A strontium, oxygen and hydrogen isotopic composition of brines, Michigan and appalachian basins, Ontario and Michigan

The effect of long-term regional pumping on hydrochemistry and dissolved gas content in an undeveloped shale-gas-bearing aquifer in southwestern Ontario, Canada

“…A secondary peak is centered near −17‰ for both overburden and bedrock wells. The latter peak is within the range of estimated glacial meltwater in the Great Lakes region (Clayton et al 1966;McNutt et al 1987;Long et al 1988;Husain et al 2004;McIntosh and Walter 2006). The larger peak is slightly lower than the center of the estimated range of modern recharge (~10‰) in the Devonian shale area (Husain et al 2004).…”

“…Aravena et al (1995) also report the presence of glacial meltwater in surficial sediments. McNutt et al (1987) and Weaver et al (1995) show that deeper saline formation waters in bedrock units have distinct stable isotope trends consistent with basinal brines, some bedrock aquifers show evidence of mixing with glacial meltwaters (Dollar 1988;McNutt et al 1987;Dollar et al 1991;Aravena et al 1995;Husain 1996). Weaver et al (1995) also show direct evidence for glaciation affecting bulk hydraulic conductivity of bedrock in southern Ontario and vertical migration of glacial waters associated with glacial-induced fracture flow.…”

Paleowaters in Silurian-Devonian carbonate aquifers: Geochemical evolution of groundwater in the Great Lakes region since the Late Pleistocene

“…Michigan Basin brines in Silurian-Devonian carbonates have 87 Sr/ 86 Sr ratios ranging from 0.7080 to 0.7095 (McNutt et al, 1987;Wilson and Long, 1993a,b), similar to the Silurian-Devonian seawater values. Brines in Illinois Basin Silurian-Devonian carbonates, on the other hand, have more radiogenic Sr isotope values (0.7092-0.7108), indicating a significant portion of the Sr 2+ came from interactions with the overlying radiogenic Upper Devonian (Stueber and Walter, 1991;McIntosh et al, 2002McIntosh et al, , 2004.…”

“…New elemental and isotope geochemical data presented in this study show that this recharge of d 18 O and dD depleted waters was regionally extensive and also pervasive in the Silurian-Devonian carbonate aquifer system in the Michigan and Illinois basins (Fig. 5b) (Clayton et al, 1966;Coplen and Kendall, 2000;Eberts and George, 2000;IAEA/WMO, 2001), whereas estimated d 18 O values for glacial meltwater in the Great Lakes region range from À25 to À11& (Clayton et al, 1966;McNutt et al, 1987;Long et al, 1988;Dettman et al, 1995;Husain et al, 2004). Together, the stable isotope chemistry and salinity patterns suggest that Pleistocene glaciation reorganized regional-scale groundwater flow and introduced geochemically distinct fluids to great depths in Paleozoic aquifers.…”

Desalination of a sedimentary rock aquifer system invaded by Pleistocene Champlain Sea water and processes controlling groundwater geochemistry

“…Figure 7 shows the relationship between Cl/Br ratio and Cl -for the groundwater groups, as well as for possible end-members, including the clay pore water sample C85-14, seawater, and brine samples. The brine samples have representative compositions of formation waters for the Cambrian and Trenton formations of southern Ontario presented by McNutt et al (1987). Sample S77, the groundwater sample with the highest salinity (TDS expressed as salinity of 11.3 g/L), plots on the seawater Cl/Br line, suggesting that seawater is a component of this sample (Fig.…”