Download Construction Stone on the Colby Campus

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Table of Contents
I.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
II.
Indiana Limestone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
III.
Granite: “Maine’s Gold” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
IV.
Vermont’s Granite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
V.
Slates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
VI.
Geologic Timescale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
VII.
Campus Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
VIII.
Building Stones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
IX.
References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
X.
Special Thanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
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Introduction: BUILDING STONES
Every rock has a piece of earth’s history to tell: a story of continents crashing together, a
violent volcanic eruption, or the quiet deposition of sediment on an ancient seafloor. Today,
rocks that were once part of a cataclysmic mountain building event may sit quietly in a library
staircase, or unnoticed in the façade of an old building, or right at the entrance of your own front
door. These weathering rocks still hold their stories and a closer look has a lot to reveal.
Rocks can be classified into three different types: igneous, sedimentary, and
metamorphic. Igneous rocks are formed directly from cooled magma. The longer it takes
magma to cool, the more time mineral crystals will have to form. One example of an igneous
rock that is common in Maine is granite. Crystals in most granite are readily observable because
the rock has cooled over tens to hundreds of thousands of years. The second rock type is
sedimentary. These rocks are formed over time as sediment consolidates. Examples of
sedimentary rocks include sandstone, mudstone and limestone. Much of what we know about
the history of life is from the help of sedimentary rocks because they preserve fossils. The final
rock type is Metamorphic. Metamorphic rocks are created by a change in a rock that has
already formed. This change often occurs because of an increase in heat or pressure which
causes the minerals in the rock to recrystallize.
All three rock types have been used as building materials around Colby Campus. The
three main rocks used in construction here are limestone (a sedimentary rock), granite (an
igneous rock), and slate (a metamorphic rock). A trip around campus will take you to many
different periods of geologic time through rocks that have formed all over the world: from as
close as Norridgewock, Maine to as far as Andhra Pradesh, India.
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INDIANA LIMESTONE
Limestone has been quarried in Indiana since
1827 and has been used in buildings all over the
country as well as all over Colby Campus. Indiana
Limestone can be found in Roberts, East Quad, West
Quad, Arey, Keyes, Lovejoy, and the Chapel. It has
also been used in the keystones for many of the
buildings.
Limestone is a rock formed chiefly of
calcium carbonate from skeletal remains of sea
organisms. Indiana limestone was deposited during
the mid-late Mississippian (335-340 million years
ago). During this time, as you can see in Figure 1,
most of North America was under shallow seas and
Figure 1: Indiana Limestone's Deposition in the Late
Mississippian
near the equator. Over time, shallow shelf
carbonates collected at the sea floor, eventually
forming limestone.
The limestone used at Colby was
quarried near Bloomington, Indiana as shown
in Figure 2. Indiana limestone is considered
to be some of the best limestone to work
with. This is due in part to the fact that it has
no bedding planes to limit the size of its cuts.
An absence of bedding planes suggests that it
was deposited at a steady rate with no gaps
and also may be explained by bioturbation
(the mixing of sediments by animals and
plants).
Indiana limestone comes in three
different color varieties: gray, buff and
variegated. Oxidation of groundwater causes
gray limestone to turn to buff. Variegated
limestone is a mix of buff and gray
limestone. The limestone used at Colby is
“gray select limestone.” The word “select” is
used to indicate that the stone be fine grained
with a minimum of inclusions and veining.
Figure 2: Bloomington, IN
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If you take a close look at the limestone used in buildings on campus you can still see
marine fossils! The most commonly preserved animals in Indiana Limestone are foraminifera
and bryozoans. Bryozoans are colonial organisms and Foraminifera are single celled organisms.
Studies of their fossil records have shown steady evolution in both organisms which helps date
the rocks they are found in. The presence of different foraminifera and bryozoans species in
fossil records can also provide clues about past environments.
GRANITE: “MAINE’S GOLD”
The granite used in the earlier construction projects on campus comes from the state of
Maine. Most of Maine’s quarries are located on the coast or near rivers where erosion has had
the opportunity to carry away the sediment and glacial till that had been deposited over the rocks.
Deer Isle Granite
Some of Maine’s most successful
quarries are in the Deer Isle area. The granite
used in East Quad, West Quad, the old retaining
walls and entrances on Frat Row all comes from
here.
In order to understand the formation of
Deer Isle granite, we must go way back to the
Acadian orogeny, which started 423 million
years ago in the late Silurian and ended 383
million years ago in the mid Devonian. The
Acadian orogeny occurred when the two
microcontinents, Avalonia and Laurentia
collided. Just before the collision, igneous
activity was occurring between Avalonia and
Figure 3: Deer Isle Granite's Formation in the Middle
Laurentia. This continued during the collision
Devonian
and granites intruded into the crust. Deer Isle
Granite as well as several other granite bodies formed. Avalonia continued crashing into
Laurentia which caused Deer Island to tilt and now, the top of the relict magma chamber is at
Crotch Island in the south and the bottom is at Flye Point in the north.
Deer Isle is a light pinkish-gray porphyritic hornblende biotite granite. The granite shows
a variation in chemistry from North to South; however, the granite on the island is a single
granite with four different facies or types. The granite formed from the mixing of two magmas:
one which was more siliceous and less aluminous and one which was more basaltic. During the
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mixing, the denser, more aluminous part, sunk to the bottom of the magma chamber while the
more siliceous part tended to the top.
For the 300 million years that have followed the Acadian orogeny, Maine has seen little
tectonic activity, but that does not mean no change has occurred. Geochemical evidence shows
that Deer Isle Granite may have originally been five miles below the earth’s surface. Since the
Acadian Orogeny, erosion and glaciation has swept away much of Maine’s surface.
Mount Waldo Granite
The Mount Waldo granitic pluton lies
east of the Penobscot River and just north of
Searsport. This granite is about thirty miles
north of Deer Isle and the two locations have
similar geologic histories. Like the granite in
Deer Isle and the surrounding areas, the Mount
Waldo Granite also formed during the Acadian
Orogeny. It too formed a considerable distance
under the earth’s surface (about 7 miles!).
Taking into account the size of this granite
body, it has been estimated that it took tens to
hundreds of thousands of years for it to
crystallize.
The two main quarries for this granite
are on Mount Waldo itself, and just east of
Mount Waldo on Mosquito Mountain. The
quarry at Mount Waldo is no longer in use;
however, Mosquito Mountain Quarry was
recently reopened.
Figure 4: Location of Granite Quarries of Interest in
Maine
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Figure 5: Mosquito Mountain Quarry: Frankfort, ME
The Mount Waldo granite itself is coarse grained and contains nearly equal parts quarts,
alkali feldspar, and plagioclase feldspar. The black specks found in the rock are mostly biotite
but there is also some hornblende. In the Mosquito Mountain Quarry in particular, there are
white alkali feldspar grains up to an inch in length. A trip to this quarry will also reveal many
xenoliths in the granite. Xenoliths form when a rock fragment from another type of rock falls
into an igneous intrusion that has not yet cooled.
Figure 6: Xenoliths at Mosquito Mountain Quarry
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Figure 7: Location of Mount Waldo Granitic Pluton
Figure 7, above shows the location of the Mount Waldo Granite in central coastal Maine.
The blue areas are all granitic and formed during the Acadian Orogeny.
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VERMONT GRANITE
Figure 8: Graniteville, Vermont
The granite in eastern Vermont is part of the plutonic series in New Hampshire. It
formed during the mid to late Devonian after the Taconic Orogeny during the Acadian Orogeny.
At this time, Vermont and the western part of New Hampshire were colliding into central New
Hampshire. Much granite was produced in this convergence zone during and after the collision.
Figure 9: Barre, VT Granite Quarry
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SLATES
Slate has been used in many of the roofs and some of the fireplaces on Colby campus.
The slate used in more recent construction projects like the Diamond Building, comes from Pen
Argyl, Pennsylvania. Slate used in older buildings was taken from a slate quarry in the Monson,
Maine area.
Figure 10: Sheldon Slate Company, Willimantic, ME (just east of Monson)
Slate is a metamorphic rock so its formation involves several main steps. First muddy
clay beds are laid down under water. This forms sedimentary rocks which are then compressed
generally by being buried under rock until a certain depth and pressure alters its minerals. Over
time this compression creates slate.
Pennsylvania Slate
Figure 11: Pen Argyl, PA
Pen Argyl slate is an upper part of the Martinsburg Formation which was deposited
during the Ordovician (457-445 million years ago). The original sediment was deposited in a
basin on the sea floor called a forearc, between a subduction zone and a volcanic island arc as the
Iapetus Ocean was closing. The slate at Pen Argyl has a generally uniform medium grain size
and is composed of muscovite (20%), chlorite (20%), calcite (15%), quartz (10%), as well as
groundmass and other “minor constituents (35%).
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Monson Maine Slate
Figure 12: Monson, Maine
Maine may be better known for its granite than slate; however, from 1880-1905, Maine
was one of the top slate producing states in America. Slate in Maine occurs in the Central Maine
slate belt which extends from Waterville to Brownville Junction. The slate here is Early
Paleozoic in Age and was deposited in the closing sea between Laurentia and an incoming island
arc. The slate used in the roofs of the older buildings on campus including Roberts and East and
West Quad comes from the Monson, ME area (Figure 11).
Slate continues to be quarried up in the Monson area today by Sheldon Slate Co. The
slate runs very deep and the company has quarried up to 1,100 feet into the earth. Instead of
using an open pit quarry, Sheldon Slate quarries underground which has allowed a more flexible
season of quarrying in Maine’s harsh winters. This same company provided the slate for the
headstones of John F. Kennedy and Jacqueline Kennedy Onassis which now sit in Arlington
National Cemetery.
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Figure 13: Steve Tatko at Sheldon Slate Co
Slate quarrying is very different than granite quarrying in that the planes of cleavage can
be manipulated to help extract the rock (Figures 12 and 13).
Figure 14: Splitting Slate Along its Natural Planes of Cleavage
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EON
ERA
PERIOD
EPOCH
MA
BUILDING STONES
Indiana Limestone
Graniteville, VT Granite
Maine Coastal Granite
Penn Argyl, PA Slate
Maine Slate
chart adapted from usgs.gov
Rock
INDIANA LIMESTONE
MAINE COASTAL GRANITE
GRANITEVILLE, VT GRANITE
PENN ARGYL, PA SLATE
MAINE SLATE
Time of Formation
Mid-late Mississippian (335-340 ma)
Latve Silurian- Mid Devonian (423-383 ma)
Mid- Late Devonian (355 ma)
Ordovician (457-445 ma)
Early Paleozoic
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Colby Campus Map with Places of Interest:
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1)
Name: Alumni Center
Building Stones:
The granite used at the entrance to the Alumni Center as well as the granite pavers near
the entrance come from Swenson’s quarry in Graniteville, Vermont
2)
Name: Cotter Union
Building Stones:
The granite used at the entrances of Cotter Union all comes from Swenson’s quarries in
Graniteville, Vermont.
The granite blocks in back of Cotter Union by the dumpsters and service entrance came
from a quarry on route 201A in Norridgewock, Maine.
The coarse aggregate used in the concrete for the building comes from a quarry in
Thomaston, Maine and the sand came from Somerhaven, Maine.
The stone in the black staircase hails from Warrangal, Anghra Pragesh, India.
3)
Name: Diamond Building
Building Stones:
The granite used in the diamond building comes from Swenson’s quarries in Woodbury,
Vermont.
The slate comes from a quarry in Pen Argyl, Pennsylvania.
4)
Name: East and West Quad
Building Stones:
The granite used in East and West Quad comes from Deer Isle, Maine.
The limestone comes from Bloomington, Indiana.
5)
Name: Lorimer Chapel
Building Stones: The granite used in the chapel was provided by Gerald Marble of
Skowhegan. Marble owned several quarries but the closest one to campus is in
Norridgewock at Dodlin hill, only a couple of miles from campus.
Limestone used in Lorimer comes from Bloomington, Indiana.
The stone walls and platform on the outside of the chapel all come from Maine.
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6)
Name: Keyes
Building Stones:
The granite comes from Crotch Island, Maine.
The Limestone comes from Bloomington, Indiana.
7)
Name: Miller Library
The granite in Miller Library comes from a quarry in South Ryegate, Vermont
The slate comes from Monson, Maine
N.B. The Kennedy headstones in Arlington National Cemetary are also made out of slate
from Monson, Maine
8)
Name: The President’s House
The slate fireplaces in the president’s house come from Pen Argyl, Pennsylvania.
9)
Name: Roberts
The granite used outside of the building comes from South Ryegate, Vermont.
The granite used for the fireplace in the dining hall comes from Deer Isle, Maine
The slate on the roof comes from Monson Maine
The limestone comes from Bloomington, Indiana
10)
Name: Roberts Row
The granite used at the old building entrances comes from West Chelmsford,
Massachusetts
The slate fireplaces inside the dorms come from Pen Argyl, Pennsylvania
11)
Name: The Steps
Building Stones: The granite used in the Steps comes from the Mt. Waldo Quarry near
Frankfort, Maine
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References Cited
Berry, Henry. Mosquito Mountain Granite Quarry, Franklin. [Internet]. Augusta (ME): Maine
Geological Survey; c2008 [cited 2009 August 4]. Available from:
http://www.maine.gov/doc/nrimc/mgs/explore/bedrock/sites/jul06.htm
Behre, Charles H. Jr. Slate in Northampton County Pennsylvania. Harrisburg (PA): The
Telegraph Press; 1927.
Behre, Charles H. Jr. Slate in Pennsylvania. Harrisburg (PA): The Commonwealth of
Pennsylvania; 1933.
Dale, T. Nelson. The Granites of Maine. Washington D.C.: Washington Government Printing
Office; 1907.
Dale, T. Nelson. Slate in the United States. Washington D. C.: Washington Government Printing
Office; 1914.
Doolan, Barry. The Geology of Vermont. [Internet]. Burlington (VT): University of Vermont;
c1996 [cited 2009 August 14]. Available from:
http://www.anr.state.vt.us/dec/geo/pdfdocs/VermontGeoWebDoolan.pdf
Hansley, Paula L. Patterns of Diagenesis in Lower and Middle Pennsylvanian Sandstones of the
Illinois Basin, Illinois, Indiana, and Kentucky. Washington D.C.: United States
Government Printing Office; 1996.
Hooke, LeB. A Geologic History of Deer Island: A Thumbnail Sketch. Orno (ME): University of
Maine; c2007 [cited 2009 July 2]. Available from:
http://www.coacommunity.net/downloads/serpentine08/GeoHistofDeerIsle.pdf
Powell, Wayne G. Indiana Limestone [Internet]. Brooklyn (NY): Brooklyn College; c 2004
[cited 2009 July 9]. Available from:
http://academic.brooklyn.cuny.edu/geology/powell/613webpage/NYCbuilding/IndianaLi
mestone/IndianaLimestone.htm
Ridgley, J. L. and V. F. Nuccio. Source Rock Pottential of the Lower Part of the Mississippian
St. Louis Limestone in South-Central Indiana. Washington D. C.: United States
Government Printing Office; 1995.
Stone, Ralph W. Building Stones of Pennsylvania. Harrisburg (PA): Commonwealth of
Pennsylvania; 1932.
Wetmore, Karen. Foram Facts- An Introduction to Foraminifera. In Learning From the Fossil
Record [Internet]. Denver (CO): Paleontological Society; c1996 [modified 2000; cited
2009 Jul 7]. Available from: http://www.ucmp.berkeley.edu/fosrec/Wetmore.html
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Special Thanks to:
Darren Clough at Maine Masonry
Anna Graves and Pat Burdick at Colby College’s Special Collections Library
Mike Oullet at Oullet Associates Inc.
Pat Murphy at Colby College’s Physical Plant Department
Steve and John Tatko at Sheldon Slate
Nick Whatley at Morningstar Marble
Ben at Freshwater Stone
Indiana Limestone Institute of America
Piazzagalli Construction
Reed & Reed Inc.