Geology Commons^™

Clay Mineralogy Of Late Pleistocene Sequences In Northwestern Washington And Southwestern British Columbia, Michael Arthur Hepp

WWU Graduate School Collection

Pleistocene clay-bearing sediments of parts of northwestern Wash­ington and southwestern British Coliambia were studied in an attempt to determine the clay mineral composition of these units; the origin of these clay minerals; and any correlation between clay mineral composi­tion, sediment type, location, or probable geologic history of the sediments. The Pleistocene stratigraphy of the area is fairly well known, although in some specific locations the stratigraphy has not been determined. Recorded work in the region dates back to Dawson (1887). The units studied range in age from the greater than 50,000 year old Double Bluff Drift to Holocene (Recent) river …

A Sedimentary Core Analysis Of Late Pleistocene To Recent Sediments In A Portion Of Bellingham Bay, Washington, James T. Lowe

WWU Graduate School Collection

Sub-bottom profiles and core sampling indicate that a trough-like depression below the bay near South Bellingham is a Pleistocene erosional paleotopographic surface sloping bayward from the uplandds to the east. A series of Late Pleistocene glacial till and glaciomarine deposits overlie the erosional surface and fill the depression. The glacial deposits are overlain by Recent sand and mud deposits which are rich in wood fragments and shell materials.

Bellingham Bay is basin-shaped with a deep narrow trough to the west. The Pleistocene basement is generally structureless and conforms to the bay bottom. Several trough shaped depressions which are overlain by …

A Paleomagnetic Reconnaissance Of The Platoro Caldera, Southeastern San Juan Mountains, Colorado, Jimmy F. Diehl

WWU Graduate School Collection

Paleomagnetic results have been obtained from twenty-five sites in intrusive and extrusive units of Oligocene age from the Platoro caldera, southwestern Colorado, All specimens from each site were subjected to af demagnetization, and the reliability of each site thereby determined. Eighteen sites gave reliable results. Because six sites from the La Jara Canyon tuff appear to have become magnetized during the same small interval of geologic time, their results were combined and their mean pole and direction used in the final calculations. The thirteen remaining reliable sites yielded a paleomagnetic pole at 84.5°N and 306.5°E (o< = 12.9°, k = 11.2). Site-mean directions have an angular standard deviation of 18°, which is considerably greater than the dispersion predicted by models based on the present geomagnetic field but consistent with results from Late Tertiary and Quaternary studies. Because site-mean directions and site poles both have Fisherian distribution, it is not possible to determine whether dipole wobble or random fluctuation caused by a changing non-dipole field could be the cause of the geomagnetic secular variation during the Oligocene; probably both contribute. Interpretations based on mid-Tertiary paleomagnetic poles are consistent with those derived from sea-floor magnetic anomaly patterns, and possibly indicate that some true polar wandering has occurred since the mid-Tertiary, Due to lack of resolution in potassium-argon dating, the polarity time-scale constructed from the Platoro caldera units can only be used as a guide for future paleomagnetic work and geological mapping in the area.

Biostratigraphy Of The Bilk Limestone (Permian), Northwestern Nevada, Erich Thomas

WWU Graduate School Collection

The Bilk Limestone (new manuscript name) described in this report is a carbonate sequence located in the Bilk Creek Mountains at the southernmost end of the Kings River Range (fig. 1), about 30 miles south of the town Denio in north-central Humboldt County, Nevada. This study investigates the biostratigraphy and general paleoecology of about 2900 feet of limestone of early to middle Permian (middle Wolfcampian to middle Leonardian) age. The limestone is interbedded with nodular chert and is considerably altered by faulting and fracturing with associated epigenetic dolomitization. The fossil content is varied, and in this report stress is placed …

Paleomagnetism Of The Snoqualmie Batholith Central Cascades, Washington, Suzanne J. Beske

WWU Graduate School Collection

Paleomagnetic results have been obtained from eight sites in the Miocene (15-18 m.y.) Snoqualmie batholith, Central Cascades, Washington. After ac magnetic cleaning, four magnetically stable sites remained, yielding a pole at 221.0°E, 84.5°N, (δ_p = 7.9, δ_m = 9.3, k = 286.4). A stability test was formulated based on the ratio of the intensity of natural remanent magnetism, NRM, (after ac demagnetization) to the weak field susceptibility. This ratio, Q_d proved effective in determining magnetically stable samples from samples showing a wide spectrum of stability from within the Snoqualmie batholith, and therefore, was strictly applied to all …

Fusulinids From The Cyathophyllum Limestone, Central Vestspitsbergen, Charles A. Ross

Geology Faculty Publications

Thirteen species of fusulinids are illustrated and described from eleven collections within the Cyathophyllum Limestone of central Vestspitsbergen. The lower collections at Tempelfjorden and the collection from Mount Lykta contain Schubertella transitoria, Triticites arcticus, and Schwageriiia anderssoni and other species typical of the Carboniferous zones C₃C through C₃E of the Ural region of the U.S.S.R. It is suggested that “Fusulinella" usvae is a species of Waeringella. Higher collections at Tempelfjorden include Parafusulina furnishi n. sp. and Pseudofusulinella tempelensis n. sp. and a loose block from higher in the succession includes Schwagerina …

Early Permian Fusulinids From Macusani, Southern Peru, Charles A. Ross

Geology Faculty Publications

Triticites patulus Dunbar and Newell and Schwagerina adamsi sp. nov. from the early Wolfcampian (Permian) part of the Copacabana Group near Macusani, southern Peru, show morphological features that add new data concerning the evolution of the genera Schwagerina and Pseudoschwagerina from lineages arising within the genus Triticites near the close of the Pennsylvanian.

Fusulinids From The Leonard Formation (Permian), Western Glass Mountains, Texas, Charles A. Ross

Geology Faculty Publications

From the Leonard Formation in the western part of the Glass Mountains, eleven species of fusulinids are recognized. The lowest member of the formation, member A, has Schwagerina dugoutensis n. sp., S. hawkinsi Dunbar and Skinner, S. hessensis Dunbar and Skinner, S. crassitectoria Dunbar and Skinner, S. guembeli Dunbar and Skinner, Monodiexodina linearis (Dunbar and Skinner), Parafusulina leonardensis n. sp., and P. allisonensis Ross. The middle member, member B, contains Schwagerina hessensis, S. hawkinsi?, Parafusulina spissisepta Ross, P. leonardensis, and Schubertella muellerriedi Thompson and Miller. Member C at the top of the formation has the distinctive species …

Permian Foraminifera From British Honduras, Charles A. Ross

Geology Faculty Publications

Fusulinids identified from the Macal Shale Group, Macal Series, south central British Honduras and Schwarerina gruperaensis Thompson and Miller, Schwagerina sp. A, Eoverbeekina aff. E. americana Thompson and Miller, Ozawainella? sp., and Staffella sp. One species of the Trochamminid genus Tetrataxis also occurs in these strata. These species suggest correlation with the lower part of the Chochal Limestone of Guatemala, the Grupera Formation of Chiapas, Mexico, and the Lenox Hills Formation (upper part of the standard Wolfcampian Series, Permian), Glass Mountains, Texas.

Fusulinids From The Hess Member Of The Leonard Formation, Leonard Series (Permian), Glass Mountains, Texas, Charles A. Ross

Geology Faculty Publications

Five fusulinid zones are recognizable in the Hess member of the Leonard formation in the eastern Glass Mountains. These zones are useful for correlation and contain two species of Schwagerina, previously described, and five species of Parafusulina which are new. The assemblage of Schwagerina crassitectoria Dunbar and Skinner and S. gaembeli Dunbar and Skinner forms the lowest zone, Parafusulina allisonensis n. sp. forms the second zone, P. deitoides n. sp. and Parafusulina sp. A form the third zone. P. spissisepta n. sp. forms the fourth zone which includes the upper Hess fossil bed of P. B. King (1931), and …