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This study revisits the hypothesis that dispersal to California's Channel Islands follows a stepping-stone pattern from mainland California, based on earlier work indicating that the floras conform to classic island- biogeographic expectations. A re-examination of data incorporating the directions of prevailing and seasonal Santa Ana winds greatly strengthens the power of the model to explain levels of endemism in the Channel Island floras, and suggests the importance of aoelian processes for island colonization. Regression analysis of percent endemism in the native flora against distances measured along the axis of winds improves the [r.sup.2] from 0.099 to 0.482. The endemic species that flower in the dry season as a percent of the native flora of the islands is also strongly related to these revised source distances ([r.sup.2] = 0.665). Furthermore, the native floras of the southern islands are nested subsets of the floras of the northern islands, and angiosperm flowering peaks during the dry season, providing seed for seasonally based dispersal. These results suggest that the northern islands may have served as a source of colonists for the southern islands, and that the pattern of aeolian inputs into an island system should be considered in other plant biogeographic studies. Keywords: aeolian, California's Channel Islands, dispersal, endemism, island biogeography, plant diversity. Cette etude revisite l'hypothese proposant que la dispersion des especes vegetales vers les << Channel Islands de Californie >> suive un patron en pierre de gue a partir de la Californie continentale, selon un travail anterieur qui indiquait que les flores se conforment a la biogeographie insulaire classique attendue. Un reexamen des donnees qui incorporent les directions des vents dominants et saisonniers de Santa Ana renforce grandement le pouvoir du modele pour expliquer les niveaux d'endemisme des flores des << Channel Islands >>, et il suggere que les processus eoliens sont importants a la colonisation des lles. Une analyse de regression du pourcentage d'endemisme de la flore native en fonction des distances mesurees le long de l'axe des vents ameliore le [r.sup.2] de 0,099 a 0,482. Les especes endemiques qui fleurissent durant la saison seche exprimees en pourcentage de la flore native des lles sont aussi fortement en relation avec ces distances de la source revisees ([r.sup.2] = 0,665). De plus, les flores natives des lles du sud forment des sous-ensembles emboltes des flores des lles du nord, et la floraison des angiospermes atteint un sommet pendant la saison seche, fournissant la semence requise a la dispersion saisonniere. Ces resultats suggerent que les lles du nord peuvent avoir servi de source d'especes pionnieres pour les lles du sud et que le patron des contributions eoliennes dans le systeme insulaire devrait etre pris en consideration dans les autres etudes en biogeographie des vegetaux. [Traduit par la Redaction] Mots-cles: eolien, << Channel Islands>> de Californie, dispersion, endemisme, biogeographie insulaire, diversite vegetale., Introduction MacArthur and Wilson's (1967) equilibrium theory of island biogeography (ETIB), originally an influential model to explain species richness on islands, remains the accepted null model for island biogeographic studies [...]

Biocomplexity contributes to asynchronous population dynamics, buffering stock complexes in temporally variable environments, a phenomenon referred to as a 'portfolio effect'. We previously revealed a weakened but persistent portfolio effect in California's Central Valley fall-run Chinook salmon (Oncorhynchus tshawytscha), despite considerable degradation and loss of habitat. Here, we further explore the timing of changes in variability and synchrony and relate these changes to factors hypothesized to influence variability in adult abundance, including hatchery release practices and environmental variables. We found evidence for increasing synchrony among fall-run populations that coincided temporally with increased off-site hatchery releases into the estuary but not with increased North Pacific environmental variability (measured by North Pacific Gyre Oscillation), nor were common trends well explained by a suite of environmental covariates. Moreover, we did not observe a simultaneous increase in synchrony in the nearby Klamath-Trinity system, where nearly all hatchery releases are on-site. Wavelet analysis revealed that variability in production was higher and at a longer time period later in the time series, consistent with increased environmental forcing and a shift away from dynamics driven by natural spawners. La biocomplexite participe a une dynamique asynchrone des populations, limitant les variations au sein des complexes de stocks dans les milieux variables dans le temps, un phenomene appele << effet portefeuille >>. Nous avons deja fait etat d'un effet portefeuille affaibli, mais persistant chez les saumons quinnats (Oncorhynchus tshawytscha), a montaison automnale de la vallee centrale de Californie, malgre la degradation et la disparition considerables d'habitats. Nous examinons plus en profondeur le moment des modifications de la variabilite et de la synchronie et les relions a des facteurs presumes influencer la variabilite de l'abondance des adultes, dont les pratiques de lacher des ecloseries et des variables environnementales. Nous observons des indices d'une synchronie croissance dans les populations a montaison automnale qui coincide dans le temps avec une augmentation des lachers d'ecloseries hors site dans l'estuaire, mais non avec une variabilite accrue du milieu nord-pacifique (mesuree par l'oscillation du tourbillon nord-pacifique); en outre, un ensemble de covariables environnementales n'explique pas bien des tendances repandues. De plus, nous n'observons pas une augmentation simultanee de la synchronie dans le systeme voisin de Klamath-Trinity, ou presque tous les lachers d'ecloseries se font sur place. L'analyse des ondelettes revele que la variabilite de la production est plus grande et presente une plus longue periode plus tard dans la serie chronologique, ce qui concorde avec un forcage environnemental accru et une dynamique de moins en moins controlee par les geniteurs naturels. [Traduit par la Redaction], Introduction Environmental stochasticity drives variation in ecological dynamics within natural systems (May 1972). In coupled human-natural systems such as fisheries, decoupling this natural environmental variation from human-induced changes to populations [...]

The anomalously warm waters of the northeast Pacific 2014-2015 brought with it a variety of subtropical and tropical fish species previously unusual or absent from California waters (Bond et al., [...]

Abstract.--A 14-month study was conducted of the marine wood borers present on suspended wooden blocks replaced monthly at nine stations in Los Angeles Harbor in 2013-2014, and compared to the [...]

Abstract.--In September 2007 and May 2014, the Asian fish tapeworm, Bothriocephalus acheilognathi Yamaguti,1934 (Cestoda: Bothriocephalidea), was found in populations of the non-native convict cichlid (Archocentrus nigrofasciatus) and mosquitofish (Gambusia affinis) [...]

Forest communities change in response to shifting climate, changing land use, and species introductions, as well as the interactions of established species. We surveyed the oak (Quercus L. spp.) community and Acorn Woodpecker (Melanerpes formicivorus (Swainson, 1827)) population within 230 ha of oak forest and savanna in central coastal California in 1979 and 2013 to assess demographic changes over a timescale relevant to mature oaks. Overall, percent canopy cover increased, particularly where coast live oak (Quercus agrifolia Nee) and California black oak (Quercus kelloggii Newberry) were most abundant. The density of stems of Q agrifolia increased, whereas the density of stems and basal area of valley oak (Quercus lobata Nee), a species favored by Acorn Woodpeckers, decreased. The number of Acorn Woodpeckers and woodpecker territories increased over the study period, coincident with the increase in percent canopy cover; however, these increases were not related spatially. Instead, increased acorn production associated with broad-scale canopy growth likely more than compensated for the loss of Q lobata. Our findings suggest that forests in this area are becoming denser and savanna is becoming more open, which so far has supported an increase in the Acorn Woodpecker population, despite potential habitat loss if Q lobata continues to decline. Key words: animal territories, community shift, land use change, plant-animal interactions, tree demographics. Les communautes forestieres changent en reponse aux fluctuations climatiques, aux changements dans l'utilisation du territoire et aux introductions d'especes, de meme qu'aux interactions entre especes etablies. Nous avons etudie les communautes de chenes (Quercus L. spp.) et les populations du pic glandivore (Melanerpes formicivorus (Swainson, 1827)) sur 230 ha de chenaie et de savane de la cote centrale californienne en 1979 et en 2013 dans le but d'evaluer les changements demographiques sur une periode de temps appropriee pour des chenes matures. Dans l'ensemble, le pourcentage de recouvrement arborescent a augmente, particulierement la oU le chene de Californie (Quercus agrifolia Nee) et le chene noir de Californie (Quercus kelloggii Newberry) etaient les plus abondants. La densite de tiges de Q agrifolia a augmente, tandis que la densite de tiges et la surface terriere du chene blanc de Californie (Quercus lobata Nee), une espece favorite du pic glandivore, ont diminue. Le nombre d'individus et de territoires du pic glandivore a augmente durant la periode d'etude, coincidant avec l'augmentation du pourcentage de couvert arborescent, mais ces augmentations n'etaient pas correlees spatialement. En fait, la production accrue de glands associee a l'augmentation a grande echelle du couvert arborescent a probablement surcompense la perte de Q lobata. Nos resultats suggerent que les forets de cette region se densifient tandis que les savanes deviennent plus clairsemees, ce qui jusqu'a maintenant a permis un accroissement des populations du pic glandivore, en depit d'un declin potentiel si la population de Q. lobata continue a decroitre. [Traduit par la Redaction] Mots-cles : domaines vitaux, modifications des communautes, changement d'utilisation du territoire, interactions plante-herbivore, demographie des arbres., Devin E. McMahon, Ian S. Pearse, Walter D. Koenig, and Eric L. Walters Introduction Forest and savanna communities can be rapidly altered by species introductions, changing land use patterns, and [...]

Fish otolith growth increments were used as indices of annual production at nine nearshore sites within the Alaska Coastal Current (downwelling region) and California Current (upwelling region) systems (~36-60°N). Black rockfish (Sebastes melanops) and kelp greenling (Hexagrammos decagrammus) were identified as useful indicators in pelagic and benthic nearshore food webs, respectively. To examine the support for bottom-up limitations, common oceanographic indices of production [sea surface temperature (SST), upwelling, and chlorophyll-a concentration] during summer (April-September) were compared to spatial and temporal differences in fish growth using linear mixed models. The relationship between pelagic black rockfish growth and SST was positive in the cooler Alaska Coastal Current and negative in the warmer California Current. These contrasting growth responses to SST among current systems are consistent with the optimal stability window hypothesis in which pelagic production is maximized at intermediate levels of water column stability. Increased growth rates of black rockfish were associated with higher chlorophyll concentrations in the California Current only, but black rockfish growth was unrelated to the upwelling index in either current system. Benthic kelp greenling growth rates were positively associated with warmer temperatures and relaxation of downwelling (upwelling index near zero) in the Alaska Coastal Current, while none of the oceanographic indices were related to their growth in the California Current. Overall, our results are consistent with bottom-up forcing of nearshore marine ecosystems-light and nutrients constrain primary production in pelagic food webs, and temperature constrains benthic food webs., Author(s): Vanessa R. von Biela[sup.1] [sup.2] , Gordon H. Kruse[sup.2] , Franz J. Mueter[sup.2] , Bryan A. Black[sup.3] , David C. Douglas[sup.1] , Thomas E. Helser[sup.4] , Christian E. Zimmerman[sup.1] [...]

While marine hermit crabs are well known for being omnivorous filter feeders, less is known about the role they may play as active carrion scavengers in intertidal ecosystems. Prior studies have revealed that intertidal hermit crabs can be attracted to chemical cues from predated gastropods. Yet their attraction is usually assumed to be driven primarily by the availability of new shells rather than by food. We conducted field experiments to assess hermit crabs' potential role as generalist carrion scavengers on the California Coast, examining their speed of attraction and the size of the aggregations they formed in response to chemical cues from freshly smashed gastropods and mussels, both of which indicated available carrion. Compared to all other marine species, hermit crabs (Pagurus samuelis, P. hirsutiusculus, and P. granosimanus) were the fastest to arrive at the provisioning sites. Hermit crabs also dominated the provisioning sites, accumulating in the largest numbers, with aggregations of up to 20 individuals, which outcompeted all other scavengers for carrion. Notably, hermit crabs arrived equally quickly for both smashed gastropod and mussel, even though the latter does not offer suitable shells for hermit crabs and even though the former only yields shell-related chemical cues over time frames longer than our experiments. These results thus suggest that shell availability is not the only, or even the primary, reason marine intertidal hermit crabs aggregate at carrion sites; they also aggregate to forage, thereby playing an important role as active carrion scavengers in intertidal ecosystems. Electronic supplementary material The online version of this article (doi:10.1007/s00227-015-2639-3) contains supplementary material, which is available to authorized users., Author(s): Mark E. Laidre[sup.1] [sup.2] , Alison L. Greggor[sup.1] [sup.3] Author Affiliations: (1) Department of Integrative Biology, University of California, Berkeley, CA, USA (2) Department of Biological Sciences, Dartmouth College, [...]

Abstract.--We provide an overview of the distribution of lowland and otherwise isolated populations of the western gray squirrel (Sciurus griseus) in the Los Angeles area of southern California, an area [...]

The summers of 2014 and 2015 generated many tales of warm-water fishes being caught in the local southern California sport fishery, including Dolphinfish (Coryphaena hippurus), Blue Marlin (Makaira nigricans), Shortbill [...]

Timroseite, [Pb.sub.2][Cu.sup.2+.sub.5][([Te.sup.6+][O.sub.6]).sub.2] [(OH).sub.2], and paratimroseite, [Pb.sub.2] [Cu.sup.2+.sub.4][([Te.sup.6+][O.sub.6]).sub.2][([H.sub.2]O).sub.2], are two new tellurates from Otto Mountain near Baker, California. Timroseite is named in honor of Timothy (Tim) P. Rose and paratimroseite is named for its relationship to timroseite. Both new minerals occur on fracture surfaces and in small rugs in brecciated quartz veins. Timroseite is directly associated with acanthite, cerussite, bromine-rich chlorargyrite, chrysocolla, gold, housleyite, iodargyrite, khinite-4O, markcooperite, ottoite, paratimroseite, thorneite, vauquelinite, and wulfenite. Paratimroseite is directly associated with calcite, cerussite, housleyite, khinite-4O, markcooperite, and timroseite. Timroseite is orthorhombic, space group [P2.sub.1]nm, a = 5.2000(2), b = 9.6225(4), c = 11.5340(5) [Angstrom], V = 577.13(4) [[Angstrom].sup.3], and Z = 2. Paratimroseite is orthorhombic, space group [P2.sub.1][2.sub.1][2.sub.1], a = 5.1943(4), b - 9.6198(10), c = 11.6746(11) A, V= 583.35(9) [[Angstrom].sup.3], and Z = 2. Timroseite commonly occurs as olive to lime green, irregular, rounded masses and rarely in crystals as dark olive green, equant rhombs, and diamond-shaped plates in subparallel sheaf-like aggregates. It has a very pale yellowish green streak, dull to adamantine luster, a hardness of about 2 1/2 (Mohs), brittle tenacity, irregular fracture, no cleavage, and a calculated density of 6.981 g/[cm.sup.3]. Paratimroseite occurs as vibrant 'neon' green blades typically intergrown in irregular clusters and as lime green botryoids. It has a very pale green streak, dull to adamantine luster, a hardness of about 3 (Mohs), brittle tenacity, irregular fracture, good {001} cleavage, and a calculated density of 6.556 g/[cm.sup.3]. Timroseite is biaxial (+) with a large 2V, indices of refraction > 2, orientation X = b, Y = a, Z = c and pleochroism: X = greenish yellow, Y = yellowish green, Z = dark green (Z > Y > X). Paratimroseite is biaxial (-) with a large 2 V, indices of refraction > 2, orientation X = c, Y = b, Z = a and pleochroism: X = light green, Y = green, Z = green (Y = Z >> X). Electron microprobe analysis of timroseite provided PbO 35.85, CuO 29.57, Te[O.sub.3] 27.75, Cl 0.04, [H.sub.2]O 1.38 (structure), O[equivalent to]Cl -0.01, total 94.58 wt%; the empirical formula (based on O+Cl = 14) is [Pb.sub.2.07] [Cu.sup.2+.sub.4.80] [Te.sup.6+.sub.2.04][O.sub.12] [(OH).sub.1.98][Cl.sub.0.02]. Electron microprobe analysis of paratimroseite provided PbO 36.11, CuO 26.27, Te[O.sub.3] 29.80, Cl 0.04, [H.sub.2]O 3.01 (structure), O[equivalent to]Cl -0.01, total 95.22 wt%; the empirical formula (based on O+Cl = 14) is [Pb.sub.1.94][Cu.sup.2+.sub.3.96][Te.sup.6+.sub.2.03][O.sub.12] [([H.sub.2]O).sub.1.99][Cl.sub.0.01]. The strongest powder X-ray diffraction lines for timroseite are [[d.sub.obs] in [Angstrom] (hkl) I]: 3.693 (022) 43, 3.578 (112) 44, 3.008 (023) 84, 2.950 (113) 88, 2.732 (130) 100, 1.785 (multiple) 33, 1.475 (332) 36; and for paratimroseite 4.771 (101) 76, 4.463 (021) 32, 3.544 (120) 44, 3.029 (023,122) 100, 2.973 (113) 48, 2.665 (131) 41, 2.469 (114) 40, 2.246 (221) 34. The crystal structures of timroseite ([R.sub.1] = 0.029) and paratimroseite ([R.sub.1] = 0.039) are very closely related. The structures are based upon edge- and corner-sharing sheets of Te and Cu polyhedra parallel to (001) and the sheets in both structures are identical in topology and virtually identical in geometry. In timroseite, the sheets are joined to one another along c by sharing the apical O atoms of Cu octahedra, as well as by sharing edges and comers with an additional Cu[O.sub.5] square pyramid located between the sheets. The sheets in paratimroseite are joined only via Pb-O and H bonds. Keywords: Timroseite, paratimroseite, new mineral, tellurate, crystal structure, Otto Mountain, California DOI: 10.2138/am.2010.3514

Telluroperite, [Pb.sub.3][Te.sup.4+][O.sub.4][Cl.sub.2], is a new tellurite from Otto Mountain near Baker, California. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins in direct association with acanthite, bromine-rich chlorargyrite, caledonite, cerussite, galena, goethite, and linarite. Various other secondary minerals occur in the veins, including six new tellurates, housleyite, markcooperite, paratimroseite, ottoite, thorneite, and timroseite. Telluroperite is orthorhombic, space group Bmmb, a = 5.5649(6), b = 5.5565(6), c = 12.4750(14) [Angstrom], V = 386.37(7) [[Angstrom].sup.3], and Z = 2. The new mineral occurs as rounded square tablets and flakes up to 0.25 mm on edge and 0.02 mm thick. The form {001} is prominent and is probably bounded by {100}, {010}, and {110}. It is bluish-green and transparent, with a pale bluish-green streak and adamantine luster. The mineral is non-fluorescent. Mohs hardness is estimated to be between 2 and 3. The mineral is brittle, with a curved fracture and perfect {001} cleavage. The calculated density based on the empirical formula is 7.323 g/[cm.sup.3]. Telluroperite is biaxial (-), with very small 2V (~10[degrees]). The average index of refraction is 2.219 calculated by the Gladstone-Dale relationship. The optical orientation is X = c and the mineral exhibits moderate bluish-green pleochrosim; absorption: X < Y = Z. Electron microprobe analysis provided PbO 72.70, Te[O.sub.2] 19.26, Cl 9.44, O[equivalent to]Cl -2.31, total 99.27 wt%. The empirical formula (based on O+Cl = 6) is [Pb.sub.2.79][Te.sup.4+.sub.1.03][O.sub.3.72][Cl.sub.2.28]. The six strongest powder X-ray diffraction lines are [[d.sub.obs] in [Angstrom]. (hkl) I]: 3.750 (111) 58, 2.857 (113) 100, 2.78l (020, 200) 43, 2.075 (024, 204) 31, 1.966 (220) 30, and 1.620 (117, 313, 133) 52. The crystal structure ([R.sub.1] = 0.056) is based on the Sillen [X.sub.1] structure-type and consists of a three-dimensional structural topology with lead-oxide halide polyhedra linked to tellurium/lead oxide groups. The mineral is named for the relationship to perite and the dominance of Te (with Pb) in the Bi site of perite. Keywords: Telluroperite, new mineral, tellurite, crystal structure, perite, nadorite, Sillen [X.sub.1], Otto Mountain, California DOI: 10.2138/am.2010.3515

Markcooperite, [Pb.sub.2](U[O.sub.2])[Te.sup.6+][O.sub.6], is a new tellurate from Otto Mountain near Baker, California, named in honor of Mark A. Cooper of the University of Manitoba for his contributions to mineralogy. The new mineral occurs on fracture surfaces and in small vugs in brecciated quartz veins. Markcooperite is directly associated with bromian chlorargyrite, iodargyrite, khinite-4O, wulfenite, and four other new tellurates: housleyite, thorneite, ottoite, and timroseite. Various other secondary minerals occur in the veins, including two other new secondary tellurium minerals: paratimroseite and telluroperite. Markcooperite is monoclinic, space group [P2.sub.1]/c, a = 5.722(2), b = 7.7478(2), c = 7.889(2) [Angstrom], [beta] = 90.833(5)[degrees], V = 349.7(2) [[Angstrom].sup.3], and Z = 2. It occurs as pseudotetragonal prisms to 0.2 mm with the forms {100} and {011} and as botryoidal intergrowths to 0.3 mm in diameter; no twinning was observed. Markcooperite is orange and transparent, with a light orange streak and adamantine luster, and is non-fluorescent. Mohs hardness is estimated at 3. The mineral is brittle, with an irregular fracture and perfect {100} cleavage. The calculated density is 8.496 g/[cm.sup.3] based on the empirical formula. Markcooperite is biaxial (+), with indices of refraction [alpha] = 2.11, [beta] = 2.12, [gamma] = 2.29 calculated using the Gladstone-Dale relationship, measured [alpha]-[beta] birefringence of 0.01 and measured 2 V of 30(5)[degrees]. The optical orientation is X = c, Y = b, Z = a. The mineral is slightly pleochroic in shades of orange, with absorption: X > Y = Z. No dispersion was observed. Electron microprobe analysis provided PbO 50.07, Te[O.sub.3] 22.64, U[O.sub.3] 25.01, C1 0.03, O[equivalent to]Cl -0.01, total 97.74 wt%; the empirical formula (based on O+Cl = 8) is [Pb.sub.2.05][U.sub.0.80][Te.sup.6+.sub.1.18][O.sub.7.99][Cl.sub.0.01]. The strongest powder X-ray diffraction lines are [[d.sub.obs] in [Angstrom] (hkl) I]: 3.235 (120, 102, [bar.1]02) 100, 2.873 (200) 40, 2.985 ([bar.1]21, 112, 121) 37, 2.774 (022) 30, 3.501 (021, 012) 29, 2.220 (221, [bar.2]21, 212) 23, 1.990 (222, [bar.2]22) 21, and 1.715 (320) 22. The crystal structure ([R.sub.1] = 0.052) is based on sheets of comer-sharing uranyl square bipyramids and tellurate octahedra, with Pb atoms between the sheets. Markcooperite is the first compound to show [Te.sup.6+] substitution for [U.sup.6+] within the same crystallographic site. Markcooperite is structurally related to synthetic Pb(U[O.sub.2])[O.sub.2]. Keywords: Markcooperite, new mineral, tellurate, uranyl, crystal structure, Otto Mountain, California DOI: 10.2138/am.2010.3513

Thorneite, [Pb.sub.6]([Te.sup.6+.sub.2][O.sub.10])(C[O.sub.3])[Cl.sub.2] ([H.sub.2]O), is a new tellurate from Otto Mountain near Baker, California, named in honor of Brent Thorne. The new mineral occurs on fracture surfaces and in small vugs in hrecciated quartz veins. Thorneite is directly associated with acanthite, cerussite, gold, hessite, iodargyrite, khinite, wulfenite, and three other new tellurates: housleyite, markcooperite, and ottoite. Various other secondary minerals occur in the veins, including three other new secondary tellurium minerals: paratimroseite, telluroperite, and timroseite. Thomeite is monoclinic, space group C2/c, a = 21.305(1), b = 11.059(1), c = 7.564(1) [Angstrom] [beta] = 101.112(4)[degrees], V = 1748.8(4) [[Angstrom].sup.3], and Z= 4. Crystals are prismatic to bladed with elongation and striations parallel to c and typically occur in parallel and random aggregates. It is yellow and transparent, with pale yellow streak and adamantine luster. Mohs hardness is estimated at 2. The mineral is brittle, with an irregular to splintery fracture and good {100} cleavage. The calculated density is 6.828 g/[cm.sup.3]. Thorneite is biaxial (+), with large 2V, but indices of refraction are too high to he measured. The optic orientation is Y = b, Z [conjunction] a = 29[degrees] in obtuse [beta]. No pleochroism was observed. Electron microprobe analysis provided PbO 73.90, ZnO 0.03, Te[O.sub.3] 20.35, Cl 2.29, [H.sub.2]O 1.28 (structure), C[O.sub.2] 2.29 (structure), O[equivalent to]Cl -0.52, total 99.62 wt%; the empirical formula (based on O+Cl = 16) is ([Pb.sub.5.94][Zn.sub.0.01])([Te.sup.6+.sub.2.08][O.sub.10])([C.sub.1.00] [O.sub.3])[[Cl.sub.1.16][O.sub.0.34][(OH).sub. 0.50]]([H.sub.2]O) The strongest powder X-ray diffraction lines are [[d.sub.obs] in [Angstrom] (hkl) I]: 10.43 (200) 35, 3.733 ([bar.5]11, [bar.2]02, 002) 27, 3.595 ([bar.4]21) 33, 3.351 (112) 66, 3.224 (51l, 131) 100, 3.093 ([bar.2]22, [bar.3]31) 30, 2.900 ([bar.6]21) 44, 2.133 (821, 622, 223, 731, 242) 38. The crystal structure ([R.sub.1] = 0.028) contains edge-sharing octahedral tellurate dimers, [[[Te.sup.6+.sub.2][O.sub.10]].sup.8-] that bond to Pb atoms, which in turn are linked via bonds to Cl atoms, C[O.sub.3] triangles, and [H.sub.2]O molecules. Keywords: Thorneite, new mineral, tellurate, crystal structure, Otto Mountain, California DOI: 10.2138/am.2010.3512

We document evidence for trophy-taking and dismemberment with a new bioarchaeological database featuring 13,453 individuals from prehistoric central California sites. Our study reveals 76 individuals with perimortem removal of body parts consistent with trophy-taking or dismemberment; nine of these individuals display multiple types of trophy-taking and dismemberment for a total of 87 cases. Cases span almost 5,000 years, from the Early Period (3000-500 BC) to the Late Period (AD 900-1700). Collectively, these individuals share traits that distinguish them from the rest of the population: a high frequency of young adult males, an increased frequency of associated trauma, and a tendency towards multiple burials and haphazard burial positions. Eight examples of human bone artifacts were also found that appear related to trophy-taking. These characteristics suggest that trophy-taking and dismemberment were an important part of the warfare practices of central Californian tribes. Temporally, the two practices soared in the Early/Middle Transition Period (500-200 BC), which may have reflected a more complex sociopolitical system that encouraged the use of trophies for status acquisition, as well as the migration of outside groups that resulted in intensified conflict. Overall, trophy-taking and dismemberment appear to have been the product of the social geography of prehistoric central California, where culturally differentiated tribes lived in close proximity to their enemies. Am J Phys Anthropol 141:83-96, 2010. [c] 2009 Wiley-Liss, Inc. KEY WORDS bioarchaeology; violence; cutmarks; Native American; trauma DOI 10.1002/ajpa.21117

Since 2012, California has been experiencing its worst drought in more than a century. Temperatures are breaking records and the region is down a year's worth of rainfall (1). Forests, [...]

We present a new method for Lu-Hf geochronology using lawsonite, an index mineral of high-pressure, low-temperature metamorphism. The method uses common cation exchange chromatography to purify Lu and Hf from the sample and analysis by muiticollector inductively coupled plasma--mass spectrometry. Lawsonite [sup.176]Lu/[sup.177]Hf ratios are elevated and are similar to other minerals commonly used in Lu-Hf geochronology such as garnet or apatite. We obtain an age of 145.5 [+ or -] 2.4 Ma for lawsonite-blueschist facies metamorphism at Ring Mountain within the Franciscan Complex, California, the lawsonite type locality. The age agrees well with published geochronology and thermochronology for the Franciscan Complex. The new method provides a powerful tool to investigate processes and time scales of blueschist to eclogite facies metamorphism, crust-mantle recycling via subduction, and the geodynamics of convergent margins. doi: 10.1130/G30292A.1

Although earthflows are the dominant erosion mechanism in many mountainous landscapes, estimates of long-term earthflow-driven sediment flux remain elusive because landslide displacement data are typically limited to contemporary time periods. Combining high-resolution topography from airborne LiDAR (light detection and ranging), total station surveying, orthorectified historical aerial photographs, and inventories of meteoric [sup.10]Be in soil pits, we quantified ~150 years of slope movement on a 1.5-km-long earthflow in the Eel River catchment, northern California, United States. Using LiDAR-derived topography, we mapped the upper half of the earthflow into three distinct kinematic zones: an upslope source area, a long narrow transport zone, and a mid-slope compressional zone. From our air photo analysis (1944-2006), average velocities are fastest in the transport zone (1.7 m/a), slowest in the source zone (

The driving forces of microplate transport remain one of the major unknowns in plate tectonics. Our hypothesis postulates that the Baja California microplate is transported along the North America-Pacific plate boundary by partial coupling to the Pacific plate and low coupling to the North America plate. To test this idea, we use numerical modeling to examine the interplate coupling on a multiple-earthquake-cycle time scale along the Baja California-Pacific plate boundary and compare the modeled velocity field with the observed geodetic motion of the Baja California microplate. We find that when the strain can localize along a weak structure surrounding microplate (faults), high interplate coupling, produced by frictional tectonic stresses, can reproduce the observed kinematics of the Baja California microplate as seen from geodetic rigid-plate motions. We also find that the northward motion of Baja California can influence the fault slip partitioning of the major faults in the North America--Pacific plate boundary region north of Baja California.

The precise tectonic role of the left-lateral Garlock fault in southern California has been controversial. Three proposed tectonic models yield significantly different predictions for the slip rate, history, orientation, and total bedrock offset as a function of distance along strike. In an effort to test these models, we present the first slip-rate estimate for the western Garlock fault that is constrained by radiocarbon dating. A channel (referred to here as Clark Wash) incised into a Latest Pleistocene alluvial fan has been left-laterally offset at least 66 [+ or -] 6 m and no more than 100 m across the western Garlock fault, indicating a left-lateral slip rate of 7.6 mm/ yr (95% confidence interval of 5.3-10.7 mm/ yr) using dendrochronologically calibrated radiocarbon dates. The timing of aggradational events on the Clark Wash fan corresponds closely to what has been documented elsewhere in the Mojave Desert, suggesting that much of this activity has been climatically controlled. The range-front fault, located a few hundred meters northwest of the Garlock fault, has probably acted primarily as a normal fault, with a Holocene rate of dip-slip of 0.4-0.7 mm/yr. The record of prehistoric earthquakes on the Garlock fault at this site, though quite possibly incomplete, suggests a longer interseismic interval (1200--2700 yr) for the western Garlock fault than for the central Garlock fault. The relatively high slip rate determined here indicates that the western and central segments of the Garlock fault show similar rates of movement that are somewhat faster than rates inferred from geodetic data. The high rate of motion on the western Garlock fault is most consistent with a model in which the western Garlock fault acts as a conjugate shear to the San Andreas fault. Other mechanisms, involving extension north of the Garlock fault and block rotation at the eastern end of the fault may be relevant to the central and eastern sections of the fault, but they cannot explain a high rate of slip on the western Garlock fault.

Three-dimensional numerical models are needed to investigate the role of nonvertical strike-slip fault segments on the deformation within restraining bends. Numerical models simulate geologic deformation of two alternative three-dimensional present-day configurations for the San Andreas fault through the restraining bend within the San Gorgonio Pass region (SGPR) in Southern California. Both models produce decreasing strike-slip rates southward along the San Bernardino strand of the San Andreas fault, similar to geologic data. The north-dipping San Andreas fault model better matches the available strike-slip data as well as the geologic uplift data for the southern San Bernardino Mountains than the vertical San Andreas fault model. We conclude that a north-dipping fault configuration is preferred for models of the San Andreas fault in the SGPR. The complexity of the active fault geometry at the SGPR promotes the transfer of strike slip from the San Andreas fault to the nearby but unconnected San Jacinto fault. Slip rates and uplift patterns are sensitive to fault geometry within strike-slip restraining bends.

In August 2004, a National Forest fire crew extinguished a 1.2 ha fire in a wilderness area ~40 km northeast of Santa Barbara, California. Examination revealed that the fire originated on a landslide dotted with superheated fumaroles. A 4 m borehole punched near the hottest (262[degrees]C) fumarole had a maximum temperature of 307[degrees]C. Temperatures in this borehole have been decreasing by ~0.1[degrees]C/d, although the cooling rate is higher when the slide is dry. Gas from the fumaroles and boreholes is mostly air with 3-8 vol% carbon dioxide and trace amounts of carbon monoxide, methane, ethane, and propane. The carbon dioxide is [sup.14]C-dead. The ratios of methane to ethane plus propane [[C.sub.1]0/([C.sub.2] + [C.sub.3])] range from 3.6 to 14. Carbon isotope values for the C[O.sub.2] range from -14%o to -23%o [[delta].sup.13]C. [sup.3]He/[sup.4]He values range from 0.96 to 0.97 times that of air. The anomalous heat is interpreted to be due to rapid oxidation of iron sulfide augmented by combustion of carbonaceous matter within the formation.

Paleomagnetic and rock magnetic measurements for 27 sites in the tonalitic ca. 108 Ma Alpine and ca. 100 Ma Ramona complexes in the suspect Yuma terrane or western zone of the Peninsular Ranges Batholith near San Diego show that single- and pseudosingle-domain magnetite carries their characteristic remanence. The Alpine and Ramona paleopoles agree with six published paleopoles from Cretaceous igneous rocks in the Yuma terrane, but all eight paleopoles are discordant for North America. Al-in-hornblende geothermobarometric depth determinations at 16 sites, plus published mapping and depth determinations, suggest that the batholith is divided into blocks by orogen-parallel faults or by orthogonal fault sets with large vertical displacements. The paleomagnetic data show that the fault blocks in the terrane underwent, on average, ENE-side-up lilting of ~10[degrees] [+ or -] 3[degrees] about an orogen-parallel axis between ca. 125 Ma and ca. 89 [+ or -] 7 Ma, but they have not been translated northward as a suspect terrane by [greater than or equal to] 500 km, excluding Neogene opening of the Gulf of California. The tilting is attributed to torque from ENE shallow underthrusting of the Farallon plate beneath the WSW overthrusting North American plate, where subsequent extension has caused differential uplift of the fault blocks. Nonsignificant dextral displacement of ~4[degrees] [+ or -] 1[degrees] (440 [+ or -] 110 km) between the eastern and western zones of the batholith suggests that this boundary represents an intra-arc fault. The large paleopole discordance found in younger sedimentary strata of Baja California is attributed mainly to compaction shallowing of the remanence and/or postdeposittonal remagnetization. Keywords: Cretaceous, geobarometry, geothermometry, paleomagnetism, Peninsular Ranges Batholith, tectonics.

We use a combination of apatite [sup.4]He/[sup.3]He, (U-Th)/He, and fission-track thermochronology to date slip on the Surprise Valley fault in northeastern California by analyzing a single sample from the Warner Range in the footwall of the fault. This sample, a granitic clast from a conglomerate, yielded a fission-track age of 11.6 [+ or -] 2.8 Ma and a (U-Th)/He age of 3.02 [+ or -] 0.52 Ma. Geologic relationships indicate that this sample was buried to a depth of ~3.3 km prior to exhumation during slip on the Surprise Valley fault. Fission-track age and length data indicate that the sample was fully reset (>120 [degrees]C) prior to exhumation, which began sometime after 14 Ma. A single aliquot of nine apatite grains was step-heated for [sup.4]He/[sup.3]He analysis; modeling of the resulting [sup.4]He distribution indicates that cooling from >80 [degrees]C to -20 [degrees]C occurred between 3 and 1 Ma. Interconsistent time-temperature (t-T) solutions to the combined [sup.4]He/[sup.3]He, (U-Th)/He, and fission-track data require two distinct periods of cooling, consistent with noncontinuous slip on the Surprise Valley fault. Early cooling and fault slip took place between 14 and 8 Ma, followed by more recent fault slip ca. 3 Ma. This timing is consistent with both local geologic relationships and with the regional timing of faulting along the western margin of the Basin and Range Province. These data demonstrate the resolving power of combined fission-track, (U-Th)/He, and [sup.4]He/[sup.3]He thermochronometric data to extract low-temperature t-T information from a single sample close to Earth's surface. Keywords: [sup.4]He/[sup.3]He thermochronology, (U-Th)/He dating, fission-track analysis, Surprise Valley fault.

Cretaceous bryozoans from western North America are very poorly known. This paper describes twelve species of cheilostomes from the Upper Cretaceous of southern California and Baja California. The only previously described bryozoan, Ceriocava eastoni Woollacott, 1966, from the Holz Member (?Turonian-Campanian), Ladd Formation of the Santa Ana Mountains, is transferred from Cyclostomata to Cheilostomata, made the type species of the new genus Zimmerella and placed in the family Chiplonarinidae. The following new Campanian--Maastrichtian species are described from the Rosario, Point Loma, and Cabrillo formations of San Diego County, California and Le Mision, Baja California: Wilbertopora sannerae sp. nov., Onychocella schopforum sp. nov., Trichinopolia californica sp. nov., and T. lata sp. nov.

We compare geodetic velocity to geologic fault slip rates to show that tectonic loading was doubled across the eastern California shear zone (ECSZ) during a cluster of major earthquake activity. New slip rates are presented for six dextral faults that compose the ECSZ in the central Mojave Desert. These rates were determined from displaced alluvial fans dated with cosmogenic [sup.10]Be and from a displaced lava flow dated with [sup.40]Ar/[sup.39]Ar. We find that the sum geologic Mojave ECSZ slip rate, [less than or equal to]6.2 [+ or -] 1.9 mm/yr, is only half the present-day geodetically measured velocity of 12 [+ or -] 2 mm/yr. These rates account for cumulative fault slip and geodetic observations that span the 60-km-wide shear zone; therefore this difference cannot be attributed to postseismic relaxation. Redistribution of tectonic loading over the earthquake cycle at a regional scale suggests that earthquake clustering may be enhanced via feedback with weakening of ductile shear zones. Keywords: transient deformation, earthquake clustering, Eastern California shear zone, slip rate, cosmogenic dating.

We used high-resolution topography, geomorphic mapping of active surface processes, and geologic mapping to study the topographic and erosional response of small drainage basins to rock uplift along the Dragon's Back pressure ridge along the San Andreas fault in the Carrizo Plain, California. We infer the history of deformation experienced by -40 small drainage basins formed in poorly consolidated sedimentary rocks. A space-for-time substitution directly images the erosional and topographic responses to deformation. Progressive deformation and rock uplift are accompanied by increases in channel steepness and basin relief. As uplift ceases, channel concavity rapidly increases, causing channels to undercut hillslopes--this undercutting promotes the consumption of hillslopes by landsliding. This undercutting also causes basin relief to be greatest after uplift has stopped. This analysis indicates that channels of the Dragon's Back pressure ridge respond to changes in rock uplift rates over thousands of years, whereas hilislope processes may take more than an order of magnitude longer to adjust to changes in rock uplift rates. Our study directly measures changes in erosional processes due to the initiation and cessation of rock uplift, which can typically only be inferred using numerical models, by direct field observations. Keywords: LiDAR data, landscape development, San Andreas fault, hillslope response, channel response.

[1] The NNW-trending White-Inyo Range includes intrusive and volcanic rocks on the eastern flank of the Sierran volcano-plutonic arc. The NE-striking, steeply SE-dipping Barcroft reverse fault separates folded, metamorphosed Mesozoic White Mountain Peak mafic and felsic volcanic flows, volcanogenic sedimentary rocks, and minor hypabyssal plugs on the north from folded, well-bedded Neoproterozoic-Cambrian marble and siliciclastic strata on the south. The 163 [+ or -] 2 Ma Barcroft Granodiorite rose along this fault, and thermally recrystallized its wall rocks. However, new SHRIMP-RG ages of magmatic zircons from three White Mountain Peak volcanogenic metasedimentary rocks and a metafelsite document stages of effusion at ~115-120 Ma as well as at ~155-170 Ma. The U-Pb data confirm the interpretation by Hanson et al. (1987) that part of the metasedimentary-metavolcanic pile was laid down after Late Jurassic intrusion of the Barcroft pluton. The Lower Cretaceous, largely volcanogenic metasedimentary section lies beneath a low-angle thrust fault, the upper plate of which includes interlayered Late Jurassic mafic and felsic metavolcanic rocks and the roughly coeval Barcroft pluton. Late Jurassic and Early Cretaceous volcanism in this sector of the Californian continental margin, combined with earlier petrologic, structural, and geochronologic studies, indicates that there was no gap in igneous activity at this latitude of the North American continental margin. Citation: Scherer, H. H., W. G. Ernst, and R. Brooks Hanson (2008), Geologic implications of new zircon U-Pb ages from the White Mountain Peak Metavolcanic Complex, eastern California, Tectonics, 27, TC2002, doi:10.1029/2007TC002141.

We performed a multibeam survey of Eel Canyon, offshore northern California. The survey revealed a significant bend in the canyon that appears to be due to the oblique compressional tectonics of the region. A series of steps within a linear depression, ~280 m above the canyon floor, extends from the canyon rim at this bend to the subduction zone and a distinct fan-like topographic rise. We hypothesize that the linear depression is a distributary channel and the steps are cyclicstep bedforms created by turbidity currents. Our interpretation indicates that turbidity currents are able to run up and overspill the 280-m-high canyon wall, resulting in a partial avulsion of the canyon and the construction of a fan lobe that is offset from the canyon mouth. Simple hydraulic calculations show that turbidity currents generated in the canyon head from failure of 2-3 m of material would be capable of partially overflowing the canyon at this bend, assuming steadyuniform flow, full conversion of the failed mass into a turbidity current, and a range of friction coefficients. These estimates are consistent with analyses of sediment cores collected in the head of Eel Canyon, which sug gest that 2-3 m of material fails on decadal time scales. Our calculations show that the overflowing parts of the currents would have large shear velocities (>10 cm/s) and supercritical Froude numbers, consistent with erosion of the distributary channel and formation of cyclic steps by turbidity currents. Keywords: submarine canyons, Eel River, turbidity currents, cyclic steps, channel formation, superelevation, avulsion.

Devonian-Middle Jurassic terrane assemblies in the Klamath Mountains and Sierra Nevada Foothills consist chiefly of ophiolite-chert-argillite sequences. Mafic-ultramafic complexes are oceanic, whereas associated fine-grained deep-water terrigenous sediments were derived mainly from adjacent, previously docked Klamath-Sierran terranes. Coeval calc-alkaline arc rocks are volumetrically rare. Geologic and petrochemical relations suggest a rifted are origin for Klamath mafic metavolcanic units inter-layered with distal turbidites in the 170-200 Ma North Fork terrane; detrital zircon U-Pb ages indicate that the clastic debris had a regional eastern Klamath source. The Eastern Hayfork cherty melange contains ophiolitic scraps and distinctive olistostromal sandstone blocks evidently derived from the nearby Eastern Klamath Antelope Mountain Quartzite. The seaward 200 Ma Rattlesnake Creek terrane is an ophiolitic melange with North Fork petrotectonic affinities. The North Fork-Eastern Hayfork-Rattlesnake Creek amalgam correlates with the Calaveras Complex and the outboard Jura-Triassic arc belt in the Sierran Foothills. Geochemical bulk-rock and zircon U-Pb age data support interpretation of the 200 Ma Jura-Triassic arc as an adjacent offshore mafic belt overlying a 300 Ma ophiolitic basement. These oceanic complexes were sutured against the Central Metamorphic Belt-Eastern Klamath-Feather River-Northern Sierra terrane backstop before deposition and deformation of the outboard Upper Jurassic Galice and Mariposa formations. Klamath-Sierran terrane assemblies reflect ~230 m.y. of transpression-transtension involving only minor episodes of subduction, producing ubiquitous ophiolite-chert-argillite lithologies and rare felsic arc rocks. In contrast, the Late Jurassic to largely Cretaceous Klamath-Sierra Nevada quartzo-feldspathic volcanic-plutonic arc attests to massive calc-alkaline magmatism attending a strong eastward component of underflow by the Farallon plate. The coeval Galice-Mariposa formations, followed by the Cretaceous Great Valley forearc and Franciscan trench deposits, are first-cycle felsic debris shed mainly from the Klamath-Sierran arc. These units record ~70 m.y. of rapid sialic crustal growth attending major periods of approximately margin-normal convergence. This profound transition in northern California included Devonian-Middle Jurassic rifting, drifting, and stranding of ophiolite-chert-argillite terranes along an adjacent curvilinear continental margin, then nearly head-on Cretaceous subduction that resulted in massive calc-alkaline igneous activity, the erosion of which generated the felsic Great Valley Group forearc basin and Franciscan Complex trench clastic sedimentary units. Keywords: transpression, transtension, convergence, terrane assembly, northern California, Mesozoic plate tectonics.

The Eastern California shear zone is an active, north-northwest-trending zone of intraplate right-lateral shear that absorbs ~25 % of Pacific-North America relative plate motion. The Stateline fault system (SFS), which includes several previously recognized, discontinuously exposed Quaternary structures along the California-Nevada border, is in this paper defined as a continuous, 200-km-long zone of active dextral shear that includes (from south to north) the Mesquite, Pahrump, and Amargosa Valley segments. Recognition of this system expands the known extent of the Eastern California shear zone ~50 km to the east-northeast from its traditionally recognized boundary along the Death Valley fault system. Proximal volcanic and rock avalanche deposits offset across the Mesquite segment of the SFS indicate 30 [+ or -] 4 km of slip on this structure since 13.1 [+ or -] 0.2 Ma. This offset is an order of magnitude larger than previous estimates across this section of the SFS, but it is consistent with larger offsets previously proposed for the central and northern sections. The total offset and averaged slip rate since mid-Miocene time (2.3 [+ or -] 0.35 mm/yr) are similar to those of other major faults across this portion of the Basin and Range, which, from east to west, include the Death Valley, Panamint Valley-Hunter Mountain, and Owens Valley fault systems. However, in contrast to these faults, the average post-mid-Miocene slip rate on the SFS is approximately twice that estimated from present-day geodetic observations and an order of magnitude greater than estimates of average post-mid-Pleistocene slip rates. This discrepancy between long-term, short-term, and geodetically derived slip rates differs from other geologic-geodetic, slip-rate discrepancies in the Eastern California shear zone, where geodetic slip rates are significantly faster than both long-term and short-term geologic slip rates. This suggests that either the slip rate on the SFS has diminished over time, such that the system is an abandoned strand of the relatively young Eastern California shear zone, or that the present-day slip rate represents a transient period of slow slip, such that strands of the shear zone must accommodate a complex spatial and temporal distribution of slip. Keywords: Eastern California shear zone, stateline fault, tectonics, fault offset, fault slip rate, and slip rate discrepancy doi: 10.1130B26138.1

National wildlife refuges in California are playing a pivotal role in moving listed species towards recovery. Their contributions focus on restoring and protecting vital wildlife habitats. While many people are [...]

[1] We investigate the relationship between frictional strength and clay mineralogy of natural fault gouge from a low-angle normal fault in Panamint Valley, California. Gouge samples were collected from the fault zone at five locations along a north--south transect of the range-bounding fault system, spanning a variety of bedrock lithologies. Samples were powdered and sheared in the double-direct shear configuration at room temperature and humidity. The coefficient of friction, [mu], was measured at a range of normal stresses from 5 to 150 MPa for all samples. Our results reinforce the intuitive understanding that natural fault gouge zones are inherently heterogeneous. Samples from a single location exhibit dramatic differences in behavior, yet all three were collected within a meter of the fault core. For most of the samples, friction varies from [mu] = 0.6 to [mu] = 0.7, consistent with Byerlee's law. However, samples with greater than 50 wt % total clay content were much weaker ([mu] = 0.2-0.4). Expandable clay content of the samples ranged from 10 to 40 wt %. Frictional weakness did not correlate with expandable clays. Our results indicate that friction decreases with increasing total clay content, rather than with the abundance of expandable clays. The combination of field relations, analytical results, and friction measurements indicates a positive correlation between clay content, fabric intensity, and localization of strain in the fault core. A mechanism based upon foliations enveloping angular elements to reduce friction is suggested for weakening of fault gouge composed of mixed clay and granular material. We provide broad constraints of 1-5 km on the depth of gouge generation and the depth at which fault weakness initiates. We show that slip on the Panamint Valley fault and similar low-angle normal faults is mechanically feasible in the mid-upper crust if the strength of the fault is limited by weak, clay-rich fault gouge.

National wildlife refuges in California are playing a pivotal role in moving listed species towards recovery. Their contributions focus on restoring and protecting vital wildlife habitats. While many people are [...]

Abstract: We surveyed algal cover, algal biomass, and physical and chemical factors at 14 sites representing a range of land use types in the Malibu Creek watershed in southern California, [...]