The summer deluge of field and labwork continues for me. This weekend, I leave for California yet again, this time to traipse around Lassen Volcanic National Park to find some new samples and to visit the SHRIMP-RG lab at Stanford to work on some previously sampled Lassen lavas. So, in the spirit of that fieldwork, I put together a bit of "this is your (field) life" with some of the volcanic terranes I've visited over my geologic career. They range from ancient volcanoes that have been mashed and mangled by millennia of tectonic action to eruptions that occurred less than 100 years ago. Enjoy!
Vinalhaven Island, Maine
This is where it all started, in a small island off the coast of Maine. I did the fieldwork my undergraduate research thesis on the shores of Vinalhaven, looking at a small, shallowly-intrused basalt (diabase, to be exact) that is part of a volcanic-plutonic package of rocks that date from Silurian. So, I got my start on very old volcanism, but even in these 400 million+ year-old rocks, I saw some great volcanic features, including a gorgeous
peperite,
accetionary lapilli and rhyolite domes (in the unit above the Vinalhaven Diabase) ... and that's not even the most famous geologic feature on the island. That might be the
"pillow piles" of gabbro within the Vinalhaven pluton.
Fondest memory: Watching seals frolic while sampling on the coastline.
Image: Landsat image from September 9, 2010. USGS/NASA.
