Borderland Disc Golf Course
Located around the Ames Estate at Borderland State Park, the
disc golf course of Borderland has become a mainstay of disc golf in the eastern
Massachusetts area. It sits close to I
95 and is an easy drive from Boston and Providence. One of the themes of Borderland is its
variety, as it moves in an out of open fields and wooded lots, wrapping around
a mansion built in the early 1900’s. Two
tees and two pin positions (white and blue) create four related but distinct
layouts with distances that range from an intermediate par 3 course, to an 8500
ft. par 68 layout. Borderland is one of
the destination courses in Massachusetts and is a must to play if you are in
the Boston or Providence areas.
Figure 1: Hole 17
Blue Tee- Ames Mansion in the
Background.
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The Avalon Terrane
The bedrock that underlies Borderland State Park is part of
the Avalon Terrane. If you form a line
from Pye Brook in Topsfield to Simmonds Park in Burlington to
Webster Fish and Game Club, anything southeast of this line is part of the
Avalon Terrane, while to the west is the Nashoba terrane and the Merrimack Belt. Similar rocks can be found in the Maritime Provinces of Canada, England and
Scandinavia. The Avalon Terrane is an
exotic terrane, a region of bedrock that originally formed in a distant
location that was then moved though plate tectonic processes to a new location
making it “exotic” to the surrounding rocks.
The Avalon Terrane likely formed in Late Proterozoic time (around
700-600 MYA) just off or on the coast of Africa as a volcanic arc. Rifting split this arc from Africa as a new
ocean (The Rheic Ocean) opened in the Early Paleozoic time. By the Mid-Paleozoic
the Avalon Terrane collided with the North American Continent causing what we
call the Acadian Orogeny. This event
welded the Avalone terrain to what is now the east coast of North America. In the Late Paleozoic the
African continent itself collided with North America, causing the Alleghanian Orogeny. Though not clearly seen at Borderland due to the massive nature of the bedrock,
folding, and metamorphism due to the Alleghanian event affected the area. This can be seen to the
south in the Narragansett coal basin, where carbon rich sediments were turned
to coal and the coal layers were compressed and folded. During the Jurassic the
opening of the Atlantic Ocean cut across the Avalone Terrane, some of it
staying as part of the North American coast, while the rest became part of Northern
Europe.
The Dedham Granite
Figure 3: (Wood
2016) #3 Blue Basket perched
on bedrock outcrop of Dedham Granite.
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The main rock type underlying Borderland is the Dedham
Granite, a light pink to grey slightly porphyritic (large visible crystals)
granite. The Dedham granite has been
dated between 630-595 MYA with the older range more prevalent in the Borderland
area. The Dedham granite is part of what geologists call a batholith, which is
a large emplacement of igneous rock. The
Dedham Granite is the intrusive core of the volcanic chain that formed the “backbone”
of the Avalon Terrane when it was a volcanic arc off the coast of Africa. In many ways it is a much older equivalent to
the granites of the Sierra Nevada in California or the rocks that underlie the
cascade volcanoes in the pacific northwest.
The rocks at Borderland are essentially the roots to an old volcanic
chain.
Despite the complex tectonic history of the area the Dedham
Granite shows very little deformation, surprising since it has moved around so
much. It still appears to retain its
original crystalline structure though there are many faults and fractures in
it. This is common with batholiths as they form a large massive block that is
difficult to compress, fold and deform.
The Dedham granite only shows up as a bedrock outcrop on the rock ridge
that forms the tees to holes 2 and 4 and the baskets to hole 3. It can
also be seen as glacial erratics on other parts of the course and on as bedrock
outcrops on hiking trails such as the ridge trail. The #3 Blue basket is placed on top of the
most dramatic outcrop of the granite on the course, where its crystalline
structure and mineralogical make up can be easily seen.
Glacial History
The state of Massachusetts was covered by the continental
ice sheet several times during the Pleistocene ice ages, and evidence of the
most recent event, the Wisconsian, is plentiful at Borderlands. Most of the disc golf course at Borderland is
underlain by a significant layer of glacial till. Glacial till is an unsorted
mixture of clay, silt, sand and boulders that was directly deposited by a glacier
or ice sheet. The till at Borderlands was likely deposited as the Wisconsian
ice sheet was melting and retreating back to the north. As it melted the ice dropped all the material
it was carrying forming the seemingly random mix material that is glacial till.
The till layer is likely 15 or so feet thick and forms a mantle of material
over the pre-existing bedrock topography, keeping its general shape. The material in till can be transported by
glaciers over great distances, sometimes on the scale of hundreds of miles. We call the larger boulders in a till that
have been transported large distances glacial erratics. Glacial erratics are most easy to spot when
they are made of a rock type not present in a local bedrock, so if you see a
non-granite rock at Borderland, you are probably looking at a glacial erratic
(or a chunk of asphalt or road rock). The most
impressive erratic at Borderlands is balancing rock, a large glacial erratic of
Dedham granite that is on a trail between the 2 and 4 baskets. It is impressive to think of the size of the glacier
necessary to carry something so big.
Figure 5: (Wood 2016) glacial till cover on hole #1.
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Figure 6: (Wood
2016) Balancing rock (Near Hole 4 Blue
basket), A large Glacial erratic of Dedham Granite. Note the large fracture running right down
the middle that nearly splits the boulder in two.
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Rock Walls
There is an interesting interplay between glacial geology
and human action that has a big impact of the feel of the course at Borderland. The course winds its way through various
segmented plots of land that surrounded the estate. Most of these plots were originally used for
agriculture in the 1800’s but over time these farms failed or people moved on. The pebbles and boulders of glacial till
caused big problems for New England farmers so they would be cleared from a
field before plowing. The farmers then
used these boulders to build the stone walls that mark the field boundaries. The
State Park has preserved the stone walls and they have become an integral part
of the course, marking out of bounds and giving borderlands its unique
feel. Some boulders are too big to move
though and these have to be left in the field and still remain to this
day. Holes 1,3,4 look to be on a plot of
land that has not had its boulders cleared as the bedrock was close to or at
the surface and contain plenty of rocky till.
Holes 2, 7, 11, 12, 17 and 18 re in areas that have been kept open, with
only a few large boulders that farmers could not move. Holes 8-10,13-16 play through a series of
wooded lots that are fairly clear of small boulders. These are farm fields that were cleared in
the 1800’s but eventually went into disuse and forest has started to grow back. Hole 5 is curious as it has a ton of boulders
and is marshy. My guess is that this was
a swampy that was not conductive to agriculture, the area was never cleared,
and extra boulders might have been put here to try to raise the ground level. It is fascinating here that every time you
cross a rock wall the plants and ground terrain change slightly, giving each
hole a slightly different character.
Figure 7 (Wood 2016). Near 12 Blue tee, this is most likely a large
glacial erratic of Dedham granite.
Boulders like this were way too large for farmers to move so they were
left in the fields.
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Figure 11: (Wood 2016)
Hole 13 Blue basket. Note rock
wall and wooded field relatively clear of boulders.
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I hope you enjoyed this look at the geology of Borderlands. Next will be something out of left field and left coast De Laveaga from Santa Cruz CA.
Links and References
Borderland Disc Golf Homepage - http://www.borderlanddiscgolf.com/
Borderland Disc Golf Facebook Page - https://www.facebook.com/borderlanddg
Chute, Newton E, Geology of the Norwood Quadrange Norfolk
and Suffolk Counties Massachusetts. Geology of Selected quadrangles in
Massachusetts, Geoloigical Survey Bulletin 1163-B. 1966. url http://pubs.usgs.gov/bul/1163b/report.pdf
Executive Office of Energy and Environmental Affairs, “Borderland
park History and Culture” Mass.gov
website, retrieved 2016. url http://www.mass.gov/eea/agencies/dcr/massparks/region-south/borderland-park-history-and-culture.html
Goldsmith, Richard, “Stratigraphy of the Milford-Dedham
Zone, Eastern Massachusetts: An Avalonian Terrane.” U.S. Geological Survey Professional Paper
1366 E-J. Washington D.C.: 1991. Electronic URL
http://pubs.usgs.gov/pp/1366e-j/report.pdf
Pollock, Jeffrey C, Hibbard, James P, and Sylvester Paul
J. “Early Ordovician Rifting of Avolonia
and Birth of the Rheic Ocean: U-Pb Detrital zircon constraints from
Newfoundland.” Journal of the Geological
Society. May 2009.
Skehan, James W. Roadside Geology of Massachusetts. Missoula:
Mountain Press Publishing Company, 2006. Print
Skehan, James W. Roadside Geology of Connecticut and
Rhode Island. Missoula: Mountain Press Publishing Company, 2008. Print
Sorota, Kristin Joy. Age
and Origin of Merrimack Terrane, Southeastern New England: A Detrital Zircon
U-Pb Geochronology Study. M.S.
Thesis. Boston College. 2013. Online.
Persistent link: http://hdl.handle.net/2345/3043
Wones, David R, and Goldsmith, Richard. “Intrusive Igneous
Rocks of Eastern Massachusetts.” U.S. Geological Survey Professional Paper 1366
E-J. Washington D.C.: 1991. Electronic URL
http://pubs.usgs.gov/pp/1366e-j/report.pdf
Zen, E-an, Gildsmith, Richard, Ratcliffe, N.M., Robinson,
Peter, Stanley R.S., Hatch, N.L., Shride, A.F.,Weed, E.G.A., and Wones,
D.R. Bedrock Geologic Map Of
Massachusetts[map]. 1:250,000. U.S. Geological Survey. 1983
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