glacial history of cape cod, nantucket, and martha’s vineyard stefan sandreuter ‘16 ge354
TRANSCRIPT
Glacial History of Cape Cod, Nantucket, and Martha’s Vineyard
Stefan Sandreuter ‘16
GE354
Outline
• Formation of Cape Cod, Nantucket and Martha’s Vineyard
• Regional Deposits
• Post-Glacial Holocene Processes
• Summary
Formation of Cape Cod, Nantucket and Martha’s Vineyard
• Three lobes of glacial ice
• Fluctuating Ice Front
• Evidenced by till overlying stratified drift; recessional moraines
Regional Deposits
• Types of deposits
• General Stratigraphy
• Age of Deposits– Cosmogenic Nuclide Dating
• Mineralogy
Cosmogenic Nuclide Ages
Martha’s Vineyard
Buzzard’s Bay
*Radiocarbon dates put glacial deposits between 24,000 and 21,500 years old.
Post-Glacial Holocene Processes
• Marine and Aeolian Processes
• Two periods of Holocene modification– 9,500 – 6,000 B.P– 6,000 B.P. to modern day
Summary
• Three lobes of ice
• Fluctuating ice sheet
• Nantucket and Martha’s Vineyard - terminal moraines of the Laurentide Ice Sheet
Summary
• Cosmogenic nuclide ages of ~23,000 and 19,000 years from Martha’s Vineyard and Buzzards Bay respectively
• Subarkose and quartz arenite sands from both outwash plains and beaches
• Constant marine and aeolian modification
Questions?