The Greenhorn Mountains contain a tectonic ally disrupted
ophiolite and both arc-derived and pelagic sediments. Age of major
sedimentary units within and bordering the thesis area is Early
Permian, based upon dates of conodonts and fusulinids from contemporaneous
but allocthanous limestones. Sediments near the south
boundary of the thesis area...
Full Text:
MOUNTAINS, NORTH
EASTERN OREGON
Abstract approved:
(William H. Taubeneck)
(Robert D. Lawrence)
The
Silicic volcanism in the central Oregon Cascade range has decreased in both the size and frequency of eruptions from its initiation at ~40 Ma to present. The reasons for this reduction in silicic volcanism are poorly constrained. Studies of the petrogenesis of these magmas have the potential for addressing this...
Surface transient storage (STS) and hyporheic transient storage (HTS) have
functional significance in stream ecology and hydrology. Both provide refugia for aquatic
communities and their longer mean residence times (compared to the main flow) increase
the potential for biogeochemical reactions that can improve water quality. As STS and
HTS have...