Mysterious Circular Structure Near Chemult, Oregon
September 27, 2007
In south central Oregon just east of the Cascade Ranges of volcanoes, a large, slightly elevated circular structure can be seen on Google Maps. It's about 27 miles (43 km) in diameter and centered at latitude 43.241201 and longitude -121.493683, just east of Chemult, Oregon. But what is it?
It's in a volcanically active area (Crater Lake is at the lower left) so perhaps it's an old caldera. But the Oregon Geological Survey does not identify it as such. And the U.S. Geological Survey has it located in the Basin and Range Geomorphic Province, not the Cascades Ranges. The rocks are all volcanic in origin, like most of those in the surrounding area. Maybe it is a meteor impact structure like Meteor Crater, Arizona or Manicouagan in northern Quebec; if so, it hasn't yet been recognized as such, because it's not listed in any crater reference.
Most likely, it is an unremarkable formation, a chance result of volcanism, erosion, crustal movement and agricultural activity that just happens to form a circular pattern. The human eye is very good at picking out patterns in random or complex images. One can hardly look at a star field without seeing what appear to be geometric shapes and alignments. In fact, in the late 1960s there was some serious work done on Schmidt-Kaler rings, circular star patterns that turned out to be phantoms of the eye-brain system trying to perceive order in chaotic fields.
To our knowledge, this feature has not been previously recognized as being interesting. If anyone knows what it is, please tell us!