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Jason C. Willett

Publications and source records attributed to Jason C. Willett.

14 recordsLinked to original sources
USGS2014

Mineral resource of the month: Mica

The mica mineral group includes 34 phyllosilicate minerals, all with a layered, platy texture. The mineral has been known for millennia: Mica was first mined in India about 4,000 years ago, where it was used primarily in medicines. The Mayans used it for decorative effect in stucco to make their temples sparkle in the sun. Today it is used in everything from electrical products to makeup.

Earth↗
USGS2011

A review of the lignite resources of Arkansas

This review of the lignite resources of Arkansas is a part of the U.S. Geological Survey's (USGS) National Coal Resource Assessment (NCRA) of the Gulf Coastal Plain Coal Province, which also includes coal-bearing areas in the states of Texas, Louisiana, Alabama, Mississippi, Tennessee, and Kentucky (see Ruppert et al., 2002 ; Dennen, 2009 ; and other chapters of this publication). Lignite mining is not planned in Arkansas in the immediate future, and the lignite resources of the state were not assessed in detail as part of the NCRA. This chapter includes reviews of the geology of the lignite-bearing units, historical mining, previous investigations of lignite resources, and coal quality. Palynological data for lignite samples collected in Arkansas as part of this work are presented in Table 1 .

Arkansas↗
USGS2006

Analytical results from samples collected during coal-bed methane exploration drilling in Caldwell Parish, Louisiana

In 2001, and 2002, the U.S. Geological Survey (USGS) and the Louisiana Geological Survey (LGS), through a Cooperative Research and Development Agreement (CRADA) with Devon SFS Operating, Inc. (Devon), participated in an exploratory drilling and coring program for coal-bed methane in north-central Louisiana. The USGS and LGS collected 25 coal core and cuttings samples from two coal-bed methane test wells that were drilled in west-central Caldwell Parish, Louisiana. The purpose of this report is to provide the results of the analytical program conducted on the USGS/LGS samples. The data generated from this project are summarized in various topical sections that include: 1. molecular and isotopic data from coal gas samples; 2. results of low-temperature ashing and X-ray analysis; 3. palynological data; 4. down-hole temperature data; 5. detailed core descriptions and selected core photographs; 6. coal physical and chemical analytical data; 7. coal gas desorption results; 8. methane and carbon dioxide coal sorption data; 9. coal petrographic results; and 10. geophysical logs.

Open-File Report↗
USGS2005

The Muralla Pircada: an ancient Andean debris flow retention dam, Santa Rita B archaeological site, Chao Valley, Northern Peru

Debris flows caused by El Niño events, earthquakes, and glacial releases have affected northern Perú for centuries. The Muralla Pircada, a northeast-trending, 2.5 km long stone wall east of the Santa Rita B archaeological site (Moche-Chimú) in the Chao Valley, is field evidence that ancient Andeans recognized and, more importantly, attempted to mitigate the effects of debris flows. The Muralla is upstream from the site and is perpendicular to local drainages. It is 1–2 m high, up to 5 m wide, and is comprised of intentionally-placed, well-sorted, well-rounded, 20–30 cm cobbles and boulders from nearby streams. Long axes of the stones are gently inclined and parallel local drainage. Case-and-fill construction was used with smaller cobbles and pebbles used as fill. Pre-Muralla debris flows are indicated by meter-sized, angular boulders that were incorporated in-place into construction of the dam and are now exposed in breeches in the dam. Post-Muralla debris flows in the Chao Valley are indicated by meter-sized, angular boulders that now abut the retention dam.

Landslides↗
USGS2004

Mineral, Energy, and Fertilizer Resources of the North Coast of Peru: Perspective from the Santa Rita B Archaeological Site

The Santa Rita B archaeological site is in the Chao Valley, approximately 65 km southeast of Trujillo, northern Peru. Location of Santa Rita B at the emergence of several drainages from the Andean cordillera is an important factor in the almost continuous occupation of the site over the past 3,000 years. Mineral resources are abundant throughout the Andes; however, the north coast of Peru was an important center for pre-Columbian mining, metallurgy, and craftsmanship. Success of the Chavin, Moche, Chimu, and other north coast cultures is directly related to the availability and exploitation of mineral and energy resources that include: gold (?silver), as electrum, mainly from placers, and copper from local oxide and carbonate occurrences and from sulfides related to copper porphyry occurrences in the cordillera. An alloy of these three metals is referred to as tumbaga, which is the primary material for Andean metalcraft. Anthracite was used for mirrors by north coast cultures and is available near Rio Chicama, Rio Santa, and east of Santa Rita B. These outcrops are a part of the Alto Chicama, Peru's largest coalfield, which extends from Rio Chicama, in the north, for 200 km southward to Rio Santa. Charcoal from the algorrobo tree and llama dung are considered to be the common pre-Columbian energy sources for cooking and metalwork; however, availability and the higher heat content of anthracite indicate that it was used in metallurgical applications. Bitumen is available from petroleum seeps near Talara, north of the study area, and may have been used as glue or as cement. Hematite, goethite, limonite, and manganese oxides from clay-altered volcanic rock may have provided color and material for ceramics. Guano from the Islas Gua?apes, Chinchas, and Ballestas was used as fertilizer for cotton and other crops.

Open-File Report↗