国产日韩欧美一区二区三区三州_亚洲少妇熟女av_久久久久亚洲av国产精品_波多野结衣网站一区二区_亚洲欧美色片在线91_国产亚洲精品精品国产优播av_日本一区二区三区波多野结衣 _久久国产av不卡

?

Book Review

2013-09-27 02:36:30A.J.,VAN,LOON
Journal of Palaeogeography 2013年2期

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.

安徽省| 龙山县| 昭苏县| 惠来县| 巴南区| 隆德县| 丘北县| 中牟县| 镇宁| 巴青县| 集贤县| 湖北省| 法库县| 新乐市| 瑞昌市| 乐昌市| 庆元县| 邹城市| 盐边县| 潞西市| 迭部县| 礼泉县| 渝北区| 汝州市| 永春县| 扶余县| 尼勒克县| 舟曲县| 花垣县| 乌拉特中旗| 巴里| 绵阳市| 昌乐县| 兴海县| 阜宁县| 清远市| 阿尔山市| 泽州县| 大厂| 西和县| 枣强县|