GSSP for the Precambrian - Cambrian Boundary


Definition:

The base of the Phanerozoic Eon, Paleozoic Era and Cambrian System is defined in a coastal section near the town of Fortune in southeastern Newfoundland, Canada. The GSSP lies 2.4m above the base of Member 2 in the Chapel Island Formation, just above the transition to storm-influenced facies. The level is marked by the first occurrence of Phycodes pedum (a trace fossil).


Location:

The Fortune Head Section is situated near the tip of the Burin Peninsula, near the town of Fortune, southeastern Newfoundland, in low cliffs that extended beyond "Fortune Dump".
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Sedimentology:

Coastal cliff exposures at Fortune Head display some 400m of the Chapel Island Formation. Member 1 consists of peritidal sandstone and shales. Member 2A consists of storm-influenced muddy deltaic and shelf sandstones and mudstones. Member 2B and 3 consist of thinly laminated siltstones of the distal shelf, deposited below wave base.
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Primary Markers:

First occurrence of the trace fossil Phycodes pedum.

Secondary Markers:

Trace fossils:
Member 1 of the Chapel Island Formation includes uppermost Precambrian sediments. It yields the trace fossils Harlaniella podolica and Palaeopascichnus delicatus. These trace fossils range into Member 2, where they are last seen 0.2m below the GSSP.

References:

Brasier, M., Cowie,J., and Taylor, M., 1994. Decision on the Precambrian-Cambrian boundary stratotype. Episodes 17/1&2, p. 95-100.