The isotopic composition of radiogenic helium and its use to study groundwater movement in confined aquifers

Andrews, John N.

doi:10.1016/0009-2541(85)90166-4

Cited by 304 publications

(127 citation statements)

References 23 publications

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“…estimated this ratio to be 0.011 + 0.004 x Ra, based on the 3 He/4He ratio of helium released at the end of a step heating experiment using Taylor IVb sample BW84-105. This is consistent with, although somewhat higher than, calculated ratios for sandstones (Andrews, 1985), and a correction based on this ratio is generally less than 5% of total 3 He . Because the correction is small, the fairly large uncertainty in the radiogenic production ratio contributes little to uncertainties in 3 Hec.…”

Section: Noncosmogenic Heliumsupporting

confidence: 88%

Surface exposure geochronology using cosmogenic nuclides : applications in Antarctic glacial geology

Brook¹

1993

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Cosmogenic 3 He, 2 6 A1, and 10 Be have been measured in a variety of Antarctic glacial deposits in the McMurdo Sound-Dry Valleys region. The goals of this project were to provide age constraints for Antarctic glacial events, to investigate production mechanisms of 3 He, 10Be, and 2 6 A1 in terrestrial rocks, to constrain the importance of loss of 3 He from quartz due to diffusion, and to refine methods of exposure-age dating.Moraines deposited in Arena Valley by the Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet, have exposure ages from -120 kyr to 2 myr. 1 0 Be and 3 He ages of 122 + 29 and 134 ± 54 kyr, respectively, for the Taylor II moraine are consistent with deposition during isotope stage 5e (-120 kyr) and with aerial expansions of the East Antarctic Ice Sheet during interglacial periods. Mean 1 0 Be exposure ages for older moraines in the valley are 362 + 26 kyr (Taylor III), 1.1 ± 0.1 myr (Taylor IVa) and 1.9 ± 0.1 myr (Taylor IVb). Because these older moraines were deposited at most -200 m above the Taylor II limit their ages suggest that major ice sheet advances during the last 2 myr have been broadly similar in magnitude to changes during the last glacial-interglacial cycle. 10 Be ages for stratigraphically older drift deposited by the Taylor Glacier allow extension of this conclusion to -3 myr.1 0 Be measurements in high altitude, pre-Pleistocene glacial deposits in the Dry Valleys preclude rapid uplift of the Transantarctic Mountains (400-1000 m/myr) suggested by controversial biostratigraphic studies of Sirius Group tills. Comparison of measured 10Be concentrations in Sirius Group deposits with those predicted with a model of the effects of uplift on 1 0 Be production suggests minimal uplift of the Transantarctic Mountains over the last 3 myr.3 He, 1 0 Be and 2 6 A1 ages for the "late Wisconsin" Ross Sea Drift, a glacial drift deposited on the coast of McMurdo Sound by the Ross Sea Ice Sheet, range from 8-106 kyr. The age range suggests that this deposit does not, as previous studies suggested, represent a single ice advance in response to lowered sea level at the last glacial maximum. The age range may reflect several ice sheet advances during the last glacial period.Paired measurements of 3 He and 1 0 Be in a number of quartz sandstones from the Dry Valleys region show that cosmogenic 3 He is not completely retained on time scales of greater than 200 kyr. The 3 He and 1 0 Be data, combined with measurements of 3 He concentrations in quartz as a function of grain size, suggest effective 3 He diffusion coefficients in quartz from ~10 -19 to 10-17 cm 2 s -1. These values are one to three orders of magnitude greater than previous experimental determinations extrapolated to low temperature. The data also suggest that 3 He diffusion rates in quartz do not follow simple volume diffusion trends and are probably sample dependent.Crushing quartz grains in vacuo releases variable concentrations of 3 He and 4 He and releases helium with surprisingly high isotopic compositions, u...

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Section: Noncosmogenic Heliumsupporting

confidence: 88%

Surface exposure geochronology using cosmogenic nuclides : applications in Antarctic glacial geology

Brook¹

1993

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“…The differences between the corrected (R c ) He isotopic ratios and the R m values in the free gas samples were mostly less than 5% in October 2008 and June 2009 (Table 1), indicating the atmospheric He contamination in the free gas samples can be neglected. The R c values are greater than the typical crustal 3 He/ 4 He (R/Ra = 0.02) (Andrews 1985), indicating the contribution of mantle-derived helium. Therefore, the proportion of mantle-derived helium in the samples can be estimated using the two-end member model for mantle and crustal helium.…”

Section: Hementioning

confidence: 70%

Hot Spring Gas Geochemistry in Western Sichuan Province, China After the Wenchuan Ms 8.0 Earthquake

Zhou¹,

Wang²,

Chen³

et al. 2015

Terr. Atmos. Ocean. Sci.

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The chemical components, He, Ne, and C isotropic ratios of gas samples collected thrice from 32 hot springs in western Sichuan Province, southwestern China in June and October 2008 and June 2009 were investigated in order to discuss the relationship between hot spring gas geochemistry and the Wenchuan Ms 8.0 earthquake. The data showed that the 3 He/ 4 He and C 13CO2 d values in spring gases in the Longmenshan fault (LMSF), Xianshuihe fault (XSHF), and Minjiang fault (MJF) zones increased obviously after the great earthquake. It was estimated that up to 62% of mantle helium contributed to the spring gas in the Kangding region based on the maximum 3 He/ 4 He (7.42 × 10 -6 ) in June 2008. Over time the mantle derived fluid contribution to the hot springs gradually decreased, but the crustal gas components: CO 2 and CH 4 derived from organic matter and radiogenic He increased. The gas geochemical data suggested that more mantle fluids migrated into the crust in western Sichuan Province after the Wenchuan Ms 8.0 earthquake.

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“…Thus, helium is predominantly of mantle origin with evidence of a small but discernible addition of radiogenic helium at all locations. In a two-component mixture of MORB-like He (8 R A ; Graham, 2002) and radiogenic He (0.05 R A ; Andrews, 1985) the proportion of mantle helium at Poás varies between 95 and 84%.…”

Section: Helium Isotopesmentioning

confidence: 99%

Monitoring of temporal and spatial variations in fumarole helium and carbon dioxide characteristics at Po^|^aacute;s and Turrialba volcanoes, Costa Rica (2001-2009)

et al. 2010

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The isotopic composition of radiogenic helium and its use to study groundwater movement in confined aquifers

Cited by 304 publications

References 23 publications

Surface exposure geochronology using cosmogenic nuclides : applications in Antarctic glacial geology

Surface exposure geochronology using cosmogenic nuclides : applications in Antarctic glacial geology

Hot Spring Gas Geochemistry in Western Sichuan Province, China After the Wenchuan Ms 8.0 Earthquake

Monitoring of temporal and spatial variations in fumarole helium and carbon dioxide characteristics at Po^|^aacute;s and Turrialba volcanoes, Costa Rica (2001-2009)

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