Thursday, August 25, 2016

The three chimneys at Lava Beds: Fleener Chimneys

Fleener Chimneys, land of burnt-out fires, California
The Fleener Chimneys are volcanic vents and spatter cones created by globs of lava. They are located in the Lava Beds National Monument park and are easily accessible via a short trail from a parking and picnic area west of FS-10.

A spatter-cone volcano forms from lava that is ejected from a vent. Active spatter-cone volcanoes are known from Hawaii. Their study helps earth scientists understand past events at Lava Beds. During a spatter cone event, a hurled-up lava fountain of very fluid particles (spatter) causes the formation of air-born lava clots that fall back to the lava surface around the vent and plaster themselves together to chimney-like structures.

Dragon's Mouth

From the turnout and picnic area, walk the short Fleener Chimneys Trail uphill. The first part is paved. Climb a few stairs to get to the Dragon's Mouth—a surface lava tube probably formed by low-viscosity lava channeling its downhill path underneath a hardened lava crust. While continuing your surface trip, you will arrive at an interpretive panel that describes the formation of the Fleener Chimneys as follows:

You are on a fault, a crack in the earth's crust, that extends for many miles. For nearly two million years lava has erupted periodically through this weakness., slowly building the Medicine Lake volcano [farther west]. Lava did not flow up through these chimneys, as you might suspect. Instead, it issued from a vertical conduit, much like water from a garden hose that is held straight up, and flowed downhill. You are standing on the hardened surface of that flow. The three chimneys were formed over the opening as thickened clots of lava were spattered higher and higher around it.
You may want to climb around to get to and look into the chimneys, which are protected by metal metal railings and also protect you from falling in. Do not drop anything into the holes to keep the (once spoiled, now cleaned) chimneys unspoiled for future generations.

Getting to the Fleener Chimneys parking and picnic area
From the visitor center, drive north on FS-10. Pass the junctions with roads to Skull and Merrill Cave and Schonchin Butte. Find the marked road to Fleener Chimneys halfway between the Balcony Cave/Boulevard Cave area and the parking area to access the Black Crater and Thomas-Wright Battlefield trails. Head west until the road bends north and ends in front of the chimneys, about half a mile west of FS-10.

Searching for more?
William Hirt: Geology of Lava Beds National Monument. Department of Natural Sciences, College of the Siskiyous, 800 College Avenue, Weed, CA 96094 [].
Geotripper: Want to see classic volcano features in California? [].
Trail Run Project: Fleener Chimneys [].

Spatter-cone lava rocks of Fleener Chimneys

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