table of contents title: rate of weathering page #: 54 date: 1/7/2013
DESCRIPTION
Rate of Weathering Effects of Climate on Weathering: Climate is the major influence on the rate of weathering of Earth’s materials. –Interaction between temperature and precipitation in a given climate determines the rate of weathering in a region.TRANSCRIPT
Table of Contents
Title: Rate of WeatheringPage #: 54
Date: 1/7/2013
Objective
• Students will be able to identify variables that affect the rate of weathering.
Rate of Weathering
• Effects of Climate on Weathering: Climate is the major influence on the rate of weathering of Earth’s materials.– Interaction between temperature and
precipitation in a given climate determines the rate of weathering in a region.
Rate of Weathering
Rate of Weathering
• Rates of Chemical Weathering:– Chemical weathering occurs rapidly in
places with warm temperatures, abundant rainfall and lush vegetation.
– Greatest effects of chemical weathering occur along the equator.
Rate of Weathering
Rate of Weathering
• Rates of Physical Weathering:– Physical or Mechanical Weathering is most
rapid in places with cool climates - Frost Wedging.
– Cooler temperatures slow reaction rates of chemical weathering.
Rate of Weathering
• Rock Type and Composition:– Not all rocks in a climate weather at the same rate.– The types of minerals in a rock play a role in how
fast a rock weathers.– Example: Limestone and Marble contain Calcite
and will weather more quickly than rocks containing mostly Quartz such as Quartzite and Granite.
Rate of Weathering
Weathered Limestone
Weathered Granite
Rate of Weathering
• Surface Area:– The greater is the exposed surface area of a rock
the faster it will weather.
Rate of Weathering
• Topography:– The slope of landscape determines the rate of
weathering.– Steep Slope = Faster weathering (rocks will fall
down because of gravity.)– Flat Surface = Slow weathering (rocks do not
move.) – Steep slopes promote erosion and continuously
expose less weathered material.
Rate of Weathering
Steep Slope = Rocks fallBecause of gravity.
Rate of Weathering
Flat Slope = Rocks have Nowhere to go.
Classwork:
• Page 170 questions 1-5.