Check out this month's On the Web links, your connection to earth science friendly Web sites. The popular Geomedia feature now available by topic.
Forensic geology on the small screen
On the Shelf: Forensic Geology
Rock of Ages: Ancient Earth, Ancient Skies
South Dakota Mapping
Evidence from the Earth, by Raymond C. Murray. Mountain Press Publishing Company, 2004. ISBN 0 87842 498 9. Paperback, $20.00.
Looking for more background and stories on forensic geology? Then look no further than Raymond Murrays recent book Evidence from the Earth. Following up on Forensic Geology, the 1975 groundbreaking guide to how geology can be of use in criminal investigations, Murray's new book takes readers behind the scenes of some notorious and interesting cases that geology has helped solve. He weaves together anecdote and hard science to explain how soils and other "earth materials" can be used as evidence and then how scientists collect and analyze the evidence. An entire chapter covers examination methods and instruments a good overview for anyone thinking about getting into the field or anyone who is looking for updated techniques. The book also has a number of illustrations and a glossary. It is an easy and interesting read for anyone curious about criminal investigations or geology.
|Earth Colors, by Sarah Andrews. St. Martin's Minotaur, 2004. ISBN: 0 3123 0197 9. Hardcover, $23.95.
Earth Colors is the ninth fiction novel in the Em Hansen mystery
series by author and geologist Sarah Andrews (see stories).
Hansen, a forensic geologist, is called upon to investigate a famous Frederick
Remington painting. Using pigment analysis and various other methods,
Hansen is determined to find out whether or not the painting is a fraud,
a case that takes her from Wyoming and Utah to Pennsylvania, and on to
|Detachment Fault, by Susan
Cummins Miller. Texas Tech University Press, 2004. ISBN 0 8967 2520 0. Hardcover,
In another geology murder mystery, Detachment Fault the second by geologist Susan Cummins Miller Tucson geologist Frankie MacFarlane investigates her second murder, after discovering a body during a fishing trip to Mexico with her brother and his girlfriend. The girlfriend, Carla, goes missing, and upon Frankie's return home, she learns that her favorite student was murdered on the college campus, and found wearing a ring much like the one Carla owned. Following the antiquities trade and money-laundering schemes, Frankie has to figure out if the two murders are related to each other or to Carla's disappearance. Miller's first book, Death Assemblage, follows Frankie as she unravels a mystery involving fossils, a murder and a manuscript while working on her dissertation. These are fun and easy reads, interspersed with some science.
Ancient Earth, Ancient Skies: The Age of Earth and Its Cosmic Surroundings.
by G. Brent Dalrymple. Stanford University
Geologists know that the rock on which we live is ancient some 4.55
billion years old according to accepted measurements. The cosmos in which our
small rock resides is even older, 13 to 15 billion years. Yet the chronology
of the creation of Earth and the universe can be a contentious subject. Brent
Dalrymple's new book, Ancient Earth, Ancient Skies, helps elucidate the
debate by providing a scientific explanation of the ages of both.
Dalrymple is well-qualified for the task as a scientist and educator, and the book was prompted by the author's expert testimony at several trials attempting to overturn laws mandating equal time for creationism in science classes in Arkansas and Louisiana during the 1980s. (A young planet is part of the creationism agenda, which also includes the instantaneous creation of all species and the denial of evolution.) Seeing the need for a review of the subject, in 1991 Dalrymple published The Age of the Earth, a scholarly monograph that received good reviews. His new book is an "updated, abridged, and greatly simplified" version of that original volume.
The book opens with a discourse on how science works and a brief overview of the origin of the universe, the Milky Way Galaxy, the solar system and Earth. This background is followed by the history of attempts to constrain our planet's age. A variety of methods sea level changes, planetary cooling, tidal friction by the moon, salt concentration in the oceans, sediment accumulation all turned out to be flawed, providing ages that were too young. However, the discoveries of a handful of physicists, chemists, astronomers and one lone geologist eventually allowed radioactivity to come to the rescue.
After this introduction, the book morphs into a text on radioactive isotopes and geochronology. As a student I had to wrestle (somewhat unsuccessfully) to understand uranium-lead dating, and my experience as a teacher suggests that today's students still agonize over these difficult concepts. Dalrymple provides one of the clearest explanations of uranium-lead dating that I have ever read. He then focuses on the scientists who provided the intellectual framework and hardware to measure and model the evolution of lead isotopes through time, and the remainder of the book deals with cosmochronology. A description of how scientists estimate the ages of the universe, our galaxy and the elements themselves will be especially interesting to geologists, as this is mostly new territory for us.
Ancient Earth, Ancient Skies provides lucid explanations of the clever ways in which scientists have determined the ages of the rock on which we live and cosmic surroundings that enfold it. Any geologist, in fact any scientist or college science major, will find this book interesting and informative, but it wasn't really written for us. Its preface implies that the target audience is the broader public, with the intent that it be used to inform debates about creationism and science. Unfortunately, the book does not contain the analogies, anecdotes, human interest stories, illustrations, photographs or even the humor that would have made it accessible to a much wider audience.
To be fair, geochronology is a tough subject, not easily generalized, and the book's conclusions might be misconstrued or misused if not presented with sufficient rigor. Ancient Earth, Ancient Skies is serious science but still a good read. I suspect that it may have the desired result, but perhaps only because scientists, having read it, will be better armed to face science's detractors.
The South Dakota
Geological Survey recently published two 1:500,000-scale geologic maps titled
Geologic Map of South Dakota and Bedrock Geologic Map Showing Configuration
of the Bedrock Surface in South Dakota East of the Missouri River. These
two maps represent major revisions of previous editions, and they are important
new sources of regional geologic information pertaining to water resources,
mining, recreation, geologic hazards, paleontology, environmental issues and
Exposures of the Jurassic Sundance Formation in the southern Black Hills of South Dakota are portrayed on the new Geologic Map of South Dakota. Courtesy of the South Dakota Geological Survey.
The new Geologic Map of South Dakota reflects the quantity and quality of geologic information that has become available since publication of previous state geologic maps more than 50 years ago. Knowledge of the geology of the Black Hills uplift has progressed tremendously in recent decades, allowing for a far more accurate and detailed portrayal of that region than previous maps of similar scale.
Compilation of newly acquired information regarding structural features and surficial deposits throughout western South Dakota also are significant advances. The portrayal of South Dakota east of the Missouri River illustrates the most complete compilation of glacial deposits in this area to date. In addition, the digital format enables evaluation of geo-referenced data of all types (agricultural, environmental, geotechnical, etc.) with respect to the underlying geology.
Similarly, the Bedrock Geologic Map Showing Configuration of the Bedrock Surface in South Dakota East of the Missouri River also represents a significant advancement in knowledge over the past half century resulting from thousands of wells and test holes drilled in this region. Because nearly all of South Dakota east of the Missouri River is mantled with glacial sediments, this map is an important new resource for understanding South Dakota's subsurface geology and, in turn, is important in the exploration for natural gas and mineral resources. It is also a fundamental tool for water resource investigations in eastern South Dakota, through the assessment of Pleistocene sediments and the configuration of the underlying bedrock surface.
These maps are available for purchase from the South Dakota Geological Survey. Call 605-677-5227, or visit the survey online at www.sdgs.usd.edu, where PDF versions of the maps are available at no charge.