Monday, May 17, 2010

Caution! Unnamed hypabyssal intrusion on the SHT

Hikers on the Superior Hiking Trail should be very very careful. There is an unnamed hypabyssal intrusion on the trail.

This intrusion was discovered on a recently published geologic map of the Crow Creek area.

The SHT runs west from the Castle Danger trailhead and descends right into the steep valley of Crow Creek. The unnamed intrusion is marked on the map with a thick blue line and the letters "db".


samh said...

Had to look this on up. Hypabyssal Intrusions: Intrusions that intrude rocks at shallow levels of the crust are termed hypabyssal intrusions. Shallow generally refers to depths less than about 1 km. Hypabyssal intrusions always show sharp contact relations with the rocks that they intrude.

Andrew Slade said...

Hmmm..."sharp contact relations." Confirms that these intrusions are up to no good.