Detrital Zircon Geochronology of the Neoproterozoic-Paleozoic Circum-Arctic: A Compilation Analysis
Plate tectonics plays a critical role in global climate control. During the Neoproterozoic, the Earth was plunged into a global glaciation called Snowball Earth, which coincided with the formation and destruction of the ancient supercontinent, Rodinia. This project worked to constrain the timing of the dispersion of the supercontinent and reconstruct continental placement and movement during the Neoproterozoic. This project included a compilation and analysis of zircon ages from the circum-Arctic during the Neoproterozoic. These ages were used to explore ancient continent provenance and plate migration. This study sheds light on the ending of Snowball Earth, and the overall relationship between tectonics and climate.
This work was in collaboration with Karol Faehnrich and Justin Strauss in the Sedimentary Geology, Tectonics, and Historical Geobiology Group at Dartmouth. I presented a poster of this project at the 2021 Wetterhahn Science Symposium.
Simplified geologic map of the modern Arctic. Yellow points indicate the locations of all samples compiled in database.
Abstract
Plate tectonics plays a critical role in global climate control. During the Neoproterozoic era (541- 1000 million years ago), the Earth’s climate feedback failed, plunging the planet into a global glaciation called Snowball Earth whose origin and ending are still disputed. This event coincided with the formation and destruction of an ancient supercontinent, Rodinia, suggesting a possible correlation. Rodinia’s history is still greatly debated, and this project worked to constrain the timing of the dispersion of the supercontinent and reconstruct continental placement and movement during the Neoproterozoic. This project included a compilation and analysis of the largest database of Neoproterozoic circum-Arctic Uranium-Lead and Lutetium-Hafnium ages from zircon grains within samples. Comparing zircon ages among samples was used to explore which rock formations were adjacent and shared sediment sources, and which ancient continent, Laurentia or Baltica, they later became a part of following Rodinia’s split. In this project, a case study was performed to examine specific provenance changes across Svalbard. This information can be used to glean the timing of Rodinia’s division, and how the plates separated, which may provide insight into the ending of Snowball Earth, and the overall effects of tectonics on climate, which can be useful in mitigating anthropogenic climate change.