Ediacaran cyclomedusoids and the paleogeographic setting of the Neoproterozoic–early Paleozoic Yreka and Trinity terranes, eastern Klamath Mountains, California

Regional Detrital Zircon Provenance of Exotic Metasandstone Blocks, Eastern Hayfork Terrane, Western Paleozoic and Triassic Belt, Klamath Mountains, California

“…The composite age spectrum for the Eastern Hayfork blocks is similar to that of several Cordilleran terranes and miogeoclinal sequences that range in age from Vendian (Ediacaran cyclomedusoids in the AMQ of the Yreka terrane; Lindsley-Griffin et al 2006) to the Cambrian-Triassic miogeoclinal composite of northern British Columbia (Gehrels 2000). The detrital zircons also exhibit similarities to the Early Proterozoic-Late Archean ages of zircons from passive-margin strata of the Laurentian craton (Cawood et al 2007).…”

“…The AMQ of the Yreka terrane was previously interpreted as part of the early Paleozoic system (Dickinson and Gehrels 2000;Gehrels et al 2000a) of northern California and northwesternmost Nevada, but new fossil data indicate that it is late Neoproterozoic (Vendian) in age (Lindsley-Griffin et al 2006). A poorly sorted quartz arenite from the AMQ has detrital modes indistinguishable from the those of the LDC allochthon (Dickinson and Gehrels 2000), but the AMQ sample collected for detrital zircon analysis was a texturally immature feldspathic granule conglomerate with a diverse zircon population.…”

“…A poorly sorted quartz arenite from the AMQ has detrital modes indistinguishable from the those of the LDC allochthon (Dickinson and Gehrels 2000), but the AMQ sample collected for detrital zircon analysis was a texturally immature feldspathic granule conglomerate with a diverse zircon population. Bond and Devay (1980) concluded that material in the AMQ was not derived from Laurentia, and Lindsley- Griffin et al (2006) proposed that it was sourced from continental fragments produced during the rifting of Rodinia.…”

Mesozoic transpression, transtension, subduction and metallogenesis in northern and central California

“…The lithic-feldspathic mineralogy reflects a transitional-continental-block provenance (Dickinson et al, 1982). U-Pb age spectra suggest that a plausible source of these distinctive Eastern Hayfork blocks was the Antelope Mountain Quartzite, an allochthon in the Eastern Klamath Yreka subterrane (Wallin et al, 2000;Lindsley-Griffin et al, 2006). This source must have been exposed along the seaward margin of the Klamath arc during Late Triassic me´lange production, but was later eroded or obscured by tectonism and ⁄ or younger sedimentary cover.…”

“…The Paleozoic zircon ages are similar to those of small, isolated Eastern Klamath stocks that intrude the Trinity and Redding subterranes (Irwin and Wooden, 1999;Gehrels and Miller, 2000;Snoke and Barnes, 2006). Neoproterozoic and older zircons may have been derived from the Yreka subterrane (Wallin et al, 2000;Lindsley-Griffin et al, 2006), hence the Eastern Klamath terrane probably was the source of older zircons in the central and southernmost North Fork terrane.…”