Newberry National Volcanic Monument, OR (USA)

June 14, 2016

Newberry National Volcanic Monument includes 50,000 acres (20,000 ha) of lakes, lava flows, and spectacular geologic features in central Oregon.

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Lava Butte

Lava Butte is located next to U.S. Highway 97 south of Bend, next to the Lava Lands Visitor Center.

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Lava Butte

Lava Butte is a cinder cone capped by a crater which extends about 60 feet (20 m) deep beneath its south rim, and 160 feet (50 m) deep from the 5,020-foot (1,530 m) summit on its north side.

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Lava Butte Summit

Like the other cinder cones in the area, Lava Butte only experienced a single eruption, about 7,000 years ago.

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Black lava flows fields

The eruption began with a fissure spewing hot cinders to form the cone. In the next phase, a river of hot basalt flowed from the base of the small volcano to cover a large area to the west with a lava flow which remains largely free of vegetation.

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Black lava flows fields

The park is also home to Lava River Cave. At 1,560 m (5,211 feet) in length, the northwest section of the cave is the longest continuous lava tube in Oregon.

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Collapsed lava tube cave - Lava River Cave

The mouth of the cave is at an elevation of 4,500 feet (1,372 m) above sea level. At its deepest point the cave is 4,350 feet (1,326 m) above sea level.

The cave's entrance appears as a large hole in the ground. At its mouth, the entrance trail drops suddenly over a jumble of volcanic rocks.

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Lava River Cave Entrance

This area is known as the Collapsed Corridor. It is the result of ground water freezing in rock cracks in the ceiling. Loosened rocks eventually fall.

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Lava River Cave

The eruption which formed this Lava River Cave occurred about 80,000 years ago. However, the specific vent that created the cave has been buried by several younger flows.

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Lava River Cave

The Lava River Cave was created by lava flowing downhill from a volcanic vent. The flow began as a river of lava flowing in an open channel.

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Lava River Cave

Eventually, a lava crust solidified over the top of the flowing lava. This formed a roof over the river, enclosing it in a lava tunnel or tube.

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Lava River Cave

When the eruption from the vent stopped, the lava drained out of the tube leaving a lava tube cave behind.

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After the cave cooled, a section of its roof collapsed. This collapsed section provided the entrance to both the uphill (southeast) and downhill (northwest) cave sections.

The southeast section extends 1,560 feet (476 m) and runs toward the source of the flow so it has a slight uphill grade. This section is not open to the public because of loose rocks in the ceiling.

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Southeast section

On the way to Newberry Volcano, you can do a quick stop at Paulina Falls. These falls are like a hydraulic jackhammer, pounding away at the softer rock beneath. Boulders lying at the base break off when the soft layer erodes away.

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Paulina Falls

At only 1300 years old, the Big Obsidian Flow is the youngest lava flow known to exist in the state of Oregon. It is also one of the most interesting.

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Big obsidian flow

Consisting of three different types of rock; white pumice, gray pumice and obsidian, it is just one of the great geological features to see while visiting the Newberry Crater National Monument.

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Big obsidian flow

During the final stage of Newberry's eruption, magma that had lost much of its gas flowed onto the surface to form a dome at the vent.

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Big obsidian flow

The final product was the Big Obsidian Flow. Obsidian is a natural glass with no crystalline structure.

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Obsidian

In North America, obsidian is found only in localized areas of the West such as Newberry or Mount Edziza in northwestern British Columbia.

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Obsidian

Like all glass, obsidian breaks with a characteristic "conchoidal" fracture. This smooth, curved type of fracture surface occurs because of the near-absence of mineral crystals in the glass.

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The intersections of conchoidal fracture surfaces can be sharper than a razor. This had obvious use for Native Americans in the area. They used the obsidian glass for trade and tools including sharp blades and arrowheads.

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Purple flowers (Penstemon Davidsonii)

I was nice to see penstemons in the area. Native American tribes used penstemons as medicinal remedies for humans and animals.

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Collecting obsidian is not permitted within the National Monument. However, obsidian can be collected in central Oregon at Glass Butte, a rock hound site on Bureau of Land Management land on Highway 20 between Bend and Burns.

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Newberry Caldera has possibly existed as long as 500,000 years, when the cone of the volcano is thought to have first collapsed.

Within the caldera, there are two lakes (Paulina Lake and East Lake). Both lakes have hot springs, and drilling in 1981 found that temperatures in the caldera reach 280 °C (540 °F) at 3,057 feet (932 m) below the caldera floor.

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Paulina Lake

This is the highest temperature ever recorded at a dormant Cascade volcano, hotter than even The Geysers of California, the world's largest producer of geothermal power.

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Driving Distance from Vancouver: 800 km (9 hours)