The Serrated Points of Central California

1940 ◽  
Vol 6 (2) ◽  
pp. 167-170 ◽  
Author(s):  
Ernest N. Johnson
Keyword(s):  
British Columbia ◽  
Sea Level ◽  
Pacific Coast ◽  
Great Part ◽  
Flood Plain ◽  
Central California ◽  
Chipped Stone ◽  
The Pacific ◽  
Plain Region ◽  
Coast Region

Serrated edges, and wonderful chipping techniques, are commonly displayed on chipped stone objects of the Pacific Coast region from California to British Columbia, but the greatest ultimate perfection of serration obtains in the so-called Stockton type points, peculiar to the delta and flood plain region near the confluence of the Sacramento and San Joaquin rivers. The distribution of these specialized forms seems to approximately conform with this great flood plain, which is, generally speaking, not much above sea-level. This area was called by the early Spaniards the “Tulares,” because a great part of it was an impenetrable swamp, covered by a rank growth of tule reeds.

Late Pleistocene stratigraphy of south-central British Columbia

1978 ◽  
Vol 15 (6) ◽  
pp. 971-980 ◽  
Author(s):  
Robert J. Fulton ◽  
Geoffrey W. Smith
Keyword(s):  
British Columbia ◽  
North America ◽  
Great Lakes ◽  
Late Pleistocene ◽  
Pacific Coast ◽  
Coastal Regions ◽  
South Central ◽  
The Pacific ◽  
Valley Area ◽  
Coast Region

The late Pleistocene deposits of south-central British Columbia record two major glacial and two major nonglacial periods of deposition. The oldest recognized Pleistocene deposits, called Westwold Sediments, were deposited during a nonglacial interval more than 60 000 years ago. Little information is available on the climate of this period, but permafrost may have been present at one time during final stages of deposition of Westwold Sediments. The latter part of this nonglacial period is probably correlative with the early Wisconsin Substage of the Great Lakes – St. Lawrence Valley area. However, deposition of the Westwold Sediments may have begun during the Sangamon Interglacial.Okanagan Centre Drift is the name applied to sediments deposited during the glaciation that followed deposition of Westwold Sediments. Okanagan Centre Drift is known to be older than 43 800 years BP and probably is older than 51 000. It is considered to correlate with an early Wisconsin glacial period.Bessette Sediments were deposited during the last major nonglacial period, which in south-central British Columbia persisted from at least 43 800 years BP (possibly more than 51 000) to about 19 000 years BP. This episode corresponds to Olympia Interglaciation of the Pacific Coast region and the mid-Wisconsin Substage of the Great Lakes – St. Lawrence Valley area. During parts of Olympia Interglaciation the climate was probably as warm as the present-day climate in the interior of British Columbia. Information from coastal regions indicates that there may have been periods of cooler and moister climate.Kamloops Lake Drift was deposited during the last major glaciation of south-central British Columbia. Ice occupied lowland areas from approximately 19 000 to 10 000 years BP. This period corresponds approximately to the Fraser Glaciation of the Pacific Coast region and the late Wisconsin Substage of central and eastern parts of North America.

The Life History and Immature Stages of Synergus pacificus McCracken and Egbert (Hymenoptera: Cynipidae)

1965 ◽  
Vol 97 (2) ◽  
pp. 185-188 ◽  
Author(s):  
David Evans
Keyword(s):  
British Columbia ◽  
Life History ◽  
Pacific Coast ◽  
Immature Stages ◽  
Central California ◽  
Larval Stages ◽  
The Pacific

AbstractSynergus pacificus McCracken and Egbert (Hymenoptera: Cynipidae) is an inquiline of oak gall cynipids in the Pacific Coast area from southern British Columbia to central California. Approximately 1,000 specimens were examined during the course of this study. Descriptions of the egg and larval stages are given, and information on life history and ecology is presented.

scholarly journals Variability in Life History Characteristics of Steelhead Trout (Salmo gairdneri) Along the Pacific Coast of North America

1966 ◽  
Vol 23 (3) ◽  
pp. 365-393 ◽  
Author(s):  
I. L. Withler
Keyword(s):  
British Columbia ◽  
Pacific Coast ◽  
Salt Water ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Central California ◽  
Late Entry ◽  
Northern Areas ◽  
The Pacific ◽  
Variation Range

Steelhead enter spawning streams in the lower mainland of British Columbia throughout all months. Those ascending streams between November 1 and April 30 are termed "winter steelhead," while "summer steelhead" enter streams between May 1 and September 30. Cheakamus River is exceptional in that initial stream entry of winter steelhead is delayed until April 1, with most fish entering during April and May. Late entry is related to delayed freshet conditions within this stream. Almost twice as many female as male steelhead were angled. Comparison with trapping results suggests that sport fisheries select for females of anadromous rainbow trout populations. Repeat spawning of winter steelhead was found to range from 5.0% for fish from the Seymour River to 31.3% for Cheakamus River. Repeat spawning among summer steelhead ranged from 4.4% (Seymour River) to 6.3% (Coquihalla River). Mean fork lengths of populations of winter and summer steelhead showed little variation (range 26.3–31.0 inches). Winter steelhead from the Cheakamus River were larger than fish from all other populations while summer steelhead from the Coquihalla River had the least mean length. In general, mean fork lengths of winter and summer steelhead were not greatly different, despite the 5–8-month shorter term of saltwater residence of the latter. However, variations in mean lengths of steelhead between different river systems may result from differences in duration of saltwater residence since mean lengths of these populations did increase with longer saltwater residence. Steelhead spent from 1 to 4 years in fresh water and from 1 to 4 years in salt water.Along the Pacific coast from central California to southern British Columbia, timing of initial stream entry showed little variation. Sex ratios were nearly 1:1. Incidence of repeat spawning decreased from south to north. Mean fork lengths of steelhead populations were greater in northern areas where fish spent more years in fresh and more years in salt water.

THE CESTODA OF CANADIAN FISHES: I. THE PACIFIC COAST REGION

1932 ◽  
Vol 7 (1) ◽  
pp. 221-243 ◽  
Author(s):  
ROBERT ARNOLD WARDLE
Keyword(s):  
British Columbia ◽  
Pacific Coast ◽  
Pacific Salmon ◽  
Ophiodon Elongatus ◽  
The Pacific ◽  
The Common ◽  
Leptocottus Armatus ◽  
Coast Region

The results are given of a survey of the cestode fauna of 1,500 fishes representing 26 species common in the straits of Georgia, British Columbia. The survey yielded only five species of adult and four species of larval cestodes. No cestodes were found in members of the Pleuronectidae and Embiotocidae and—with one exception—the Scorpaenidae, and the rate of infection in other families was singularly low.The cestodarian species in Hydrolagus colliei is regarded as identical with the Atlantic Gyrocotyle urna Gr. et Wag. The common cestode of the Pacific salmon is regarded as Eubothrium oncorhynchi n. sp., closely allied with the European Eubothrium crassum Bloch. Bothriocephalus scorpii Müll. occurred in Leptocottus armatus and Hexagrammos decagrammus, Bothriocephalus occidentalis Linton in Leptocottus armatus and Sebastodes maliger, and Gilquinia tetrabothrius v. Ben. in Squalus sucklii; a redescription is given of the two latter species. The larval forms recorded were two species of Diphyllobothrium in Oncorhynchus, a species of Nybelinia in Ophiodon elongatus, and a species of Phyllobothrium in Oncorhynchus.

Summary of Coastal Geologic Evidence for past Great Earthquakes at the Cascadia Subduction Zone

1995 ◽  
Vol 11 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Brian F. Atwater ◽  
Alan R. Nelson ◽  
John J. Clague ◽  
Gary A. Carver ◽  
David K. Yamaguchi ◽  
...  
Keyword(s):  
British Columbia ◽  
North America ◽  
Subduction Zone ◽  
Forest Soils ◽  
Pacific Coast ◽  
Cascadia Subduction Zone ◽  
Level Change ◽  
The Past ◽  
The Pacific ◽  
Juan De Fuca

Earthquakes in the past few thousand years have left signs of land-level change, tsunamis, and shaking along the Pacific coast at the Cascadia subduction zone. Sudden lowering of land accounts for many of the buried marsh and forest soils at estuaries between southern British Columbia and northern California. Sand layers on some of these soils imply that tsunamis were triggered by some of the events that lowered the land. Liquefaction features show that inland shaking accompanied sudden coastal subsidence at the Washington-Oregon border about 300 years ago. The combined evidence for subsidence, tsunamis, and shaking shows that earthquakes of magnitude 8 or larger have occurred on the boundary between the overriding North America plate and the downgoing Juan de Fuca and Gorda plates. Intervals between the earthquakes are poorly known because of uncertainties about the number and ages of the earthquakes. Current estimates for individual intervals at specific coastal sites range from a few centuries to about one thousand years.

Gyrodiform gastropods from the Pacific Coast Cretaceous and Paleocene

1987 ◽  
Vol 61 (1) ◽  
pp. 70-100 ◽  
Author(s):  
W. P. Popenoe ◽  
L. R. Saul ◽  
Takeo Susuki
Keyword(s):  
British Columbia ◽  
New Taxa ◽  
Late Cretaceous ◽  
West Coast ◽  
Pacific Coast ◽  
Northern California ◽  
Color Patterns ◽  
New Subgenus ◽  
The Pacific

Seven previously described and seven new taxa of gyrodiform naticoids from West Coast Late Cretaceous–Paleocene age strata are discussed. Gyrodes (Gyrodes) dowelli White of Turonian age is a typical Gyrodes; G. robustus Waring from the Paleocene has the shape of Gyrodes s.s. but lacks the crenulations. G. greeni Murphy and Rodda, G. yolensis n. sp., G. quercus n. sp., G. banites n. sp., G. canadensis Whiteaves, G. pacificus n. sp., and G. expansus Gabb comprise the new subgenus Sohlella, which thus ranges from Cenomanian through Maastrichtian. Gyrodes robsauli n. sp. resembles “Polinices” (Hypterita) helicoides (Gray), and Hypterita is reassigned to the Gyrodinae as a subgenus of Gyrodes. Gyrodes onensis n. sp. of Albian age is similar to the G. americanus group of Sohl (1960). Three texa—Natica allisoni (Murphy and Rodda) of Cenomanian age and N. conradiana Gabb and N. conradiana vacculae n. subsp. of Turonian age—which have all been previously considered to be Gyrodes are placed in Natica. Well marked relict color patterns on N. conradiana and N. conradiana vacculae suggest that these naticids from northern California and southern British Columbia were tropical forms.Diversity of taxa and size of specimens are reduced at the end of the Turonian, suggesting a change in West Coast marine conditions at that time.

scholarly journals MIS 5e sea-level history along the Pacific Coast of North America

2021 ◽  
Author(s):  
Daniel R. Muhs
Keyword(s):  
North America ◽  
Sea Level ◽  
Baja California ◽  
Pacific Coast ◽  
Level Indicator ◽  
Sequence Of Events ◽  
Marine Terraces ◽  
The Pacific ◽  
Mis 5E ◽  
Good Agreement

Abstract. The primary last interglacial, marine isotope substage (MIS) 5e records on the Pacific Coast of North America, from Washington (USA) to Baja California Sur (Mexico), are found in the deposits of erosional marine terraces. Warmer coasts along the southern Golfo de California host both erosional marine terraces and constructional coral reef terraces. Because the northern part of the region is tectonically active, MIS 5e terrace elevations vary considerably, from a few meters above sea level to as much as 70 m above sea level. The primary paleo-sea level indicator is the shoreline angle, the junction of the wave-cut platform with the former sea cliff, which forms very close to mean sea level. Most areas on the Pacific Coast of North America have experienced uplift since MIS 5e time, but the rate of uplift varies substantially as a function of tectonic setting. Chronology in most places is based on uranium-series ages of the solitary coral Balanophyllia elegans (erosional terraces) or the colonial corals Porites and Pocillopora (constructional reefs). In areas lacking corals, correlation to MIS 5e can sometimes be accomplished using amino acid ratios of fossil mollusks, compared to similar ratios in mollusks that also host dated corals. U-series analyses of corals that have experienced largely closed-system histories range from ~124 to ~118 ka, in good agreement with ages from MIS 5e reef terraces elsewhere in the world. There is no geomorphic, stratigraphic, or geochronology evidence for more than one high-sea stand during MIS 5e on the Pacific Coast of North America. However, in areas of low uplift rate, the outer parts of MIS 5e terraces apparently were re-occupied by the high-sea stand at ~100 ka (MIS 5c), evident from mixes of coral ages and mixes of molluscan faunas with differing thermal aspects. This sequence of events took place because glacial isostatic adjustment processes acting on North America resulted in regional high-sea stands at ~100 ka and ~80 ka that were higher than is the case in far-field regions, distant from large continental ice sheets. During MIS 5e time, sea surface temperatures (SST) off the Pacific Coast of North America were higher than is the case at present, evident from extralimital southern species of mollusks found in dated deposits. Apparently no wholesale shifts in faunal provinces took place, but in MIS 5e time, some species of bivalves and gastropods lived hundreds of kilometers north of their present northern limits, in good agreement with SST estimates derived from foraminiferal records and alkenone-based reconstructions in deep-sea cores. Because many areas of the Pacific Coast of North America have been active tectonically for much or all of the Quaternary, many earlier interglacial periods are recorded as uplifted, higher elevation terraces. In addition, from southern Oregon to northern Baja California, there are U-series-dated corals from marine terraces that formed ~80 ka, during MIS 5a. In contrast to MIS 5e, these terrace deposits host molluscan faunas that contain extralimital northern species, indicating cooler SST at the end of MIS 5. Here I present a standardized database of MIS 5e sea-level indicators along the Pacific Coast of North America and the corresponding dated samples. The database is available in Muhs (2021)  [https://doi.org/10.5281/zenodo.5557355].

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