I've still got rocks in my head

I'd like to boast that a burning intellectual curiosity led me to geology, but in truth, a friend put rocks in my path. A declared English major, I was pondering how to meet the onerous undergraduate science requirement at the University of Rochester, N.Y.

"Geology 101," M.L. said decisively. "it's not hard, and they take you on great field trips."

Having struggled with chemistry and physics in high school, I liked the sound of "not hard." I signed up for the course, taught that semester by an enthusiast who brought earth science alive. We visited nearby drumlins and eskers, glacial ponds and rock outcrops along the Genessee River, which flows down its deep, stratified gorge through the very heart of Rochester.

I found it all too easy to get hooked on geology and ended up with a double major – barely squeezing in enough credits for a diploma in English. I learned more than I'd ever thought possible about the sciences underpinning geology (including chemistry and physics), but my old passion for words resurfaced as I worked toward my master's thesis on a suite of Florida Key limestones.

After completing my project, I felt no inner urge to delve more deeply into the complex history of these or other rocks, but i'd loved writing that thesis. For a time, I found my niche in popular science reporting with geology as a focus.

I don't do this much now, but having once been intimate with geology, I find that i can't walk away from it, any more than I can tune out the haunting Latin roots of everyday speech. (Miss Schleyer, who once threw up her hands at my reading of "The Aeneid" with an explosive "Ye gods and little fishes!" would take pride in that.)

Geology, in fact, has proved to be even more broadly valuable than Latin, not to mention some of the other things I've studied. It adds piquancy to my travels: That's not just a river I've crossed, but the collective muscle of an entire drainage basin. It helps make sense of the news, even apart from earthquakes and volcanoes. Surprisingly, human events often relate in some way or other to the resources locked in rocks.

I find myself engaged in earth history on the most ordinary of days, in part because the boundary between two rock formations (a geologic "contact") runs right through our farm. On a certain ridgetop, I can walk among the cedars on the weathered surface of the Ramp Creek formation of Indiana limestones and dolomites, deposited more than 300 million years ago on what was then a shifting marine delta. Geodes, weathered out from the rock, dot the ground like rough earthen Easter eggs. Kids love the geodes, especially the ones with partly hollow centers and a loose fill that rattles with promise. A hammer blow may yield a glittering interior of crystalline quartz or disappointingly grubby rubble. The neat thing is that you never know what you'll find until you open one up. In his younger days, my son got good entertainment out of those rocks.

From the cedar grove, you can follow a path down to the streambed and wade atop the older Edwardsville formation of siltstones, shales, and limestones. Some of the rocks are riddled with the fossil remains of ancient crinoids, or sea lilies, invertebrate animals that swayed from the ocean bed on delicate calcified stalks.

I don't consciously think of crossing a geologic contact every time I make the familiar journey from cedars to stream, but I am aware of the boundary somewhere in my bones, and it makes the farm that much more evocative to me.

Recently, I sat at an outdoor dinner party with two young geologists visiting Indiana University. Wanda, a clay mineralogist from Argentina, and Francesca, a hydrologist from northern Italy, had come to geology obliquely, as I had (and in part for the field trips). Like me, they marveled at their profession's power to stretch muscles and broaden horizons. At our table under the trees, we three became positively rhapsodic.

"Geology keeps you young," Wanda declared, deftly summing up what we'd so earnestly been trying to get at.

Maybe one day I'll meet a jaded geologist, but I doubt it. In writing this, I called my neighbor, a crinoid specialist who taught paleontology (life history) at Indiana University until his "retirement" a few years ago. Gary remains active in the profession in countless ways (he still leads a dynamite field trip), and I knew he could answer whatever question I posed about our local rock formations.

My call led to a visit. We pored over local contour maps from 1908 (predating our house but not the farm's original settler's cabin) and from 1986, long after the creek valley south of the farm had been flooded to provide our town's first municipal water supply.

It was fascinating to compare the maps and to trace the Edwardsville/Ramp Creek contact through our own stream valley. I felt like an undergraduate again, and Gary certainly didn't seem to mind interrupting his afternoon for the impromptu tutorial. It got me thinking of sitting in on a refresher course in stratigraphy or paleontology.

Or at least tagging along on a field trip.