The Rocks Speak

Previous Columns

• Onion skins and rock tombstones - 4/26/2013

  Rock seems quite solid, doesn't it? Many features, however, such as joints, faults and random fractures act as conduits for root growth, slow percolation of water and weathering far below the earth's...

  
• 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.