Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Research”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,189 records · Page 66Linked to original sources
USGS2023

Preliminary surficial geologic map of Leuhman Ridge and the surrounding area, Edwards Air Force Base and Air Force Research Laboratory, Kern and San Bernardino Counties, California

This preliminary geologic map presents mapping of the Leuhman Ridge area of Edwards Air Force Base, California, conducted between April 2020 and June 2021. The report focuses on surficial materials and bedrock to evaluate potential faults and other geologic features that may influence groundwater movement. The preliminary work confirms that the Spring Fault, previously mapped by Dibblee (1960, 1967), is a Quaternary-active fault but does not find convincing evidence to support the existence of the Leuhman Fault (Dibblee, 1960; 1967) within the map area. Several more possible and probable faults are identified by a combination of geomorphic lineaments and brecciated rock. Pleistocene and Holocene eolian deposits are widespread, manifesting as sand sheets, dunes, and admixtures into alluvial fans. Also, an incised pediment forms much of the upland south of Leuhman Ridge. In general, field observations indicate that Quaternary alluvial and eolian deposits are thin; this suggests that secondary bedrock porosity and permeability, defined by degree of weathering and fracture density that includes fault-related fracturing, are more important factors in the location and flow patterns of groundwater.

California↗
USGS2026

Annotated bibliography of scientific research on new world screwworm ( Cochliomyia hominivorax ) myiasis in wildlife

The New World screwworm ( Cochliomyia hominivorax ; NWS) is a parasitic blowfly that lays its eggs in open wounds of live, warm-blooded animals including livestock, wildlife, and potentially humans. The larvae consume living animal tissue, and if untreated, the infestation can lead to death. Although NWS was eradicated in the United States in 1966, it has been moving northward from its endemic range in South America during the past decade and could seriously threaten the health of U.S. wildlife populations, making detection, treatment, and surveillance of the disease far more difficult across this multi-sector disease system. As the likelihood of NWS reintroduction to the United States increases, veterinarians, wildlife managers, and conservation specialists need to be informed and prepared to respond. The existing knowledge about NWS interactions with wildlife hosts is lacking, especially regarding North American species where the NWS has been eradicated for more than 50 years. To address this knowledge gap, we compiled an annotated bibliography that consolidates key information from the existing literature on NWS infestation in wild animals.

Open-File Report↗
USGS1948

Tests and researches on building stones

In 1941, the "Association Francaise de Normalisation" (French Association of Standardization) decided to create a Commission for the purpose of writing out a standard for building stones. When this Commission met under the chairmanship of Mr. Pol Abraham, Architect, they realized how far behind was our precise technical knowledge of this kind of material, and found the necessity of determining exactly the testing and acceptance methods. They expressed the wish that a careful study of the subject be entrusted to a specialized laboratory. This wish was received by the Ministry of Production, which, after an agreement with the competent organizing committees, entrusted our laboratory with this work. The main object was to establish the difficulty of stone-cutting in order to permit a classification of the stones according to the difficulty met when working them up into shape, to refer the other technical properties of the stones to this property, and finally to see what relation exists between the figures obtained. To this end nine stones were chosen by the Commission, from the hardest to the softest: Hauteville, Comblanchien, spotted Larrys, yellow Massangis rock, Euville rock, fine-grained Lavoux, soft Maximin rock, "banc royal" Mery, and "bane royal" Billy. Each type of stone included three large blocks of 0.75 by 0.75 by 0.5 meters to be dressed by hand by specialized workmen, the difficulty of stone-cutting being determined by the time spent for the dressing and preparation of the surfaces. After this operation, detail of which will be given later, we had an important quantity of material which we were to use to the best advantage. I thought that it would be interesting to determine on each one the maximum of physical, chemical and mechanical tests in order not only to be able to compare them in precise conditions, but also to set up each sample as a standard intended for future studies. In other words, each element in the mentioned list must, in my mind, be able to serve in the future as reference to which we will compare the other kinds of calcareous stones used for building. As all the available material was not used, we were able to keep some as a reserve in case later comparisons would be necessary.

Open-File Report↗