Monday, April 4, 2016

A drumlin in the Arnold Arboretum: Peters Hill—the third-largest hill in the Boston area of Massachusetts

Peters Hill summit
A vista point in the Arnold Arboretum: Peters Hill summit

Boston's Peters Hill in the south part of the Arnold Arboretum is a 240-feet-high drumlin. To get there from the Hunnewell Visitor Center at the other end of the park, you may want to walk southbound via Linden Path, Leventritt Shrub & Vine Garden, Bussey Hill Road, Valley Road, and Conifer Path to the Walter Street Gate, from where you can access Peters Hill Road surrounding Peters Hill. Various small trails lead up to the top and over the hill sides.

From the top of Peters Hill, Boston's skyline is visible. On a clear day high-rises such as the Prudential Tower, Hancock Tower, One Boston Place and the Federal Reserve Bank building can be seen. The distance between the Peters Hill summit to the Hancock Tower is 4.23 miles, according to an information panel.

Various fruit trees including crabapples grow on the gentile slope just downhill from the summit. The panel explains:

They were mostly planted in the 1940s and '50s. Before this was the Arnold Arboretum, colonial farmers planted fruit tree orchards on this same hill. They made cider and fed their animals on the fruit that fell from the trees.

Switching from agricultural history to geology, we also learn that beneath Peters Hill a probably unique type of rock is present, called Roxbury puddingstone. Peters Hill and other hills in the Arboretum were formed when glaciers altered the landscape. These drumlins consist of debris—sand, rocks, gravel, boulders—piled up thousands of years when glaciers melted. Peters Hill is merely one of many sites in and around Boston that gives evidence of ice age activity in this area [1]. Estate gardener and garden writer Danial Mount mentions three drumlins. He explored a drumlin a day [2]:

I gave  myself a generous three days to wander over and around the three drumlins that punctuate the topography of the Arnold Arboretum. It is a landscape shaped by glaciers, with outcroppings of Roxbury puddingstone and swampy lowlands, and has the third-largest hill in the Boston area, Peter's Hill, with a 180-dgree view of downtown Boston.

References and more to explore
[1] Arnold Arboretum - teacher guide [bostongeology.com/geology/fieldtrips/teacher/arboretum.htm].
[2] Daniel Mount: Boston's Arnold Arboretum: A Multihued Jewel. Summer 2012, page 13 [www.mountgardens.com/articles/Boston_Arnold_Arboretum.pdf].

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