scholarly journals Oxygen and hydrogen stable isotope measurements of ground waters for the central west side of the San Joaquin Valley, California

1985 ◽  
Author(s):  
T.B. Coplen ◽  
Carol Kendall ◽  
G.H. Davis
Keyword(s):  
Stable Isotope ◽  
San Joaquin Valley ◽  
West Side ◽  
Ground Waters ◽  
Isotope Measurements

Hydrothermal Sr contamination of the Dippin sill, Isle of Arran, Western Scotland

1984 ◽  
Vol 48 (348) ◽  
pp. 311-322 ◽  
Author(s):  
A. P. Dickin ◽  
C. M. B. Henderson ◽  
F. G. F. Gibb
Keyword(s):  
Stable Isotope ◽  
Hydrothermal Alteration ◽  
Closed System ◽  
Hydrothermal Systems ◽  
Hydrothermal Fluids ◽  
Drill Core ◽  
Sr Isotope ◽  
Core Section ◽  
High Silica ◽  
Isotope Measurements

Abstract The Dippin sill, which is emplaced into the Triassic sediments of SE Arran, is an alkaline basic sheet which displays pronounced hydrothermal alteration. The 40-m-thick sill has suffered pervasive contamination with radiogenic Sr, introduced from the Triassic sediments by hydrothermal fluids. Stable isotope measurements suggest that fluids were of meteoric origin, but were restricted to a small closed-system circulation. Initial 87Sr/86Sr ratios in the sill were raised from an original value of 0.7032 to a maximum of 0.7091, contamination being especially pronounced near the contacts at Dippin Head itself (localities 12 and 14) and in a drill core section through the sill above Dippin. Hydrothermal Sr was incorporated into an early-formed high-CaO, high-Sr analcime, which replaced unstable high-silica nepheline in interstitial patches. However, this high-CaO analcime, along with plagioclase, was later replaced by a low-CaO, low-Sr analcime, allowing Sr leaching from the margins of the sill. Hydrothermal fluids are thought to have migrated up to 1 km laterally, up the dip of the sill, mainly via tension joints forming in the cooling intrusion. Pooling of hot fluids at the upper end of the sill probably raised water/rock ratios in this region and allowed greater Sr contamination during mineralogical alteration. The undersaturated mineralogy of the sill accounts for its pervasive hydrothermal Sr contamination, which contrasts markedly with the relatively undisturbed Sr isotope compositions of Hebridean granites involved in hydrothermal systems.

Stable isotope measurements and modeling to verify the authenticity of dairy products

2017 ◽  
pp. 239-256
Author(s):  
Emad Ehtesham ◽  
Federica Camin ◽  
Luana Bontempo ◽  
Russell D. Frew
Keyword(s):  
Stable Isotope ◽  
Dairy Products ◽  
Isotope Measurements

scholarly journals Radiocarbon and Stable Isotope Analyses of Archaeological Bone Consolidated with Hide Glue

Radiocarbon ◽  
2002 ◽  
Vol 44 (1) ◽  
pp. 59-62 ◽  
Author(s):  
C M Takahashi ◽  
D E Nelson ◽  
J S Southon
Keyword(s):  
Stable Isotope ◽  
Simple Method ◽  
Stable Isotope Analyses ◽  
Isotope Analyses ◽  
Isotope Measurements

We tested a simple method for removing a collagen-based glue preservative from bone destined for radiocarbon and stable isotope analyses. The method is sufficient for bone samples from which only stable isotope measurements are required. For 14C dating, such samples of age less than about 10 ka can be adequately dated, but for older samples, the circumstances must be carefully evaluated.

scholarly journals Policy Innovation and Governance for Irrigation Sustainability in the Arid, Saline San Joaquin River Basin

2020 ◽  
Vol 12 (11) ◽  
pp. 4733
Author(s):  
Nigel W. T. Quinn
Keyword(s):  
Water Quality ◽  
Resource Management ◽  
River Basin ◽  
San Joaquin Valley ◽  
Irrigated Agriculture ◽  
Policy Response ◽  
The West ◽  
West Side ◽  
Salt Load ◽  
San Joaquin River

This paper provides a chronology and overview of events and policy initiatives aimed at addressing irrigation sustainability issues in the San Joaquin River Basin (SJRB) of California. Although the SJRB was selected in this case study, many of the same resource management issues are being played out in arid, agricultural regions around the world. The first part of this paper provides an introduction to some of the early issues impacting the expansion of irrigated agriculture primarily on the west side of the San Joaquin Valley and the policy and capital investments that were used to address salinity impairments to the use of the San Joaquin River (SJR) as an irrigation water supply. Irrigated agriculture requires large quantities of water if it is to be sustained, as well as supply water of adequate quality for the crop being grown. The second part of the paper addresses these supply issues and a period of excessive groundwater pumping that resulted in widespread land subsidence. A joint federal and state policy response that resulted in the facilities to import Delta water provided a remedy that lasted almost 50 years until the Sustainable Groundwater Management Act of 2014 was passed in the legislature to address a recurrence of the same issue. The paper describes the current state of basin-scale simulation modeling that many areas, including California, are using to craft a future sustainable groundwater resource management policy. The third section of the paper deals with unique water quality issues that arose in connection with the selenium crisis at Kesterson Reservoir and the significant threats to irrigation sustainability on the west side of the San Joaquin Valley that followed. The eventual policy response to this crisis was incremental, spanning two decades of University of California-led research programs focused on finding permanent solutions to the salt and selenium contamination problems constraining irrigated agriculture, primarily on the west side. Arid-zone agricultural drainage-induced water quality problems are becoming more ubiquitous worldwide. One policy approach that found traction in California is an innovative variant on the traditional Total Maximum Daily Load (TMDL) approach to salinity regulation, which has features in common with a scheme in Australia’s Hunter River Basin. The paper describes the real-time salinity management (RTSM) concept, which is geared to improving coordination of west side agricultural and wetland exports of salt load with east side tributary reservoir release flows to improve compliance with river salinity objectives. RTSM is a concept that requires access to continuous flow and electrical conductivity data from sensor networks located along the San Joaquin River and its major tributaries and a simulation model-based decision support designed to make salt load assimilative capacity forecasts. Web-based information dissemination and data sharing innovations are described with an emphasis on experience with stakeholder engagement and participation. The last decade has seen wide-scale, global deployment of similar technologies for enhancing irrigation agriculture productivity and protecting environmental resources.

Stable isotope measurements of atmospheric CO2 and CH4

2004 ◽  
pp. 272-304 ◽  
Author(s):  
B.H. Vaughn ◽  
J. Miller ◽  
D.F. Ferretti ◽  
J.W.C. White
Keyword(s):  
Stable Isotope ◽  
Atmospheric Co2 ◽  
Isotope Measurements

scholarly journals Diet and Radiocarbon Dating of Tollund Man: New Analyses of an Iron Age Bog Body from Denmark

Radiocarbon ◽  
2018 ◽  
Vol 60 (5) ◽  
pp. 1533-1545 ◽  
Author(s):  
Nina H Nielsen ◽  
Bente Philippsen ◽  
Marie Kanstrup ◽  
Jesper Olsen
Keyword(s):  
Mass Spectrometry ◽  
Stable Isotope ◽  
Iron Age ◽  
Radiocarbon Dating ◽  
Bone Collagen ◽  
Scientific Investigations ◽  
Bog Body ◽  
General Diet ◽  
Isotope Analyses ◽  
Isotope Measurements

ABSTRACTTollund Man is one of the most famous Iron Age bog bodies due to his well-preserved head. Since he was unearthed in 1950 in Bjældskovdal, Denmark, he has been subjected to several scientific investigations, but until now no attempts to reconstruct his general diet through isotope analyses have been conducted. Furthermore, previous radiocarbon (14C) analyses have only been able to date him broadly to the 3rd–4th century BC. In this study, stable isotope measurements (δ13C, δ15N) on bone collagen from Tollund Man’s femur and rib showed that the diet of Tollund Man was terrestrial-based and that the crops he ate probably were grown on manured fields. Accelerator mass spectrometry (AMS) 14C dates were obtained on both the <30kDa and >30kDa fractions of ultrafiltered collagen. Results showed that the ultrafiltration removed contamination from older substances from the burial environment. The femur was dated to 2330±23 BP, the rib to 2322±30 BP. These dates statistically agree with a previously published AMS 14C age on skin. By combining the new dates with the previous date of his skin it was possible to narrow down the age of Tollund Man to the period 405–380 cal BC (95.4% confidence interval).

Standards for stable isotope measurements in natural compounds

Nature ◽  
1978 ◽  
Vol 271 (5645) ◽  
pp. 534-536 ◽  
Author(s):  
R. GONFIANTINI
Keyword(s):  
Stable Isotope ◽  
Natural Compounds ◽  
Isotope Measurements
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