Monday Geology Picture: Glacial Erratic Boulder, New Hampshire

My favorite glaical erratic, circa 2015.
My favorite glacial erratic, circa 2015.

I’m visiting family in New Hampshire at the moment… and also spending a little time with my favorite glacial erratic. I’ve posted about this particular glacial erratic before here and here. For this week’s Monday Geology Picture post I thought I’d share another shot of this stunning glacially deposited boulder. Enjoy!

Monday Geology Picture: A Glacial Erratic in the New Hampshire Woods

A glacial erratic in the woods near the Mervine Family Cabin in New Hampshire.
A glacial erratic in the woods near the Mervine Family Cabin in New Hampshire.

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.

Monday Geology Picture: Sunbathing by My Favorite Glacial Erratic

Sunbathing by my favorite glacial erratic. Franklin Pierce Lake, June 2013. Photograph by Jackie Gauntlett.
Sunbathing by my favorite glacial erratic. Franklin Pierce Lake, June 2013. Photograph by Jackie Gauntlett.

Happy Labor Day to all of my American readers! I hope that you all enjoy the holiday. Weather permitting, I plan on spending some time sunbathing by my favorite glacial erratic. I’m currently on vacation in New Hampshire and Cape Cod for about a week. I just finished up six weeks of field work in Alaska. My husband and I also visited New Hampshire for a couple of days on our way to Alaska back in July. After spending most of the past year in South Africa and six weeks in chilly northern Alaska, it’s nice to be home for a visit. And I’m always happy to visit my favorite glacial erratic!

Monday Geology Picture(s): My Favorite Glacial Erratic

The glacial erratic in front of my parents' lakeside cabin.

New England is full of glacial erratics: rocks which were transported and dropped by glaciers and which have a different lithology from the rocks upon which they have been deposited. Often, erratic rocks have an angular shape because they were broken off of bedrock by glaciers and have not yet had time to be weathered and rounded by water, wind, and other erosional forces. Glacial erratics can range in size from very small pebbles to very large boulders, but usually it is the boulders which are noticed since these stand out in the landscape and are not easily transported away.

I remember becoming interested in geology as a child when I began noticing large boulders in the middle of fields and the forest around my native New Hampshire. I asked my science teacher about these boulders, and he told me they were called glacial erratics and taught me a little about ice ages. Most of the erratic boulders seen throughout New England today were deposited during the last ice age, which reached a maximum around ~22,000 years ago and which ended ~10,000 years ago.

My favorite glacial erratic, which is shown in this week’s geology picture, sits on a small island in front of my parents’ lakeside cabin on Franklin Pierce Lake in New Hampshire. My parents purchased the cabin about 5 1/2 years ago, and although I had long moved away from home when they bought the cabin, I quickly fell in love with it (and its erratic island!) and try to visit regularly. Every year, my husband and I spend at least a couple of weeks at the cabin. Back in May, the cabin served as a geologist lair when my fellow geoblogger Dana Hunter visited for a few days. If you are brave, you can swim or kayak to the little island from my parents’ cabin and jump off the erratic.

An erratic jump! This picture gives you a better sense of the scale of this enormous erratic boulder.

Does anyone else have a favorite glacial erratic to share?