Science Under the Dome: Snowball Earth in Your Backyard

Early Proterozoic Evolution of the Earth System

John Zawiskie at the Geographic South Pole
John Zawiskie at the Geographic South Pole.

Join geologist John Zawiskie, Cranbrook Institute of Science Wayne State Department of Geology, and explore the current state of the evidence for major changes in the climate system, atmosphere and biosphere of the Earth that occurred during a crucial 300 million-year period of the Early Proterozoic Eon (2.5 to 1.5 billion years ago).

This period includes the beginning of near-global glaciation “snowball Earth,” the spread of free oxygen in the ocean and atmosphere, and the proliferation and evolution of microbial life.

John on an interlobate moraine at Pontiac Lake Recreation area
John on an interlobate moraine at Pontiac Lake Recreation area in Oakland County, Michigan.

This history is recorded in the strata of the Huronian and Marquette Range Supergroups in Ontario and the upper peninsula of Michigan, respectively.

John will provide an overview of the geologic setting and evidence through field photographs and video clips of the bedrock exposures and link them to the local surface rocks of southeast Michigan, which were derived from the northern bedrock and transported south during the recent glaciation. Some key rock and fossil specimens will be available at the program for visitors to examine.


Friday, Apr. 5, 2013 at 7 p.m.

Early Proterozoic banded iron
Early Proterozoic banded iron, Negaunee FM., Jasper Knob, UP.
Early Proterozoic dropstones in glacial metavarvite
Early Proterozoic dropstones in glacial metavarvite, Gowganda Fm., Huronian Supergroup, Ontario, Canada.
Early Proterozoic Grypania
Early Proterozoic Grypania – oldest known eukaryotic organism (multicellular algae) and one of the rarest fossils on Earth – Marquette Supergroup UP.
Early Proterozoic Lorraine Quartzite
Early Proterozoic Lorraine Quartzite, Jasper Metaconglomerate Member, Huronian Supergroup, Ontario, Canada.

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