Filters: Tags: Isotopes (X)210 results (320ms)
Origin and age of saline waters in Busko Spa (southern Poland) determined by isotope, noble gas and hydrochemical methods: Evidence of interglacial and pre-Quaternary warm climate recharges
Macrofaunal and isotopic estimates of the former extent of the Colorado River estuary, upper Gulf of California, Mexico
Twenty-two igneous and metamorphic rock samples were collected in a 20-km-long swath centered on the Alaska Highway between Tetlin Junction, Alaska, and the Canada border. Igneous and metamorphic rock samples were submitted to the Apatite to Zircon, Inc. laboratory (A2Z), where zircon U-Pb age analysis, using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), was performed by Paul O'Sullivan. The 15 felsic plutonic rock samples and one gabbro sample yield Cretaceous zircon U-Pb weighted-mean ages ranging from 95.7 Ma to 106.2 Ma. Zircons from a metadiorite yield a Triassic weighted-mean age of about 241.9 Ma. Metamorphic zircons from two samples with felsic igneous protoliths yield Mississippian...
Utilizing geochemical, hydrologic, and boron isotopic data to assess the success of a salinity and selenium remediation project, Upper Colorado River Basin, Utah.
Stream discharge and geochemical data were collected at two sites along lower Ashley Creek, Utah, from 1999 to 2003, to assess the success of a site specific salinity and Se remediation project. The remediation project involved the replacement of a leaking sewage lagoon system that was interacting with Mancos Shale and increasing the dissolved salinity and Se load in Ashley Creek. Regression modeling successfully simulated the mean daily dissolved salinity and Se loads (R(2) values ranging from 0.82 to 0.97) at both the upstream (AC1) and downstream (AC2/AC2A) sites during the study period. Prior to lagoon closure, net gain in dissolved-salinity load exceeded 2177 metric tons/month and decreased after remediation...
Genetic differentiation in carbon isotope discrimination and gas exchange in Pseudotsuga menziesii : A common-garden experiment.
Reconstruction of past climates from stable isotope records of palaeo-precipitation preserved in continental archives
Scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center investigated the sedimentary and geochemical properties of the lower reaches of the Pascagoula River along the Mississippi coast of the Gulf of Mexico by collecting estuarine, riverine and marsh sediments. This was done in order to increase understanding of the region's environmental history, describe the long-term (millennial-scale) depositional history, and identify sedimentary intervals associated with extreme marine intrusions. To this end, the group obtained long sediment cores, shovel-dug sediment slabs and marsh and riverine channel/estuarine surface samples from a north-south transect along the river edge from...
Stable isotopes of delta(18)O, delta(2)H, and (13)C, radiogenic isotopes of (14)C and (3)H, and ground water chemical compositions were used to distinguish ground water, recharge areas, and possible recharge processes in an arid zone, fault-bounded alluvial aquifer. Recharge mainly occurs through exposed stream channel beds as opposed to subsurface inflow along mountain fronts. This recharge distribution pattern may also occur in other fault-bounded aquifers, with important implications for conceptualization of ground water flow systems, development of ground water models, and ground water resource management. Ground water along the mountain front near the basin margins contains low delta(18)O, (14)C (percent modern...
Sulfate reduction in a lake and the groundwater of a former lignite mining area studied by stable sulfur and carbon isotopes
Potential tools for tracking ocean climate: Variability in stable isotopes in living coralline algae