On a recent hike into the Ossipee Ring Dike Complex in NH we went looking for Basalt. To put it simply a Ring Dike is the extinct core of an old (many millions of years old) volcano and Basalt is a rock, quite similar to granite, that is formed from extruded lava that cools under certain conditions to form hexagonal columns. If you want more info on Ring Dikes and Basalt I’ll include some links at the bottom.
Anyway, The Ossipee Mountain Ring Dike is the largest and most complete ring dike in the U.S. so it follows that there should be lots of basalt there. Here’s some hiding under a birch tree.
A few years ago we were traveling in the Sierra Mountains in California and we came upon a Geological site called the Columns of the Giants. This site included some towering cliffs of basalt columns.
Other examples of Columnar Basalt include Devils Tower in Wyoming (known as the Bear Lodge, by local Native American tribes)
and the Devil’s Postpile near Yosemite National Park in California.
So our thought was that we might find some similar formations in the Ossipee’s. Our hike took us to the summit of Turtleback Mountain.
The summit of 2203 feet does not have a spectacular view, but it’s a bare summit (is that Basalt or is that Granite) with a nice view and a good crop of blueberries at their absolute peak.
Two Cedar Waxwings were hanging around picking blueberries too.
After all the hiking, blueberry picking, bird watching, etc. I thought I had better check for unwanted Drones flying around. Seems from the news that they are just about everywhere these days. After my
nap observations it was only a short hike off the summit to a connecting trail that leads down to a series of gorgeous waterfalls, but still no significant basalt formations. We did see some nice Fungi though.And then we found what we were looking for. A large outcropping of columnar basalt
You must keep in mind that these mountains in the Northern Appalachian Range are almost half a billion years old. By comparison the Rockies are about 80 million years old and the Sierras and Tetons less than 10 million years old. These mountains are really, really, old and have been ground down by wind, water, and ice to their current altitude of less then 6,288 feet (Mount Washington). Who knows how high they were when new, it is believed that the Ossipee Ring Dike Volcano was over 10,000 feet.. And to all our Western Friends who sneer at our puny little mountains, keep in mind that we are often hiking a vertical of over 4,000 feet up 35〫-45〫 talus slopes, across bogs and rivers, and through thick forest with roots that like nothing better than to trip you up. Come on out and try it some day. But I digress. What I’m trying to say is; to find an outcropping like this still existing in these old mountains is nothing short of thrilling.
Note the broken hexagonal piece in the lower left of the above picture. Detail below.
Here you cans see the fracture lines on a large broken piece of the cliffside.
We were totally blown away with this find and it turned an average hike on a small mountain into a spectacular hike. As we proceeded down the trail we found several of the waterfalls that this region, overseen by the “Lakes Region Conservation Trust“, is famous for.
And lastly, for our friend Tom, the requisite fish picture from the small pond at the trailhead.