Ancient groundwaters in the Amadeus Basin, Central Australia: evidence from the radio-isotope 36Cl

Helium-4 characteristics of groundwaters from Central Australia: Comparative chronology with chlorine-36 and carbon-14 dating techniques

“…Prior work has shown that 36 Cl/Cl derived residence times of groundwaters from the Great Artesian Basin, Australia (Bentley et al, 1986;Love et al, 2000;Torgersen et al, 1991;Radke et al, 2000) and the Amadeus Basin (Cresswell et al, 1999a) are comparable to residence times calculated from hydrodynamic flow modeling (based on Darcy's Law). This implies that the input 36 Cl/Cl ratio of recharge water, and the 36 Cl/Cl ratio of water added to the system -by groundwater mixing for example -is well constrained.…”

“…This potentially enables the application of this chronometer on waters up to 2 Ma. The advantages of this technique are the simple geochemistry of chloride anions, which have high solubility and minimal adsorption in groundwater systems; the low chloride content of most aquifer materials (excluding evaporites); and chloride's conservative behaviour in water, allowing it to travel at virtually the same velocity as groundwater (Bentley et al, 1986;Cresswell et al, 1999a;Love et al, 2000).…”

“…Descriptions of the flow systems in the Alice Springs and Uluru regions may be made by seeking congruence between 4 He and 14 C and 36 Cl-derived ages. Using this approach, it may be possible to identify deep pockets of ancient groundwater in the Amadeus Basin (Cresswell et al, 1999a), due to irregular basement topography, or the disruption of flow due to heavily folded units near Alice Springs.…”

Origin and formation mechanism of salty water in Zuli River catchment of the Yellow River

“…Groundwater age is an extremely important indicator of the groundwater replenishment (Bethke & Johnson, ; Cresswell et al., ; Jasechko, ). Tritium ( 3 H), a radioactive isotope of hydrogen with a concentration that spiked in precipitation approximately 50 years ago as a result of aboveground thermonuclear testing, is commonly applied in hydrologic cycle research to determine whether modern water supplies exist (Cartwright & Morgenstern, ; Egboka et al., ; Morgenstern et al., ; Robertson & Cherry, ; Solomon et al., ; Young et al., ).…”

“…() conclude that drainage at higher altitude may be associated with gravity‐driven flows and the main geochemical processes constraining groundwater salinity is the dissolution of halite and gypsum. In addition, quantifying groundwater age by radioisotopes to trace groundwater migration pathways is also effective for identifying regional water cycles through isotopic methods (Bethke & Johnson, ; Cartwright, Cendon, Currell, & Meredith, ; Clark & Fritz, ; Cresswell, Jacobson, Wischusen, & Fifield, ; Hagedorn, ; Kalin, ). For example, tritium ( 3 H), a radioactive isotope of hydrogen with a concentration that spiked in precipitation approximately 50 years ago as a result of aboveground thermonuclear testing, is commonly applied in hydrologic cycle research to determine whether modern water supplies exist (Cartwright & Morgenstern, ; Egboka, Cherry, Farvolden, & Frind, ; Morgenstern, Stewart, & Stenger, ; Robertson & Cherry, ; Solomon, Poreda, Cook, & Hunt, ; Young, Broughton, Bradd, & Holland, ).…”