The term out‐of‐hospital has long been used as a kind of shorthand to refer collectively to births that occur in birth centers or at home. However, this term has also been a persistent cause of concern among health care providers who attend births in these settings, and researchers and midwives...
The Cottage Grove Reservoir has been impacted by a point source (Black Butte Mine), where mercury mining and processing has occurred within its watershed from the 1890's to the late 1960's. Total mercury concentrations in surface sediments transect samples, core samples, tributary samples, and representative food web species were measured...
An abandoned cinnabar mining and roasting site is in the major sub-basin of the
watershed for Cottage Grove Reservoir, Oregon. Average surface sediment total
mercury concentration in the river draining this sub-basin (0.61±0.52 μg /g) was
about ten-fold higher than three smaller tributaries to the reservoir. Total mercury in reservoir...
The Central Oregon High Cascade Range is an anomalously mafic segment of the
Cascade Arc due to ongoing intra-arc extension, which allows most magmas to traverse
the crust without stalling and evolving to more evolved compositions. North Sister, a
composite volcano in this arc segment, has produced a seemingly monotonous...
Full Text:
Province (Lawrence, 1976)
intersects the Cascade Arc at the latitude of the Three Sisters Volcanic
Understanding continental crust formation and modification is a fundamental and longstanding geologic problem. Influx of mantle-derived basaltic magma and partial melting of the crust are two ways to drive crustal differentiation. This process results in a low density upper crust and denser, more refractory lower crust, creating significant and vastly...
Full Text:
., Grunder, A. L., Leeman, W. P., and Lupton,
J. E.,2009, Mantle source provinces beneath the Northwestern
Inheritance from pre-existing mantle domains and fluid and melt contributions from active subduction together produce the geochemical signatures of mantle-derived arc basalts. In this context, this work evaluates the evolution of Cascadia mantle sources by documenting the isotopic and compositional characteristics of primitive basalts along a transect across the Eocene-Oligocene...
Multiple episodes of Oligocene and younger silicic volcanism are represented in the high lava plateau of central and southeastern Oregon. From 12 Ma to Recent, volcanism is strongly bimodal with nearly equal volumes of basalt and rhyolite. It is characterized by moderate to high silica (SiO₂ > 72 wt. %)...
The variable length, six-electrode plasma source for atomic
emission spectroscopy described here is operated from three
compact, simple, and inexpensive direct current power supplies. The
vertical arcs formed between the three electrode pairs completely
entrain the sample and are typically operated at 40 V and 20 A.
Three concentric quartz...