Landscapes of New York State

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John Sims
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1 Regents Earth Science Landscape Development Worksheet Name: Landscapes of New York State The varied scenery of New York State is due, in part, to our wide variety of landscape regions. Like most land areas, New York can be divided into several distinct landscape regions with remarkably sharp boundaries between landscape regions. Landscapes develop in response to differences in climate and geology. New York s climate is relatively uniform. Climatic differences have not been very important in the formation of our varied landscape regions; however New York does have a great variety of geological structures and rock types. Long Island was formed when the southward moving continental glaciers formed two (2) long ridges of glacial till. The southern half of the island is composed of fine sand washed into place by the melt water from the glaciers. Except at its extreme western end, there are no bedrock exposures on Long Island. The south shore of Long Island is protected by a series of barrier islands. These islands are composed of sand transported by the melt water of the glaciers and washed along the shore by wave action and long shore currents. These barrier islands terminate in the sand spits that guard the entrance to New York Harbor. This large, deep and wellprotected harbor helped to make New York City one of the most important centers of trade and finance in the world. Landscapes of NY Worksheet 1

2 The Triassic lowlands is a region of red sedimentary rocks, mostly shales and sandstone of Mesozoic age located west of the lower Hudson River. It is bounded on the east by the Palisades, a thick intrusion of igneous rock that forms the great cliffs along the Hudson River from New York City north to Haverstraw. The Palisades intrusion occurred about 200 million years ago when the Atlantic Ocean was born as North America moved westward and separated from Africa and Europe. The Hudson Highlands and Taconic Mountains is a region of very old bedrock and complex geologic structures. Many of the rocks are high grade metamorphic rocks exposed by the erosion of an ancient continents of North America and Africa about 400 million years ago. Westchester and the New England Highlands are a part of this complex landscape region. The Hudson and Mohawk valleys were cut by the Hudson and Mohawk rivers through relatively weak sedimentary rocks. These valleys provided important low level trading routes to the American interior in colonial times. They were later followed by more modern transportation passages; the Erie Canal and the New York State Thruway (I-90). West of the Hudson Valley is the Catskill Mountains and Appalachian Plateau. The Catskills are composed of thick layers of sedimentary rocks deposited as a delta in an inland sea about 400 million years ago. The sediments probably originated in the great Taconic Mountain range that existed where we now find the Hudson and Taconic Highlands. This delta has been deeply eroded by a variety of small rivers. The topographic relief of this landscape region decreases from the Catskill Mountains into the Appalachian Plateau of southwestern New York State. Landscapes of NY Worksheet 2

3 The Adirondack Mountains are the only true mountain landscape of New York State. They are the southward extension of the Precambrian core of North America known as the Canadian Shield. The Adirondacks are a great dome, pushed up in the middle to expose a core of ancient plutonic and metamorphic rocks. New York s highest point, Mount Marcy, at about 5,200 feet is located in the Eastern Adirondacks. West of the Adirondacks is the Tug Hill Plateau. It is a hilly region of poor drainage and copious (that means a lot!) snowfall that is one of the most sparsely populated landscapes of New York. North of the Adirondacks is the St. Lawrence Lowlands, which follows the St. Lawrence River and the shore of Lake Champlain, east of the Adirondacks. Western New York is situated on both the Allegany Plateau to the south and the Erie-Ontario Lowlands to the north. The Erie-Ontario Lowlands borders Lakes Erie and Ontario. It is underlain by layers of by the Finger Lakes. sedimentary rocks dip gently to the south. The glaciers left many characteristic features that dominate the landscape including moraines, drumlins, eskers and kames. The glaciers also deepened and dammed the valleys now occupied The Niagara River, as is the entire Great Lakes Basin of which the river is an integral part, is a legacy of the last Ice Age. 18,000 years ago southern Ontario was covered by ice sheets 2-3 kilometers thick. As they advanced southward the ice sheets gouged out the basins of the Great Lakes. Then as they melted northward for the last time they released vast quantities of meltwater into these basins. Our water is "fossil water"; less than one percent of it is renewable on an annual basis, the rest leftover from the ice sheets. Landscapes of NY Worksheet 3

4 The Niagara Peninsula became free of the ice about 12,500 years ago. As the ice retreated northward, its melt waters began to flow down through what became Lake Erie, the Niagara River and Lake Ontario, down to the St. Lawrence River, and, finally, down to the sea. There were originally 5 spillways from Lake Erie to Lake Ontario. Eventually these were reduced to one, the original Niagara Falls, at Queenston-Lewiston. From here the Falls began its steady erosion through the bedrock. Landscapes of NY Worksheet 4

5 Niagara Falls formed where the Niagara River runs over the resistant Lockport Dolostone. The dolostone forms the cap rock of Niagara Falls. Erosion is causing the falls to move steadily upstream at a rate of about 2 meters (6 yards) per year. Directions: Answer the following questions on Landscapes of New York using the provided reading material above, your E.S.R.T. (page 2) and your knowledge of New York State. 1. What two (2) characteristics most influence landscape development? 2. Which of these factors is the most variable within New York State? 3. What agent of erosion and deposition formed Long Island? 4. What processes are now modifying the shorelines of Long Island? 5. What rock type is the Palisades Sill? Landscapes of NY Worksheet 5

6 6. Why is the Westchester landscape so complex? 7. The Catskills are a former that has been dissected by stream erosion. 8. What feature of the geology is responsible for the locations of the Hudson and Mohawk river valleys? 9. What event pulled the rocks apart to allow the intrusion of the Palisades magma? 10. What is the structural form of the Adirondack Mountains (what type of mountains are they?)? 11. Where can you find abundant landforms created by glaciers? 12. What type of rock holds up Niagara Falls? 13. Why do so few people inhabit the Tug Hill Plateau? 14. Use your reference tables to label the nine (9) landscape regions of New York State. 15. The only true mountain landscape in New York State is labeled. 16. New York s plateau landscapes are and. 17. The plains (lowlands) landscapes are,,, and Landscapes of NY Worksheet 6

7 The Hudson and Taconic Highlands are difficult to classify because of their complexity. They show characteristics of both mountain and plateau landscapes. 18. According to the ESRT, New York s Catskills are part of what major landscape region? 19. The Adirondacks are really part of what Canadian feature? 20. Looking at the ESRT, would you say that New York has more or fewer landscape regions than other states? Landscapes of NY Worksheet 7

Geologic History Review

Geologic History Review 1. The climate that existed in an area during the early Paleozoic Era can best be determined by studying (1) the present climate of the area (2) recorded climate data of the area since 1700 (3) present