Tel.  001(559) 278-4524
Fax. 001 (559) 278-5980
E-mail: kputirka@csufresno.edu

Office: Science I 228

Links: EES Department, University Homepage
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Teaching Interests and Philosophy

For majors in Earth & Environmental Sciences, I teach Mineralogy (GEOL 12), Analytical Methods in the Earth Sciences (GEOL 100), and Igneous and Metamorphic Petrology (101). At the graduate level, I teach Volcanology (GEOL 271) and Geochemistry (GEOL 224). Research is a key component to an Earth Science education and so students in my classes conduct small research projects, which involve field and laboratory experiences. Our new X-ray fluorescence (XRF) and X-ray diffraction (XRD) instruments are utilized as lab components in these courses. For non-majors, I teach Environmental Earth and Life Science (NSCI 115). A goal in this course is to illustrate how a scientific understanding of our planet is crucial to many aspects of our daily lives.

Research Activities in Mineralogy and Igneous Petrology

Partial melting and the transport of melt from Earth's interior to its surface are responsible for creating all those things that make our planet habitable. Our lakes, oceans and atmosphere were all derived from degassing of the mantle through volcanic eruptions, and the crust we live on was produced through the delivery of low density melts to Earth's surface. The core, which provides a portion of the heat the drives mantle circulation and plate tectonics, was also a product of partial melting, only in this case, dense Fe-rich metallic liquids sank downwards, rather than rising upwards.

My research interests are two-fold. I am interested in how the internal engine of our planet works. My research group thus attempts to estimate the depths and pressures of partial melting in Earth's mantle, to better understand mantle circulation. The questions I am attempting to answer are: How hot are mantle plumes, and at what depth does melting begin? How can plumes be identified? I am also interested in understating how volcanoes work. On this topic, my students and I investigate the ascent and transport of magma through the crust and uppermost mantle, and attempt to determine the various controls on magma transport and eruption. The relevant questions here are: How deeply rooted are magma plumbing systems, and at what depths are magmas stored prior to eruption? Do such storage depths change over time, or vary with tectonic environment? What are the controls on the transport of magma through the crust?

To address these issues, my students and I use the geochemistry of rocks and minerals from areas of active and ancient volcanic activity. I also focus on the calibration and application of mineral-melt equilibria (geothermometers and geobarometers for crystallization and melting).

Downloads: The worksheets in the Excel workbook Cpx-Plag-Ol Thermobar can be used to calculate the P-T conditions of crystallization for clinopyroxene and plagioclase phenocrysts, and crystallization temperatures for olivines, when suitable mineral and "liquid" compositions are used as input. The pdf file Notes on Use of Workbook gives instructions for use of the individual worksheets, and a brief summary of the models.

Laboratory Facilities : We have a state-of–the-art X-ray fluorescence (XRF) instrument (acquired in 2003) and an X-ray Diffractometer (XRD; acquired in 2005) here at CSU Fresno – both manufactured by PANalytical (formerly Phillips). The XRF is a MagiX Pro, with a 4 kW tube, and a Helium attachment that allows us to analyze loose powders and liquids. Our XRD is the X'Pert Pro with an X'Celerator detector. These instruments play important roles in the projects described below.

How Hot are Mantle Plumes? Mantle plumes are thought to represent thermally buoyant rising limbs of mantle convection cells. These cells do not coincide with plate boundaries, as we once thought, but they do reflect the large-scale plate motions that begin with plate subduction. Mantle plumes are thought to drive the volcanic activity at “hot spot” volcanoes like Hawaii , Yellowstone and Iceland . One methods for identifying hot spots is thermometry – hot spots must be “hot” relative to ambient mantle. We use olivine-melt equilibria to determine the maximum temperatures that are attained during partial melting (Putirka, 1999, 2005a). Temperature estimates at Hawaii and Iceland suggest that mantle “plumes” are 150-250 K hotter than ambient mantle; such T differences are consistent with geophysical models for the generation of thermally driven, deep-seated mantle plumes. (see Putirka, 2005a).

Volcanic Activity in the North-Central Sierra Nevada : In collaboration with Cathy Busby (UC Santa Barbara) Brian Cousens ( Carleton Univ. , Ottawa Canada ) and Horacio Ferriz (Cal State Stanislaus), we have begun a field/geochemical investigation of volcanic rocks that outcrop in the Sonora Pass region in the central Sierra Nevada . This study includes volcanic rocks that were poured from the Little Walker Caldera, near Bridgeport , CA , and several vents that at one time existed both north and south of Hwy. 4 ( Sonora Pass hwy.). Volcanic rocks cover a large part of the northern Sierra Nevada , but our current understanding of the tectonic significance of such volcanic activity is limited. Through mapping and geochemical analyses we hope to determine the volcanic evolution of this grossly understudied region of CA.

The Craters of the Moon Lava Field, Idaho : Along with Mel Kuntz of the U.S.G.S. we examining magma transport issues for lava flows from the Craters of the Moon Lava field (COM), which lies within the Snake River Plain (SRP) of ID. These lavas represent the trace of the Yellowstone hot spot. Our initial results indicate an interesting evolution of magma conduits. Lavas erupted at the COM appear to stall within the crust, at about 20-25 km. But lavas that erupted closer to the axis of the SRP move more rapidly and erupt at higher temperatures. Apparently the crust beneath the COM still contains low-density granitoids that act as a magma trap, which was otherwise obliterated by earlier magmatic events in other parts of the SRP.

Magma Transport: Hawaii : Samples taken form the surface of any volcano represent only the latest stages of volcano growth. The HSDP (Hawaii Scientific Drilling Project) samples provide a much more detailed view of Mauna Kea volcano, at Hawaii . For the first time we are able to look at how a volcanic plumbing system evolves over 100's of thousands of years. Our initial results suggest that at the early stages of Mauna Kea's development, magmas moved rapidly through the plumbing system, but with time, as Mauna Kea moved off the hot spot, mama was more likely to be stored within the crust, prior to eruption. It now also seems possible that we can map the thermal gradient radiating away from the Hawaiian mantle plume. Mauna Loa appears to tap the hottest part of the plume, followed by Kilauea and Mauna Kea .

New Crystallization Barometers and Thermometers : Thermometers and barometers are extremely important in igneous petrology because they provide the only means we have for determining where magma chambers form, and the depth extents of magma plumbing systems. New barometers are being developed using various mineral-melt equilibria, to better understand how magmas evolve.

Selected Publications:

Putirka, K. (2005a) Mantle potential temperatures at Hawaii, Iceland, and the mid-ocean ridge system, as inferred from olivine phenocrysts: Evidence for thermally–driven mantle plumes , Geochemistry, Geophysics, Geosystems, paper # 2005GC000915.

Putirka, K., (2005b) Igneous thermometers and barometers based on plagioclase + liquid equilibria: test of some existing models and new calibrations, American Mineralogist, v. 90, p. 336-346.

Putirka, K. and Condit, C. (2003) A cross section of a magma conduit system at the margins of the Colorado Plateau, Geology, v. 31, 701-704.

Putirka, K., Ryerson, F. J., and Mikaelian, H. (2003) New igneous thermobarometers for mafic and evolved lava compositions, based on clinopyroxene + liquid equilibria, American Mineralogist, v. 88, p. 1542-1554.

Putirka, K. (1999a) Melting depths and mantle heterogeneity beneath Hawaii and the East Pacific Rise: Constraints from Na/Ti and REE ratios, Journal of Geophysical Research, v. 104, p. 2817—2829.

Putirka, K. (1999b) Clinopyroxene+liquid equilibrium to 100 kbar and 2450 K, Contributions to Mineralogy and Petrology, v. 135, p. 151-163.

Putirka, K. (1997) Magma transport at Hawaii: Inferences based on igneous thermobarometry, Geology, v. 25, p. 69–72.

Putirka, K., M. Johnson, R. Kinzler, and D. Walker (1996) Thermobarometry of mafic igneous rocks based on clinopyroxene-liquid equilibria, 0-30 kbar, Contributions to  Mineralogy and Petrology, v. 123, p. 92-108.