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September-October 2010

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Media Reviews: September/October 2010

 

 Historic Photos of Colorado Mining Review by Ed Raines. Turner Publishing Company, Nashville, Tenn.; 216 pages; 2009; $40 (hardbound). http://www.turnerpublishing.com/

This well-done book is a photographic essay of Colorado mining from its infancy in 1859 through the development of a modern industry during the first two decades of the twentieth century. The book is arranged into six chapters or segments. The first covers the initial gold rushes and the sometimes monumental efforts to develop mining in the Colorado Rockies. The second illustrates the development of the silver industry between 1867 and 1895. This is followed by a review of underground mining techniques. Chapter 4 is devoted to the special conditions of mining in the San Juans. The fifth chapter covers the last two great rushes, those to Creede and to Cripple Creek. The final chapter, “Mining for Industry,” explores Colorado mining as it responded to the industrial demand for raw materials that include iron, molybdenum, zinc, and others. Each chapter begins with several introductory paragraphs that set the stage for the photographs to come. The photographs themselves are sharply reproduced, and most are essentially page size. Each is accompanied by a cogent and informative caption. Most have not been published before, and two struck me as particularly interesting. The first shows three silver “nuggets” mined at Aspen and weighing collectively more than 1 ton. The second is a rare illustration of square-set timbering in a stope fully 30 feet high. Although the location is not given, it is likely taken in one of the bonanza stopes underlying Fryer Hill at Leadville.

An important aspect of the book is the careful attribution of each photo in a final section titled “Notes on the Photographs.” Here we find that many of the photographs are from the collections of the Denver Public Library, the Colorado Historical Society, the Library of Congress, and the author's personal stash. In most instances the call or box number of the photo is given.

This is the sort of book of which there cannot be too many. It makes a nice companion to such earlier but still available photographic works devoted fully or in part to Colorado mining history that include Secure the Shadow (a collection of Lachlan McLean Colorado mining photographs) by Smith and Wieler (1980), Fading Shadows by Leroy and Finney (1973), and the three-volume set titled The Mineral Belt (Digerness, 1977–1982). Historic Photos of Colorado Mining is certainly recommended to those persons interested in high-country mining, the great difficulties involved, and the development of progressively better mining and milling techniques in response to the demand for increased production that marked the phenomenal sixty-year period beginning in 1859.

Robert B. Cook
Auburn University
Auburn, Alabama

A Sea Without Fish: Life in the Ordovician Sea of the Cincinnati Region by David L. Meyer and Richard A. Davis Indiana University Press, Bloomington and Indianapolis. 368 pages; 2009; $44.95 (hardbound).

David Meyer and RichardDavis's new book, A Sea With-out Fish: Life in the Ordovician Sea of the Cincinnati Region, is superbly written, richly illustrated, up-to-date, fairly thorough, and downright entertaining in places. Upper Ordovician rocks of the tristate area around Cincinnati (Ohio-Indiana-Kentucky) are world famous for their hyperabundant, well-preserved fossils. Numerous technical and nontechnical writings covering Cincinnatian fossils have been published for more than 150 years. Several noteworthy Cincinnatian publications have come out in the last decade or so, but this is certainly the best summary so far.

The 368-page book has sixteen chapters and fourteen color plates. Chapter 1 gives good, readable introductions to the Ordovician, sea levels, fossil preservation styles, paleoecology, tectonic setting, and many other subjects. Chapter 2 surprised and thrilled me with a historical review, accompanied by photos(!), of early Cincinnatian fossil researchers such as U. P. James, Miller, Faber, Dyer, Foerste, Ulrich, and others. It's nice to finally put faces to many of the names that are cited in the literature. The historical chapter also includes some humorous anecdotes about these “founders” of Cincinnatian paleontology. I am intrigued by the reference to early Cincinnatian geologic maps that were never published (someone should!). Chapter 3 gives a nice overview of the basics of scientific naming, species authorships, biologic classification/taxonomy, type specimens, and rules of priority. Chapter 4 discusses stratigraphic concepts, limestone varieties, biostratigraphy, absolute age dating, transgressive-regressive cycles, storm beds, hardgrounds, and seismites and stresses the legitimacy of the “layer-cake” approach to Cincinnatian stratigraphy, despite the presence of lateral facies changes.

The next ten chapters deal with Cincinnatian fossils themselves and are arranged by taxonomic groups (algae to conodonts to trace fossils). This section of the book will be of most interest to aficionados of the Cincinnatian series, from amateur collectors to professional paleontologists. Each chapter gives excellent summaries of the anatomy and lifestyles of each group of organisms, followed by generally complete descriptions of the Cincinnatian representatives, most of which are illustrated by black-and-white photos. Many rare groups and species are at least mentioned (I would have liked to have read about and seen photos of all of them). Not surprisingly, given the authors' specialties, the sections covering cephalopods and echinoderms are especially well written and thorough. Being fairly familiar with Cincinnatian geology and paleontology, I was pleased to be made aware of several updated genus names of fossils. Occasionally, an outdated genus name is still used. I do have issues with a few species identifications, taxonomic assignments, and inferred biologic affinities (what paleontologist doesn't have “issues” there!). For example, Tetradium should not be confidently referred to as a coral, conulariids are not scyphozoans (they are not even diploblastic), Diplocraterion cf. luniformis is not a soft-sediment trace (it is the bivalve boring Petroxestes pera), and some of the trilobite names are a bit off. But these are minor quibbles.

Considering the generous number of pages in the book, it doesn't seem fair of me to ask, “Please sirs, may I have some more?” The book makes me want a 100 percent comprehensive photo atlas of Cincinnatian fossils. That's a Herculean task (takers, anyone?), but the quality of this book could be improved by the addition of just a few more photos of just a few more species in each fossil-group chapter (especially the graptolites and bryozoans). However, the authors do state that “This volume is not intended as a comprehensive taxonomic work.”

Chapter 15 gives an excellent overview of Cincinnatian paleogeography, paleoceanography, and depositional environments. Chapter 16 discusses ancient ecosystems and interspecies interactions that have been observed in or inferred from Cincinnatian fossils. I was delighted to read that several Cincinnatian-like marine biotas can be found in a few places in modern oceans. The book ends with a bit of a surprise: a five-page epilogue contains a wonderful time-travel story describing an imaginary snorkel and dive in the ancient sea that is now the Cincinnati area.

In terms of illustrations, most of the black-and-white photos in the book could have been improved by boosting the contrast a bit. Some of the figured fossils would have been better served with more magnified photos.

A Sea Without Fish is a fantastic book. Casual collectors will learn something; advanced collectors and geology students will learn something; even professionals will learn something, guaranteed. I was repeatedly thrilled to learn something new, even after being familiar with the Cincinnatian for three decades. I'm not recommending that you add this book to your library—I'm ordering you to!

James St. John
The Ohio State University - Newark 
Newark, Ohio

 Flint Ridge: Ohio's Original Art & Industry, DVD by by Effigy Digital Productions. Order from James R. Johnston, POB 366, Ashley, OH 43003; 740/747-3819. 90 minutes; 2008; $25 (includes postage and handling).

The beautiful flint from Flint Ridge in eastern Licking County, Ohio, has been known and utilized for centuries—artifacts made from the flint have been found from Canada to Florida and from Kansas City to Delaware, including such famous sites as Meadowcroft, Pennsylvania, and Big Bone Lick, Kentucky.

The geologic origin of that flint is an interesting topic. Unfortunately, you won't learn much about it from this DVD, as the geology is so basic as to be almost laughable; however, this is not a geology video but an archaeology one. Also, some could quibble with the classification scheme used—indeed, two archaeologist friends I showed it to (one amateur and one professional) did just that, but perhaps that is to be expected in such a contentious field.

If you just want to look at beautiful flint or beautiful artifacts, then this is the video for you; it is truly a feast for the eyes. Hundreds of artifacts are shown, with their distinctive features labeled—stem shape, thickness, notches, fluting, and so on. (The definitions came at the very end; it would have been more useful for this non-archaeologist if they had come earlier.) Artifact after artifact is presented, for an hour and a half. Beautiful as they are, the eyes glaze over. I recommend watching this video in two or three sessions.

Although dated 2008, when I tried to visit the Effigy Digital Production website for additional titles and information, it came up as having expired.

Dale Gnidovec
Orton Geological Museum
The Ohio State University
Columbus, Ohio

Studies on Agate: Microscopy, Spectroscopy, Growth, High Temperature, and Possible Origin by Terry Moxon. Terra Publications. 96 pages; 2009; £27 (softbound).

Terry Moxon is one of the few mineralogists in the world who is actively conducting research into the mysteries of agate geochemistry and textural development. In fact, he has been doing this for thirty-five years; it is his passion. This book is a compilation of articles from Moxon's research and numerous experiments, many of which were performed with equipment and faculty support at Cambridge University. Agate connoisseurs will notice that the chapter describing the formation of agates in Agates II, Zenz's second beautiful picture-book on agates, was written by Moxon.

Studies on Agate is an oversized, soft-covered book, printed on high-quality paper with good color reproduction. References are indicated by footnotes in the text and all citations are found in the back of the volume. The first chapter provides a rudimentary discussion of silica types and brief descriptions of well-known agate localities worldwide. The next two chapters discuss standard methods of viewing agates under optical and electron microscopes and the advantages and limitations of each. This may be new information for many nontechnical readers and is important for future discussions in the book.

Chapter 4 is a description of X-ray diffraction methods and research into the possible age of agates as a measure of their crystallinity. All agates are microcrystalline, but certain ones have a coarser structure than others. Moxon noticed that some agates from very old rocks had a coarser texture than others that were younger. It was presumed that the agates formed soon after the rocks in which they were enclosed. Therefore, the question was posed, did a correlation exist between the age and the coarseness of agates? To test this, he analyzed by X-ray diffraction twenty-six agates from rocks of vastly different ages from around the world. With some exceptions, the data suggested that older rocks, and presumably older agates, have larger microcrystalline structures than younger ones. Furthermore, this coarsening of crystalline size over time might be used as a rough age-dating scheme. Complications exist such as the cessation of growth caused by a common siliceous material called moganite found in agates or the impact of temperature from local hot springs that can accelerate the process.

In the next chapter, Moxon explores the effect of iron in the +3 valence state on the formation of silica and eventually agate formation. Small concentrations of iron (or other ionic species) in the colloidal silica solutions can change the average charge balance of colloidal silica particles and cause the precipitation of silica. The effects of pH, or the measure of acidity or alkalinity, can also affect the process. Chapter 6 describes the types of water that exist in agates and their loss at various temperatures. This has implications for the formational temperature of agates.

Cathodoluminescence results when a substance is bombarded by electrons causing the substance to emit light, mainly in the visible range. This is a standard tool for observing material qualities and, especially, impurities or structural defects. Chapter 7 discusses another experiment using this method that was devised to determine if the number of structural defects in agates increased with age. Certainly, we humans can identify with this. Although the red emission band from excitation by cathodoluminescence showed a decrease in intensity with age, suggesting the breaking of some silicon/oxygen bonds, the effects of age expressed in other wavelengths were more ambiguous. Results in general did not produce a robust age versus structural defect correlation. Apparently, agates age better than we do.

The last chapter, “Agate Genesis,” is perhaps the most important for the intellectually inquisitive agate collector who asks the question, how did my agate come into existence. It discusses and compares ideas from the past and lists numerous problems with understanding the processes of agate formation. Even though Moxon concludes that the processes of agate genesis are still poorly understood or, in some cases, just not understood at all, he provides considerable information about the possible mechanisms for their formation, and in more detail than will probably be found elsewhere.

I recommend Studies on Agate for the inquisitive agate collector, wood collector, professional mineralogist, or anyone interested in the mechanisms that produce one of the most common and beautiful forms of silica on the earth. It is not a pretty picture-book about agates; those already exist. Minor typos such as an omitted figure number and a formula requiring correction were noted. Moxon is an internationally recognized expert on agate genesis, and his writing indicates an appreciation for the complexities of these aesthetically compelling manifestations of microcrystalline silica. If you have questions about agates, post them on his website: http://agateworld.co.uk. Moxon will provide an intelligent and informed response, but don't expect definitive answers.

Richard D. Dayvault
Grand Junction, Colorado

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