A Plain of Volcanoes

A Plain of Volcanoes (HM1CWI)

Location: Arco, ID 83213 Butte County
Country: United States of America

N 43° 32.911', W 113° 0.548'

  • 0 likes
  • 0 check ins
  • 0 favorites
  • 212 views
Inscription
The shallow arc of Idaho's Snake River Plain spans southern Idaho, gently rising from west to east. Current theories suggest that the plain marks the path of continental movement over a deep hotspot now lying beneath the Yellowstone Plateau. As the continent drifted southwestward over millions of years, calderas—super-volcanoes 10 - 40 miles (15 - 64 km) wide—erupted over the hotspot.

In the past 17 million years , there have been about a dozen catastrophic eruptions releasing huge volumes of rhyolitic magma and ash. Between these super-eruptions were long periods when more fluid basaltic lava flowed from more than 8,000 shield volcanoes and numerous lave cones. Remnants of these dot the Eastern Snake River Plain today. Layer upon layer of basalt flows extend 3,000 - 6,000 feet (1,000 - 2,000 m) below the surface, completely covering the rhyolite "basement."

(Left Graphic Description)
Sinking Rivers And A Flowing Aquifer
Streams that flow here are indirect tributaries to the Snake River. The aptly named Lost River flows to an area north of here known as "the sinks" where it soaks into the ground, becoming part of an aquifer the volume of Lake Erie. The aquifer flows through pores and fractures in the rock hundreds of feet beneath the surface, eventually emerging from springs along the Snake River Canyon at Thousand Springs about 100 miles (160 km) to the southwest.

(Middle Graphic Description)
Big Southern Butte
Big Southern Butte, rising 2,500 feet (760 m) above the Eastern Snake River Plain, is a prominent reminder of the region's volcanism. About 300,000 years ago, the butte intruded through surrounding layers of basalt, rising to an elevation of 7,560 feet (2,300 m). It is one of the largest composite rhyolite domes in the world.

(Right Graphic Description)
Ancient calderas are evidence of the North American Continent's movement over the Yellowstone hotspot.
When Yellowstone Caldera erupted 640,000 years ago, it released about 240 cubic miles (1,000 km 3) of material, covering half of North America in 6 feet (2 m) of debris.
Details
HM NumberHM1CWI
Tags
Marker ConditionNo reports yet
Date Added Friday, September 5th, 2014 at 11:33am PDT -07:00
Pictures
Sorry, but we don't have a picture of this historical marker yet. If you have a picture, please share it with us. It's simple to do. 1) Become a member. 2) Adopt this historical marker listing. 3) Upload the picture.
Locationbig map
UTM (WGS84 Datum)12T E 337701 N 4823690
Decimal Degrees43.54851667, -113.00913333
Degrees and Decimal MinutesN 43° 32.911', W 113° 0.548'
Degrees, Minutes and Seconds43° 32' 54.66" N, 113° 0' 32.88" W
Driving DirectionsGoogle Maps
Area Code(s)208
Closest Postal AddressAt or near 5914-6148 Unnamed Road, Arco ID 83213, US
Alternative Maps Google Maps, MapQuest, Bing Maps, Yahoo Maps, MSR Maps, OpenCycleMap, MyTopo Maps, OpenStreetMap

Is this marker missing? Are the coordinates wrong? Do you have additional information that you would like to share with us? If so, check in.

Check Ins  check in   |    all

Have you seen this marker? If so, check in and tell us about it.

Comments 0 comments

Maintenance Issues
  1. Is this marker part of a series?
  2. What historical period does the marker represent?
  3. What historical place does the marker represent?
  4. What type of marker is it?
  5. What class is the marker?
  6. What style is the marker?
  7. Does the marker have a number?
  8. What year was the marker erected?
  9. Who or what organization placed the marker?
  10. This marker needs at least one picture.
  11. Can this marker be seen from the road?
  12. Is the marker in the median?