Department of Geology Professor Nicholas Pinter  Geology Home Page   Nicholas Pinter Home Page

My work on the tectonic evolution of the western Basin and Range began with my dissertation research in the northern Owens Valley. That research focused on deformation preserved on the Volcanic Tableland -- the surface of the Bishop ashflow tuff -- and on terraces of the Owens River north of the town of Bishop. The Volcanic Tableland beautifully preserved hundreds of fault scarps, recording earthquakes and brittle deformation across the Owens Valley during the past 760,000 years. Three uplifted terraces of the Owens River can be correlated with three glacial advances in the Sierra Nevada just to the west, and they record eastward tilting of the Owens Valley block apparently since Late Pliocene time.

This evidence for eastward tilting of the Owens Valley has, until recently, been difficult to reconcile with evidence of tilting in the opposite direction from lake sediments preserved in the Waucoba embayment and elsewhere. Recent collaborative work with Susann Lueddecke (my lovely wife) and Phil Gans (at U.C. Santa Barbara), however, has used high-precision Ar/Ar analyses to re-date the Waucoba units and other deposits along the range-front of the White-Inyo Mountains. Some time prior to around 3 millions years ago, a regional tectonic event caused a wave of normal faulting in the western Basin and Range -- deformation that continues to the present day. In the Owens Valley, this event gave birth to the White-Inyo Mountains frontal fault, it caused a surge of coarse sedimentation into the valley, and reversed the polarity of block tilting from westward to eastward in the Owens Valley and the White and Inyo Mountains.