Interpreting Pre-Quaternary Climate

Interpreting Pre-Quaternary Climate from the Geologic Record

by Judith Totman Parrish

Columbia University Press, 1998, Perspectives in Paleobiology and Earth History Series, 338 p.
ISBN: 0-231-10206-2, $ 65.00

Paleoclimatology is a hot topic nowadays and books published in the field are numerous. Some 80 books on Paleoclimatology have appeared in the last 10 years alone covering all aspects of paleoclimatology. So what is the need for the issue of still another 338 pages?

Says Parrish: "Although I didn't set out to write a textbook, part of my motivation for tackling the job was that no textbook exists for the way I teach paleoclimatology at the University of Arizona. In writing the book, I assumed some knowledge of geology, especially sedimentary geology and paleontology, but tried to provide at least a few basics for each topic, so it can be used as a textbook in senior- and graduate-level classes."

Indeed, most of the recent books on paleoclimatology emphasize quite different topics. A quick recherché on Amazon.com shows that only 10 of the 146 titles are especially devoted to pre-Quaternary climates, and the majority of books deal with Holocene climate or climate prediction. Most books emphasizing pre-Quaternary climate trace the climatic evolution either of the whole Phanerozoic ( Frakes et al., 1992) or of selected intervals ( Vakhrameev, 1991; Prothero and Berggren, 1992; Allen et al., 1994). Although virtually all paleoclimate books devote a chapter to paleoclimatic indicators or compare paleoclimatic modeling results to geologic climate tracers, none really evaluates the value of paleoclimatic indicators in detail. From this point of view, Parrish’s book is very timely as it clearly is the most comprehensive compilation on Phanerozoic paleoclimatic indicators to date.

The structure of Parrish’s book is very clear. An excellent introduction provides a guide to the volume and an overview of general principles behind all paleoclimatic indicators discussed in the book. Very helpful in this chapter is a table summarizing the parameters that define paleoclimate and their potential geologic indicators. The second chapter evaluates the paleoclimatic potential of fossils. Microfossils are discussed in some detail, but most of the discussion concerns isotopic geochemistry of foraminifera that would have deserved its own chapter. I was surprised to see that transfer functions are not discussed in more detail. A comparison is missing of paleoclimate data as derived from the different microfossil groups. A short discussion of the CLIMAP program - although concerning Quaternary climate - would have been useful to underline the great paleoclimatic potential of microfossils. The macrofossil discussion is very detailed for some groups (e.g. mollusks) but sketchy for other climatically sensitive groups, such as corals. A strength in this section is the short introduction clearly summarizing the danger of circular reasoning in using macrofossils for paleoclimatic analysis as well as for paleogeographic studies. The third chapter is devoted to marine lithologic indicators of paleoclimate and provides a comprehensive and in places highly original overview. One example is the graphic summary of a reef database by Flügel and Flügel-Kahler (1992) to indicate the paleolatitudinal range of reefs through time and the paleoclimatic bearing of Phanerozoic reefs. The chapter on terrestrial and freshwater biotic indicators (chapter 3) is relatively short but contains all relevant information on the subject. It concentrates on plant macrofossils – reflecting their great potential in paleoclimatic analyses. The longest chapter in Parrish’s book concerns the discussion of terrestrial and freshwater lithologic indicators (chapter 4). As I am personally not very familiar with continental deposits, this chapter was the most challenging to read and my view may best reflect the impression of a graduate student reading the book. Thanks to the frequent and clearly organized tables it was quite easy to get a quick overview of the discussed climate indicators. Each potential climatic indicator is introduced by a short summary providing useful definitions and an informative introduction. Although I occasionally got lost at a particular point, I always could acquire the major points and conclusions. The sixth chapter gives a short but excellent comparison of various paleoclimatic modeling approaches. The strengths and weaknesses of conceptual and numerical models are discussed in sufficient detail to allow the reader an evaluation of the different approaches. The final chapter gives a summary of some key indicators of past climate and an outlook of what can be achieved by combining various climatic tracers (integrative paleoclimatology). Although this chapter could have been organized more properly, the case studies are well selected and insightfully discussed.

Although the book is designed as a "sourcebook that provides an entry into the literature" it goes far beyond any comparable review on Phanerozoic climatic indicators. Every conceivable paleoclimatic indicator is introduced at the beginners level, but the discussion then quickly shifts into details that are hardly understood without fundamental knowledge in sedimentary geology, paleontology, and isotope geochemistry. To my taste, the general principles behind each paleoclimatic indicator are often not discussed in sufficient detail, and the sections move too quickly into excessive discussions of particular publications and case studies.

This affects the readability of Parris's book, but it also helps getting an insight into the discussions and controversies in the field. A deeper understanding is especially supported by the comprehensive reference list encompassing about 1500 citations. A glossary of the key paleoclimatic terms is lacking but would have been necessary considering the vast amount of terms floating around in the literature. I also missed a critical appraisal of published Phanerozoic climate curves (e.g. Frakes et al., 1992) by evaluation of the paleoclimatic indicators on which the curves are based. Parrish’s book is richly illustrated throughout. All figures contain important information and were mostly adapted from high-quality reference sources. A significant drawback, however, is the quality of the illustrations. Many figures would have benefited from redrawing. The tables are excellent throughout: useful in all cases and commonly original.

In summary, I cannot say that reading Parrish’s book is fun; it is work, sometimes even hard work, but work that pays back. The book is a must for everybody working on paleoclimatic interpretations in the widest sense, that is, almost every modern geoscientist.