Friday, March 18, 2011

Plant of the Week


Spiderwort
Tradescantia ohiensis Raf.
other common names: blue jackets, cow slobbers, Job’s tears, Ohio spiderwort, widow tears
Tradescantia: in honor of John (the older) Tradescant, gardener to Charles I, King of England in the early 17th century
Ohiensis: meaning “of or from Ohio”
Spiderwort family: Commelinaceae

Photograph by Thomas Rosburg, Wildflowers of the Tallgrass Prairie: The Upper Midwest, Second Edition

Wednesday, March 16, 2011

An Interview with Paul Garvin: Part 3

What other areas of geology particularly interest you?
I have a lot of interest in natural disasters, like earthquakes, volcanic eruptions, landslides, hurricanes, and floods, and their impacts on human activity. Decision makers continue to make foolish, and very serious, mistakes about land use because they are ignorant of, or they ignore, simple principles of earth dynamics. I taught several courses at Cornell College on this subject. I am also interested in forensic geology (the study of geologic materials for the purpose of solving crimes).

You are currently doing archaeological research. Tell us more.

My research might best be called mineralogy in service of archaeology. I have a passion for archaeology, which stems from my boyhood days as an amateur arrowhead collector in Idaho. I have no formal training in the discipline, but my knowledge of mineralogy has helped me answer some important questions about how, for example, aboriginal Iowans made their pottery. I have been collaborating with the Office of the State Archaeologist in Iowa City on a study of pottery that was excavated at a site at the Dows Preserve (across from Palisades-Kepler State Park). The Woodland peoples admixed crushed rock (temper) with the clay, in order to control shrinkage during drying and firing, so as to prevent cracking. Through a microscopic study of pottery sherds, I have discovered that different potters preferentially selected (and deselected) specific rock types for inclusion in their pottery. This knowledge has enabled to us determine whether the pottery was made locally or imported to the use area. (There is more to this, but I’ll stop here.)

Paul Garvin, Iowa’s Minerals: Their Occurrence, Origins, Industries, and Lore