I enjoyed going back to geology, in a popular survey reminiscent of Basin and Range by John McPhee. I did not take notes, and I am recording this reading a few weeks after I finished, so I cannot record any of the dense collection of facts that form the book. The book begins with the early formation of the earth, as revealed by the oldest rocks, including the Morton gneiss, and the Acasta gneiss. Zircons recovered from thes rocks can be analyzed for radioactive decay of the occasional uranium atom substituting for zirconium. The book contains many references to spots of geological interest in the US, from the obvious, like to grand canyon, to Todt hill on Staten Island. The prose was smooth, and the author manages to create tension as he surveys geology, writing about impacts and extinctions. ( )

Timely Take-Aways for Life-Long Learning
How the Mountains Grew: ?A New Geological History of North America
John Dvorak
August 2021
Pegasus Books, an imprint of Simon & Schuster
Themes: Science, Nature, Ecosystems, Geology, Geologic History, Mountains

Tracing the geologic history of Earth, HOW THE MOUNTAINS GREW by John Dvorak skillfully weaves common knowledge and established theories with new research findings. The well-established theory of plate tectonics changed our perception of how our continent was formed. However, recently uncovered evidence demonstrates that scientists are just beginning to understand the complexity of our changing landscapes.

This epic story of the geological history of North America celebrates our rapidly changing knowledge of Earth’s past. Of particular note to Earth Science teachers and geology buffs, this engaging narrative also appeals to readers interested in broader areas of science from astrophysics to climate change. From young adults to seniors, Dvorak’s conversational style will be popular with leisure readers.

Let’s explore seven timely take-aways for life-long learners:

1) In the 1960s, the theory of plate tectonics became widely accepted. However, it was not able to explain the existence of the Black Hills or the diamonds of Arkansas. The intertwining of geology with other traditional and emerging sciences is needed to trace the entire span of geological history.
2) On August 17, 2017, the first gravitational waves were detected in the direction of the constellation Hydra. This confirmed the collision of neutron stars. These collisions are responsible for most of the heavier elements in the universe such as gold and silver. Prior to this discovery, these collisions were purely theoretical.
3) In 2015, the International Commission on Stratigraphy determined that the 4.030 billion year old Acasta Gneiss found in the remote Northwest Territories of Canada represents a major milestone in geologic history marking the beginning of the Archean Eon. It’s considered to be the oldest known rock on Earth.
Luis and Walter Alvarez published a paper in 1980 hypothesizing that an extraterrestrial body caused the mass extinction of the dinosaurs. In 2016, a scientific drilling project penetrated the seafloor identifying the Chicxulub impact crater.
4) In geodynamics, delamination is the loss of the lowermost lithosphere from its tectonic plate. Asthenosphere rises to replace the sinking lithosphere. This process causes uplifts and sometimes volcanism playing an important role in the continuing “growth spurt” of mountains such as the Sierra Nevada. Seismic tomography allows geoscientists to generate images from the crust to the core. 5) In 2019, delamination was found through seismic tomography in the Appalachian Mountains.
6) In 2019, a fossilized forest containing palm-like trees was found near Cairo, New York demonstrating that complex forests existed at least as early as 388 million years ago.
7) Although working groups at the major geological societies have not yet recognized the Anthropocene as the current geological epoch, the term as been used informally for a couple decades. The benchmarks for this new epoch include the impact by humans on the natural world. From human-made rock such as concrete and bricks to plastic fragments, human have already made profound changes in the rock record.

Whether helping educators keep up-to-date in their subject-areas, promoting student reading in the content-areas, or simply encouraging nonfiction leisure reading, teacher librarians need to be aware of the best new titles across the curriculum and how to activate life-long learning. - Annette Lamb ( )