Geologic history and correlation of the Jurassic of southwestern Oregon and California

Abstract

Research Article| January 01, 1942 Geologic history and correlation of the Jurassic of southwestern Oregon and California N. L. TALIAFERRO N. L. TALIAFERRO Search for other works by this author on: GSW Google Scholar GSA Bulletin (1942) 53 (1): 71–112. https://doi.org/10.1130/GSAB-53-71 Article history received: 28 Apr 1941 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation N. L. TALIAFERRO; Geologic history and correlation of the Jurassic of southwestern Oregon and California. GSA Bulletin 1942;; 53 (1): 71–112. doi: https://doi.org/10.1130/GSAB-53-71 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The generally accepted correlations of the Jurassic of southwestern Oregon and California are as follows: Galice and Mariposa, Dothan and Franciscan, Myrtle and Shasta. The Dothan is said to be younger than the Galice. On the other hand it has been stated that the Dillard, the lower part of the original Myrtle, is the equivalent of the Franciscan. Since the Dillard unconformably overlies Dothan and Galice, it is clear that one or the other of these correlations must be erroneous. Evidence is presented to show that the Dothan is older than the Galice and cannot be the same age as the Franciscan. The Dillard, as originally defined, includes Knoxville (Upper Jurassic) and possibly infolded Lower Cretaceous, but the great bulk of the Dillard is to be correlated with the Franciscan. The Myrtle, as mapped and defined, includes beds of both Upper Jurassic and Lower Cretaceous age and at least one important unconformity. The name should be redefined and restricted or abandoned.The Nevadan orogeny took place in the late Kimmeridgian and uplifted the Sierra Nevada and depressed the belt now occupied by the Coast Ranges. In the geosyncline thus formed the Franciscan and Knoxville were deposited. There is no unconformity between the Franciscan and Knoxville; these groups were deposited during the Portlandian and Tithonian.At the base of the Lower Cretaceous is a widespread unconformity. The diastrophism which closed the Jurassic is called the Diablan orogeny. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.