresholds that may turn on and off sedimentation without a period external forcing. I am working on a probabilistic model to identify sequences of sedimentary facies that are likely due to external environmental change.

facies

 

THE LATE PALEOZOIC ICE AGE

At the end of the Paleozoic, Earth plunged into a long ice house with ice sheets in southern Gondwana. Insight into the major feedbacks regulating our climate system can be gained by studying the rates of ice house initiation and collapse, as well as the high frequency glacial interglacial pacing during this ancient cold period.

paradox

 

THE ANCIENT CARBON CYCLE

The carbon isotopic record of ancient carbonates provides an indirect observation of the ancient carbon cycle, and the carbon cycle is intricately tied to climate and the history of oxygen on Earth. However, interpreting this carbon isotopic record can be complicated by diagenesis of samples, and perhaps by the transient effect global diagenetic events may have on the ocean.

carbon

 

METEORIC DIAGENESIS

Meteoric diagenesis occurs when carbonate rocks are infiltrated with fresh water over long periods of time. These reactions result in phase changes and isotopic exchange between fluids and minerals. The carbon and calcium isotopic fingerprint of meteoric diagenesis encodes information about the ancient terrestrial system that can be extracted through a merger of probabilistic predictive models and data.

Ca