Postdoctoral Associate,
National High Magnetic Field Laboratory
Research
Mercury in sediments
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from Percival et al. (2018)
Mercury (Hg) in sedimentary rocks has been used as the main indicator of large igneous provinces (LIPs) throughout the earth's history because the main source of Hg before the anthropogenic was volcanic. Major environmental events (or changes or even crises) like mass extinctions were mainly caused by large volcanoes. I believe that Hg studies could produce some hints about the climate crisis we are facing.
Re-Os ages in the Upper Jurassic through the Agardhfjellet Formation, Svalbard
Agadhfjellet Formation, Svalbard
Photographed by J. Nagy
The Agardhfjellet Formation in Svalbard covers the Middle and Upper Jurassic and Lowermost Cretaceous, consisting of four members: Oppdalen, Lardyfjellet, Oppdalsåta, and Slottsmøya (from bottom to top). Stage boundaries from the Upper Jurassic has not been defined well because of ammonite provincialism. In this case, radiometric dating methods play a critical role in correlating rocks globally. Uranium-Pb method is the most well-known dating skill, but it is not applicable because the lack of volcanic ash layers within the Agardhfjellet formation. The best alternative could be Re-Os dating method by organic-rich shale because of high affinity of Re and Os to organic matter in ancient ocean.
Jurassic in Geological Time Scale
The Jurassic Period is one of the most popular geological times for everyone because of "Jurassic Park." Because there were diverse ammonite species at that time, the major method to define each stage is biostratigraphy, especially ammonite zones. However, the provincialism of ammonite speices in the Late Jurassic makes it challenging to connect two different oceans (Boreal vs. Tethyan). Absolute ages by the Re-Os dating method could shed light on the lack of connection between two worlds. For more information about Jurassic stratigraphy, please click the link below
https://jurassic.stratigraphy.org/
Hesselbo et al. (2020) from GTS 2020
Paleoenvironment by geochemistry
Climate change (or crisis) has attracted the public's attention for several decades over the world. While climate models are trying to predict our future, geologists are looking back on the earth's history, when the earth's climate had dramatically changed. For more than 4.5 billion years, the earth has experienced dynamic environmental changes - temperature, sea level, geography, etc. Geochemists try to decipher the paleoenvironment (ancient environment) when sedimentary rocks were deposited through chemical elements such as Re, Mo, and U for redox conditions.
from NOAA website (climate.gov)
Publications
- Park, J., Stein, H.J., Hannah, J.L., Georgiev, S.V., Hammer, Ø., and Olaussen, S. (2024) Re-Os geochronology of the Late Jurassic black shales in the Agardhfjellet Formation, Svalbard: A cornerstone to global faunal linkage and temperature-driven Osi change, Palaeogeography, Paeoclimatology, Palaeoecology
https://doi.org/10.1016/j.palaeo.2023.111878
- Park, J., Stein, H.J., Georgiev, S.V., and Hannah, J.L. (2022) Degradation of mercury (Hg) signals on incipient weathering: core versus outcrop geochemistry of Upper Permian shales, East Greenland and Mid‐Norwegian shelf: Chemical Geology. https://doi.org/10.1016/j.chemgeo.2022.121030