Physical Sciences and Mathematics Commons^™

An Introduction To Using Modflow The Usgs Modular Finite-Difference Ground-Water Computer Modeling System, Jessica N. Pfundt

Geology Graduate and Undergraduate Student Scholarship

MODFLOW is the U.S. Geological Survey (U.S.G.S.) Modular Finite-Difference Ground-Water computer modeling system. This program incorporates basic concepts derived from previous computer groundwater modeling programs. MODFLOW improves upon these programs because it is easy to modify, simple to use and maintain, can be executed on a variety of computers with minimal changes, and is relatively efficient with respect to computer memory and execution time (McDonald and Harbaugh, 1988).

Spatial Variation Of Naticid Gastropod Predation In The Eocene Of North-America, Thor A. Hansen, Patricia H. Kelley

Geology Faculty Publications

Although, the fossil record of naticid gastropod drilling has played an important role in the controversy over predator-prey evolution, little is known about variation of drilling frequencies within single horizons or how predation patterns are influenced by environmental variables. Without an understanding of spatial variation in drilling, temporal patterns in drilling are difficult to interpret. We surveyed 27,554 specimens of molluscs from the Cook Mountain interval (upper middle Eocene) and Jackson Group (late Eocene) of the U.S. Gulf and Atlantic Coastal Plain to document spatial variation in naticid drilling frequencies. The Jackson Group assemblages from the Moodys Branch and Yazoo …

Net Shore-Drift And Artificial Structures Within Grays Harbor, Willapa Bay, And Mouth Of The Columbia River, Washington, B. Patrice (Berenthine Patrice) Thomas

WWU Graduate School Collection

Net shore-drift, the overall result of sediment transport in the littoral zone, was studied along the shore within Grays Harbor, Willapa Bay, and mouth of the Columbia River, Washington. The length and direction of drift cells, which are discrete sediment compartments, was delineated using geomorphologic and sedimentologic indicators. Eight drift cells were identified in Grays Harbor, seven within Willapa Bay, and three along the section of the Columbia River shore studied. Drift cell lengths range from 200 m to approximately 6 km with an average of 1.5 km. Net shore-drift directions vary considerably with maximum fetch identified as the most …

Kinematic Implications Of Paleomagnetic Data From Lago Verde And Northern Isla Chiloe, Southern Chile, Brian C. (Brian Christopher) Steele

WWU Graduate School Collection

Paleomagnetic techniques were used to determine crustal rotations at two locations along the Liquine Ofqui fault zone (LOFZ) in southern Chile, South America. East of the fault zone, near the town of Lago Verde, twelve sites drilled in intermediate volcanic rocks and diorite yielded a paleomagnetic pole at 82°S, 210.8°E (A₉₅=8.3°), which, when compared to a Late Cretaceous reference pole (the mean of Butler et al. (1991) and Somoza (1994) poles) implies 17.7° ± 11.1° of in situ, clockwise rotation. At Cocotue Beach, west of the fault zone on Isla Chiloe, seven sites drilled in middle Tertiary …

Sediment Production And Delivery In The Upper South Fork Nooksack River, Northwest Washington, 1940-1991, Jeffrey A. Kirtland

WWU Graduate School Collection

Identifying sources and timing of sediment production and delivery provides information useful to understanding the geomorphology of a forested mountainous watershed in the western Cascade Range of Washington State. Sediment production and delivery is studied by constructing a partial sediment budget for the upper South Fork of the Nooksack River drainage (South Fork drainage). The period of the partial sediment budget extends from 1940 through 1991 and encompasses the pre- and post-management history of the watershed.

Four major sediment production and delivery sources - landsliding, streambank erosion, sheet and rill erosion and road-related erosion - were identified in the South …

Magnetic Anisotropy Fabrics From The Cascadia Accretionary Prism, Bernard A. Housen, Takaharu Sato

Geology Faculty Publications

Magnetic anisotropy fabrics were measured in 495 specimens collected from the Cascadia accretionary prism to characterize the development of mineral preferred orientation fabrics during deformation. Comparison of high-field and low-field susceptibilities was used to determine the relative contributions of the paramagnetic clay minerals and the ferrimagnetic trace minerals (magnetite, greigite, pyrrhotite) to the magnetic susceptibility fabrics. Sites 888 and 891 have anisotropy of magnetic susceptibility (AMS) fabrics that are controlled primarily by the ferrimagnetic minerals. Sites 889/890 and 892 have AMS fab­rics that are controlled, to varying degrees, by both paramagnetic clays and the ferrimagnetic minerals. Rock magnetic experi­ments indicate …