Walter Alvarez has a new book out, and its publication reminded me that though I read and appreciated The Mountains of St. Francis, I had never read his most famous work — the account of how he and his father and a team of other researchers zeroed in on an extraterrestrial impact explanation for the end-Cretaceous extinction. So last week I read T. rex and the Crater of Doom (1997). It’s excellent in that it shows in an appropriate level of detail the sequence of insights, speculations, observations, searches, arguments, and collaborations that led to a revolutionary new way of envisioning Earth history. Alvarez writes for a general audience, and somehow manages to convey a sense of the science without ever getting bogged down in jargon. His analogies are excellent, his writing is kind, and each chapter is tidy and economical with its language. As a result, though the story being told is BIG, the book is fairly brief. It would be an ideal entry point into historical geology for anyone, and I wish I’d read it long ago. Recommended.