Landscapes

1. Landscapes Drainage Patterns, Landscapes of NY and the Affects of Human Activites

2. To start… • Rocks that are durable resist weathering and erosion • Durable rocks form the higher portions of a landscape (ex. plateaus, mountains, and cliffs)

3. Softer rock erodes faster than harder, durable rock • If layers of a hill differ in durability, the softer rocks will wear away faster, giving the hill an uneven or stepped appearance

4. Drainage Patterns • Drainage patterns are determined by the way tributaries join to form larger streams • Streams tend to follow zones of weaker rock because they erode into valleys

5. Dendritic/ Random: Develops in horizontal rock layers with little difference in resistance

6. Other types of drainage • Rectangular/Trellis: Observed in folded, faulted and jointed rocks with much difference in resistance

7. Radial- occurs on domed landscapes with little difference in resistance, like volcanoes- looks like spokes of a wheel

8. Final One… • Annular: A pattern of concentric circles found in areas of domed structure with much difference in rock resistance

9. Human Activities Affect Landscapes • Farming and construction projects can increase erosion • Contour plowing curves around a hill, rather than up and down the hillside, helping to slow water runoff and erosion.

10. Strip mining removes layers of soil to dig up minerals found in bedrock. • When finished, engineers can even out the land, replace the soil and add plants • People move more soil and rock than all rivers combined!

11. Landscapes of NYS • St. Lawrence/Champlain Lowlands: low-lying plain along the St. Lawrence River and Lake Champlain • Adirondack Mountains: only true mountain region in NYS made up of resistant rocks • Appalachian Uplands: NY’s largest region that is mostly flat layers of sedimentary rocks. Used to be the bottom of an ocean, pushed up over the years

12. More Landscapes • The Finger Lakes: formed by a continental glacier which deepened and widened pre-existing valleys. As the glaciers melted, the till blocked outlets to the south forming the lakes • The Erie-Ontario Lowlands: lie south of the Great Lakes with NY borders. Although it is a plains landscape, these lowlands have many hills composed of unsorted glacial till. Good soil, deposited and mixed by glaciers, and a climate moderated by the lakes makes this an important agricultural area

14. Even More… • Tug Hill Plateau: small region of elevated sedimentary rock layers. Poor drainage caused by glacial deposits and abundant winter snowfall make this one of the least-inhabited areas in the state • Hudson-Mohawk Lowlands/Plains: Follows a zone of easily eroded limestones and shales • New England Highlands: a region of intensely folded and faulted metamorphic rocks.

16. Last Few • Triassic Lowlands: a section of sandstones and shales deposited in a fault basin. This region is geologically younger than the surrounding highlands. An intrusion of basaltic magma was eroded by the Hudson River, forming the high cliffs of the Palisades. • Atlantic Coastal Plain: largely composed of glacial sediments. The land south of the moraines of LI is composed of sorted material wasted out of glaciers.