Cordilleran Section (104th Annual) and Rocky Mountain Section (60th Annual) Joint Meeting (19–21 March 2008)

Paper No. 30
Presentation Time: 8:00 AM-12:00 PM

LAMINITES IN THE CAMBRIDGE ARGILLITE (EDIACARAN), HEWITT'S COVE, HINGHAM, MASSACHUSETTS


WILLIAMS, Jessica, Department of Geosciences, Southern Utah University, 351 W. University Blvd, Cedar City, UT 84720, LOHRENGEL II, C. Frederick, Department of Geosciences, Southern Utah University, 351 W. Center St, Cedar City, UT 84720, BEUTHIN, Jack D., Department of Geology & Planetary Science, University of Pittsburgh at Johnstown, Johnstown, PA 15904 and MCMENAMIN, Mark A.S., Geology and Geography, Mount Holyoke College, South Hadley, MA 01075, jajw77@hotmail.com

Laminated Cambridge Argillite of the Boston Bay Group (Ediacaran) low-grade metasediments can be found in outcrop at Hewitt's Cove, Hingham, Massachusetts. These laminated sediments are finely graded layers 2 to 8 cm thick that are commonly interpreted in the literature as fine-grained turbidites (Stow sequences). Rhythmically laminated facies also occur that do not support a sediment-gravity flow interpretation. These rhythmites raise the possibility of sedimentation influenced by agents such as tides, waves, or wind. The Cambridge Argillite appears to consist of a subtle, but definite, mosaic of laminite facies that record multiple depositional processes, and perhaps multiple water depths.