Ray Wiggers' April 2005 Newsletter

Dear Friends,

I find myself greeting the onset of spring by attending to the one teacher's task I don't particularly like: writing, administering, and grading a pile of college exams. One of the more common lines I hear at such times comes from students whose performance on a recent test hasn't matched their expectations. "Well, I knew the material," they tell me, "but I'm just not the verbal type." Generally, a sense of diplomacy keeps me from pointing out that the ten minutes of tragically eloquent self-justification that usually accompanies such a comment is in fact quite impressively verbal.

Instead, I infer that the disappointed student wishes the test had been a lot more like TV: less text, more friendly pictures. But in fact words in print, including those in my tests, are themselves pictures only once removed. When one reads the term elephant, for instance, one sees, or should, a very big mammal with a prehensile snout contentedly flapping its ears in the warm confines of one's own mind. And there is this magical aspect of pictures once removed: they exercise and inform the imagination in a way that other pictures often do not.

While I suspect that most of the readers of this page are by no means in the verbally deprived category, I'd still like to show my openness to modern social trends by composing the rest of this newsletter prologue in a warm, fuzzy, nonthreateningly visual format.(If this concept proves popular, I may even incorporate an emotionally sanitized puppet show in the next edition.)

So. In just a few days, and and my latest band of fellow travelers will be heading south to investigate and admire

PART I. NONLINEAR SOLILOQUIES & SERMONS

A. The Glittering Streams of the Goldilocks Zone

We take too much for granted. We forget the grand cosmic luck upon which all our lives depend. For example: our small, rocky world occupies, from our own biochemical perspective, just about the best place that any planet in any solar system can. Astronomers drolly call the Earth's own region of space the Goldilocks Zone -- the allusion being that our planet's position with respect to the Sun is, like the best of the Three Bears' bowls of porridge, not too hot, not too cold, but just right.

But not too hot or too cold for what? Well, for many things - and most fundamentally, for liquid H20 to exist at the surface. That has made all the difference. The living organisms of this world, from bacteria to saguaro cacti to human beings, are achingly dependent on this simple if quirky chemical compound. But the situation inside the Goldilocks Zone is a different matter; whatever water there once was on Venus and Mercury has long since boiled away into space, and with it, the hope for life as we know it. And outside the situation isn't much better. There is an abundant supply of water on at least some of the outer planets and moons, but due to the much lower temperatures of the outer solar system it's mostly in the form of ice.

One of the most beautiful and intriguing manifestations of our own planet's supply of liquid water is what it does when it moves downhill, in a pattern geologists call channel flow. Here's one example of this process:

B. A Fossil's Travels in Space and Time

One of the great joys of being a wandering lecturer is that I often get the chance to meet and learn from local experts. Last month, that's precisely what happened when I had the honor and delight of addressing the annual meeting of the Jo Daviess Conservation Foundation, in Galena, Illinois. Afterward, Lester Johnson, a scientist with his county's soil and water conservation district, invited me to see a rather unprepossessing roadcut located along a little-used two-laner in the otherwise beautiful hill county between Galena and the upper Mississippi. The reason Lester wanted to show me this spot quickly became apparent. Wedged between the Ordovician-Period dolostone and a thin mantle of windblown glacial silt known as loess sits a thick layer of unconsolidated sediment that quickly turns the boots and trouser legs of its inquisitive beholder a rusty, muddy brown. This deposit goes by the name of the Grover Gravel. It's one of the most enigmatic aspects of Earth history to be found in the American Midwest.

While it may lack scenic appeal, I will be incorporating this stop in my future tours of this region of already abundant geological venues. Embedded in the Grover's matrix are smoothed and polished chunks of chert -- a very resistant rock made of microcrystalline quartz. Apparently this material, found here and there in the Driftless (unglaciated) Area of northwestern Illinois and southwestern Wisconsin, was deposited by some ancient river -- perhaps an ancestral version of the Mississippi itself. But when, exactly? Geologists still aren't sure. Most have surmised that it dates at most to a few million years ago -- from either the Pliocene Epoch or the succeeding Pleistocene. But some have suggested it may be as old as 100 million years or so, in which case it would have formed in the Cretaceous Period, the final chapter of the time of the dinosaurs. Whatever the truth of the matter really is, the roadcut is a doorway that beckons us into a time rarely glimpsed, due to the forces of erosion that have now reduced the Grover Gravel's extent in this part of the country to a few surviving locations.

PART II. REVIEWS IN THE REALM OF NATURAL HISTORY

A. Books: Botany & Lichenology. For many years now my interests in botany have included one of the most intriguing forms of life -- the lichens. These composite organisms, symbiotic relationships between a fungal host and photosynthetic algae and cyanobacteria, exhibit such an impressive variety of forms and colors, and inhabit such a variety of habitats, that one can only marvel at them. While a number of keys and field guides to the lichens have been around for decades, naturalists were justly elated by the recent publication of The Lichens of North America by Brodo, Sharnoff, and Sharnoff (hardback; Yale University Press; ISBN 0300082495). Quite modestly priced, given its impressive bulk and stunningly beautiful color photography, this book is a requirement for every person whose interest in the natural world extends beyond equivocal dabbling. I personally have profited more than I can say from this guide's taxonomic revision and discussions of lichen ecology and ethnobotany.

As the scene above shows, flowing water has a great tendency to collect itself into well-defined thoroughfares. During a rainstorm, you may notice that water moves down a slope in a different way --as a broad sheet with no definable borders. However, such flow quickly coalesces into grooves and rills that etch themselves into the landscape. Where I work, on the crest of a glacial end moraine in Lake Forest, Illinois, the power of even small streams is evident in the deep ravines that run down to the Lake Michigan shore. At this time of year, melting snow and early spring rains ensure plenty of runoff, and it is in these few short weeks when these local creeks do almost all the erosive work they'll accomplish in the span of the year. Two months from now their beds will most likely be completely dry.

Another remarkable feature of streams, and one which we take too much for granted, is how they connect with one another. As they do so, they form large and intricate drainage patterns. Tributaries merge into fewer, larger tributaries that in turn lose their identity in the master channel, or trunk stream. The most prevalent drainage pattern is the one termed dendritic -- from the Classical Greek dendron, or tree. Indeed, the pattern of the trunk and its tributaries does resemble the main stem and ramifying branches of a lofty oak.

Stream channels are a familiar sight practically everywhere on Earth -- even our thirstiest deserts have them. (And it is these arid landscapes that have the most picturesque terms for streambeds: washes, arroyos, gullies, gulches, pouroffs, and wadis.) But what we did not realize until quite recently is that surface drainage channels are not necessary restricted to the Goldilocks Zone, after all. We now know that two worlds beyond it -- the planet Mars and Titan, the aptly named moon of Saturn that is larger than the planet Mercury -- have flow channels of their own. While it's very possible that the Martian surface was previously warm enough for liquid water to flow across it, what made the dendritic patterns on far-distant Titan, whose surface, thought to be a mixture of water ice and hydrocarbon compounds, is a frigid -250 degrees Fahrenheit? Only time and additional space probes will tell. For now, let's just imagine that Titan has its own equivalent of Goldilocks, who considers the numbing cold and bubbling springs of liquid methane just right by her extraterrestrial standards.

(For images of extraterrestrial drainage channels, see this Mars Global Surveyor gallery and the European Space Agency slide show of shots taken by the Huygens Titan lander.)

The pieces of chert provide their own important clues. Apparently they are derived from now largely obliterated strata of the Silurian Period -- the span of time that followed the Ordovician. But that's not the only treasure one finds here. There are also beautiful fossils of marine animals that flourished in the tropical seas of 500 to 400 million years ago. After only a few minutes of rummaging about, I discovered a rounded lump of tabulate coral, which I believe belongs to the genus Calapoecia. If my identification is correct, it means I've found one of the few fossil coral genera that survived the great mass extinction that took place at the end of the Ordovician.

Imagine, as I did, the journey that particular fossil coral has taken. It was first formed by tiny colonial animals, the ancestors of those who now build the great barrier reefs of today's oceans. At some point in the far-distant past this hard-walled little dwelling-house, the diameter of a silver dollar, was buried in lime mud of a shallow tropical sea that then covered the heartland of proto-North America. No doubt many other layers of rock formed above it, too. For hundreds of millions of years the coral remained buried, while above it oceans and ice ages came and went, and untold species and ecosystems rose and fell. But then the inexorable forces of erosion finally exposed it to the open air. Not long thereafter, the fossil was freed from the matrix of rock that had enclosed it and, as luck would have it, it was washed down into the channel of the mysterious river cited above. Then it was carried downstream some now immeasurable distance and dumped it at its present site. Had I not picked it up myself and put it in my pocket, it might have embarked on yet another journey, down to the modern Mississippi.

But of course its journey is not over, even with my interference. I am merely that beautiful little fossil's temporary custodian. I would like to think that it will travel, long after my time is done, through many other human hands, to excite again and again the same sense of wonder it has given me. Thanks, Lester.

A Ghostly Beauty. Participants in my upcoming tour of Wisconsin's Kettle Moraine and Door Peninsula (see my Tours Page) will have the opportunity to see many wildflower species, but none could be more fascinating than this. It's squawroot (Conopholis americana), a highly advanced dicot that has given up what seems the absolute birthright of all plants -- the ability to photosynthesize. Devoid of the green pigment chlorophyll, it acquires its food by parasitizing the roots of forest trees. When it bursts into glorious bloom it reveals its evolutionary affinity with wood betony (shown in the February 2005 newsletter). These two species are related at the order level.

On the Rocks. When one thinks of a glacier, one naturally thinks of moving lobes of ice. But here a mass of large boulders is doing much the same thing in Colorado's evocatively named Never Summer Range. Termed a rock glacier, this giant tongue-shaped structure, just behind the trees on the farther shore of Lake Agnes, moves downhill much the same way a regular glacier does. In fact, it may retain an ice core that formed during colder episodes of the modern Ice Age. For more on this lovely locale, visit my Southwestern Geology Gallery.

The Toughest of a Tough Breed. It may not have the grace or grandeur of the Eastern white pine, but the jack pine (Pinus banksiana) is impres-sively tolerant of extremely poor soils and frigid or blustery climes. But in my view, the specimen at center in the photo at right takes the prize for adaptability. It's growing directly out of a glacially abraded outcrop of iron ore (otherwise known as banded iron formation, or BIF) along the Mag-netic Lake hiking trail in northern Minnesota's Superior National Forest. Incidentally, this rock, so crucial to our metal-hungry civilization, is no longer being formed. According to modern theory, it can only be pro-duced when the Earth's supply of free oxygen was much smaller than it is now.

Having said that, I must also note that Lichens of North America suffers somewhat from trying to fulfill too many missions at once. On one hand, its size and handsome design mark it as the most laudable of coffee-table books -- one which can keep the browsing naturalist's rapt attention for hours. On the other, its extensive keys and technical descriptions of hundreds of species show that it is also supposed to be a rigorous work suitable for the serious student. These two approaches do not necessarily dovetail well. At nine pounds, the book is much too ungainly to be carried into the field, unless one has a pack mule. It's a guide that must be relegated to a place where it will not be jostled and battered to pieces.

And two other things. Having used it extensively, I confess that its keys are not as well written as some; they can be confusing and even misleading. And despite its 794-page length, the book doesn't list all the species I've come across in the United States alone. But, as every botanist who uses keyed guides knows, even an ambitious a work like this, however competently researched and compiled, can never be a perfected form in its first edition.

B. Books: Geology & Mining History

When I was an undergrad, my only really dismal Earth-science course was Economic Geology -- perhaps because my professor, on loan to Purdue from a here-unidentified eastern-European country, was a man for whom English was not a second language, but a twelfth. My fellow students and I sat dumbfounded at his bizarre take on the syntax and pronunciation of the technical jargon of our own mother tongue. To this day, I recall his Planet-X description of the environment in which aluminum ores form: "According to thees hypothayziss, bauxites accoomilate in swemps, when strems changes his meanders." Nevertheless, I find an appreciation of the geology and history of mining growing in my middle age. How could it not, after I've spent so much time in Upper Michigan's magnificent Keweenaw Peninsula?

Two books on the great nineteenth-century copper boom of that ancient region are well worth reading. I suggest you tackle them in this order: first Angus Murdoch's vintage Boom Copper (paperback; reprinted by the Quincy Mine Hoist Association of Hancock, MI; no ISBN) and then David Krauses' much more recent The Making of a Mining District: Keweenaw Native Copper, 1500-1870 (hardback; Wayne State University Press; ISBN 0814324061). While the former title is an interesting specimen of 1940s-era journalistic narrative, the latter is an adaptation of its author's Ph.D. dissertation. But that doesn't mean that Krause's account is dry and academic. It combines excellent research and fresh reappraisal with a lucid prose style that is painfully lacking in most modern Americans with higher degrees. And, just as importantly, Krause's work corrects Murdoch's hyperbolic and and science-challenged approach. But if there is one thing that makes this writer's text applicable even to persons with no great interest in mining or Michigan history, it is that he provides an excellent overview of the not always benign transition in American science from the age of the amateur observer to that of the professional theoretician.