Geology Reports⌕ Search

Geology topics

G.L. Bertoldi

Publications and source records attributed to G.L. Bertoldi.

3 recordsLinked to original sources
USGS1982

Data for ground-water test hole near Zamora, Central Valley Aquifer Project, California

Preliminary data are presented for the first of seven test holes drilled as a part of the Central Valley Aquifer Project which is part of the National Regional Aquifer Systems Analysis Program. The test hole was drilled in the SW 1/4 SE 1/4 sec. 34, T. 12 N. , R. 1 E., Yolo County, California, about 3 miles northeast of the town of Zamora. Drilled to a depth of 2,500 feet below land surface, the hole is cased to a depth of 190 feet and equipped with three piezometer tubes to depths of 947, 1,401, and 2,125 feet. A 5-foot well screen is at the bottom of each piezometer. Eighteen cores and 68 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, diatom identification, thermal conductivity, and chemical analysis of water. Geophysical and thermal gradient logs were made. The hole is sampled periodically for chemical analysis and measured for water level in the three tapped zones. This report presents methods used to obtain field samples, laboratory procedures, and the data obtained. (USGS)

Open-File Report↗
USGS1971

Chemical quality of ground water in the Dos Palos-Kettleman City area, San Joaquin Valley, California

The Dos Palos-Kettleman City area of this report includes approximately 1,350 square miles on the central-western side of the San Joaquin Valley, California. Large-scale farming operations in the area have used ground water as the major source of irrigation water for nearly three quarters of a century. In 1968, completion of the San Luis Canal part of the California Aqueduct, made surface water available to farmers. In time the widespread use of this imported water may cause chemical-quality changes in the native ground water. To document conditions prior to any possible changes, 361 samples of ground water were taken before deliveries of surface water were begun. The data will serve as a base to which future investigations can be compared. To establish any trends, the results were compared to earlier chemical data for the area. The results indicated that only minor changes in chemical quality had occurred between 1951 and 1968. Water from an upper water-bearing zone is markedly different from water in a lower water-bearing zone. Water in the upper zone is of various chemical types, and the concentration of dissolved solids increases from east to west across the area. Water in the lower zone is a sodium sulfate type and is fairly consistent throughout the zone.

California↗