Volcanoes in eastern Oregon are a great geologic road trip.

Doc,
I see that volcanoes are your field of interest. I'm a self-professed volcano nut, and I'm already planning next spring's road trip, maybe to the High Lava Plains of eastern Oregon. The name alone is intriguing! I have heard there are some little cinder cones way out there. What do you know about them? Been there? Worth the visit?
Denise Hodgkins,
Port Angeles, WA

Denise,
There are indeed some young-looking cinder cones and lava flows in eastern Oregon. I think you are referring to Jordan and Diamond Craters. I've been to both areas, and they are definitely worth the visit.



Coffee Pot cone in the far distance.

The Jordan Craters are in the southeast corner of the state, off Highway 95 near the town of Jordan Valley. There a number of cinder cones and lava fresh lava flows- they look as if they erupted yesterday (read about cinder cones in my first-ever Doctor Rock post). However, radiocarbon dates indicate that the most recent eruption, at Coffee Pot Crater, was 3200 years ago. Until usable material for radiocarbon carbon dating was found, this cone was widely held to be only 1-200 years old. It is the only cone in the Jordan Craters accessible by road. Here is a map
http://www.blm.gov/or/resources/recreation/googlemap.php?lat=43.14588&lng=-117.4588
use the 'satellite' tab in the upper right to see topography. The lava flows are the dark areas. Coffee Pot erupted 30 square miles of basalt lava.
The area is administered by BLM. The round trip to the single road accessible cinder cone, Coffee Pot Crater, is 52 miles. The roads are not paved. Be wary. It's not a good idea to take a big rig in there. When I was there in the spring, snow had just melted and roads were a quagmire. I barely made it back out of there in my all-wheel-drive Forester. Pay attention to the weather, and only go after the roads have had a chance to dry out. It is remote country- no services, poor cell coverage, no help. Be smart.
There is a great route guide here: http://www.everytrail.com/guide/birch-creek-ranch-jordan-craters
The Global Volcanism Program (a must-visit site for you volcanophiles out there) has sparse information about the Jordan Craters here: http://www.volcano.si.edu/volcano.cfm?vnum=1202-19.
A pamphlet (a bit dated, from 1977) explains some of the detailed geologic features you can see in the Jordan Craters: http://www.oregongeology.com/pubs/og/OBv39n08.pdf

This is Little Red cone in the Diamond Craters.

The other place is the Diamond Craters, 40 miles southeast of Burns and Malheur Lake. The essential info is on this great website for volcanophiles: http://volcano.oregonstate.edu/diamond-craters. There are about a dozen vents in the area, and a signed nature trail takes you to many of the points of interest. The oldest cone is maybe 60,000 years old, but the youngest is a meer 6,000 or so. While you are in the area, consider traveling the Diamond Loop Back Country Byway, a 67-mile unpaved back-country drive. Well worth it!



click to open.

 

Pillow basalt

Doc,
I recently stumbled on a Youtube video showing lava flowing underwater in Hawaii. The flow was called 'pillow basalt', but I didn't understand how it formed. Is there a place to see this without scuba diving or being near lava flowing into the ocean? That looked dangerous!
Jim Gilbertson
Pocatello, Idaho

Jim
The video you saw may have been one of these:
http://www.youtube.com/watch?v=5G8W9sZtBTM or
http://www.youtube.com/watch?v=xsJn8izcKtg

They show a very small protion of a lava flow entering the ocean on the south coast of Hawai'i's  Big Island.


Pillows are blobs of lava that form underwater. The surface
hardens instantly, but glowing lava remains inside.

HOW DO PILLOWS FORM?
Pillows only form underwater, either in the sea or in lakes. Just so happens I have a whole page on my Northwest Geology Field Trips blog devoted to this very

These fabulous pillows are at Cape Disappointment State
Park at the mouth of the Columbia River.

question. I really like pillows. They are the remnants of the dynamic environment where incandescent flowing lava enters water, hissing, boiling, clouds of steam and sometimes explosions of shattered lava.

These fabulous pillows are near Orofino, ID.
Photo by Vic Camp

There are places in the US to see pillows that are now above water. You can see them near Orofino, Idaho. Another site in Idaho is on the Snake River Canyon rim a few miles downstream from Perrine Bridge
I know about sites in Washington State best, including  Hurricane Ridge in Olympic National Park, Cape Disappointment State Park, Lopez Island in the San Juans, and many places in eastern Washington (here's an example). A search of the internet found spots in California, Oregon and Maine.
If you know of some good locations, please leave directions in a comment!
Here are some places to see basalt lava pillows on dry land:
Fishing Rock State Park, near Depoe Bay, Oregon.

Avila Point, California, south of San Luis Obispo.

Rodeo Beach, north of San Francisco.

These pillows are below the lighthouse at Point Bonito, CA

Point Bonito Lighthouse, Marin Headlands, north of San Francisco.

Lake Combie Complex in the  Sierra foothills at 38°59.034´N, 121°00.366´W

Stark's Knob off  US 4 north of Schulerville, NY.

North Haven Island, Maine