Kern Canyon Research Articles

Thermal evolution of the Sierra Nevada batholith, California, and implications for strain localization

The Sierra Nevada batholith (California, USA) hosts multiple shear zones of different ages and different styles of deformation. In this study we present new data syntheses and maps of U-Pb zircon and hornblende and biotite Ar age distributions through the batholith in order to examine the temporal and thermal settings under which contractional and transpressional shear zones arose. These maps highlight the localization of intrabatholithic shear zones at the boundaries between swaths of some of the oldest and youngest plutons, and help to distinguish deformation styles in the southern and central Sierran arc. We also present new ^(40)Ar/^(39)Ar ages and crystallization and deformation temperatures from along the Kern Canyon fault system in the southern part of the batholith, and contrast these new constraints with previously published thermochronological conditions for shear zones to the north. The transpressional proto–Kern Canyon fault was continuously active from ca. 95 to 85 Ma. Deformation temperatures along the fault increase by ∼100 °C from north to south, following the trend of increasing pluton emplacement pressures. These observations, in conjunction with a steep cooling path for the southeastern section of the batholith east of the proto–Kern Canyon fault, support previous interpretations that rapid exhumation in the southernmost part of the batholith followed the arrival and low-angle subduction of an oceanic plateau (the Shatsky Rise conjugate). We suggest that local forces such as these triggered mid-Cretaceous shear zone development in the southern Sierra Nevada batholith, while shear zones in the central part of the batholith, which record the transition from 100–90 Ma compression to 90–80 Ma transpression, were triggered by changing kinematic patterns in regional subduction forcing. This idea is supported by our thermochronologic color contour maps, which reveal an east-west–trending older (and colder) swath within the batholith that may have prevented the more northern shear zones from propagating southward. We contrast the cooling paths of regions within the southernmost part of the batholith, and propose a two-part deformation history in which (1) the 95–85 Ma ductile proto–Kern Canyon fault initiated in the southeast as a compressional structure that transitioned to transpressional, and (2) the 85–75(?) Ma ductile to brittle Kern Canyon–White Wolf fault initiated in the southwest, accommodated extrusion of shallowly subducted accretionary material and thinning of the overlying batholith, and then overprinted the proto–Kern Canyon fault along its northern end. Shear zone activity within the central Sierra Nevada batholith can thus be distinguished by location: in the central zone deformation arose from regional forces, and in the southern zone deformation was triggered by local forces.

Ledantevirus: a proposed new genus in the Rhabdoviridae has a strong ecological association with bats.

The Le Dantec serogroup of rhabdoviruses comprises Le Dantec virus from a human with encephalitis and Keuriliba virus from rodents, each isolated in Senegal. The Kern Canyon serogroup comprises a loosely connected set of rhabdoviruses many of which have been isolated from bats, including Kern Canyon virus from California, Nkolbisson virus from Cameroon, Central African Republic, and Cote d'Ivoire, Kolente virus from Guinea, Mount Elgon bat and Fikirini viruses from Kenya, and Oita virus from Japan. Fukuoka virus isolated from mosquitoes, midges, and cattle in Japan, Barur virus from a rodent in India and Nishimuro virus from pigs in Japan have also been linked genetically or serologically to this group. Here, we analyze the genome sequences and phylogenetic relationships of this set of viruses. We show that they form three subgroups within a monophyletic group, which we propose should constitute the new genus Ledantevirus.

Kolente virus, a rhabdovirus species isolated from ticks and bats in the Republic of Guinea

Kolente virus (KOLEV) is a rhabdovirus originally isolated from ticks and a bat in Guinea, West Africa, in 1985. Although tests at the time of isolation suggested that KOLEV is a novel rhabdovirus, it has remained largely uncharacterized. We assembled the complete genome sequence of the prototype strain DakAr K7292, which was found to encode the five canonical rhabdovirus structural proteins (N, P, M, G and L) with alternative ORFs (>180 nt) in the P and L genes. Serologically, KOLEV exhibited a weak antigenic relationship with Barur and Fukuoka viruses in the Kern Canyon group. Phylogenetic analysis revealed that KOLEV represents a distinct and divergent lineage that shows no clear relationship to any rhabdovirus except Oita virus, although with limited phylogenetic resolution. In summary, KOLEV represents a novel species in the family Rhabdoviridae.

Morphological and molecular diversification of slender salamanders (Caudata: Plethodontidae: Batrachoseps) in the southern Sierra Nevada of California with descriptions of two new species

Slender salamanders of the genus Batrachoseps achieve relatively high diversity in the Kern Canyon region at the southernend of the Sierra Nevada of California through high turnover of species with small geographic ranges. The status of severalpopulations of Batrachoseps in this region is enigmatic, and both morphological and molecular data have suggested thatsome populations do not belong to any of the currently recognized species. Identification of species in this region is com-plicated by the apparent extinction of Batrachoseps relictus in the vicinity of its type locality in the Lower Kern RiverCanyon. Here we analyze a comprehensive morphological dataset to evaluate diversity in the Kern River Canyon region.We conclude that populations from Breckenridge Mountain are conspecific with B. relictus, while populations from northof the Kern River previously treated as B. relictus belong to an undescribed species. The morphological data also showthe distinctiveness of populations from the Upper Kern River Canyon. Thus, we describe two new species, Batrachosepsbramei sp. nov. for populations from the Upper Kern River Canyon and Batrachoseps altasierrae sp. nov. for populationsfrom the southern Sierra Nevada previously referred to B. relictus. B. bramei sp. nov. and B. relictus are members of thenigriventris group; B. altasierrae sp. nov. belongs to the group formerly called the relictus group, which we rename thediabolicus group. We conclude by presenting allozyme and mitochondrial DNA sequence data that support the distinctiveness of these newly described species and provide a hypothesis of relationships within the nigriventris group.

Map of the late Quaternary active Kern Canyon and Breckenridge faults, southern Sierra Nevada, California

Surface traces of the Quaternary active Kern Canyon and Breckenridge faults were mapped via aerial reconnaissance, analysis of light detection and ranging (LiDAR) elevation data, review and interpretation of aerial photography, field reconnaissance, and detailed field mapping. This effort specifically targeted evidence of late Quaternary surface deformation and, combined with separate paleoseismic investigations, identified and characterized the North Kern Canyon, South Kern Canyon, and Lake Isabella sections of the Kern Canyon fault and the Breckenridge fault. The mapping presented here provides definitive evidence for previously unrecognized Holocene and late Pleistocene east-down displacement along the Kern Canyon and Breckenridge faults. Our results indicate that much of the Kern Canyon fault has undergone Quaternary reactivation to accommodate internal deformation of the otherwise rigid Sierra Nevada block. This deformation reflects ongoing, seismogenic crustal thinning in the southern Sierra Nevada, and highlights the effects of localized tectonic forces operating in this part of the Sierra Nevada.

Updated paleomagnetic pole from Cretaceous plutonic rocks of the Sierra Nevada, California: Tectonic displacement of the Sierra Nevada block

We report remanent magnetization measurements from 13 sites in Cretaceous plutonic rocks in the northern Sierra Nevada (38°N–39.5°N). By increasing the number of available paleomagnetic sites, the new data tighten constraints on the displacement history of the Sierra Nevada block and its pre-extensional position relative to interior North America. We collected samples in freshly exposed outcrops along four highway transects. The rocks include diorite, granodiorite, and tonalite with potassium-argon ages (hornblende) ranging from 100 Ma to 83 Ma. By combining our results with previous paleomagnetic determinations from the central and southern Sierra Nevada (excluding sites from the rotated southern tip east of the White Wolf–Kern Canyon fault system), we find a mean paleomagnetic pole of 70.5°N, 188.2°E, A 95 = 2.6° ( N = 26, Fisher concentration parameter, K = 118). Thermal demagnetization indicates that the characteristic remanence is generally unblocked in a narrow range within 35 °C of the Curie temperature of pure magnetite. Small apparent polar wander during the Cretaceous normal-polarity superchron, plus prolonged acquisition of remanence at the site level, may account for the low dispersion of virtual geomagnetic poles and relatively large K value. Tilt estimates based on overlapping sediments, stream gradients, and thermochronology of the Sierra Nevada plutons vary from 0° to 3° down to the southwest. Without tilt correction, the mean paleomagnetic pole for the Sierra Nevada is essentially coincident with the North American reference pole during the Cretaceous stillstand (125 Ma to 80 Ma). At 95% confidence, the apparent latitude shift is 1.1° ± 3.0° (positive northward), and the apparent rotation is negligible, 0.0° ± 4.7°. Correcting for each degree of tilt, which is limited to 3° on geologic evidence, increases the rotation anomaly 2.2° counterclockwise, while the apparent latitude shift remains unchanged.

Late Quaternary slip rate on the Kern Canyon fault at Soda Spring, Tulare County, California

The Kern Canyon fault represents a major tectonic and physiographic boundary in the southern Sierra Nevada of east-central California. Previous investigations of the Kern Canyon fault underscore its importance as a Late Cretaceous and Neogene shear zone in the tectonic development of the southern Sierra Nevada. Study of the late Quaternary history of activity, however, has been confounded by the remote nature of the Kern Canyon fault and deep along-strike exhumation within the northern Kern River drainage, driven by focused fluvial and glacial erosion. Recent acquisition of airborne lidar (light detection and ranging) topography along the ∼140 km length of the Kern Canyon fault provides a comprehensive view of the active surface trace. High-resolution, lidar-derived digital elevation models (DEMs) for the northern Kern Canyon fault enable identification of previously unrecognized offsets of late Quaternary moraines near Soda Spring (36.345°N, 118.408°W). Predominately north-striking fault scarps developed on the Soda Spring moraines display west-side-up displacement and lack a significant sense of strike-slip separation, consistent with detailed mapping and trenching along the entire Kern Canyon fault. Scarp-normal topographic profiling derived from the lidar DEMs suggests normal displacement of at least 2.8 +0.6/–0.5 m of the Tioga terminal moraine crest. Cosmogenic 10Be exposure dating of Tioga moraine boulders yields a tight age cluster centered around 18.1 ± 0.5 ka ( n = 6), indicating a minimum normal-sense fault slip rate of ∼0.1–0.2 mm/yr over this period. Taken together, these results provide the first clear documentation of late Quaternary activity on the Kern Canyon fault and highlight its role in accommodating internal deformation of the southern Sierra Nevada.

Quaternary reactivation of the Kern Canyon fault system, southern Sierra Nevada, California

The Kern Canyon fault, the longest fault in the southern Sierra Nevada, is an active structure and has been reactivated at discrete times over the past ~100 m.y. in response to changing lithospheric stresses. After initiation as a Cretaceous transpressional structure, the Kern Canyon fault transitioned into a dextral strike-slip shear zone that remained active as it was exhumed into the brittle regime during regional Late Cretaceous uplift of the Sierra Nevada batholith. The Kern Canyon fault was reactivated during Miocene regional extension as part of a transfer zone between two differentially extending domains in the southern Sierra Nevada. Subsequent normal displacement along the fault began in Pliocene time. New evidence for fault activity, which continued into late Quaternary time, includes its current geomorphic expression as a series of meters-high, west-side-up scarps that crop out discontinuously along the fault’s 130-km length. Relocated focal mechanisms of modern earthquakes confirm ongoing normal faulting, and geodetic measure ments suggest that the Sierra Nevada is uplifting relative to the adjacent valleys. This evidence for recent activity overturns a long-held view that the Kern Canyon fault has been in active for more than 3.5 m.y. Its reactivation indicates that deformation repeatedly localized along a pre existing crustal weakness, a Cretaceous shear zone. We propose that a system of inter related normal faults, including the Kern Canyon fault, is responding to mantle lithosphere removal beneath the southern Sierra Nevada region. The location of the active Kern Canyon fault within the Sierra Nevada–Great Valley microplate indicates that deformation is occurring within the microplate.

Tectonic control on southern Sierra Nevada topography, California

In this study we integrate the apatite (U‐Th)/He thermochronometric technique with geomorphic, structural, and stratigraphic studies to pursue the origin and evolution of topographic relief related to extensive late Cenozoic faulting in the southern Sierra Nevada. The geomorphology of this region reflects a transition from a vast region to the north characterized by nonequilibrium fluvial modification of a relict low‐relief landscape, little affected by internal deformation, to a more complex landscape affected by numerous faults. Regionally, the relict landscape surface is readily resolved by age‐elevation relationships of apatite He ages coupled to geomorphology. These relationships can be extended into the study area and used as a structural datum for the resolution of fault offsets and related tilting. On the basis of 63 new apatite He ages and stratigraphic data from proximal parts of the San Joaquin basin we resolve two sets of normal faults oriented approximately N–S and approximately NW. Quaternary west‐side‐up normal faulting along the N–S Breckenridge–Kern Canyon zone has resulted in a southwest step over from the Owens Valley system in the controlling structure on the regional west tilt of Sierran basement. This zone has also served as a transfer structure partitioning Neogene‐Quaternary extension resulting from normal displacements on the NW fault set. This fault system for the most part nucleated along Late Cretaceous structures with late Cenozoic remobilization representing passive extension by oblate flattening as the region rose and stretched in response to the passage of a slab window and the ensuing delamination of the mantle lithosphere from beneath the region.

Step-over in the structure controlling the regional west tilt of the Sierra Nevada microplate: eastern escarpment system to Kern Canyon system

The Sierra Nevada and Great Valley are coupled, and behave as a semi-rigid microplate. The microplate formed as it was calved off the western edge of the Nevadaplano in the late Miocene, at which time westward regional tilting began. Tilting is controlled by west-side-up normal faulting primarily along the eastern Sierra escarpment system. Uplift and exhumation along the eastern Sierra are balanced by subsidence and sedimentation along the western Great Valley. The west tilt of the microplate is expressed by the west slope of a regional relict landscape surface that developed across much of the Sierra Nevada basement, and by the westward continuation of the surface as the basal Eocene nonconformity of the west-dipping Great Valley Tertiary section. The rigid behaviour of the microplate breaks down along its southern ∼100–150 km segment as expressed by seismicity, pervasive faulting and the development of a deep marine basin, the San Joaquin Basin (SJB), whose facies and palaeogeographic patterns diverge from regional patterns of the rest of the Great Valley. The disrupted state of the southern segment of the microplate resulted from its Late Cretaceous position above a regional lateral ramp in the underlying Franciscan-related subduction megathrust. The Kern Canyon fault system began its polyphase history as a complex oblique dextral shear zone above the megathrust lateral ramp. It was remobilized in the Neogene as an oblique transfer structure partitioning differential extension between the southern Sierra Nevada and the SJB. In Quaternary time, the Kern Canyon zone was again remobilized as a west-side-up normal fault system whose geomorphic and structural expressions are best developed south of ∼36.4° N. This normal fault system controls the west tilt of the relict landscape surface in the southern Sierra region, as well as the west dip pattern in the strata of the adjacent SJB. To the east of the Kern Canyon normal fault system, the relict landscape surface slopes continuously southwards from the high eastern Sierra into a low-lying, multiply extended terrane. Thus, from ∼36.4° N southwards, the west tilt along the western Sierra and the west dip of the adjacent Great Valley strata are controlled by the Kern Canyon system. Fresh normal scarps along the eastern Sierra escarpment system become more subdued and ultimately die out southwards from ∼36.4° N. Thus, currently, the controlling structure for the west tilt of the microplate steps westwards in the south from the eastern escarpment system over to the Kern Canyon system.

Petrology of the Mount Whitney Intrusive Suite, eastern Sierra Nevada, California: Implications for the emplacement and differentiation of composite felsic intrusions

The Mount Whitney Intrusive Suite is a nested intrusion composed of three granitic plutons that were emplaced along the eastern margin of the Sierra Nevada batholith between 88 and 83 Ma. Geologic relations indicate the suite was formed by magmas that spread laterally at a depth of ~10 km after initially rising along fractures developed at an extensional stepover between the proto–Kern Canyon fault and the Sierra Crest shear zone. Cenozoic uplift and erosion have exposed the interior of the suite, making it possible to study textural and compositional variations within the body that yield insights into the complementary roles of source variability and crystal fractionation in producing zoned intrusions. Although isotopic data indicate that contributions to the Mount Whitney Intrusive Suite from preexisting crustal rocks increased over time, major differences in the compositional and textural zoning of its members also refl ect gradual warming of the upper crust. The oldest pluton is isotopically and compositionally diverse, and consists of distinct phases that apparently underwent limited mixing and fractionation following their emplacement into cool host rocks. Conversely, the younger members are more isotopically uniform, and the youngest displays regular pluton-scale variations in composition and texture consistent with individual inputs having mixed, fractionated, and undergone textural coarsening as it cooled slowly within the older members or wall rocks warmed by them. A thermal model of the suite indicates that the intervals during which successive magma inputs were likely to hybridize and undergo subsequent in situ differentiation increased as the intrusion grew. For recharge at an interval intermediate between those required for 50% crystallization in different parts of the suite, model results suggest that the outer part would have developed as a composite body in which individual phases underwent limited differentiation, whereas the inner part would have developed as a more homogeneous body capable of large-scale differentiation. These predictions match trends among the suite’s members and suggest that warming of the upper crust may account for much of its textural and compositional diversity. Local differentiation also occurred in the upper parts of the younger members, where rhyolitic melts were segregated as a result of solidifi cation front instability.

Phylogenetic relationships of seven previously unclassified viruses within the family Rhabdoviridae using partial nucleoprotein gene sequences

Partial nucleoprotein (N) gene sequences of the rhabdoviruses Obodhiang (OBOV), Kotonkon (KOTV), Rochambeau (RBUV), Kern canyon (KCV), Mount Elgon bat (MEBV), Kolongo (KOLV) and Sandjimba (SJAV) were generated and their phylogenetic positions within the family Rhabdoviridae were determined. Both OBOV and KOTV were placed within the genus Ephemerovirus. RBUV was joined to the same cluster, but more distantly. MEBV and KCV were grouped into a monophyletic cluster (putative genus) with Oita virus (OITAV). These three viruses, originating from different regions of the world, were all isolated from insectivorous bats and may be specific for these mammals. African avian viruses KOLV and SJAV were joined to each other and formed another clade at the genus level. Further, they were grouped with the recently characterized rhabdovirus Tupaia virus (TRV). Although the genetic distance was great, the grouping was supported by consistent bootstrap values. This observation suggests that viruses of this group may be distributed widely in the Old World. Non-synonymous/synonymous substitution ratio estimations (dN/dS) using a partial N gene fragment (241 codons) for the three rhabdovirus genera revealed contrasting patterns of evolution, where dN/dS values follow the pattern Ephemerovirus > Vesiculovirus > Lyssavirus. The magnitude of this ratio corresponds well with the number of negatively selected codons. The accumulation of dS appears evenly distributed along the gene fragment for all three genera. These estimations demonstrated clearly that lyssaviruses are subjected to the strongest constraints against amino acid substitutions, probably related to their particular niche and unique pathobiology.

New Taxa and Nomenclatural Changes in Allophyllum, Gilia, and Navarretia (Polemoniaceae)

Studies of certain species problems in Allophyllum, Gilia, and Navarretia resulted in the following nomenclatural changes: Gilia subg. Kelloggia is reduced to sectional status, two new species and one new subspecies are described (Gilia lottiae, Navarretia myersii, N. hamata subsp. parviloba), two subspecies are elevated to species (Navarretia jaredii, N. rosulata), one variety is elevated to subspecies (N. nigelliformis subsp. radians), and eight new combinations are proposed (Allophyllum gilioides subsp. violaceum, Gilia brecciarum subsp. jacens, G. sinistra subsp. pinnatisecta, Navarretia leucocephala subsp. bakeri, N. leucocephala subsp. minima, N. leucocephala subsp. paucifora, N. leucocephala subsp. plieantha, and N. intertexta subsp. propinqua). These changes are included in treatments of the same genera contributed by the author to the Jepson Manual: Higher Plants of California (Hickman, 1993). This report is presented in order to validate nomenclatural changes found necessary during preparation of treatments of Allophyllum, Gilia, and Navarretia for the Jepson Manual: Higher Plants of California (Hickman, 1993). A more detailed account of studies that led to some of the decisions will be forthcoming elsewhere. ALLOPHYLLUM (NUTTALL) V. GRANT Allophyllum is a small genus occurring in the mountains of the western United States. All species are annual, the stems leafy, corollas short-or longtubed, and blue, purple, pink, or white. Although segregated from Gilia by Grant & Grant (1955), it was maintained as a section of Gilia by Cronquist (1984). Characters distinguishing Allophyllum from Gilia are its nonscapose habit, leafier stems, and distinctive trichome type (fine-stalked, gland-tipped), seeds generally boat-shaped, and leaf-lobes thickened at the tip, not fine-pointed as in Gilia. Allophyllum violaceum (Heller) A. & V. Grant and A. gilioides (Bentham) A. & V. Grant are closely related species, with the former occurring generally at higher elevations. Typical A. violaceum occurs from 2,000 to 2,900 m in the high Sierra Nevada of California and in the mountains of western Nevada. The plants are small (generally 6-12 cm tall), have few-lobed leaves, and 2-3 flowers per cluster. Allophyllum gilioides occurs at lower elevations, mostly below 2,000 m; the plants are larger (14-60 cm tall), with larger, many-lobed leaves, and a glomerate inflorescence, 4-8 flowers per cluster. The two taxa intergrade in some areas at middle elevations (1,200-1,800 m) where their ranges overlap, as in Kern Canyon in the southern Sierra Nevada. Since a clear distinction between them is not possible throughout, I propose the following new combination. Allophyllum gilioides (Bentham) A. & V. Grant subsp. violaceum (Heller) Day, comb. et stat. nov. Basionym: Gilia violacea Heller, Muhl. 1: 56. 1904. Allophyllum violaceum (Heller) A. & V. Grant, Aliso 3: 106. 1955. Gilia gilioides Bentham var. violacea (Heller) Cronq., Intermountain Flora 4: 132. 1984. TYPE: U.S.A. California: Nevada Co., lower end of Donner Lake, Heller 6873 (holotype, DS; isotypes, NY, UC).

Isolation of Fukuoka virus, a member of the Kern Canvon serogroup viruses of the family Rhabdoviridae, from cattle

Four virus strains with identical antigenic properties were isolated from blood samples of 4 sentinel calves having a fever and leukopenea in cultures of HmLu-1 cells derived from baby hamster lung. The virus was identified as Fukuoka virus, classified as a member of the Kern Canyon serogroup viruses of the family Rhabdoviridae, on the basis of its antigenic properties.

Intra-arc strike-slip fault exposed at batholithic levels in the southern Sierra Nevada, California

The Kern Canyon fault is a major north-trending fault that is continuous for a distance of 140 km in the southern Sierra Nevada, California. Previous geologic mapping and geochronological work along the northern third of the fault indicate that dextral offset occurred sometime after 80 Ma and before 3.5 Ma; this offset was interpreted to be the result of Cenozoic basin-and-range extension. Our new results from the central third of the fault (Kernville-Lake Isabella region) indicate an earlier right-lateral movement history, contemporaneous with emplacement of the largest plutons in the Sierra Nevada. The older structure is termed the proto-Kern Canyon fault zone. The Cenozoic fault trace is a narrow zone of brittle deformation, whereas the Cretaceous fault zone is a broad zone of ductile deformation. U-Pb zircon geochronology on plutonic and metavolcanic rocks involved in the ductile deformation, as well as a pluton that postdates ductile deformation, demonstrate that the proto-Kern Canyon fault zone was active at 85 Ma, and may have begun to move as early as 105 Ma. Longitudinal strike-slip faults are common in modern magmatic arcs where convergence is oblique. The proto-Kern Canyon fault zone may have originated in response to a moderate northward component in subduction of the Farallon plate or perhaps a strong northward component for the Kula plate.

Growth of California encephalitis and other viruses in Aedes dorsalis (Diptera: Culicidae) cell cultures.

Aedes dorsalis cells were evaluated for their susceptibility to California encephalitis (CE) virus, a bunyavirus, and 13 other viruses (6 bunyaviruses, 5 togaviruses, 2 rhabdoviruses). Those viruses naturally vectored by mosquitoes (CE, Jamestown Canyon, Trivittatus, Turlock, Hart Park, Western equine encephalomyelitis and St. Louis encephalitis) and by Culicoides (Lokern, Main Drain and Buttonwillow) grew well in Ae. dorsalis cells. A tick-borne virus (Powassan) and 2 nonarthropod-borne viruses (Modoc and Rio Bravo) failed to replicate. The 2 rhabdoviruses Kern Canyon and Harl Park, grew in the Ae. dorsalis cultures, but multiplication occurred only after a 3-day latent period. Kern Canyon virus (insect vector, if any, unknown) has not been previously reported to replicate in mosquito cells. None of the viruses that grew in the mosquito cells produced overt cytopathic effects. Two subpopulations of Ae. dorsalis cells were more susceptible than parental cells to CE Virus by infectivity and immunofluorescent-antibody assays.

Comment and reply on ‘Mapped offset on the right-lateral Kern Canyon fault, southern Sierra Nevada, California’

Research Article| March 01, 1979 Comment and reply on ‘Mapped offset on the right-lateral Kern Canyon fault, southern Sierra Nevada, California’: COMMENT Gerald J. Lensen Gerald J. Lensen 1Earth Deformation Studies, New Zealand Geological Survey, P.O. Box 30368, Lower Hutt, New Zealand Search for other works by this author on: GSW Google Scholar Geology (1979) 7 (3): 118–119. https://doi.org/10.1130/0091-7613(1979)7<118b:CAROMO>2.0.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Gerald J. Lensen; Comment and reply on ‘Mapped offset on the right-lateral Kern Canyon fault, southern Sierra Nevada, California’: COMMENT. Geology 1979;; 7 (3): 118–119. doi: https://doi.org/10.1130/0091-7613(1979)7<118b:CAROMO>2.0.CO;2 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 SocietyGeology Search Advanced Search Abstract No Abstract Available. 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.

Comment and reply on ‘Mapped offset on the right-lateral Kern Canyon fault, southern Sierra Nevada, California’

Comment and reply on ‘Mapped offset on the right-lateral Kern Canyon fault, southern Sierra Nevada, California’

Mapped offset on the right-lateral Kern Canyon fault, southern Sierra Nevada, California

The north-trending Kern Canyon fault, the longest fault within the southern Sierra Nevada, has been mapped from lat 36°00′N to its northern end near lat 36°40′N. The fault cuts and offsets granitic plutons as young as 80 m.y., but despite the fact that many recent earthquake foci plot close to the fault, it does not appear to offset an overlying 3.5-m.y.-old basalt flow. Seven granitic plutons are clearly offset by the fault in a right-lateral sense. In the area mapped, offset of plutonic contacts is 6.5 to 13 km and increases southward by 0.2 km/km.

Thermal inactivation of rabies and other rhabdoviruses: stabilization by the chelating agent ethylenediaminetetraacetic acid at physiological temperatures

Thermal inactivation of rabies and several other rhabdoviruses was studied using virus suspended in several different diluents. Rabies serogroup viruses were more stable than Kern Canyon or vesicular stomatitis viruses. Limited studies of two fish rhabdoviruses requiring low temperatures (less than 33 C) for replication indicated that they were not markedly more thermolabile than rabies virus. Bovine serum protein components in complex cell culture media stabilized virus at 56 C, but at temperatures of less than or equal to 37 C, sodium tris (hydroxymethyl)-aminomethane (NT) buffer containing ethylenediaminetetraacetic acid (EDTA) (NTE) was a much more efficient stabilizer of virus infectivity. Chelating agents EDTA and ethyleneglycol-bis-(beta-aminoethyl ether)tetraacetic acid were equally efficient in protection of rabies virus infectivity; the effect of each was lost when excess Ca2+ was added. Bovine serum in NT or NTE buffers produced a thermostabilizing effect at 37 C not provided by the same serum concentration in complex cell culture media. Bovine serum was more efficient than EDTA in stabilizing virus infectivity during repeated cycles of freezing and thawing.