Library to host geologist Larry Broeker

ROSEBURG, Ore. – Roseburg Public Library invites the public to a presentation on the geology, geomorphology and geoecology of Oregon’s Table Rocks presented by Larry Broeker at 6:30 p.m. Thursday, Sept. 11.

Broeker is a retired geologist at Umpqua National Forest who speaks regularly about the iconic landforms of southern Oregon and northern California.

About 7 million years ago, a massive outpouring of runny lava swept down the ancestral canyon of the Rogue River 44 miles from source fissures thought to be buried beneath Olson Mountain, an extinct High Cascades shield volcano located a few miles east-southeast of Lost Creek Lake.

The lava spread across the northern part of the Rogue Valley and solidified to a depth varying between 100 and 200 feet.

Over the past seven millennia, tectonic forces and geologic processes have imperceptibly transformed the Rogue Valley into the present-day horseshoe-shaped landforms of Table Rocks.

The free program will be held at the library, located at 1409 NE Diamond Lake Blvd., and is open to the public. For more information, contact Roseburg Public Library staff at 541-492-7050 or library@roseburgor.gov.