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At least 1,657 records · Page 92Linked to original sources
USGS1997

The U. S. Geological Survey in the early 1900's - Reminiscences of D. Foster Hewett, Adolph Knopf, and Frank C. Calkins

In December, 1962, 81-year-old Donnel Foster Hewett hosted a dinner party for what was then the “younger crop”of U.S. Geological Survey geologists in Menlo Park, California. His aim was to give them the benefit of some collective wisdom about what life in the Survey was like in the “good old days,” with particular attention paid to the personalities of some of the men who had played prominent roles in the Survey's development. To this end he recruited two other Survey old-timers: Adolph Knopf (80), a Visiting Professor at nearby Stanford University, and Frank Calkins (84), a USGS Annuitant in the Menlo Park headquarters. Following a convivial dinner, these three distinguished gentlemen delivered their remarks to an appreciative and responsive audience. In an act of great foresight, someone, perhaps Hewett himself, had arranged to have the proceedings tape-recorded. Walden P. Pratt, of the USGS in Denver, Colo., obtained a copy of the tape and transcribed it.

Open-File Report↗
USGS1985

An approach for appraising the accuracy of suspended-sediment data

Procedures are presented for appraising the accuracy of suspended-sediment data. Types of errors involved are sampling error, spatial error, temporal error, and sediment-discharge error. The standard error of estimate is used to represent errors. Suspended-sediment data for 17 U.S. Geological Survey gaging stations in Arizona, California, Nebraska, New Mexico, Pennsylvania, and Washington are used in applications of the procedures. For the study sites, the magnitudes of the different types of error apparently vary directly with percentage of sediment-water mixture that is sand; when the percentage sand is relatively high, magnitudes of the different types of error have a relatively wide range. For seven sites of the Sacramento River , Calif., and its tributaries, the standard sampling error apparently can range from 2.5 percent when percentage sand is relatively low to 20 percent when percentage sand is relatively high. For 16 sites in Arizona, California, Nebraska, New Mexico, and Pennsylvania, the coefficient of variation for concentrations of suspended sediment across streams apparently can range from 2.5 percent (low percentage sand) to 70 percent (high percentage sand). (USGS)

Professional Paper↗
USGS2008

Geologic Map of the Eastern Three-Quarters of the Cuyama 30' x 60' Quadrangle, California

The map area encompasses a large part of the western Transverse Ranges and southern Coast Ranges of southern California. The San Andreas fault (SAF) cuts the northern part of the map. The area south of the SAF, about 80 percent of the map area, encompasses several distinct tectonic blocks bounded by major thrust or reverse faults, including the Santa Ynez fault, Big Pine fault (and structurally continuous Pine Mountain fault), Tule Creek fault, Nacimiento fault, Ozena fault, Munson Creek fault, Morales fault, and Frazier Mountain Thrust System. Movement on these faults is as old as Miocene and some faults may still be active. In addition, the Paleocene Sawmill Mountain Thrust south of the SAF and the Pastoria Thrust north of the SAF place Cretaceous and older crystalline rocks above Pelona Schist (south of the SAF) and Rand Schist (north of the SAF). South of the SAF, each tectonic block contains a unique stratigraphy, reflecting either large-scale movement on bounding faults or different depositional environments within each block. On Mount Pinos and Frazier Mountain, intrusive and metamorphic rocks as old as Mesoproterozoic, but including voluminous Cretaceous granitoid rocks, underlie or are thrust above non-marine sedimentary rocks as old as Miocene. Elsewhere, marine and non-marine sedimentary rocks are as old as Cretaceous, dominated by thick sequences of both Eocene and Cretaceous marine shales and sandstones. Middle Miocene to early Oligocene volcanic rocks crop out in the Caliente Hills (part of Caliente Formation) and south of Mount Pinos (part of the Plush Ranch Formation). Fault-bounded windows of Jurassic Franciscan Complex ophiolitic rocks are evident in the southwest corner of the area. North of the SAF, marine and non-marine sedimentary rocks as old as Eocene and Miocene volcanic rocks overlie a crystalline basement complex. Basement rocks include Cretaceous intrusive rocks that range from monzogranite to diorite, and Jurassic to late Paleozoic intrusive and metamorphic rocks. The Jurassic to late Paleozoic intrusive rocks include diorite, gabbro, and ultramafic rocks, and the metasedimentary rocks include marble, quartzite, schist, and gneiss.

Scientific Investigations Map↗