Glacial Origins and Features of Long Island Interior Coastal Plain Continental Shelf Long Island s Geology
0 Ma Phanerozoic 540 Ma Proterozoic 2500 Ma Archean 3800 Ma Hadean 4600 Ma C M P Geologic Time on Long Island Paleozoic Mesozoic Cenozoic Tertiary Quat. PaleogeneNeogene Carb. Holocene Pleistocene Pliocene Miocene Oligocene Eocene Paleocene Cretaceous Jurassic Triassic Permian Pennsylvanian Mississippian Devonian Silurian Ordovician Cambrian Geologic Time Scale Ma 0.01 1.6 5 23 35 57 RIP 65 146 208 245 290 323 360 408 439 510 540 Barrier islands Glacial deposits Coastal plain Basement Pleistocene Climate and Sea Level History Wisconsin
Glacial Deposits on Long Island Ice-Contact Deposits - rock debris released by wasting ice. Till (diamictite) - poorly to unsorted mix of boulders, cobbles, gravel, sand, and mud. Deposited in contact with glacial ice. Erratics - large boulders deposited with till. Meltwater Deposits - gravel, sand, silt, clay deposited by flowing meltwater. Outwash - layered sediments deposited by flowing meltwater. Loess - very fine, wind-blown rock flour.
Loess Glacial till Stratified drift (outwash delta), Caumsett State Park, Long Island Erratic boulder, Lloyd Neck, New York
Glacial polish, erratic boulder Erratic boulders, Port Jefferson harbor, Long Island Glacial erratics, Smithtown Harbor, Long Island
Glacial Landforms on Long Island Moraines - linear ridges of till accumulated at glacial margins. Terminal - marking farthest extent of ice advance. Recessional - deposited during pauses in ice recession. Push - folded and faulted glacial deposits bulldozed by advancing ice. Hill and Hole - localized push moraine and associated depression. Diagram from Fuller (1914, Fig. 3) showing position of ice margin and formation of two terminal moraines during two separate advances of glacial ice. Cross-cutting of older terminal moraine by younger terminal moraine
Diagram from Sirkin (1982, Fig. 2) showing terminal moraine and correlation of recessional moraine segments across Long Island. Cross-cutting of Ronkonkoma terminal moraine by Harbor Hills recessional moraine attributed to minor re-advance of ice. Diagram from Sirkin (1996, Fig. 10a) showing combined Harbor Hill and Ronkonkoma terminal moraine and recessional moraine segments in western Long Island and central Long Island. Recessional moraine Terminal moraine
Till south of the Ronkonkoma Moraine Charles King: Longwood High School Glacial Erratics found in East Moriches, south of the Ronkonkoma Moraine Charles King: Longwood High School Digital Elevation Model - Long Island, New York Horizontal resolution - 10 m Vertical resolution -.1 m VE - 2X Shaded by elevation
Major Glacial Features of Long Island Moraines Roanoke Point Moraine Harbor Hills Moraine? Ronkonkoma Moraine Glacial Depositional Landforms on Long Island Kames - hills formed by the accumulation of sediment in depressions on wasting ice. Kettles - depressions formed as stranded ice blocks melt after being buried in till or outwash sediments. Kame Delta - lobate hills formed as outwash delta deposited into proglacial lake.
Kame Outwash Moraine Kettle Kame Deltas Eastern Nassau, Western Suffolk
Hempstead Harbor Oyster Bay Huntington Dix Hills Old Westbury Hills West Hills Manetto Hills Half Hollow Hills younger moraine Kame Deltas older moraine
Kettle Ponds Lake Ronkonkoma - Kettle Pond Eastern L.I. - Kettle Ponds Sears Pond Calverton Lake Panamoka Penny Pond Bellows Pond Deep Pond Hampton Bays Swans Pond
Kame and Kettle Topography South Fork Kame and kettle topography Outwash plain
Glacial Landforms on Long Island Tunnel Valley - steep-sided valley carved into sediments beneath glacial ice by meltwater flowing through ice tunnels. Tunnel valleys have several distinctive characteristics: 1. Lack of streams and drainage basins. 2. May trend both uphill and downhill. 3. Anastomosing, trending both N-S and E-W. 4. Large tunnel valleys mark major channels for meltwater flow between ice lobes.
Glacial Landforms on Long Island Outwash plain / fan - elevated, relatively flat region consisting of layered deposits of stratified outwash deposited south of the ice margin. Outwash channel - broad, unbranched channel eroded by flowing meltwater south of the ice margin. Tunnel Valleys - formed by water flowing beneath the glacier
meltwater channels ice meltwater tunnels outwash plain
Tunnel Valleys Tunnel Valleys of the North Shore Lloyd Neck Eatons Neck A Huntington Moraine Profile Ice Moraine Outwash Fan A A A
Northport Moraine Profile A Ice Moraine Outwash Fan A A A N Northport Area Tunnel Valleys N Outwash Fan
N Ocean Ave. Waterside Rd. Bread and Cheese Hollow Rd. Main Street. 25A Middleville Rd. Old Bridge Rd. 25A Elwood Rd. Vernon Valley Rd. Bellerose Ave. Stony Hollow Pulaski Rd. Port Jefferson Tunnel valley Outwash fan
Central Long Island (Hauppauge - Farmingville area) Lake Ronkonkoma Kettle lake Moraine Post glacial stream valley Meltwater channel Meltwater channel North Formation of gaps in Ronkonkoma Moraine South Ronkonkoma Moraine Proglacial Lake Upper Carmens River, Eastern Long Island - Glacial meltwater channel
Upper Lake, eastern Long Island - Glacial meltwater channel Push moraine, tunnel valleys, necks and harbors Kame and kettle moraine, wave-straightened shoreline
Hill and Hole Push Moraine Sean Tvelia Suffolk County Community College Eroding terminal moraine, Montauk Point, New York