Boulder, Colo., USA: GSA s dynamic online journal,
Geosphere, posts articles online regularly. Locations and topics studied this month include the Central Anatolian Plateau; the Southern Rocky Mountain Volcanic Field; petrogenesis in the Grand Canyon; and the evolution of the Portland and Tualatin forearc basins, Oregon.
A physical and chemical sedimentary record of Laramide tectonic shifts in the Cretaceous-Paleogene San Juan Basin, New Mexico, USA
Kevin M. Hobbs; Peter J. Fawcett
Abstract: Fluvial siliciclastic rocks bracketing the Cretaceous-Paleogene (K-Pg) boundary in the San Juan Basin, New Mexico (USA), provide records of regional fluvial and tectonic evolution during the Laramide orogeny. Petrographic analyses of sandstones from the Upper Cretaceous Fruitland Formation and Kirtland Formation and the Paleocene Ojo Alamo Sandstone and Nacimiento Formation show that the rivers depositing these sediments were sourced in areas where unroofing of crystalline basement rocks
Quiet time: 5 little-known nature preserves not far from L A yahoo.com - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from yahoo.com Daily Mail and Mail on Sunday newspapers.
Preserves throughout the West are often run by private conservancies. They can be large or small but share a common goal of protecting particular landscapes. “Often, they’re in place to protect certain plants or animals or eco-systems types or special features, sometimes it’s historical or archeological features,” said Nature Conservancy biologist Sophie Parker. As an example, for 50 years, her organization has worked to protect the remote Amargosa River in the Mojave Desert and the native pupfish and Amargosa toads that live nowhere else.
Preserves also reflect an ethos of land stewardship and a strong belief that wild places should be open to the public for free. The Wildlands Conservancy, which manages more than 20 preserves in the West, believes that access to nature is a birthright. One of its core beliefs: “Free access to our preserves removes the socio-economic barriers that tend to promote a disconnect with nature.”
April 7, 2021 at 10:30 pm by Sean Crommelin
During the historic California drought from 2012 to 2015, warm temperatures and piddling precipitation took the state for a whirl unlike any other. In the 2015 wet season, the Sierra Nevada snowpack reached its lowest peak in half a millennium, while reservoirs left boats grounded and farmers with little water to tend their crops and livestock.Â
The canopy of a valley oak tree (Quercus lobata).
Courtesy of Leander Anderegg
Governor Jerry Brownâs yearslong Emergency Drought Declaration instituted increased water efficiency standards to combat the new water scarcity, leading to longstanding changes in patterns of water use in Californiaâs metropolitan centers which outlived the drought itself.Â