The Rocks Speak

Previous Columns

• Come to this joint often? - 3/1/2013

  No, we aren't talking about funny cigarettes or seedy bars. Geologic joints are the most common of brittle fracture systems in rocks.

• How old is Olde? Look at 'half lives' - 2/8/2013

  Principles of relative-age dating allow geologists to understand which rocks are older than others, but they don't reveal how old they are in years.

• Observing rock layers exercises your mind - 1/18/2013

  No, the term "relative age dating" does not refer to a socially taboo subject, just a series of logical observations, called principles.

• Finding Elvis when he's right below your feet - 12/14/2012

  Have you ever seen imaginary objects in cloud shapes? That's what's so creative about our human minds: We can look at them and imagine we see animals, a pirate ship or Elvis.

  
• Petrified wood tells tales - 11/30/2012

  Change is the only constant, and that's true of the Rogue Valley's climate, which hasn't always been the same.

• Hooked on 'phossils' — right along I-5 - 11/16/2012

  Fossils are of interest to most everyone, even to those of us slowly becoming fossils.

  
• High on rocks and a 'pot of porridge' - 10/19/2012

  The magnificent High Cascade volcanoes are relative youngsters, built on the surface of older, slightly tilted and deeply eroded Western Cascade volcanoes.

• Humbled volcanic titans are right in our backyard - 10/4/2012

  All of us are enthralled by the large, High Cascade volcanoes such as Mount McLoughlin and Mount Shasta.

• Our Payneful rocks - 8/31/2012

  Keeping one eye on the road, another on an unruly child and a third on the yellow-brown cliffs on the northeast side of the Rogue Valley, one might wonder how those cliffs originated.

• Jump in, take a swim in Cretaceous waters - 8/10/2012

  If we dusted off our time machine and traveled to the Bear Creek Valley 100 million years ago, we'd find ourselves bobbing like corks on a vast ocean.

• Mount A won't blow - 7/6/2012

  Although Mount Ashland has a volcanic shape, it won't erupt any time soon. It isn't and never was a volcano.

• Exploring the rocks of Roxy Ann Peak - 6/22/2012

  Jump-start your imagination to envision the spaceship that Michael Rennie used ("The Day the Earth Stood Still," 1951-movie version) when deciding whether humans should be exterminated.

• Pilot Rock is what's left of an old volcano - 5/11/2012

  Pilot Rock, protruding like a hitchhiker's thumb on the Rogue Valley skyline, is our very own facsimile of Devil's Tower.

• Table Rocks: 7 million years in the making - 5/4/2012

  Editor's Note: Oregon Outdoors kicks off its newest feature today, "The Rocks Speak," a column by local geologist Jad D'Allura aimed at shedding light on the ground beneath your feet.