|Excerpts from Dorothy Sterling, The Outer Lands, A Natural History Guide to Cape Cod Martha's Vineyard Nantucket Block Island and Long Island, Natural History Press, Garden City, New York, 1967.
The Outer Lands
The Big Ice
The glacier grew from year to year. During century- long winters cold winds whistled and snow piled on top of snow. The mountain of blue ice thickened until the pressure of its own weight set it moving. Grinding down from Labrador to cover more than half of North America, the glacier put the finishing touches on our continent. Nowhere is its imprint more clearly seen than on the Outer Lands-the sandy hills and scrub- covered moors that string out along the shores of the Atlantic from Long Island to Cape Cod.
Millions of years before the Great Ice, these lands were part of an ancient coastal plain where forests grew and dinosaurs roamed. Time and again invading seas drowned the forests and left them covered with mud and clay .The dinosaurs disappeared and eons later camels and horses grazed on the marshy plains while giant sharks swam in the waters offshore.
Some thirty thousand years ago-only yesterday as geologic time is figured-the glacier began its fateful march. As it advanced through New England, the mile- thick ice sheet sliced off mountain peaks, flattened hills and widened valleys. Like a giant steam shovel it dug into the rocky core of the continent. prying boulders loose from their beds, it ground them in its mill of moving ice.
When the glacier reached the soft margins of the coastal plain it scooped out the basins of bays and sounds and pushed on toward the sea. Halted by currents of warm air, it dumped the load of rocks and pebbles it had carried from the mainland. These glacial dump heaps, tom from once-solid bedrock, formed ridges hundreds of feet high. Known as moraines, they are the framework of the Outer Lands.
The southemmost advance of the glacier can be seen today on Long Island in the double row of hills that stretches from Queens to Orient Point and Montauk. Off Montauk, the moraine has been covered by rising seas, but it reappears again in the hills of Block Island, Martha's Vineyard and Nantucket. ***
A hundred centuries of trees and grasses have clothed these uplands with a top dressing of soil, but minutes of digging will uncover the stones and pebbles of which they are built-the gravelly material that geologists call till. Sometimes, when the grinding ice failed to digest its rocky burden, it dropped boulders. These boulders are scattered across the Outer Lands -"like nuts in a frosting," one writer said-but they are most prominent along Long Island's north shore and in the Falmouth- Woods Hole area of Cape Cod, Block Island, Nashaquitsa Cliffs on the Vineyard and the Clay Pounds of Truro, just north of Cape Cod Light.
Plains and Ponds
Whenever a warming sun shone on the great ice sheet, streams of water flowed from its surfaces. Swift- moving in summer, sluggish in winter, these rivers of meltwater cascaded down the face of the hills. Carrying fragments of rock and gravel, they built broad fan- shaped plains that sloped from the bottom of the hills to the ocean floor. Today these outwash plains are the potato fields and truck farms of Long Island, the moors of Nantucket, the Vineyards's Great Plains and Cape Cod's grassy "South Sea".
The Sea's Work
If you had been able to fly over the Outer Lands at the end of the Ice Age you would have seen barren gravel banks. The hills and plains were there, dusted with boulders and pockmarked by kettle holes. But there were no beaches, no stretches of green marsh, no dunes or woods. Cape Cod, wider than it is today, ended abruptly at the Truro highlands. Long Island's south shore fronted on the Atlantic Ocean without the protective barrier of Fire Island or Jones Beach.
Seeds left by the glacier or dropped by birds sprouted in the gravelly soil. Animals traveled over from the mainland, following land bridges that no longer exist. And the sea began its mighty work.
Fed by melting ice, the waters of the ocean rose rapidly. They filled the shallow bays and sounds that the glacier had dug, flooded low-lying plains and began a steady, relentless attack on the hills. The bedrock torn from the continent had been ground coarsely by the mill of ice. Now it was the sea's turn to refine it.
Waves battered against the gravel banks, carrying away rocks, stones and clay. Undermined by the storms of winter, washed out by spring rains, boulders tumbled from the bluffs. A million times, and a million times a million, the smaller fragments of the glacial till somersaulted along the ocean floor. Pulled by winds and pushed by currents, they were swept out to sea and tossed back to shore. Rocks rubbed against each other. Stones clattered over the surface of the boulders at high tide. Filing, scraping, polishing rough edges, the endless motion of the waves turned the coarse gravel into smooth pebbles and the pebbles into sand.
Over the centuries, the restless ocean laid down a broad border of sand around the Outer Lands. It shaped harbors and bays, carved inlets-and then proceeded to rearrange them. Borrowing newly made sand from the beaches, the waves built bars and shoals offshore. The bars became spits and the spits, peninsulas. The shoals grew into islands and the islands joined to form long barrier beaches. A barrier beach is exactly what its name implies. A narrow strip of sand running parallel to the shore, it acts as a barrier to the ocean. Protecting the land in front of it, it transforms open harbors into sheltered bays.
A glance at a map of the Outer Lands will show the work of the sea. *** Along Long Island's south shore from Coney Island to Southampton the waves have thrown up almost a hundred miles of barrier beaches. Fire Island, Rockaway Beach, Jones Beach-these are all new lands formed since the Ice Age.
Like the Lord, the sea giveth and it taketh away. It builds and it destroys. Local histories are filled with accounts of lost islands and peninsulas. *** Records of the lighthouses built along the coast show that the work of the sea is a continuing process. On the advice of no less an engineer than George Wash- ington, Montauk Point Light, erected in 1797, was placed 200 feet back from the sea. There, he predicted, it would stand for 200 years. And there it has stood while waves hammered at the cliff in front of it. Today, after 170 years, less than 40 feet of land remains between the base of the lighthouse and the cliffs edge.
Wind and Weather
The wind plays its own part in the endless shaping and reshaping of the shores. Each sector of the Outer Lands boasts that it is the windiest spot on the North Atlantic. Although the Weather Bureau refuses to take sides it has recorded 9l-mile-per-hour winds at its stations on Block Island and Nantucket-windy enough for any man's taste.
In summer the prevailing wind comes from the southwest. In winter it drives across the open ocean from the northeast with terrific force. Blasting the face of the cliffs, it starts avalanches of gravel that slide to the water's edge. While feeding the sea its daily diet of stones the wind also picks up sand grains and heaps them into dunes. And the dunes move too, creeping inland to build sand hills and valleys of their own.