Landscapes & Drainage Systems

Landscape Region of various landforms (hills, valleys, streams) related by a common origin.

Most landscapes classified as: Mountains Plateaus Plains Unique geologic structures & topographic relief. Landscapes usually identified by elevation of region.

Mountain Landscapes

Characteristics Greatest relief Deformed rock structures Young rivers Igneous and metamorphic rocks & folded sedimentary rock Tectonic forces push up mountains (e.g., marine fossils at high elevations!) Young rivers Stream gradient high Velocity fast V-shaped valleys

Complex Geologic Cross Sections

ESRT pp. 2 - 3 Identify 3 landscapes that show high relief. 1. Adirondack Mountains 2. Taconic Mountains 3. The Catskills

Plateau Landscapes

Characteristics Moderate relief (lowlands) Relatively flat or “rolling” uplands Streams often cut deep valleys. Plateaus are uplifted, then water cuts downwards Undisturbed, FLAT layers of sedimentary rock form base.

Uplift followed by stream erosion carved out Grand Canyon Plateau

Plateau Geologic Cross Section

ESRT p. 2 Identify 3 landscapes that show moderate relief. 1. Tug Hill Plateau 2. Allegheny Plateau 3. Appalachian Plateau

Plains Landscapes

Characteristics Lowest relief (flat, low elevation) Usually flat sedimentary rock layers Leveling forces uniform Undisturbed (horizontal) sedimentary rock is common

Plains Geologic Cross Section

ESRT pg 2 Identify 3 landscapes that show low relief. 1. Interior Lowlands 2. Erie-Ontario Lowlands 3. Hudson-Mohawk Lowlands

Identify the Landscape with the Correct Cross Section

Factors Affecting Development 1. Climate Humid – rounded features, plenty of soil to protect bedrock Arid – bare, steep slopes 2. Vegetation Plants protect soil from erosion 3. Bedrock - resistance to weathering 4. Human activity – construction

Boundaries between landscapes 3. Change in rock structure Folding Faults - create difference in elevation (e.g., cliffs) 1. Sudden change in elevation 2. Change in rock type

Drainage Patterns Determined by the way tributaries join to form larger streams/rivers

Drainage Patterns Resistance of bedrock to weathering & erosion affects drainage pattern If rock is: Evenly worn away --> resistance is uniform Escarpment (cliffs) --> resistance varies

Review Questions 1. In what NYS landscape region is 42°N, 72°W? 2. What type of rock makes up the Erie-Ontario Lowlands? 3. Mt. Marcy, the highest mountain in NYS, is part of what landscape? 4. What type of landscape regions are found along the entire NYS-Canadian border? New England Province Sedimentary rocks Adirondack Mtns. Lowlands/plains

Rectangular Dendritic 5. Which of the drainage patterns below is likely to develop on faulted mountains? 6. Which of the drainage patterns below is likely to develop on bedrock of uniform resistance to erosion? Rectangular Dendritic

Landscape Regions of NYS – p. 2 St. Lawrence Lowlands Adirondack Mountains Erie-Ontario Plains (Lowlands) Tug Hill Plateau Hudson-Mohawk Plains (Lowlands) New England Province (Highlands) = Taconic Mtns Newark Lowlands Atlantic Coastal Plain (LI and SI- glacial sediments) The Appalachian Plateau contains: The Catskills The Allegheny Plateau