Physical Geology 2005

 


Photo courtesy of NEsoil

 


Globe courtesy of Tom Patterson

 

 

Related Links

1. NEsoil power point slideshow on soil formation

2. State soils photo gallery

 

 


Photo courtesy of Tom Patterson
Swiss/French Paleontologist
Louis Agassiz, 1807-1873,
"father of modern glacial geology"

 

 

 

 

 

 

 

 

 

What is Eolian?

It is the name for any process that pertains to the activity of the wind. Eolian processes are ver important in arid environments. (USGS, deserts)

 

 

 

 

 

 

 

 

 

 

 

 

Soil defined:

Soil is a natural body occuring on the land that has horizons, or layers, and can support rooted plants. The five factors in soil formation are time, parent material, slope, biota(organic life), and climate. The parent material can be glacial, volcanic, organic, loess or colluvium; Massachusetts soil is formed from a glacial parent material.

 

 

 

 

 

 

 

 

 


Pyramide represents different concentrations of sand, silt and clay and the names used to describe those soils.
Courtesy of the University of Massachusetts

 

 

 

 

 

 

 

 

 

 

State soil of Massachusetts: Paxton Soil

Very deep, well drained soil formed in deeply compacted glacial till consisting mostly of granite, gneiss and schist. Paxton soils are found on the smooth convex sides andn top sides of hills and drumlins. It is well suited for both agriculture and woodland but not for development due to its slow permeability. (NEsoil)

 

 

Massachusetts by county. NEsoil

 

 

 

 

Soil Proflies Defined:

  • A horizon - organic and mineral matter
  • B horizon - transitional, altered mineral matter with less organics
  • C horizon - altered bedrock (Parker)

 

 

 

 

 

 

 

 

 

Massachusetts Soil Geology - Formation and Characteristics

Overview

The soils of Massachusetts are the result of a recession of the most recent glaciation, the Wisconsinan from the northern United States and Canda. The soils consist of

Glacial Processes

The soil alive today in New England is the result of millions of years of glacial history on earth.

  • Throughout earth history, over 30 glacial ('ice-ages') periods have occurred. (NESoil)
  • currently we live in an interglacial (between 'Ice-Ages') period
  • 4 major ice advances and subsequent retreats/melts have happened during the Pleistocene epoch (1.8 MYBP-8 KYBP)*
  • It is helpful to remember how incomprehensibly immense the geologic time scale is, and the rate at which change occurs
  • From oldest to youngest these ages are the Nebraskan, Kansan, Illonoian, and Wisconsinan
  • representation of glacial/interglacial rhythm

The glaciation and recession of the Wisconsinan period formed present-day Massachusetts

  • The Wisconsinan advance covered all of New England, much of the northern United States and almost all of Canada. This glaciation produced today's Massachusetts soil and peaked 18,000 years ago


Photo courtesy of Tom Patterson

  • It was over one mile thick in some places.
  • The ice extended South because of a large mound of ice to the north.
  • The slowly advancing ice sheet plowed up soil and carried it long distances.
  • Rock outcrops were polished and smoothed, hills softened and valleys were filled with ice
  • As the advancing ide sheet absorbed ocean water, considerable amounts of continental shelf were exposed. (Patterson)
  • 1000 years after peaking, the ice-sheet suddenly began to retreat.
  • It moved at a rate of 100's to 1000's of meters/year, receding from Ohio to the Hudson Bay (2000 km) in less than 1000 years. (Patterson)
  • Glacial sheets broke off upon contact with the ocean
  • Melting created a rapid change in global sea level that slowed 8,000 YBP
  • Terrestial animals and plants advanced North to fill to the void of the glacier in conjunction with soil development.
  • Marine organisms migrated north as waters warmed and currents changed. (Patterson)
  • The maximum temperature of the Holocene was reached between 5,000 and 6,000 YBP.
  • The Wisconsinan glaciation lingered in Canda and finally melted by 6,000 YBP. (USGS)


Glacial melt from present-day Northern-Canadian mountains. Photo Courtesy of Tom Patterson

How were glaciers discovered?

  • Although many societies may have observed similar phenomena, Swis peasants observed boulders in their pastures fallen from the Alps (erratics) and deduced that the mountains had once been much larger due to this movement. They also observed the similarity between bedrock knobs of valley walls and ones emerging from the melting ice of existing glaciers.(USGS)
  • Swiss Geologist Louis Agassiz made early observations of the North-Central and North-East United States. He noticed smooth rock outcrops, rounded hills, valleys choked by sand and gravel-- all signs of deposition from glacial melt waters. (USGS)

Products: Soil, landforms, vegetables

Glacial deposits and landforms

 


Massachusetts is almost entirely glacial till and glacial outwash. Map courtesy of NEsoil

What is glacial till?
Glacial till is unsorted and stratified material depostied beneath and within glacial ice done by the ice itself. It is the oldest surficial deposit. There are two types, basal and ablation:

  • basal - has a dense restrictive layer which impedes water movement.
  • ablation - deposited on the land by melting ice. Less compact than basal till.


Glacial till in Massachusetts. Note the larger elements mixed with smaller sediment. Photo courtesy of NEsoil.

landform which results: drumlin
Drumlin: a smooth, elongate, oval-shaped hill or mound of compacted glacial till. The long axis of the hill is paralell to the direction of the glacial flow.


A Massachusetts drumlin located on Paxton soil. Photo courtesy of NEsoil

Drumlins of Canada--note the uniform direction of glacial movement. Photo courtesy of Tom Patterson

What is glacial outwash?
Glacial outwash is sediment deposited by glacial meltwater consisting of stratified layers of sand and gravel sized particles. It is often associated with aquifers (groundwater areas).

landform which results: esker
An Esker is a narrow, winding ridge of stratified gravel and sand deposited by a stream flowing beneath a glacier. (NEsoil)

And, what is a glacial lacustrine/marine deposit?
Glacial lacustrine is a fine textured sediment depostied in a glacial lake during glacial recession. Glacial lacustrine deposits have poor drainage and hold substantial amounts of water. These deposits can be well-suited for agriculture due to its water retention capacity.

Soil

The departure of the Wisconsinan Ice-Age left behind the geologic features and soil composition that characterizes New England and Massachusetts today.

  • After the glacier left, winds deposited sand-to-silt-sized particles in addition to the above processes.
  • Unconsolidated glacial deposits were greatly weathered and created soils.
  • Most upland soils in New England have a thin (18-36 inches) eolian cap which deepened rapidly after the ice left. (NEsoil)
  • On average, Massachusetts recieves about 40 inches/year of rainfall
  • There are 53 identified soil types in Massachusetts
  • Massachusetts Soil Series Information
  • The soils of Massachusetts vary widely; from dense glacial till, loamy ablation till, coarse sand formed in outwash plains, sandy glacial fluvial deposits, loamy wind-blown deposits, gravelly fluvial deposits, excessiively-drained glacial outwash and till derived from granite, gneiss and schists
  • Land relief and biota vary widely throughout the state of Massachusetts; from drumlins, to lake sediments, to mountaneous areas, to soils bordering beach.

Three examples of county soils

1. Barnstable County- (Cape Cod-coastal peninsula, South Shore) glacial outwash, plains are the most common landform. Soils are overwhelmingly sandly loam or coarse sand.
2. Essex County- (North Shore) Soil almost entirely sandy or silty loam.
3. Norfolk and Suffolk counties- (Central, Boston Area) Soils mostly sandy or silty loam or beach.

Vegetables and other phenomena

How did the recession of the Wisconsinan glacier affect human life?

  • Over a few thousand years the vegetation in New England and Northern Canada changed from tundra to woodland to closed forest.
  • A diversity of human colonies existed between 13,000 YBP and 11,000 YBP
  • Human artifacts suggest that large mammals were hunted prior to a late-Pleistocene extinction of the 'megafauna' (Bonnichsen, 151)
  • From 14,000 YBP to 13,000 YBP Massachusetts became free of ice
  • Evidence suggests that humans switched from hunting large mammals to hunting caribou with more sepcialized tools are the 'megafauna' extinction.

What is done with the soil today?

  • About 10.5% of Massachusetts 5 million acres of total land is farmland
  • Almost half of the farmland is used as cropland- including federal farm land, conservation reserve land, pasture and irrigated land.
  • The average farm size is 100 acres
  • Cranberries from Massachusetts provide 30% of the U.S. value(ClassBrain)
  • The geologic processes of the last glaciation have allowed humans to develop more settlements, houses, urban areas, etc. in addition to growing vegetables and fruits, raising animals, and reserving land as 'undisturbed.'
  • The Wisconsinan Ice-Age has allowed people such as Henry David Thoreau, Samuel Adams, John Hancock, John F. Kennedy, William Lloyd Garrison, Louisa May Alcott, E.E. Cummings, Emily Dickinson, the author of this page, and many others to do the work that they do in the land of Massachusetts.

Key:

*MY-Million Years
KY- Thousand Years
BP- Before Present
YBP- Years Before Present

 

 

Literature Cited

http://carleton.ca/~tpatters/teaching/climatechange.htm

http://www.classbrain.com/artstate/publish/article_704.htm

http://www.earlham.edu/~parkero/Geos211/2005/LectureHTML/2205PhysGeol22Glacial_files/frame.htm

American Farm Bureau- http://www.fb.org/today/class/mafb.html

http://www.ma.nrcs.usda.gov/technical/

http://www.nesoil.com

http://pubs.usgs.gov/gip/deserts/eolian.htm

http://pubs.usgs.gov/gip/ice_age/ice_age.pdf

"The environmental setting for human colonization of northern New England and adjacent Canada in Late Pleistocene time." Bonnichsen, Robson, Jacobson, George L., Jr., Davis, Ronald B., and Borns, Harold W., Jr. (from Late Pleistocene History of Northeastern New England and Adjacent Quebec, Harold W. Borns, Jr., Pierre LaSelle, and Woodrow B. Thompson, eds. Special Paper 197,USGS, 1985)

"The Last Interglacial-Glacial Transition in North America: Introduction" Clark, Peter U.(from The Last Interglacial-Glacial Transition in North America. Special Paper 270, USGS, 1992)

 

 

 

Author: Benjamin Jaffe
Creation/revision date: April 12, 2005

Link to other Student Webpages for 2005 Earlham Physical Geology

This website was prepared as an assignment for Geosciences 211 (Physical Geology) taught in the spring of 2005 at Earlham College, Richmond, Indiana.

Earlham College Geosciences Department Earlham Geosciences 211: Physical Geology

Copyright 2005 Earlham College. Revised April 26, 2005 . Send corrections or comments to parkero@earlham.edu

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