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Full-Text Articles in Physical Sciences and Mathematics

Potential Petroleum Reservoir Rocks Of North-Central Oregon, Alfred J. Riddle Aug 1990

Potential Petroleum Reservoir Rocks Of North-Central Oregon, Alfred J. Riddle

Loma Linda University Electronic Theses, Dissertations & Projects

Petroleum explorationists have commonly assumed, based on the presence of volcanic and/or volcaniclastic rock, that regions such as northcentral Oregon do not hold potential as petroleum basins. The typical argument has been that volcanic flows have no effective porosity or permeability and poorly sorted volcaniclastic sediments contain a high percentage of mineralogically unstable grains which are too easily and rapidly altered into clays and zeolites for any significant or effective porosity to be retained.

The objective of this study was to determine if potential petroleum reservoir rocks do exist in north-central Oregon. Through field and laboratory study and by comparing …


A Modified Nance Unilateral Molar Distalizer, Tracy J. Reiner Jun 1990

A Modified Nance Unilateral Molar Distalizer, Tracy J. Reiner

Loma Linda University Electronic Theses, Dissertations & Projects

This clinical study evaluated a modified Nance appliance designed by the author to distalize molars unilaterally for Class II correction. This fixed appliance did not rely upon extraoral traction or intraoral elastics. Twelve unilateral Class II patients aged 13 to 17 were treated nonextraction with the appliance. Pretreatment and posttreatment photographs were taken of the palatal soft tissue and did not reveal any untoward changes as a result of the Nance acrylic button. All molars were corrected to an Angle's Class I relationship. Molar correction was evaluated visually and molar distalization was measured using an acrylic jig fitted to the …


Geology And Economic Potential Of The Muddy Ranch Inlier, North-Central Oregon, Mustafa Kamal Jun 1990

Geology And Economic Potential Of The Muddy Ranch Inlier, North-Central Oregon, Mustafa Kamal

Loma Linda University Electronic Theses, Dissertations & Projects

There has been confusion for many years regarding the lithology and age of the rocks exposed in the Muddy Ranch Inlier in north-central Oregon. Taylor (1960) referred to these rocks as metasediments and informally named them the "Muddy Ranch phyllite". My studies indicate the inlier consists of weakly metamorphosed siltstone, mudstone, and less abundant sandstone.

Due to the absence of fossil evidence, it was not possible to determine the age of these rocks. However, from the stratigraphic setting and correlation with similar rocks exposed along structural trend to both the northeast and southwest, rocks of the Muddy Ranch Inlier may …


Geology Of The Butler Basin, Grant And Wheeler Counties, Central Oregon, Martin R. Aguirre Jun 1990

Geology Of The Butler Basin, Grant And Wheeler Counties, Central Oregon, Martin R. Aguirre

Loma Linda University Electronic Theses, Dissertations & Projects

The Butler Basin lies along the John Day River in Central Oregon, astraddle the boundary of Wheeler and Grant counties. Strata exposed in this geomorphic basin, formed by an erosionally breached anticline, range in age from Permo-Triassic to Neogene. The basement rocks of the basin are poorly exposed but lithologically similar to the Permo-Triassic Blue Mountains island-arc rocks which crop out to the south and southeast of the basin in the John Day Inlier. Overlying the basement rocks are Early Cretaceous conglomerates with lenses of sandstone and siltstone informally named the "Goose Rock Conglomerate." Pebble and cobble lithologies present in …