Stromatolites: Ancient, Beautiful, and
The lead author, Bob Leis, is a stromatolite enthusiast who was hooked after he purchased his first example. Wanting to learn more about these fossils, Leis found that there was little available in the popular literature that described or explained these beautiful forms. He decided to fill that void by researching and then publishing this book. Leis teamed up with Bruce Stinchcomb, a retired geologist, who has published numerous books making geology and paleontology topics accessible to the general reader.
I stumbled on Stromatolites while searching Amazon for another book on a different paleontological topic. Amazon was kind enough to recommend this book to me intuitively knowing of my interest in stromatolites. The reviews linked to Amazon were all very positive but had no influence on my purchase since I hadn’t read them until after I did my own review.
The bulk of Stromatolites consists of eleven chapters, each heavily illustrated with full color photographs of beautiful specimens. Most of the specimens are cut and polished examples as you may find at Rock and Mineral shows but there are also many specimens photographed in the field - some as large as automobiles. Where appropriate, artist’s illustrations of paleoenvironments are included. Each chapter ends with a Glossary and a Bibliography. Stromatolites ends with a page and a half general Index.
Stromatolites begins with a brief Introduction. Here Leis offers an outline of earth history from the geological standpoint and the view of early single celled life forms. A time line of earth history is nicely illustrated with annotations showing when stromatolites were the most abundant.
The first chapter explains just what these fossils actually represent. Leis explains that stromatolites occur in a few differing forms but usually we most often recognize them as layered structures forming flat or domal shapes. All shapes of stromatolites are the product of bacterial colonies or mats. The layers are generated as the mats get covered with sediments. These sediments are then fused into the structure while the bacterial colony continues its upward growth. With periodic sediment incorporation and regrowth, the familiar layered structure of the stromatolite is formed. It may be of interest to know that stromatolites are actually considered trace fossils as the original bacterial colony itself is not fossilized. Leis also admits that there are times when it is difficult to be certain that a layered rock is truly a stromatolite so you’ll see reference to stromatolite, stromatolitic and moneran mats.
In Chapter 2, stromatolites are revealed as evidence of the earliest fossilized remains of life on the earth. Here Stinchcomb presents a history of investigations into stromatolites that surprisingly begins with Paleozoic stromatoporoids in the 1850's. Next up was the discovery of Eozoon canadense in the 1860's; this later was determined to be a pseudofossil. Archeozoon and then Cryptozoon were discovered in the early 20th century with the latter being the first true stromatolite. Other structures are discussed here including Microbial Induced Sedimentary Structures (MISS). These are much more difficult to identify as they, “were originally films, globs, or chips of moneran [Prokaryotes: Archaea and Bacteria] mats that covered the sea bottom or other surfaces and then were preserved by partial mineralization.” (p. 23) Stinchcomb reveals that the glory days of stromatolite dominance had all but ended before the middle Ordovician.
Leis includes a chapter on Banded Iron Formations (BIF). BIF’s are not stromatolites but their existence is evidence of the Great Oxidation Event that produced the vast iron deposits around the earth. The oxygen that allowed for BIF formation was produced by stromatolites and other bacterial mats as cellular production of energy by photosynthesis developed, with oxygen as a waste product. BIF specimens are beautiful in their own right and are widely collected.
The oldest stromatolites are those from the Archean, 4 bya to 2.5 bya. These most ancient forms are discussed by Stinchcomb and illustrated in Chapter four. So far, the oldest confirmed stromatolites are 3.5 bya examples from Australia.
The largest chapter is devoted to a chronologically arranged worldwide collection of stromatolites (Chapter 5, Stromatolites Through Time and Around the Globe). Of local interest is a Silurian laminar stromatolite from Huntsville, Ohio. Ordovician specimens are shown as well but none from our local area (more on that topic later). I was surprised to learn that one of my favorite stromatolite fossils - a black and gold layered type from Bolivia - is actually a fresh water form. Prior to reading Stromatolites I had incorrectly assumed that stromatolites were all from salt water environments.
Stinchcomb also wrote an introductory section to Chapter 5. Here is another professional geologist that understands the benefit of amateur/avocational collectors. The major portion of this introduction to the chapter regards just that understanding. Stinchcomb express displeasure with “some” who criticize commerce in rocks and fossils. He believes that efforts to halt this commerce by prohibiting collecting is counterproductive to the learning experience for the public. Misunderstanding of the difference between the rare cultural artifacts that are the realm of archeology with the abundance of paleontological objects is part of the problem. Stinchcomb quotes John Pojeta, “the more eyes looking for fossils, the better for paleontology, as this increases the likelihood of some previously unknown types being found.” This quote should be made into a banner.
Stromatolites has a chapter that reveals many examples of specimens that resemble stromatolites but are, in fact, not. Here, Stinchcomb explains that some are not even fossils at all. Specimens identified as Cretaceous “sand stromatolites” are in fact concretions of non-biological origin. The scope of information in this chapter alone would serve the beginning collector well.
Stinchcomb includes a chapter on hot spring deposits. Leis offers additional chapters on petrified wood and other material of biogenic origin; where to find stromatolites; and modern stromatolites.
Overall, this is a wonderful book that is a welcome addition to the literature available to the general public covering a less flashy topic than dinosaurs. But how can one not be amazed by fossils that illustrate the earliest forms of life on the earth? Stromatolites answered a lot of the questions I had about stromatolites but not all of them. I still have some questions about the author’s use of the terms stromatolite and stromatolitic. I noted that Leis captioned a specimen of Australian Tiger Iron (a BIF) stromatolitic but later in the same caption he called it a stromatolite. (p. 54) The specimen in question is highly folded tectonically, as many BIF’s are, giving it the appearance of a conical stromatolite in cross section. This is doubly confusing since in his chapter concerning BIF’s, Leis states clearly that BIF’s are not true stromatolites at all but sedimentary structures that may be described as chemical trace fossils.
I have found myself reading and re-reading Stromatolites. In doing so, I have been able to identify a specimen of my own that had lost it’s provenance and was also able to correct age and locality information on another specimen.
One minor complaint I have is the authors’ use of coins for scale in almost all of the photographs. I certainly know how big a U.S. penny is but I have no idea of the size of a Canadian dollar coin, an Australian half-penny coin or the mystery Russian coin in Figure 5-22, p.57. Stromatolites is a book of worldwide interest and inclusion of a metric scale would have been more universally understandable.
On a more serious note, I discovered an error of fact in Stromatolites. Figure 5-83, p. 69, purportedly illustrates an Ordovician stromatolite from Winchester, Kentucky. Interestingly, this is the only photograph in the book that was printed inverted from life position (perhaps a publishing error). Leis states in the caption that, “rockhounds call it red algae.” Recalling the definition of stromatolites as trace fossils, this particular fossil is a body fossil that preserves cellular structure easily visible under low power magnification. These fossils have been described in the professional literature as Solenopora sp. - a red corraline algae. More recent work by Riding, 2004 maintains that Solenopora is not an algae at all but a Chaetetid sponge. Neither of these interpretations can be confused with a stromatolite. I have collected this material myself and have some knowledge of it but I did verify what I have stated here with Dr. Brenda Hunda, Curator of Invertebrate Paleontology at the Cincinnati Museum Center Geier Collections and Research Center and with Dan Phelps, geologist and president of the Kentucky Paleontology Society.
Readability - Suitable for general readers high school and up.
On the Upside - Excellent photographs and reconstructions. To date this is the best source for information on stromatolites available to the collector. Very reasonably priced for a book with such high quality color photographs.
On the Downside - The error concerning Solenopora disturbed me as it begs the question, are there other errors that I did not catch because I lacked personal knowledge?
Overall Rating - Stromatolites is well worth buying for enthusiasts of stromatolites and BIF specimens. The one error is unfortunate but it doesn’t greatly degrade from the value of Stromatolites as a very good reference on the subject.