Lecture 17

Lecture 17

The way of the windis a strange, wild way.

- Ingram Crockett

Glacial deposition, and Wind

Webpage for course (daytime)

Webpage for course (nighttime)

Why such interest in Glaciers?

Glaciers as erosion deposition process is very unusual

Glaciers were important in fairly recent history

Because we live in Maine

Glaciers

Can erode larger portions of mtns

Transport and deposit the material

Over 10,000s years

Grains can be the size of trucks

Glaciers

Can erode larger portions of mtns

Transport and deposit the material

Over 10,000s years

Grains can be the size of trucks

In lowlands – deposition on large scale

till

MorainesFig. 11-18

Moraines

terminal

lateral

medial

recessional

Special features unique to glacial deposition

erratics

kames

eskers

kettles

drumlins

erratics

Fig. 11-19

Fig. 11-23bl

kame

Fig. 11-23br

kettles

Fig. 11-23tl

esker

Fig. 11-23tr

drumlin

Mechanisms of Transportation and Deposition

Water - streams, rivers, etc., freshwater and marine

Wind Gravity – downslope movementIce – glaciers

Some sedimentary rocks form of atoms dissolved in water and precipitated elsewhere

Some meteorology…

Low pressure High Pressure

deserts

Frosted grainsventefacts

Interesting features

Fig. 12.14, p. 281

Why is the desert floor covered with rocks?

Fig. 12.12, p. 280

Why is the desert floor covered with rocks?

Deflation

Fig. 12.13, p. 281

Dust Bowl

Fig. 12.15, p. 282