December 15, 2014
Monday Geology Picture: A Glacial Erratic in the New Hampshire Woods
Posted by Evelyn Mervine
I spent the last two weeks of November visiting my family in New Hampshire. While I was in the US, I went on some long jogs and walks and took pictures of some glacial erratics, which can be found all around the Mervine Family Cabin in southern New Hampshire. This week’s “Monday Geology Picture” features a glacial erratic in the woods just down the road from the cabin. This large, angular rock was deposited during the retreat of the last ice age.
I wonder whether the depth of this boulder beneath the surrounding leaf litter and top soil could be used to relatively accurately date how long it has been here.
11000 years…give or take…end of the last ice age.
I have seen glacial boulders in so NH and elsewhere. There was a gorgeous Massabesic gneiss boulder on the shores of Great Bay. This one here is probably younger, its shape is too edgy. Is the rock type of this boulder different from the bedrock of this place? Is there a rock face nearby from which it may have fallen?
Um Hello… This isn’t exactly erratic in New Hampshire at all. Just take a look at all the stone walls and ask any farmer who has tilled or cleared large tracts of land there…..
“Erratic” is a standard geological term. See here: https://blogs.agu.org/georneys/2012/12/16/geology-word-of-the-week-g-is-for-glacial-erratic/