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A. A. Pucci

Publications and source records attributed to A. A. Pucci.

7 recordsLinked to original sources
USGS2006

Applications of universal kriging to an aquifer study in New Jersey

This article describes the use of kriging for optimizing data collection and utility in a regional ground-water investigation of the Potomac-Raritan-Magothy aquifer system in central New Jersey. Kriging was used to (1) estimate the altitude of an aquifer surface, (2) estimate hydraulic conductivities from point data, and (3) estimate the associated kriged errors. The selection of locations for additional data collection, based on the kriged errors, was effective in terms of improving the aquifer surface data base. In another application, hydraulic conductivity values were kriged, first using equal weights, then unequal weights to account for the reliability of the data. The weighting values that were used for unequal weighting were estimated by an analysis of variance. Although inclusion of the data reliability in the kriging will increase the kriged errors, the accuracy of the range of uncertainty in the interpolated values also increases.

Groundwater↗
USGS2005

Geochemical variations in a core of hydrogeologic units near Freehold, New Jersey

Solutes were determined for 26 pore-water samples extracted from Tertiary and Cretaceous core material from a 1,320-foot-deep test borehole at Freehold, New Jersey. The cored materials are sediments that form a multilayered aquifer system of seven aquifers and eight confining units in the New Jersey Coastal Plain. The sediments are of marine origin in the upper 650 feet of the core and primarily nonmarine below 650 feet. Total concentrations of silica and major anions (SO 4 -2 and Cl - ) and cations (Ca +2 , Mg +2 , total Fe, Mn +2 , Na + , and K + ) in the pore-water samples varied with depth. Three core intervals are defined by water- chemistry variations, the environment of deposition (marine or nonmarine), and the degree of alteration (weathered or unweathered) of the units. Calcium, magnesium, sulfate, and total-ion concentrations were greater in the midcore (unweathered marine) interval than in the upper (weathered marine) and lower (fluviodeltaicsilicate) intervals of the core. Generally, pore-water chemical types in confining units were distinct from those found in aquifers–particularly in the midcore interval. In this interval, observed variations in pore-water chemistry in part reflect carbonate dissolution and cation exchange reactions common in Coastal Plain sediments. However, high concentrations of sulfate in unweathered marine sediments indicate novel processes may be important factors influencing pore-water chemistry in confining units.

Groundwater↗
USGS1997

Variations in pore-water quality, mineralogy, and sedimentary texture of clay-silts in the lower Miocene Kirkwood Formation, Atlantic City, New Jersey

Properties of and pore-water solute chemistry in confining units in the New Jersey Coastal Plain were studied to determine whether leakage of solute-enriched pore water from confining units affects regional aquifer-water chemistry, which ultimately may result in aquifer waters with high sodium and bicarbonate concentrations. Pore-water samples collected from a continuously cored borehole in the lower Miocene Kirkwood Formation at Atlantic City, NJ, were analyzed: 15 samples were obtained from clay-silt confining-unit sediments, and four samples were from silt interbeds in the sand of the major confined aquifer in the region, the Atlantic City 800-ft sand. The samples were analyzed to assess interrelations among mineralogy, texture, fluidretention properties, sediment chemistry, and pore-water chemistry, and to document the scale of variation in these properties. Linear regressions were developed to describe the relations of constituents dissolved in 14 pore-water samples collected from the lower confining unit overlying the Atlantic City 800-ft sand and from the silt interbeds in the upper sand unit of the Atlantic City 800-ft sand. The regressions were for concentrations of magnesium and calcium (m = 0.27, R2 = 0.99); concentrations of sodium and the sum of calcium and magnesium (m = 0.17, R 2 = 0.92); concentrations of sulfate and the sum of calcium and magnesium (m = 1.14, R 2 = 0.99); and concentrations of sodium and sulfate (m = 0.14, R 2 = 0.89). The percentage of fine sand was greatest in the shallowest sampled interval, where pore-water concentrations of calcium, magnesium, and sulfate were greatest. The pore-water samples were of three distinct water-quality types (hydrogeochemical facies): a calcium-sulfate type, a mixed calcium-sodium-sulfate-chloride-bicarbonate type, and a sodium-sulfate-bicarbonate-chloride type. The first two types were found only in the lower confining unit; the third type was found only in the composite confining unit underlying the Atlantic City 800-ft sand. Each of these hydrogeochemical facies generally is found within distinct intervals over a range of tens of feet in the core. Krige estimates of pore-water–constituent variations with depth were made by using only the analytical results for the 14 samples from the lower confining unit overlying the Atlantic City 800-ft sand and the silt interbeds in the upper sand unit of the Atlantic City 800-ft sand. Geostatistical analysis of the pore-water–quality data generally resulted in two types of semivariograms. One semivariogram type best fits concentration trends with depth for calcium, magnesium, strontium, sodium, sulfate, and specific conductance; lithium and chloride may also fit this semivariogram type. The other semivariogram type best fits concentration trends with depth for silica, cation exchange capacity, and dissolved inorganic carbon. The scale of variation of the concentrations and properties is indicated by the maximum lag autocorrelation distance of the theoretical semivariograms (the range) and ranged from 44 to 110 ft (13.4–33.5 m). The scale of variation of pore-water major-ion concentrations of sulfate, chloride, calcium, and magnesium alone is on the order of 65–70 ft (19.8–21.3 m). The semivariograms for all pore-water constituents except silica have significant variance at the smallest lag distance, indicating that the constituent concentration varied over a larger scale than the sampling interval. The dominant exchangeable cation in the sediment is calcium. Cation exchange reactions do not appear to be the dominant process in the sediments of the lower confining unit above the Atlantic City 800-ft sand, because a linear correlation exists between the concentration of sodium and the sum of calcium and magnesium concentrations in the pore water; concentrations of all these constituents increase in the upward flow direction, and the ratio of sodium to chloride in the pore water is about 1.0. Two significant principal components explained 82.5% of the total variation in pore-water solute chemistry. Principal component 1 represents about 53% of the variation in pore-water quality and includes calcium, magnesium, sulfate, strontium, and lithium. Coupled chemical processes in the confining units, such as incongruent dissolution of carbonate and other mineral phases or redox transformations of sulfur, likely explain the covariance of these constituents. Principal component 2 represents about 30% of the variation and includes sodium, dissolved inorganic carbon, and chloride. Covariance of sodium and chloride probably is caused by the presence of residual seawater.

New Jersey↗
USGS1997

Sr-isotopic evidence for leakage of pore water from clay-silt confining units to the Atlantic City 800-foot sand, Atlantic City, New Jersey

The evolution of water quality in confined aquifers in the New Jersey Coastal Plain may be affected by leakage of pore water from the adjacent confining units. We investigated the distribution and sources of solutes, particularly Sr, in pore water mechanically extracted from clay-silt core samples collected from depths of 552–840 ft (168–256 m) in the lower Miocene Kirkwood Formation at Atlantic City, New Jersey (Ocean Drilling Program Leg 150X). The sampled sediments consist of thin clay-silt stringers in the upper part of the Atlantic City 800-ft sand, a major aquifer, and the massive clay-silt units above and below it. The distribution of Sr and the ratio of 87 Sr to 86 Sr in the pore water and adjacent shell material were used to identify the possible sources of, and physical processes that may affect the distribution of, Sr in the pore water. Concentrations of Sr in 14 pore-water samples from the clay-silt unit above the aquifer and the clay-silt interbeds in the upper part of the aquifer ranged from 2.74 to 28.19 µM/L; those in the four pore-water samples from the clay-silt unit below the aquifer ranged from 0.52 to 7.30 µM/L. Concentrations of Sr in the samples varied with depth but correlated strongly with pore-water concentrations of Ca, Mg, Na, and SO4. Cation-exchange processes may be responsible, in part, for the lower concentrations of Sr, Ca, and Mg in pore water from the clay-silt unit below the aquifer than in that above the aquifer. 87 Sr/ 86 Sr values in 11 samples of aragonitic mollusk shells (bearing no visible evidence of recrystallization) collected from depths in the clay-silt unit similar to those from which the pore-water samples were collected ranged from 0.708468 to 0.708713 , and decreased (Sr in the shells was less radiogenic) with depth. This trend is consistent with the decrease in the 87 Sr/ 86 Sr value in seawater through time during the early Miocene. The 87 Sr/ 86 Sr values in 12 pore-water samples from the studied stratigraphic interval ranged from 0.708257 to 0.708527 and also decreased with depth. The Sr-isotope ratios in the pore water were lower than those in the shell material from nearby or adjacent sediments for all samples but one. Because the only known source of Sr with an isotope ratio this low is shell material from sediments deeper than the strata from which the pore-water samples were collected (including pre-Miocene stratigraphic units), the isotope ratio in the pore-water samples from the lower Miocene claysilt units may result from upward movement of pore water into lower Miocene strata through geologic time, which could create the observed difference in Sr isotope ratios between the pore water and shells.

New Jersey↗
USGS1989

Aquifer-test analysis of the upper aquifer of the Potomac-Raritan-Magothy aquifer system, Union Beach Borough, Monmouth County, New Jersey

The hydraulic properties of the upper aquifer of the Potomac-Raritan-Magothy aquifer system and of the overlying and underlying confining units were determined from and aquifer test in the vicinity of Union Beach Borough, New Jersey, near Raritan Bay. The April 1986 test included the pumping of 2 test wells for 72 hours at a combined discharge rate of 1,375 gal/min, and the measurement of water levels in 10 observation wells. No lateral recharge boundary in Raritan Bay affected the observed water-level changes. Assuming leaky artesian conditions, the average transmissivity and storage coefficient of the upper aquifer are 7,754 sq ft/day and 0.00044 respectively. The leakance of the combined confining units ranges from 0.000030 to 0.000076/day/ft. On the basis of lithologic samples from a nearby well, the overlying and underlying confining units were assumed to have similar hydraulic properties. By using this assumption, the vertical hydraulic conductivity of the confining units ranges from 0.010 to 0.027 ft/day.

New Jersey↗