- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
- Abstract
- Affiliation
- All
- Authors
- Book Series
- DOI
- EISBN
- EISSN
- Full Text
- GeoRef ID
- ISBN
- ISSN
- Issue
- Keyword (GeoRef Descriptor)
- Meeting Information
- Report #
- Title
- Volume
NARROW
GeoRef Subject
-
all geography including DSDP/ODP Sites and Legs
-
Canada
-
Western Canada
-
British Columbia
-
Vancouver Island (1)
-
-
-
-
Cascadia subduction zone (1)
-
Coast Ranges (1)
-
North America
-
Peninsular Ranges Batholith (1)
-
-
Oceania
-
Melanesia
-
Vanuatu (1)
-
-
-
Pacific Ocean
-
East Pacific
-
Northeast Pacific
-
Monterey Canyon (2)
-
Monterey Fan (1)
-
Santa Monica Basin (1)
-
-
-
North Pacific
-
Northeast Pacific
-
Monterey Canyon (2)
-
Monterey Fan (1)
-
Santa Monica Basin (1)
-
-
Northwest Pacific
-
Emperor Seamounts (1)
-
-
-
West Pacific
-
Northwest Pacific
-
Emperor Seamounts (1)
-
-
-
-
Queen Charlotte Fault (4)
-
San Andreas Fault (1)
-
San Francisco Peninsula (1)
-
San Juan Islands (1)
-
San Pedro Basin (1)
-
Santa Barbara Basin (1)
-
Santa Lucia Range (1)
-
Santa Maria Basin (1)
-
United States
-
Alaska
-
Aleutian Islands
-
Adak Island (2)
-
-
-
California
-
Central California (2)
-
Channel Islands (1)
-
Hosgri Fault (2)
-
Los Angeles County California
-
Palos Verdes Peninsula (1)
-
-
Marin County California
-
Point Reyes (1)
-
-
Monterey Bay (3)
-
Monterey County California (1)
-
Salinian Block (1)
-
San Francisco Bay region (1)
-
San Gregorio Fault (2)
-
San Luis Obispo County California
-
San Luis Obispo California (1)
-
-
Santa Barbara Channel (1)
-
Santa Barbara County California
-
Point Sal (1)
-
-
Sierra Nevada Batholith (1)
-
Southern California (3)
-
Transverse Ranges (1)
-
Ventura Basin (1)
-
Ventura County California
-
Ventura California (1)
-
-
-
Mojave Desert (1)
-
Washington
-
San Juan County Washington (1)
-
-
-
-
elements, isotopes
-
carbon
-
C-13/C-12 (1)
-
-
isotope ratios (2)
-
isotopes
-
radioactive isotopes
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
stable isotopes
-
C-13/C-12 (1)
-
Nd-144/Nd-143 (1)
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
Sr-87/Sr-86 (1)
-
-
-
metals
-
alkaline earth metals
-
strontium
-
Sr-87/Sr-86 (1)
-
-
-
lead
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
rare earths
-
neodymium
-
Nd-144/Nd-143 (1)
-
-
-
-
-
fossils
-
Chordata
-
Vertebrata (1)
-
-
Invertebrata
-
Cnidaria
-
Anthozoa (1)
-
-
-
Plantae
-
Pteridophyta (1)
-
-
-
geochronology methods
-
Ar/Ar (1)
-
optically stimulated luminescence (1)
-
-
geologic age
-
Cenozoic
-
Quaternary
-
Holocene (1)
-
Pleistocene
-
upper Pleistocene
-
Weichselian
-
upper Weichselian
-
Younger Dryas (1)
-
-
-
-
-
upper Quaternary (1)
-
-
Tertiary
-
Neogene
-
Miocene (1)
-
-
Paleogene
-
Eocene (2)
-
-
-
-
Mesozoic
-
Cretaceous (1)
-
Franciscan Complex (1)
-
-
-
igneous rocks
-
igneous rocks
-
plutonic rocks
-
granodiorites (1)
-
-
volcanic rocks
-
basalts
-
alkali basalts
-
hawaiite (1)
-
mugearite (1)
-
-
-
glasses
-
volcanic glass (1)
-
-
-
-
-
minerals
-
carbonates (1)
-
-
Primary terms
-
absolute age (1)
-
Canada
-
Western Canada
-
British Columbia
-
Vancouver Island (1)
-
-
-
-
carbon
-
C-13/C-12 (1)
-
-
Cenozoic
-
Quaternary
-
Holocene (1)
-
Pleistocene
-
upper Pleistocene
-
Weichselian
-
upper Weichselian
-
Younger Dryas (1)
-
-
-
-
-
upper Quaternary (1)
-
-
Tertiary
-
Neogene
-
Miocene (1)
-
-
Paleogene
-
Eocene (2)
-
-
-
-
Chordata
-
Vertebrata (1)
-
-
continental shelf (5)
-
continental slope (1)
-
crust (1)
-
data processing (1)
-
deformation (2)
-
earthquakes (3)
-
engineering geology (1)
-
faults (9)
-
geochemistry (1)
-
geodesy (1)
-
geophysical methods (11)
-
igneous rocks
-
plutonic rocks
-
granodiorites (1)
-
-
volcanic rocks
-
basalts
-
alkali basalts
-
hawaiite (1)
-
mugearite (1)
-
-
-
glasses
-
volcanic glass (1)
-
-
-
-
inclusions (1)
-
Invertebrata
-
Cnidaria
-
Anthozoa (1)
-
-
-
isotopes
-
radioactive isotopes
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
stable isotopes
-
C-13/C-12 (1)
-
Nd-144/Nd-143 (1)
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
Sr-87/Sr-86 (1)
-
-
-
lava (1)
-
magmas (1)
-
mantle (1)
-
marine geology (1)
-
Mesozoic
-
Cretaceous (1)
-
Franciscan Complex (1)
-
-
metals
-
alkaline earth metals
-
strontium
-
Sr-87/Sr-86 (1)
-
-
-
lead
-
Pb-206/Pb-204 (1)
-
Pb-207/Pb-204 (1)
-
Pb-208/Pb-204 (1)
-
-
rare earths
-
neodymium
-
Nd-144/Nd-143 (1)
-
-
-
-
mud volcanoes (1)
-
North America
-
Peninsular Ranges Batholith (1)
-
-
ocean floors (5)
-
Oceania
-
Melanesia
-
Vanuatu (1)
-
-
-
oceanography (2)
-
Pacific Ocean
-
East Pacific
-
Northeast Pacific
-
Monterey Canyon (2)
-
Monterey Fan (1)
-
Santa Monica Basin (1)
-
-
-
North Pacific
-
Northeast Pacific
-
Monterey Canyon (2)
-
Monterey Fan (1)
-
Santa Monica Basin (1)
-
-
Northwest Pacific
-
Emperor Seamounts (1)
-
-
-
West Pacific
-
Northwest Pacific
-
Emperor Seamounts (1)
-
-
-
-
paleobotany (1)
-
paleoclimatology (1)
-
paleoecology (1)
-
paleontology (1)
-
Plantae
-
Pteridophyta (1)
-
-
plate tectonics (3)
-
reefs (1)
-
sea-level changes (2)
-
sedimentary rocks (1)
-
sedimentation (3)
-
sediments
-
clastic sediments
-
sand (1)
-
-
marine sediments (2)
-
-
shorelines (1)
-
slope stability (4)
-
soil mechanics (1)
-
stratigraphy (2)
-
tectonics
-
neotectonics (1)
-
-
tectonophysics (1)
-
United States
-
Alaska
-
Aleutian Islands
-
Adak Island (2)
-
-
-
California
-
Central California (2)
-
Channel Islands (1)
-
Hosgri Fault (2)
-
Los Angeles County California
-
Palos Verdes Peninsula (1)
-
-
Marin County California
-
Point Reyes (1)
-
-
Monterey Bay (3)
-
Monterey County California (1)
-
Salinian Block (1)
-
San Francisco Bay region (1)
-
San Gregorio Fault (2)
-
San Luis Obispo County California
-
San Luis Obispo California (1)
-
-
Santa Barbara Channel (1)
-
Santa Barbara County California
-
Point Sal (1)
-
-
Sierra Nevada Batholith (1)
-
Southern California (3)
-
Transverse Ranges (1)
-
Ventura Basin (1)
-
Ventura County California
-
Ventura California (1)
-
-
-
Mojave Desert (1)
-
Washington
-
San Juan County Washington (1)
-
-
-
-
rock formations
-
Toro Formation (1)
-
-
sedimentary rocks
-
sedimentary rocks (1)
-
-
sedimentary structures
-
channels (1)
-
-
sediments
-
sediments
-
clastic sediments
-
sand (1)
-
-
marine sediments (2)
-
-
High-resolution geophysical and geochronological analysis of a relict shoreface deposit offshore central California: Implications for slip rate along the Hosgri fault
Abstract The San Juan–southern Gulf Islands Archipelago of Washington State, USA and western Canada is located on the upper plate of the Cascadia subduction zone, in the forearc between the trench and volcanic arc. Onland and island investigations show many faults within the region that primarily represent old, inactive faults associated with transport, subduction and accretion of tectonostratigraphic terranes. However, until recently little geologic investigation and mapping have been done in the offshore. From these narrow straits, channels and sounds we have collected and interpreted high-resolution multibeam echosounder bathymetric data, 3.5 kHz sub-bottom and Huntec seismic-reflection profiles, and piston-cores to identify and date recently active faults. Previous studies by us focused on the earlier recognized active Devils Mountain fault zone that bounds the southern part of the Archipelago and the recently reported newly mapped active Skipjack Island fault zone that bounds the northern part. These transcurrent fault zones appear to be deforming and rotating the Archipelago. We concentrate on the unique deformation occurring within the seaways to determine the relationship and styles of faulting associated with these active bounding fault zones and relate the fault geometry and kinematics to one other subduction complex, the New Hebrides island arc of Vanuatu.
Late Quaternary sea level, isostatic response, and sediment dispersal along the Queen Charlotte fault
Focused fluid flow and methane venting along the Queen Charlotte fault, offshore Alaska (USA) and British Columbia (Canada)
Slope failure and mass transport processes along the Queen Charlotte Fault, southeastern Alaska
Abstract The Queen Charlotte Fault defines the Pacific–North America transform plate boundary in western Canada and southeastern Alaska for c. 900 km. The entire length of the fault is submerged along a continental margin dominated by Quaternary glacial processes, yet the geomorphology along the margin has never been systematically examined due to the absence of high-resolution seafloor mapping data. Hence the geological processes that influence the distribution, character and timing of mass transport events and their associated hazards remain poorly understood. Here we develop a classification of the first-order shape of the continental shelf, slope and rise to examine potential relationships between form and process dominance. We found that the margin can be split into six geomorphic groups that vary smoothly from north to south between two basic end-members. The northernmost group (west of Chichagof Island, Alaska) is characterized by concave-upwards slope profiles, gentle slope gradients (<6°) and relatively low along-strike variance, all features characteristic of sediment-dominated siliciclastic margins. Dendritic submarine canyon/channel networks and retrogressive failure complexes along relatively gentle slope gradients are observed throughout the region, suggesting that high rates of Quaternary sediment delivery and accumulation played a fundamental part in mass transport processes. Individual failures range in area from 0.02 to 70 km 2 and display scarp heights between 10 and 250 m. Transpression along the Queen Charlotte Fault increases southwards and the slope physiography is thus progressively more influenced by regional-scale tectonic deformation. The southernmost group (west of Haida Gwaii, British Columbia) defines the tectonically dominated end-member: the continental slope is characterized by steep gradients (>20°) along the flanks of broad, margin-parallel ridges and valleys. Mass transport features in the tectonically dominated areas are mostly observed along steep escarpments and the larger slides (up to 10 km 2 ) appear to be failures of consolidated material along the flanks of tectonic features. Overall, these observations highlight the role of first-order margin physiography on the distribution and type of submarine landslides expected to occur in particular morphological settings. The sediment-dominated end-member allows for the accumulation of under-consolidated Quaternary sediments and shows larger, more frequent slides; the rugged physiography of the tectonically dominated end-member leads to sediment bypass and the collapse of uplifted tectonic features. The maximum and average dimensions of slides are an order of magnitude smaller than those of slides observed along other (passive) glaciated margins. We propose that the general patterns observed in slide distribution are caused by the interplay between tectonic activity (long- and short-term) and sediment delivery. The recurrence (<100 years) of M > 7 earthquakes along the Queen Charlotte Fault may generate small, but frequent, failures of under-consolidated Quaternary sediments within the sediment-dominated regions. By contrast, the tectonically dominated regions are characterized by the bypass of Quaternary sediments to the continental rise and the less frequent collapse of steep, uplifted and consolidated sediments.
Slope failure and mass transport processes along the Queen Charlotte Fault Zone, western British Columbia
Abstract Multibeam echosounder (MBES) images, 3.5 kHz seismic-reflection profiles and piston cores obtained along the southern Queen Charlotte Fault Zone are used to map and date mass-wasting events at this transform margin – a seismically active boundary that separates the Pacific Plate from the North American Plate. Whereas the upper continental slope adjacent to and east (upslope) of the fault zone offshore of the Haida Gwaii is heavily gullied, few large-sized submarine landslides in this area are observed in the MBES images. However, smaller submarine seafloor slides exist locally in areas where fluid flow appears to be occurring and large seafloor slides have recently been detected at the base of the steep continental slope just above its contact with the abyssal plain on the Queen Charlotte Terrace. In addition, along the subtle slope re-entrant area offshore of the Dixon Entrance shelf bathymetric data suggest that extensive mass wasting has occurred in the vicinity of an active mud volcano venting gas. We surmise that the relative lack of submarine slides along the upper slope in close proximity to the Queen Charlotte Fault Zone may be the result of seismic strengthening (compaction and cohesion) of a sediment-starved shelf and slope through multiple seismic events.
Abstract A compilation of offshore and island geologic, marine acoustic, and seafloor sampling data for the Channel Islands National Park was used to construct geologic and potential marine benthic habitat maps of selected areas around various Channel Islands. For this investigation, we focused on three offshore areas around Santa Rosa Island (the north-central area west of Carrington Point, an area off and west of East Point, and an area off and west of South Point), and most of the shelf area around Santa Barbara Island. The maps represent the most detailed offshore mapping in the region to date, and they provide insights into the geology and potential benthic habitats in the area that can be used to manage marine biological and other resources. The geology of the offshore areas is essentially an extension of the Tertiary geologic formations that have been mapped on the islands, but locally covered by deposits of Quaternary marine sediments. Structures in the north-central part of Santa Rosa Island and in the northeastern part of Santa Barbara Island appear to represent the most active regional tectonic processes, while the areas in the southern parts of Santa Barbara Island appear more passive, with few well-defined faults. The first potential marine benthic habitat maps for the Channel Islands National Park are presented here, and they illustrate that diverse and favorable habitats exist. For example, the extensive areas of rugose, differentially eroded bedrock outcrops on the midshelf seafloor of the islands provide good habitats for demersal rockfish ( Sebastes spp.), and rock outcrops in the nearshore areas provide hold-fasts for kelp, which can provide habitat for larval and young-of-the-year rockfish. Although true habitat is not well known in the areas studied, the potential habitat maps provide an effective management tool that can be used to protect and conserve the most promising probable habitats.
Geometry and Late Pleistocene Displacement of the Shoreline and Oceano Fault Zones, San Luis Obispo Bay, California
High-resolution sonar data are necessary to map bottom substrate for habitat studies but are lacking over much of the continental shelf. With such data, areas covered by sediment can be distinguished from bedrock areas with an accuracy of ~90%. Without these data, the extent of sediment as thick as 10 m cannot be resolved, and estimates of the extent of rocky seafloor are exaggerated. A study area north of Anacapa Island in Southern California interpreted as a large rocky area after mapping with low-resolution seismic systems was found to have exposed rocky bottom in only 10% of the area when mapped with high-resolution, side-scan sonar. The area of rock was estimated using video-supervised, sonar-image classification of textural derivatives of the data calculated from gray-level co-occurrence matrices. The classification of soft bottom was found to be ~90% accurate using an independent data set, derived from seafloor sampling records. Two general types of rock exposure are observed—sparse linear outcrops of layered sedimentary rocks and more massive, rounded outcrop areas of volcanic rocks. The percentage of exposed rock in volcanic areas exceeded that in sedimentary rock areas by a factor of 5 in the study area north of Anacapa Island. South of Point Arguello, 80% of the shelf seafloor is underlain by sedimentary rock units. The percentage of area that is exposed, rocky-reef habitat may be greater in other areas of coastal seafloor if the bedrock is predominantly volcanic.
Conventional bathymetry, sidescan-sonar and seismic-reflection data, and recent, multibeam surveys of large parts of the Southern California Borderland disclose the presence of numerous submarine landslides. Most of these features are fairly small, with lateral dimensions less than ~2 km. In areas where multibeam surveys are available, only two large landslide complexes were identified on the mainland slope— Goleta slide in Santa Barbara Channel and Palos Verdes debris avalanche on the San Pedro Escarpment south of Palos Verdes Peninsula. Both of these complexes indicate repeated recurrences of catastrophic slope failure. Recurrence intervals are not well constrained but appear to be in the range of 7500 years for the Goleta slide. The most recent major activity of the Palos Verdes debris avalanche occurred roughly 7500 years ago. A small failure deposit in Santa Barbara Channel, the Gaviota mudflow, was perhaps caused by an 1812 earthquake. Most landslides in this region are probably triggered by earthquakes, although the larger failures were likely conditioned by other factors, such as oversteepening, development of shelf-edge deltas, and high fluid pressures. If a subsequent future landslide were to occur in the area of these large landslide complexes, a tsunami would probably result. Runup distances of 10 m over a 30-km-long stretch of the Santa Barbara coastline are predicted for a recurrence of the Goleta slide, and a runup of 3 m over a comparable stretch of the Los Angeles coastline is modeled for the Palos Verdes debris avalanche.
Trail of sand in upper Monterey Canyon: Offshore California
Neotectonics of the Offshore Oak Ridge Fault near Ventura, Southern California
Reinterpretation of onshore and offshore geologic mapping, examination of a key offshore well core, and revision of cross-fault ties indicate Neogene dextral strike slip of 156 ± 4 km along the San Gregorio–Hosgri fault zone, a major strand of the San Andreas transform system in coastal California. Delineating the full course of the fault, defining net slip across it, and showing its relationship to other major tectonic features of central California helps clarify the evolution of the San Andreas system. San Gregorio–Hosgri slip rates over time are not well constrained, but were greater than at present during early phases of strike slip following fault initiation in late Miocene time. Strike slip took place southward along the California coast from the western fl ank of the San Francisco Peninsula to the Hosgri fault in the offshore Santa Maria basin without significant reduction by transfer of strike slip into the central California Coast Ranges. Onshore coastal segments of the San Gregorio–Hosgri fault include the Seal Cove and San Gregorio faults on the San Francisco Peninsula, and the Sur and San Simeon fault zones along the flank of the Santa Lucia Range. Key cross-fault ties include porphyritic granodiorite and overlying Eocene strata exposed at Point Reyes and at Point Lobos, the Nacimiento fault contact between Salinian basement rocks and the Franciscan Complex offshore within the outer Santa Cruz basin and near Esalen on the flank of the Santa Lucia Range, Upper Cretaceous (Campanian) turbidites of the Pigeon Point Formation on the San Francisco Peninsula and the Atascadero Formation in the southern Santa Lucia Range, assemblages of Franciscan rocks exposed at Point Sur and at Point San Luis, and a lithic assemblage of Mesozoic rocks and their Tertiary cover exposed near Point San Simeon and at Point Sal, as restored for intrabasinal deformation within the onshore Santa Maria basin. Slivering of the Salinian block by San Gregorio–Hosgri displacements elongated its northern end and offset its western margin delineated by the older Nacimiento fault, a sinistral strike-slip fault of latest Cretaceous to Paleocene age. North of its juncture with the San Andreas fault, dextral slip along the San Gregorio–Hosgri fault augments net San Andreas displacement. Alternate restorations of the Gualala block imply that nearly half the net San Gregorio–Hosgri slip was accommodated along the offshore Gualala fault strand lying west of the Gualala block, which is bounded on the east by the current master trace of the San Andreas fault. With San Andreas and San Gregorio–Hosgri slip restored, there remains an unresolved proto–San Andreas mismatch of ∼100 km between the offset northern end of the Salinian block and the southern end of the Sierran-Tehachapi block. On the south, San Gregorio–Hosgri strike slip is transposed into crustal shortening associated with vertical-axis tectonic rotation of fault-bounded crustal panels that form the western Transverse Ranges, and with kinematically linked deformation within the adjacent Santa Maria basin. The San Gregorio–Hosgri fault serves as the principal link between transrotation in the western Transverse Ranges and strike slip within the San Andreas transform system of central California.
Contents
Back Matter
Seamounts at the continental margin of California: A different kind of oceanic intraplate volcanism
Widespread fluid expulsion on a translational continental margin: Mud volcanoes, fault zones, headless canyons, and organic-rich substrate in Monterey Bay, California
Fluid Flow in the Offshore Monterey Bay Region
ABSTRACT Fluid flow out of the seafloor offshore Monterey Bay region is extensive. To date 16 major active and ancient, or dormant, seep sites have been identified and many of these sites are composed of smaller sites too numerous to map at a regional scale. These seeps have been identified by the presence of chemosynthetic communities that are primarily composed of chemoautotrophic organisms or by carbonate deposition and buildups. Of the 17 identified sites, 9 active cold seep sites support living chemosynthethic communities. Seven major dormant seep sites have been identified based upon the presence of carbonate deposits or buildups. Identified seep sites are primarily concentrated along fault trends associated with the boundary of the Salinian block or Palo Colorado-San Gregorio fault zone, and along the lower flanks and crests of tectonically uplifting slopes. A combination of transpressional squeezing and overburden pressures, vertical advection through hydrocarbon and organic-rich sediment, and seaward flow of meteoric waters supply fluids to the seep sites.