Paleogene Sediment Dispersal and Paleotectonics in Northern California

Remagnetization of Cretaceous forearc strata on Santa Margarita and Magdalena Islands, Baja California Sur: Implications for northward transport along the California margin

“…Here, J's and Os are north latitude and east longitude of sampling locality; li and D i are in situ inclination and declination of paleomagnetic directions in degrees (I c, D c, corrected for structrual tilt; dip is 90 ø clockwise of strike); N is number of samples (sites); R is vector sum of N unit vectors; k is the concentration parameter [Fisher, 1953] Regionally extensive remagnetization may have been a result of widespread exhumation, surface uplift, or both [Pullaiah et al, 1975]. Western California and Baja California underwent extensive Late Cretaceous to early Paleogene tectonism related to the exhumation of blueschists [Blake et al, 1988;Sedlock, 1996Sedlock, , 1998], and surface uplift is implied by the presence of Franciscan detritus in early Tertiary conglomerate near Stonyford [Dickinson et al, 1979]. Exhumation has been attributed to underplating and syn-subduction extension [Sedlock, 1996[Sedlock, , 1998], and surface uplift has been related to [Harbert, 1991 ] …”

Detrital zircon U–Pb reconnaissance of the Franciscan subduction complex in northwestern California

“…The Franciscan Coastal Belt may have been translated north a moderate distance after accretion. Based mainly on Dickinson et al (1979Dickinson et al ( , 1988Dickinson et al ( , 2012, Heller et al (1985Heller et al ( , 1987, Underwood and Bachman (1986), Renne et al (1990), Wells et al (2000Wells et al ( , 2014, Wyld (2000), Stewart et al (2003), Reed (2004) Figure 6H shows the distinctive data pattern exhibited by mid-Maastrichtian to Palaeocene strata from one specific portion of the unnamed forearc basin of southernmost California (Jacobson et al 2011; see also Sharman et al 2014). Key populations are ca.…”

Hydrogen Isotopes in Eocene River Gravels and Paleoelevation of the Sierra Nevada

“…The development of competence requires transcriptional activation of the com regulon, which comprises 105 to 124 genes (8,9), including recA (10). The RecA protein plays a key role in transformation by catalyzing homologous recombination between the internalized DNA and the recipient genome.…”

“…One view is that the bulk of elevation gain took place in the Pliocene about 3 to 5 million years ago (Ma) (3)(4)(5) and is the result of removal of dense mantle lithosphere (6)(7)(8). In contrast, the Sierra Nevada may have existed as a major topographic feature throughout the Cenozoic (9)(10)(11)(12)(13) and the apparent young uplift may be due, in part, to climatic changes at 3 to 5 Ma (14,15). To provide a further test, we determine Eocene (È40 to 50 Ma) stream gradients and headwater elevations by measuring the hydrogen isotope composition of kaolinite from Eocene fluvial sediments that record the isotopic composition of Eocene surface waters from ancient sea level continuously upstream into the modern (and ancient) range.…”