Microbial mats in siliciclastic depositional systems through time, edited by Nora Noffke & Henry Chafetz,2012.SEPM Special Publication 101.Society for Sedimentary Geology (SEPM), Tulsa, OK, USA (order through https://members.sepm.org/iMISpublic/Core/Orders/).
“Siliceous stromatolites” are still poorly known among earth scientists, apart from specialists.The book under review here is a collection of papers based on presentations made at the “Microbial mats in sandy deposits (Archean to Today)” SEPM Research Conference, held in Denver and Dinosaur Ridge (May 2010).This book is useful because the knowledge about microbial mats develops quickly,particularly since ever more relationships with specific depositional conditions become clear.This holds certainly for the much less well known field of microbial mats in siliceous sediments: only a few years ago I was confronted in the field with deformed structures in siliciclastic Palaeoproterozoic sediments, and these structures were too enigmatic for me to explain.Now I know that these enigmatic structures represent what are called now “microbially induced sedimentary structures” (MISS)by specialists in stromatolites.
After a short introductory text by the editors, the morphology and distribution of MISS are dealt with by Bose,who also compares MISS from modern siliciclastic and carbonate settings.In my opinion, this is by far the best contribution to this book, and the most valuable for nonspecialists who deal with MISS, as Bose makes clear that all MISS types (and currently 17 types are distinguished)are known nowadays from siliciclastic settings, whereas one of these is not known from carbonate environments.This emphasizes how much siliciclastic MISS have been and still are undervalued! Another interesting aspect of this chapter is that it makes clear how MISS, which typically occur on supratidal to intertidal flats, are distributed over 6 zones.As the author mentions: “The results of this study demonstrate that subtle variations in MISS and their facies changes can be used to indicate small variations in water depth, regardless of the sediment type”.Wonderful data for researchers in palaeogeography!
The second chapter, by Buatois & Mángano, was also a pleasure to read.Their contribution is valuable, as it provides an overview.It deals with the trace-fossil record of organism/matground interactions in space and time.The other chapters represent mainly local or regional field studies.Commonly sound science, and commonly with some interesting aspects that would, in my opinion, be more suitable for publications in specialist journals.TheJournal of Palaeogeographywould for some of these articles have been a good choice!
In short, the book is valuable, particularly because of its first two chapters.Therefore it belongs, although relatively expensive, in the libraries of geological institutes.
Journal of Palaeogeography2013年2期