The End of the Dinosaurs: Chicxulub Crater and Mass Extinctions

The book is a good review of current thinking concerning mass extinctions, especially the K/T event. The geochemistry section is clear for those of us who are not specialists in the field. The history of research concerning the K/T event is interesting in its coverage of the progression from denial to cautious scepticm to acceptance. The elucidation of pre K/T extinctions was new to this reviewer and does give a different impression of earth history and the progression of evolution. Overall it is a good book for the lay public and those in the sciences who are not versed in extinctions and bolide impacts through time.

Charles Frankel's book "The End of the Dinosaurs: Chicxulub Crater and Mass Extinctions" is a well-written, thoroughly researched thesis on the theory of a meteor impact that resulted in the mass extinctions of dinosaurs and other species 65 million years ago. The author requires no prior knowledge of geology, astronomy, archeology, or paleontology. Instead, he carefully outlines all of the accumulated scientific evidence from these fields of science and presents a convincing argument in support of the impact theory as the cause of the mass extinctions documented in the fossil record. He also presents opposing theories and his arguments against them. The book is nicely illustrated with interesting photographs that supplement the salient points of each chapter. The book is an easy read, especially for a scientific thesis, and is constructed concisely and intuitively, without the repetitiveness often suffered in similar non-fiction works. I enjoyed reading it on vacation in the Caribbean where I was delighted to be able to spot, in some exposed cliffs, the K-T geologic boundary the author describes so well! I later shared the book with my 14 year old son, who used the book as his primary resource for a school paper on the subject of an important historical event. My son also found the book to be fascinating, lucid, and eminently readable. I highly recommend this outstanding work of non-fiction.

The End of the Dinosaurs: Chicxulub Crater and Mass Extinctions written by Charles Frankel is an account of the hunt for, finding, and the theory and controversy assoicited with the great mass extinction that rocked the Earth 65 million years ago.This book encompasses some great detective work and recounts the birth of the cosmic hypothesis that the effects of a giant impact created on the eart's biosphere led to the exticntion of one very successful life forms on earth... dinosauria.The descriptions of the crater geology is in terms that the layperson can understand and comprehend. This is ment to pique your interest into Earth sciences and there is and index and bibliography for further study if warrented.What I found to be the greatest asset in reading this book is the detective work involve in finding the impact area on earth that coinsided with the correct time frame to prove that the impact of an extraterresstial source was one of the contributing factors that caused the extinction of the dinosaurs.There are photos within this book that show impacts throughout the earth, but the only one that can be linked to 65 millions years ago is Chicxulub in the Northern edge of the Yucatan in Mexico. It amazes me how the geologists work and came up with this site. Iridium was only one of the clues that the geologists used to track down the date of tthe impact, but closer to the impact site there were other telltale signs. Around the Gulf of Mexico, unusual outcrops are found at the K-T boundary. K-T stands for Late Cretaceous-Tertiary begining. In El Penon, Mexico, a thick sandstone unit is interpreted to be a catastrophic tsunami deposit, laid down by the impact. Where it is capped by a fine clay displaying a wavy pattern, thought to mark the oscilation of the current as the tsunami wave sloshed back and forth across the continental platform. When you take a cross-section of the clay you can really see the the ripple marks, making testament to the current switching directions.From Mexico, to Haiti and around the Gulf of Mexico you see this clay layer and sandstone around the K-T boundary denoting an impact, but what really piqued my interest here was the fine of the ejecta known as spherules and tektites. Tektites are spashes of the impact melt that take on aerodynamic shapes as they spin through the Earth's atmosphere.On a different note... why are comet more dangerous to Earth than asteroid... because of the sublimation of the ices heated by sunlight. The jets of gas act as reactors and constantly modify the comet's trajectory. Thus, making comets less predictable than asteroids.This book takes the reader on a journey into Earth Science and shows us what can happen... fascinating what asteroids, meteorites, bolides and comets can do to the rich complexity of the biosphere, not only then, but today as well.

This great little book is far more than promised by the title -- although I must admit that I grabbed it because of the title, so I can hardly fault them for picking something dinosaur oriented.Yes, we get a history of the scientific controversies leading to the widespread acceptance of a meteorite/comet strike as the cause of the extinction of the dinosaurs. But there's more: the book reviews the evidence for associations between bolide strikes and all of the major mass extinctions in earth history. In prose that's clear, but not dry, Frankel reveals what we know -- and don't know -- about these events. Good illustrations and intelligent speculation round out a first-rate and quite up-to-date overview of a rapidly developing field. One subtext of Frankel's work is how scientist adapt (and in some cases don't adapt) to new evidence. For example, the Siberian Tunguska explosion of 1908 is now widely acknowledged to have been a strike from a comet fragment, but only 20 or so years ago you could read about it primarily in UFO magazines and "mysteries of the unexplained" books. Because science lacked an explanation for it, the explosion was largely ignored.I second the recommendation of "The Eternal Frontier."

So many theories of the KT extinctions have been forwarded by scientist and lay person alike that it is almost refreshing to have it come down to the confrontation between two, or a few, major theories, in this case the "impactist" and "volcanist" theories. Frankel does a fine job of presenting a balanced and fair account of the contenting theories, particularly Courtillot's Deccan Traps volcanism (for which see Evolutionary Catastrophies or my review of it) and their supporting data. He is, however, thoroughly in the impactist camp. He gives an excellent description of the astroid and of how scientists were able to work out its size, the size of its crater, and its subsequent atmospheric and environmental effects. This is probably the best of the three books (T. Rex and the Crater of Doom, Evolutionary Catastrophies, and End of the Dinosaurs) I've recently read on the subject, although all three are worth reading.