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Arizona National Monuments currently under review by the Secretary of the Interior

AZGS OFR-04-2017 On 26 April 2017, President Donald Trump signed an executive order to review designations of a number of national monuments established under the Antiquities Act of 1906. Section 2 of that executive order requires the...Show More Summary

High Water Across the West: The Humboldt River at Winnemucca and Humboldt Station

When I started putting these photos together—while thinking about our last post about the Humboldt River in Carlin Canyon—I somehow (and quite erroneously) figured I could throw a whole bunch of high-water Humboldt River photos together in one blog post. Show More Summary

AZGS receives $64k to update and publish digital geologic map data

Digital geologic map for Dome Rock, Arizona The AZGS was notified last week that we will be receiving $64k from the National Geological and Geophysical Data Preservation Program, administered by the USGS, for FY18. We will be supplying the required state match, for a project total of ~$130k. Show More Summary

South Dunsmuir Ridge

I finally got to a sweet corner of town last week, the sunny side of Dunsmuir Ridge, this lovely hill in the Google Maps 3D view. The view is to the north-northwest, such that the Hayward fault runs straight up about a thumb’s width from the left edge. The maps below start with the 1915 […]

AZGS mine files spurs silver exploration in Arizona’s Plomosa Mountains

Ramsey Mine ca. 1987 Imagine a room crowded with file cabinets whose drawers are stuffed with 100,000s of pages of unpublished mine reports, correspondence, geologic maps, mine maps, drill hole data, rock chemistry, and assay results for more than 20,000 mines in Arizona. Show More Summary

Here's a Hawaiian Mystery for You: Where Did These Circles Come From?

We were on a desolate plain on the south side of Kilauea Caldera on the Big Island exploring the ongoing volcanic activity. The smoking pit of Halemaumau Crater with her bubbling lake of molten lava was only a half mile or so north of us, so yes, we were in a closed area (but legally in this instance!). Show More Summary

The True Story of the Mar-a-Lago "Sinkhole"

What really happened at Mar-a-Lago on Monday – and what to do if it happens to you. -- Read more on ScientificAmerican.com

A Flight Around the World's Highest Mountains: Mauna Kea and Mauna Loa

Mountains that make their own weather can be frustrating because...they make their own weather. High mountains in the path of consistent winds force air masses upwards, causing the water vapor within to condense, forming clouds and as often as not, rain. Show More Summary

High Water Across the West: The Humboldt River in Carlin Canyon — With the Carlin Canyon Unconformity!

Well, there we have it: the Carlin Canyon unconformity with the Humboldt River running nearly bankfull on April 11th of this year. Looking downstream, back toward the tunnels, we're actually still looking at the unconformity, but it's cropping out poorly on the slope below the tilted limestone beds of the Pennsylvanian-Permian Strathearn Formation. Show More Summary

Geology of the Biff’s site

Because I walk through the area regularly, I’ve kept an envious eye on the excavation at the southeast corner of 27th Street and Broadway. Since the building slated for the site doesn’t have a name yet, I’ll call it the Biff’s site after the much-loved but long-departed Biff’s Coffee Shop that once sat there. It’s […]

The Most Desolate Place in the United States? The Mauna Loa Weather Observatory

If I seem to be missing in action, it would be because I've been stuck on planes and in airports on my way to the conference and field trips of the Cordilleran Section of the Geological Society of America. Just my luck that they happen to be meeting in Hawai'i this year. Show More Summary

Revisiting the 2006 debris flow of Santa Catalina Mountains

Bouldery debris flow levee, Santa Catalina Mtns. Historic rainfall precipitates 100s of debris flows | For five days in late July 2006, the mountains of southern Arizona received unusually heavy rainfall. A final burst of precipitation on the morning of 31 July produced over 400 hillslope failures in the Santa Catalina Mountains of Pima County (Fig. Show More Summary

Sea level as a metronome of Earth’s history

Sedimentary layers record the history of the Earth. They contain stratigraphic cycles and patterns that precisely reveal the succession of climatic and tectonic conditions that have occurred over millennia, thereby enhancing our ability to understand and predict the evolution of our planet.

37 Years Ago, America's Relationship with Volcanoes Changed Forever

The Mount Saint Helens eruptions was a scientific boon -- Read more on ScientificAmerican.com

The Unsung Waterfalls of Yosemite Valley

One takes their chance when deciding to visit Yosemite Valley in the springtime. The storms of winter are never quite done by then, and you may find yourself in a valley full of clouds. That's where I found myself a week back, touring the Yosemite region with my students. Show More Summary

Zn-Pb-Ag Mining Prospect in Patagonia Mtns, AZ: Ramping up!

Drilling at Taylor Deep. (Courtesy of Arizona Mining) According to a story in the Northern Miner, Arizona Mining is planning for substantial Zn production, ~ 9,100 tonnes ore/day, as early as 2020. Pending permitting. The Taylor Deep...Show More Summary

High Water Across the West: Honey Lake

I've recently had the opportunity to travel across part of the Great Basin of eastern California and northern and central Nevada, and have noticed a lot of high water, almost everywhere. Honey Lake, which has been dry to only partly filled during the last several years, is once again a lake. Show More Summary

The Dimond Canyon water gap

In a city full of geologic features, Dimond Canyon stands out as a classic example of a water gap. But it can be hard to see, even from the prime viewpoint of Leimert Bridge. Let’s abstract ourselves by studying the overhead views shown in maps. Google Maps, with the terrain view turned on, is where […]

Update: Arizona Reservoir Volume Status Spring 2017

As we head into summer here is a quick look at the state of Arizona's reservoirs at the end of February 2017. It was a good winter for recharge and the smaller reservoirs are faring well. Not so much, the Colorado River's Lake Mead and Powell. Reservoir data courtesy of CLIMAS - Climate Assessment for the Southwest. Posted 5/15/2017

Trump Exe. Order could impact four AZ National Monuments

On 26 April 2017, President Trump signed an executive order requiring the Department of the Interior to review national monuments comprising more than 100,000 acres and created since 1996. This review involves 20 national monuments. Physiographic features of Vermilion Cliffs Natl. Show More Summary

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