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G.L. Bertoldi

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

8 recordsLinked to original sources
USGS1983

Data for ground-water test hole near Butte City, Central Valley aquifer project, California

This report provides preliminary data for the third of seven test holes drilled as 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 NE 1/4 sec. 32, T. 19 N., R. 1 W., Glenn County, California, about one-half mile south of the town of Butte City. Drilled to a depth of 1,432 feet below land surface, the hole is cased to a depth of 82 feet and equipped with three piezometer tubes to depths of 592 feet, 968 feet, and 1,330 feet. A 5-foot well screen is at the bottom of each piezometer. Each screened interval has a cement plug above and below it to isolate it from other parts of the aquifer , and the well bore is filled between the plugs with sediment. Nine cores and 49 sidewall cores were recovered. Laboratory tests were made for mineralogy, hydraulic conductivity, porosity , consolidation, grain-size distribution, Atterberg limits, X-ray diffraction, and chemical quality 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↗
USGS1983

A Pleistocene diatomaceous clay and a pumiceous ash, Yolo County ( California).

Discusses a diatomaceous clay of Pleistocene age, cored from 534-544ft, and a pumiceous ash found at a depth of 453ft in a test hole. Tests on the clay indicate that it is highly susceptible to compaction, and therefore, it could contribute, or perhaps has contributed, to land subsidence in the area of the test hole. The pumiceous ash is considered to be younger than about 450 000 yr. -from Authors

California Geology↗
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↗
USGS1968

Determination of channel capacity of the Merced River downstream from Merced Falls Dam, Merced County, California

This study evaluates the adequacy of a reach of the Merced River between Merced Falls and the confluence with the San Joaquin River to carry flood releases from New Exchequer and McSwain Dams and Reservoirs. The flood release from these reservoirs is to be restricted so that flows will not exceed 6,000 cfs (cubic feet per second) in t he Merced River at the gaging station near Stevinson (about 5 miles upstream from the mouth). Computed floodwater profiles based on channel conditions in late 1967 and observed water-surface profiles for historic floods were used in the analysis. The conclusions reached are contingent on there being no levee failures during periods of high flow. Evaluation of historical flood records at gaging stations between Merced Falls and Stevinson indicates that a reduction in peak discharge occurs as the floods traverse the study reach. Reduction in peak discharge is dependent on river stage, prior river flows, magnitude of tributary inflow, bank storage and infiltration to the ground-water reservoir, and diversion for irrigation. For example, in late June 1967 a peak discharge of 9,860 cfs at Merced Falls was reduced by irrigation diversions to 6,850 cfs at a site 3 miles downstream and further reduced to 6,490 cfs at the gaging station near Stevinson. Backwater effect from high stages on t he San Joaquin River will increase stages on the Merced River and the effect may extend as far as 8 miles up stream from the junction of the two rivers. Backwater may cause some overbank flooding along the 8-mile reach when Merced River flows at Stevinson exceed 4,000 cfs . Most of the area subject to such inundation lies between levees that are a considerable distance--up to half a mile-- from the main channel . In the reach upstream from the backwater effect, a discharge of 4, 500 cfs near Stevinson will cause flooding at two locations, one of which is about 10 miles upstream an the other about 18.5 miles upstream from the confluence . When the discharge is 6,000 cfs , additional sites will be inundated, particularly the 20.5-mile reach of channel downstream from the Highway 99 crossing. A discharge of 6,000 cfs will pass through all bridge openings in the reach but overbank flooding may occur if debris should lodge against the bridge piers and significantly reduce the waterway area . Peak flows in Dry Creek, as measured 18.7 miles upstream from the mouth of Dry Creek, will be attenuated due to channel storage and will increase the discharge of the Merced River at Cressey by only about 50 per cent of t he Dry Creek peak discharge. Furthermore, Dry Creek seldom carries floodflows during periods of high water on the Merced River.

California↗