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.
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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.
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Figure 2: (From U.S. Geological Survey Modified by Wood 2016). Map showing the terranes of Eastern Massachusetts. Green areas represents the Avalon Terrane, Orange the Nashoba Terrane and Blue the Merrimack Belt/Terrane. The lime green area just below borderlands is the Narragansett coal basin.
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The Dedham Granite
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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.
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Figure 4: (Wood 2016) From near #3 Blue basket looking straight down. Close up of Dedham Granite showing its crystalline texture. Several small joints are present striking across the picture. The Dedham granite is usually dull grey at Borderlands though some glacial erratics will have a more pink or orange hue.
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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.
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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.
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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 8: (Wood 2016) Hole #1 White basket. The chaotic jumble of boulders and dirt here is typical of glacial till. Unlike other places on the course the till on hole 1 appears relatively undisturbed by human actions like farming and wall building (though the forest does look like it was cut in the past).
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Figure 9: (Wood 2016) From left side of 11 fairway 10 Blue Basket in foreground, 11 baskets in distance. Terrain typical of the cleared open lots. Notice the two larger glacial erratics in front of the far basket.
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Figure 10: (Wood 2016) Hole 14 from white tee. Typical topography of wooded terrain on back 9 of course. Rock walls are present both Parallel to the fairway and cutting across it 150 ft. from tee. The rock walls consist of boulders taken from the adjacent fields. Larger boulders are still present in the field lots, such as the one on the right side of image. Compare this to the rocky terrain on holes 1 or 5 where the boulders were not cleared.
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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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Figure 12: (Wood 2016) Hole #5 White tee. This area is slightly lower and marshier than most of the rest of the course. Notice the abundance of boulders, in contrast to the cleared fields on the next several holes.
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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
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Skehan, James W. Roadside Geology of Massachusetts. Missoula: Mountain Press Publishing Company, 2006. Print
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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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