Franciscan complex calera limestones: Accreted remnants of farallon plate oceanic plateaus
The Calera Limestone, part of the Franciscan Complex of northern California, may have formed in a palaeoenvironment similar to Hess and Shatsky Rises of the present north-west Pacific1. We report here new palaeomagnetic results, palaeontological data and recent plate-motion models that reinforce this assertion. The Calera Limestone may have formed on Farallon Plate plateaus, north of the Pacific-Farallon spreading centre as a counterpart to Hess or Shatsky Rises. In one model2, the plateaus were formed by hotspots close to the Farallon_Pacific ridge axis. On accretion to North America, plateau dissection in the late Cretaceous to Eocene (50-70 Myr) could explain the occurrence of large volumes of pillow basalt and exotic blocks of limestone in the Franciscan Complex. Partial subduction of the plateaus could have contributed to Laramide (70-40 Myr) compressional events3. ?? 1985 Nature Publishing Group.
Citation Information
Publication Year | 1985 |
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Title | Franciscan complex calera limestones: Accreted remnants of farallon plate oceanic plateaus |
DOI | 10.1038/317345a0 |
Authors | J.A. Tarduno, M. McWilliams, M.G. Debiche, W.V. Sliter, M.C. Blake |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Nature |
Index ID | 70013009 |
Record Source | USGS Publications Warehouse |