Ned Brown has provided geologists and anyone else interested in the geology of northwest Washington State an up to date book on the geology of the San Juan Islands (and non San Juan Islands Fidalgo Island). And if your interested in deciphering accretion tectonics anywhere, this book should be in your library. Ned has put together a clear compilation of the San Juan Island bedrock geology as it is currently understood. He also provides a good overview of how geologists extract stories out of rocks from microscopic study of minerals to zapping zircons with lasers. The book is full of excellent graphics and ends with some guidance to good outcrop sites.
I do a fair bit of geology work in the San Juans. For many years I have been heavily relying on 1975 maps of the San Juan Islands produced by Joe Vance and John Whetten published in Geology and Water Resources of the San Juan Islands (Russel, editor, 1975). My copy of that work is very dog eared.
I anticipate that my copy of Ned's book will become dog eared as well. The book already answered a question I had about an outcrop at the Lopez Island ferry landing and another outcrop at the north end of Blakely.