The topics covered in this chapter can be summarized as follows:

Section Summary
8.1 Stream Erosion and Deposition Erosion and deposition of particles within streams is primarily determined by the velocity of the water. Erosion and deposition of different-sized particles can happen at the same time. Some particles are moved along the bottom of a river while some are suspended in the water. It takes a greater velocity of water to erode a particle from a stream bed than it does to keep it in suspension. Ions are also transported in solution. When a stream rises and then occupies its flood plain, the velocity slows and natural levées form along the edges of the channel.
8.2 Stream Types Youthful streams in steep areas erode rapidly, and they tend to have steep, rocky, and relatively straight channels. Where sediment-rich streams empty into areas with lower gradients, braided streams can form. In areas with even lower gradients, and where silt and sand are the dominant sediments, meanders are common. Deltas form where streams flow into standing water.
8.3 What Makes a Map? Maps are used to share spatial data, and geologists often create maps using a topographic base map. All maps contain standard cartographic elements such as a title, scale, north arrow, legend, and other ancillary information that helps the reader understand the map. Topographic maps in Canada are indexed in the National Topographic System. Contour lines are drawn to show relief of the landscape on a topographic map.
Lab 8 Exercises The best way to learn about important cartographic elements and mapping is to make a map yourself! Fluvial features along a meandering segment of the Elbow River in Calgary, Alberta can be identified and mapped based on satellite imagery. A good map conveys information about your interpretations to your reader. Adding a reference point with a UTM coordinate and a reference to the NTS map sheet on which your map resides helps your reader situate your interpretations in a larger context.


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A Practical Guide to Introductory Geology Copyright © 2020 by Siobhan McGoldrick is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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