By Mike Cook
Did you know southern New Mexico contains parts of five geologic provinces and contains rocks that are nearly two billion years old?
Those are just two of the fascinating facts in a new book, “The Geology of Southern New Mexico’s Parks, Monuments, and Public Lands” (GSNM) published by the New Mexico Bureau of Geology and Mineral Resources, a research and service division of the New Mexico Institute of Mining and Technology in Socorro. The book was edited by Peter A. Scholle, Dana S. Ulmer-Scholle, Steven M. Cather, Shari A. Kelley, Belinda Harrison and Jennifer Eoff, and includes a cover photograph of Organ Mountain-Desert Peaks National Monument by Las Cruces photographer Wayne Suggs.
The 400-page edition is broken into six parts: the Mogollon Slope/Colorado Plateau, the Basin and Range, the Rio Grande rift, the Mogollon-Datil volcanic field and the Great Plains, along with a separate section on the Permian Basin.
The earliest geologic history of the Organ Mountains region is well more than one billion years ago, the books says. Between 1.7 and 1.1 billion years ago, “volcanic islands and continents collided with the fledgling North American continent to build what is now much of the Southwest.”
Closer to home, GSNM says “the majority of rocks exposed in the Organ Mountains are intrusive or volcanic in origin, the latter including both ash-flow tuffs and lavas.” The oldest rocks in the area are 1.4-billion-year-old granites. And get this: “Thin layers of Pleistocene volcanic ash in the upper part of the Camp Rice Formation include those from the Yellowstone caldera in Wyoming and the Long Valley caldera in California. These far-traveled ashes are a testament to the explosive power of the these modern calderas.”
All told, the book “provides an understanding of the exposed rock units (and fossils) that record more than 1.7 billion years of geologic and biologic changes in this region.”
The book contains nearly 400 color photographs, plus maps and other illustrations that detail the state’s geology from the Precambrian Era through the Paleozoic and Mesozoic eras to the present-day Cenozoic. (We’re in the Holocene Epoch of the Quatenary Period of the Phanerozoic Eon.)
Elephant Butte was formed more than 419 million years ago, Carlsbad Caverns is 250-300 million years old, the City of Rocks is about 56 million years old and the Organ Mountains rose about 36 million years ago. During the Pennsylvanian Period, about 300 million years, ago, “as much as 80 percent of New Mexico was submerged beneath warm, shallow, tropical seas, (because it) lay close to the equator at that time.” Human settlement, by contrast, began about 12,000 years ago.
Cost: $29.95 at www.geoinfo.nmt.edu/publications/guides/nmparks/southern/.
"book" - Google News
May 30, 2020 at 05:34AM
https://ift.tt/2XOGJWq
New book details the geology of southern New Mexico - Las Cruces Bulletin
"book" - Google News
https://ift.tt/2Yv0xQn
https://ift.tt/2zJxCxA
Bagikan Berita Ini
0 Response to "New book details the geology of southern New Mexico - Las Cruces Bulletin"
Post a Comment