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Macalester College Geology Department

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People in the Department

John Craddock - Professor
Structural Geology

I cover the structural geology, tectonics, and geophysical end of our curriculum in addition to a variety of introductory courses and January field excursions (Costa Rica, Mojave Desert, etc.). This includes Structural and Field Geology (GEOL 255), Geophysics (GEOL 301), Dynamic Earth and Global Change (GEOL 150), and Oceanography (GEOL 100). My research interests include using microstructural techniques to analyze rock fabrics and interpret geologic structures.

Office: 114 OLRI | Phone: 651-696-6620 | Email:

Kristi Curry Rogers - Assistant Professor (Sabbatical Fall 2011)
Vertebrate Paleontology

I'm a vertebrate paleontologist most interested in studying dinosaur evolution and paleobiology. My current research focuses on the evolutionary history of Titanosauria - the latest surviving and perhaps most diverse lineage of long-necked sauropod dinosaurs. Titanosauria includes over 40 species that had a near-global distribution during the Late Cretaceous. They are of particular interest to me and my students because of the incredible array of adult body sizes attained within the group. Titanosauria includes the largest land-living animals of all time, as well as species thought to be dwarfs. Among dinosaurs, titanosaurs may be one of the only groups to experience a body size reduction during their evolutionary history. With regard to paleobiology, I am most interested in understanding dinosaur life history, and utilize bone histology to explore and reconstruct growth patterns in extinct dinosaurs, living birds, and other vertebrates. To these ends, I also conduct field research in Montana, Madagascar, and Zimbabwe. I am jointly appointed in the Biology Department at Macalester, and teach a selection of courses that relate to my research interests, including: (1) Dinosaurs (GEOL 101), (2) Biodiversity and Evolution (BIOL 270), (3) Comparative Vertebrate Anatomy (BIOL 394), and (4) Vertebrate Paleobiology (GEOL 394).

Office: 115 OLRI| Phone: 651-696-6799 | Email:

Kelly R. MacGregor - Associate Professor and Chair
Glacial Geomorphology

As a geomorphologist, I study the forces that shape the physical surface of our planet. I measure active processes in the field (such as glacier motion, subglacial erosion, water velocity, and sediment transport), and use these data to constrain numerical models of landscape evolution over geologic timescales. My current research focuses on understanding the role of glaciers in shaping alpine landscapes. I use tools such as GPS to understand how glaciers behave over daily to annual timescales, and numerical models to examine their role in creating the fantastic mountainous landscapes we see today. In addition to my work on glaciers, I am interested in the effects of dams on sediment and water transport in river systems. By looking at historical data and making measurements of current river dynamics, we can quantify changes in sediment transport, which has important implications for riparian habitats over time. I teach a wide range of classes, including Geomorphology (Geol 260), Rivers and the Environment (Geol 194), Environmental Geology (Geol 120/Envi 194), History and Evolution of the Earth (Geol 155), and Glaciers and Climate (Geol 394).

Office: 116 OLRI | Phone: 651-696-6441 | Email:

Raymond R. Rogers - Professor (Sabbatical 2011-2012)
Stratigraphy and Paleontology/Taphonomy

My research is focused on sedimentary geology and vertebrate taphonomy. With regard to the rocks, I am most interested in terrestrial depositional systems. My work (click here to see my research page) to date has focused on the reconstruction of nonmarine depositional systems and the application of sequence stratigraphic methods in nonmarine records. With regard to the fossils, I have spent most of my time exploring the taphonomy of dinosaur-bearing rocks. My work on rocks and dinosaurs (and dinosaur precursors) has taken me to the Cretaceous foreland basin of Montana, the Triassic Ischigualasto Basin of Argentina, the Triassic-Jurassic Karoo-equivalent rocks of southern Zimbabwe, and the Mahajanga Basin of Madagascar. I am fortunate to teach a selection of courses that relate to my research interests, including: (1) History and Evolution of Earth (GEOL 155), (2) Paleobiology (of both Vertebrates and Invertebrates), and (3) Sedimentology and Stratigraphy (GEOL 265).

Office: 111 OLRI | Phone: 651-696-6434 | Email:

Karl R. Wirth - Associate Professor
Mineralogy/Petrology/Planetary Geology

My research utilizes geochemistry to study the origins of igneous rocks and the evolution of continental and oceanic crust. I teach Mineralogy (GEOL 250) and Petrology (GEOL 302), as well as several introductory courses including Exploring the Solar System (GEOL 102) and Dynamic Earth and Global Change (GEOL 150). I regularly lead students on field excursions during the January intersession to Hawaii, Costa Rica, or the Galápagos Islands, and I teach Geologic Field Methods during summer. Recent research with students has focused on rocks in the Bering Sea region, southern Ontario and northern Minnesota, the Galápagos Islands, Tanzania, and Cozumel.

Office: 113 OLRI | Phone: 651-696-6449 | Email:

Jeff Thole - Laboratory Supervisor and Instructor
Igneous Petrology/Hydrogeology

I teach the laboratory sections of both of our introductory courses (GEOL 150 and 155) and have taught Mineralogy (GEOL 250) on a number of occasions. I came to Macalester after 5 years of doing hydrogeology with two different environmental consulting firms here in the Twin Cities. My other duties include maintaining, running, and user instruction for the instrumentation housed in the Macalester Scienc e Division's Keck Laboratory (see our Department Resources page). I also manage our student work study force, maintain departmental computer facilities, maintain our web content, and do a plethora of other tasks.

Office: 112 OLRI | Phone: 651-696-6426 | Email:

Affiliated Faculty - Environmental Studies
Louisa Bradtmiller - Assistant Professor
Climate Science

I am an isotope geochemist and paleoclimatologist/paleoceanographer interested in the ocean's role in climate change over glacial-interglacial timescales. My recent research includes the use of uranium-series isotopes in the reconstruction of glacial ocean circulation rates, and in the characterization of those same isotopes in modern seawater and sediments. I am also involved in ongoing research into ocean biogeochemistry and nutrient cycling, with a focus on the transfer of carbon between the ocean and atmosphere during periods of past climate change. I started at Macalester in Fall 2009.

Office: 249C OLRI | Phone: 651-696-6837 | Email:

Visiting Assistant Professor - Geology
Colin Robins

My research is a product of personal interests in soil genesis, geomorphology, arid system processes, and the relationships between landscape change and human activity. My main research focus at present seeks to identify soil-geomorphologic controls on the distribution of a restricted-habitat, gypsophilic plant species in Clark County, NV. I am also continuing research on the genesis, mineralogy, and chemistry of carbonate-cemented soils as relevant to new applications of isotope geochronology to desert landforms and/or paleosols. Whenever possible, I also enjoy using GIS to assess spatial aspects of soil-geomorphologic processes. I will be teaching four Geology courses during the 2010-2011 academic year: Dynamic Earth & Global Change (GEOL 150) and Geomorphology (GEOL 260) in the Fall, and Geological Hazards (GEOL 194) and Soil Properties & Genesis (GEOL 294-01) in the Spring.

Office: 116 OLRI | Phone: 651-696-8159 | Email:

Barbara Ekeberg - Department Coordinator

Barb joined the Chemistry Department in September, 1988, as Administrative Assistant. In 1997, her role expanded to become the Department Coordinator for both the Physics and Geology Departments. In her position, she provides secretarial support for all three departments in addition to other duties in the Chemistry Department. She enjoys getting to know the students each year. For relaxation, she likes tennis, gardening, traveling and watching professional basketball.

Office: 118 OLRI | Phone: 651-696-6105 | Email:

Macalester College · 1600 Grand Avenue, St. Paul, MN 55105  USA · 651-696-6000
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