Student Research
Sarah Glancy (UPS Class of 2009). Sarah is studying the petrology of a suite of "chemically anomalous" volcanic rocks collected from various sites on the Olympic Peninsula. These rocks include hornblende-bearing basaltic andesites, hornblende dacites, and tuffs. In addition to characterizing and dating these rocks, she is evaluating the hypothesis that some or all of them could be related to passage of one or more slab windows beneath western Washington during the Eocene.
Ben Shapiro (UPS Class of 2009). Ben's project seeks to understand why Gravelly Lake (Pierce County, WA) is chemically different (higher in pH and most cations) from other lakes in the vicinity (all of which are kettle lakes). Specifically he is evaluating the hypothesis that springs feeding the lake may have interacted with carbonate in the aquifer. Ben is also using sediment traps to determine whether calcareous algae contribute to the blue color of the lake during summer months.
Matthew Loewen (UPS Class of 2008). Matt's project focused on the petrology and geochemistry of Eocene ("Challis event") plutonic and volcanic rocks in Eastern Washington. Using a combination of trace element and Sr-Nd isotopic data he was able to show that these rocks formed by melting of thickened crust and then ascended rapidly. These results are consistent with the hypothesis that Challis magmatism was related to passage of the Kula-Farallon slab window. Matt's Nd isotopic data also reveal the existence in eastern Washington of at least three distinct lower crustal domains. Matt is now at Oregon State where he is working on a project at Mt. St. Helens.
Christian Manthei (UPS Class of 2006). Christian studied the distribution of heavy metals in sediment cores collected from Tacoma-area lakes and from Commencement Bay to see what factors influence the behavior of lead, copper, and other pollutants after they are deposited. His results indicate that redox-driven dissolution and reprecipitation processes can lead to enrichment of metals in the upper sediment layers of lakes, but that this process is less important in marine environments. Christian is currently a graduate student in petrology / isotope geochemistry in the Geology Department at the University of Arizona.
Click here to read Christian's GSA Abstract
Rachel Peters (UPS Class of 2006). Rachel's research focused on the geochemistry of the Teanaway dikes, a swarm of Eocene basaltic-andesite dikes that intrude sedimentary rocks of the Swauk Formation in Central Washington. She demonstrated the Teanaway rocks are chemically distinct from the younger and more voluminous Columbia River Basalts, and that the Teanaway magmas came from a heterogeneous mantle source. After working an an environmental consultant for a year, Rachel is applying to graduate programs in chemistry for 2009.
Click here to read Rachel's GSA Abstract
Kevin Stein (UPS Class of 2006). Kevin worked on a suite of granitic xenoliths collected from the Tumalo Cinder Cone, a small volcano located west of Bend, OR. The goal of his work is to establish the age and composition of the crust under this region of the Oregon Cascades. Based on age dating and geochemistry, Kevin found that the xenoliths are derived from a young (<1 Ma) pluton that is geochemically distinct from any of the felsic volcanic rocks in the region. After working in medial research for the past year Kevin is planning to start work on a PhD in medicine in the Fall of 2008.
Click here to read Kevin's GSA Abstract
Joe Gustafson (UPS Class of 2005): "Petrology in the Western Oregon Cascades: A Study of Four Miocene Plutons". Joe studied the petrology of four plutons in the Oregon Cascades, including the Nimrod granite, which is the only "true granite" in that portion of the Cascades. He showed that this granite probably formed by fractional crystallization of a dioritic magma, accompanied by late-stage potassium addition. Another outcome of his study was the discovery that the compositions of Cascade magmas (in particular their Ca/Na ratios) have changed systematically over the past 35 Ma. We think this effect records the gradual thickening of the crust beneath the Cascades. Joe is currently a graduate student in hydrology at the University of Arizona.
Click here to read Joe's GSA Abstract
Melissa Wolfe (UPS Class of 2005): "Petrology and Geochronology of Felsic Volcanic Rocks on the Olympic Peninsula: Implications for Eocene Tectonics". Melissa worked on felsic volcanic rocks from four localities on the Olympic Peninsula. The rocks at three of these sites are adakites and probably formed in response to subduction of the Kula-Farallon Ridge during the Eocene. Melissa dated two of these adakite deposits and based on these ages was able to constrain the timing and location of ridge subduction. Her adakite data show that the rocks fall into two groups which differ in Ca/Na ratio, an effect that we think may reflect spilitization of the slab. She is currently a graduate student in the Geology Department at the University of Kansas.
Click here to read Melissa's GSA Abstract
Peter Bell (UPS Class of 2004). Peter worked with the USGS on a study of slag-contaminated sediment from Lake Roosevelt, the water body behind Grand Coulee Dam. He worked out a procedure for separating slag grains from the rest of the sediment and then used a sequential extraction procedure and SEM imaging to determine where various elements were hosted in the sediments. He showed that some elements (e.g., Cd) are primarily present on grain surfaces while others are still contained in slag grains (and thus presumably less bioavailable) . Peter now works for an environmental consulting firm in Minnesota.
Click here to read Peter's GSA Abstract
Cara Ponzini (UPS Class of 2004): "Petrology of the Index Batholith, North Cascades, Washington". Cara's project focused on the petrology of the Index batholith, but also included the first regional comparison of chemical data from Cascade arc batholiths. She identified a difference in the composition of Cascade arc rocks - both plutonic and volcanic - in northern Washington versus those to the south. We think this difference may reflect a change in the composition of the crust that occurs around the latitude of Highway 2. Cara is currently in law school at Lewis and Clark.
Click here to read Cara's GSA Abstract
Erika von Schneidemesser (UPS Class of 2004). Erika developed a procedure for extracting and analyzing organic compounds in a sediment core collected in the Thea Foss, Tacoma. She identified phthalates at all depths within the ~60 cm long core, which suggests that these synthetic organic compounds (which may be carcinogenic) can persist in sediment for many decades. She is currently a graduate student at the University of Wisconsin - Madison.
Kristin Hill (UPS Class of 2003): "Petrology of Mafic Plutons Associated with the Snoqualmie Batholith, North Cascades, Washington". Kris studied the petrology of four small gabbro and diorite bodies that are associated with the Oligocene Snoqualmie batholith. All four bodies have geochemical traits indicative of an arc setting, but only one is demonstrably related to the Snoqualmie batholith (based on field evidence). After graduation Kris went to graduate school at Western Washington University where she conducted gravity surveys at Mt. Baker and received her M.S. in 2007.
Click here to read Kris's GSA Abstract
Pete Doumit (UPS Class of 2002): "Stratigraphy of the Type Section of the Bumping River Tuff, Mt. Rainier National Park, WA". Pete studied the stratigraphy and geochemistry of a 1250 foot section through the type locality of the Bumping River Tuff, which erupted about 24 Ma forming the Mt. Aix caldera. After UPS he went to the University of Northern Colorado where he received his M.S. in Geology.
Kerry Schmidtbauer (UPS Class of 2002): "Petrology and Mode of Emplacement of Andesite Bodies Near Enumclaw, WA: Magmatism West of the Main Cascade Arc". Kerry worked on two andesite plugs that form isolated "hills" in the Puyallup River Valley near Enumclaw, WA. Her main goal, aside from describing their petrology, was to determine their mode of emplacement, specifically whether they were volcanic necks or erosional remnants of one of more sills. Based on chemical differences and crystal size distribution, Kerry determined that the two bodies were separate intrusions and probably represent volcanic necks. Kerry is currently a graduate student in geology at Boston University.
Click here to read Kerry's GSA abstract.