Taxonomy term

usgs

Mineral Resource of the Month: Talc

When people think of talc, they often think of talcum and baby powder. However, these uses of talc are minor compared to its use in industrial manufacturing. The leading use of talc in the United States is in the production of ceramics, where it is a source of magnesium oxide, serves as a flux to reduce firing temperatures, and improves thermal shock characteristics of the final product. Worldwide, the major use of talc is as a paper constituent, where it fills the interstices between cellulose paper fibers, reduces paper transparency, improves ink receptivity, and absorbs undesirable tree sap residues that can generate blemishes in the paper.

03 Mar 2014

Mineral Resource of the Month: Iron and Steel

Iron is one of the most abundant elements on Earth, but it does not occur in nature in a useful metallic form. Although ancient people may have recovered some iron from meteorites, it wasn’t until smelting was invented that iron metal could be derived from iron oxides. After the beginning of the Iron Age in about 1200 B.C., knowledge of iron- and steelmaking spread from the ancient Middle East through Greece to the Roman Empire, then to Europe and, in the early 17th century, to North America. The first successful furnace in North America began operating in 1646 in what is now Saugus, Mass. Introduction of the Bessemer converter in the mid-19th century made the modern steel age possible.

03 Feb 2014

Down to Earth With: Sally Jewell

Most people who find their way into public office start locally, perhaps by running for a seat on the school board or city council. Sally Jewell’s first foray into public service came at the behest of President Obama, who last year nominated her as the 51st Secretary of the Department of the Interior (DOI) — the first Secretary in more than a decade with a background in geoscience.

28 Jan 2014

When water, gravity and geology collide: Firsthand observations of the impacts of the 2013 Colorado floods

Around almost every bend in the road on our tour of the Colorado Front Range and points downstream in the weeks after the September floods, the physical devastation confronted us like a punch in the gut. Even though we had all seen graphic images on the news, observing the destruction firsthand, especially from a geologic perspective, was truly stunning and humbling.

21 Jan 2014

Mineral Resource of the Month: Phosphate Rock

As a mineral resource, “phosphate rock” is defined as unprocessed ore and processed concentrates that contain some form of apatite, a group of calcium phosphate minerals that is the primary source for phosphorus in phosphate fertilizers, which are vital to agriculture.

02 Dec 2013

Mineral Resource of the Month: Thallium

Thallium, a grayish-white metal similar to tin in appearance, was discovered spectroscopically in 1861. Like lead, it is heavy yet soft, and can be cut easily with a knife. When exposed to air, thallium’s luster quickly tarnishes to a blue-gray color owing to the formation of a film of thallium oxide. Its concentration in Earth’s crust is estimated at 0.7 parts per million; mostly it is found in association with potassium minerals in clays, soils and granites, but in general it is not commercially recoverable from those sources. Manganese nodules, found on the ocean floor, also contain thallium.

04 Nov 2013

Tackling "Boundary Faults" across the Alaska-Yukon border: A report from the field

Our two dusty trucks roll across the airstrip, casting long, late-May shadows down the runway. We spot our colleagues from the Yukon Geological Survey and realize we’ve found the right place after an exhausting 12-hour drive from Anchorage punctuated by several U-turns to find the right unmarked access driveway off the Alaska Highway at the south end of Kluane Lake. The evening air is crisp, and the towering peaks to the south are capped with snow.

15 Oct 2013

Iowa impact crater confirmed

An airborne geophysical survey mapping mineral resources in the Midwest has confirmed that a 470-million-year-old impact crater nearly five times the size of Barringer (Meteor) Crater in Arizona lies buried several hundred meters beneath the town of Decorah, Iowa.

07 Jul 2013

Down to Earth With: The Geographers of the Solar System

Certain government officials have super cool titles: for example, Planetary Protection Officer (NASA's Catharine Conley) and Oceanographer of the Navy (David Titley). I think Geographer of the Solar System would be right up there. Alas, no one actually has that title, but in a little-known office of the U.S. Geological Survey (USGS) nestled in the hills above Flagstaff, Ariz., I met a dozen or so people who could reasonably qualify for it.

13 May 2012

VA quake felt far and wide, here's why

A significant earthquake today shook residents in Virginia, but the event could be felt far and wide along the East Coast.

23 Aug 2011

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