This book is similar in format to Precambrian Iron-Formations of the World, published in 1973 as a special issue of Economic Geology (vol. 68, no. 7). Both have 16 papers and begin with descriptions of iron formations or iron districts followed by topical papers on various aspects o f the iron formation problem. New basic data on Precambrian iron bearing and associated rocks has continued to accumulate since 1973, and the present volume admirably fills the need to compile this widespread information and to reexamine these enigmatic rocks in the light of new discoveries.