Geological Features of
Rocky Neck State Park
Rocky Neck State Park is located on the shore of Long Island Sound in East Lyme Connecticut
Rocky Neck State Park Location
Rocky Neck
Known by Native Americans and Colonists for it’s abundance of wildlife and fish
The park was first founded in 1931710 acres were set aside for:
beach goers on it’s rock free white beaches and it clear waters
Hikers to walk on many of it’s diverse trails trough caves and scenic salt marshes
Campers to use one of it’s 160 campsites Bird watchers to observe many of species such
as Cranes , Herons, Swans, and Osprey that utilize Bride Brook salt marsh
Rocky Neck State Park Information
Map Of the Park
Rocky Neck has many geological formations that represent both glacial and tectonic activity.
Why Rocky Neck State Park?
450-250 million years ago (Paleozoic era) several crustal plates including Avalonia (island in Atlantic) Africa and Eurasia collide into the Proto North America plate closing the Lapetos Ocean
Collision caused metamorphic changes in the rock causing folding and the creation of the Appalachian mountains
235 million years (Mesozoic era) plate tectonics had reversed and the super continent known as Pangaea started to break apart causing rift basins to form along the break up
Avalonia stayed attached to North America (southeast Ct)
Tectonic history Rocky Neck State ParkProto North America
AvaloniaRift Valley
Metamorphic Rock- Is transformation of one rock type into another as a result of exposure of intense heat or pressure and forms compressed mineral layers
Tectonic history Rocky Neck State Park
Compressed layers of Granitic Gneiss
Tectonic activity compressed the land forming ridges running north and south through out the park forming crescent shaped beaches
Evidence of Tectonic Activity
West Headland
East Headland
Crescent Beach
When the land is compressed near the coast line salt marshes often fill in the valley
Evidence of Tectonic Activity cont.
West ridge East ridge
Salt Marsh
Compression of plates has resulted rocks to metamorphosis and fold under pressure and heat
Evidence of Tectonic Activity cont.
Potter Hill Granitic gneiss
Streaks of pink granite
Other MineralsPink-Orange
FeldsparQuartzGraniteTourmalineBiotite
Evidence of Tectonic Activity cont.
Potter Hill
Granitic gneissMetamorphic
rock, formed from intense heat and pressure during formation
Banded texture of elongated mierals
Evidence of Tectonic Activity cont.
Granitic gneiss
Pegmatite veins in granitic gneiss rock found on Potter Hill
Formed under less pressure and heat
Evidence of Tectonic Activity cont.
Pegmatite vein
More ridges as a result of compression from east to westWoodland
environment
Evidence of Tectonic Activity cont.
West ridge East ridge
24,000 years ago Connecticut was covered by glacier
For 5,000 years the glacial boundary stayed over Connecticut containing large amounts of loose sediments, sand, rocks, and clay which form terminal moraines marking the furthest boundary of the glacier
Glacial History Rocky Neck State Park
Glacial till consists of loose sediments rocks, sand, and clay covered much of CT’s coastal bedrock
Evidence of Glacial Activity
Glacial Till
Rocks, sand, and clay make up the terminal moraines marking the glaciers boundary and formed: Long Island, Block Island, Martha’s Vineyard, Nantucket, and Cape Cod
Evidence of Glacial Activity cont.
Glacial direction
N
S
Long Island
Glacial BouldersAre moved
from the north during glacial movement south
Evidence of Glacial Activity cont.
Glacial Boulders
Glacial polishing on Potter HillAs the
glacier glides over the rock the ice acts like sandpaper, scratching the bedrock
Evidence of Glacial Activity cont.
Glacial polishing
Local rock was carved to make the pavilion
Facilities
http://www.ct.gov/dep/cwp/view.asp?a=2716&q=325108&depNav_GID=1650 (2008)
Work Cited
Write a paragraph describing how tectonic activity has shaped Rocky Neck State Park
In your paragraph explain two sources of evidence of tectonic activity at the park
Write a paragraph describing how glacial activity has shaped Rock Neck State Park
In your paragraph explain two sources of evidence of tectonic activity at the park
Assessment
