Regional Variations of River Water Composition Resulting From Halite Solution, Mackenzie River Drainage Basin, Canada

Abstract

The composition of surface waters in the Mackenzie River drainage basin falls into three general groups: (1) rivers entering the Slave‐Mackenzie system from the west which have sum‐of‐constituents 100–200 mg/1 and chloride in the range < 1 mg/1 in their headwaters to 2–5 mg/1 at their mouths; (2) surface waters on the Canadian Shield which have lower sum‐of‐constituents (<100 mg/1) and chloride (<1 mg/1); and (3) the Slave and Mackenzie rivers and the Great Bear and Great Slave lakes, which have sum‐of‐constituents 100—200 mg/1 and chloride 5–10 mg/1. Hydraulic head cross sections with evidence of solution collapse structures and anomalous depositional thicknesses indicate extensive solution of Middle Devonian halite and movement of the resulting brines to discharge areas at the principal Devonian outcrop near the Slave River. Chemical and isotopic analysis of saline springs in the discharge area confirms an origin by solution of halite (and gypsum) by meteoric water.

Modeling of water-rock interaction in the Mackenzie basin: Competition between sulfuric and carbonic acids

“…K + is mainly provided by the dissolution of K-feldspar and biotite minerals in granitic rocks and soils, and partly removed from solutions through illite precipitation. Over the six sub-basins, calculated Na + and Clconcentrations are lower than measured concentrations but this difference can be explained by the dissolution of halite minerals (Hitchon et al, 1969;Millot et al, 2003). In the model, chlorine is only supplied by rainwater and Na + comes from both rainwater and the dissolution of plagioclase minerals.…”

Influence of the Pacific Decadal Oscillation on hydrochemistry of the Rio Grande, USA, and Mexico

“…Long‐term variability in river chemistry needs to be assessed for effective management of water and land resources, particularly in semiarid regions with rapid population and economics growth. Pioneered by Clark [1924] and followed by Livingstone [1963], water chemistry has been extensively studied over the major world rivers, notably the Amazon [ Gibbs , 1972; Stallard and Edmond , 1981, 1983, 1987; Markewitz et al , 2001], the Mississippi [ Clark et al , 2003], the Mackenzie [ Hitchon et al , 1969; Levinson et al , 1969; Reeder et al , 1972], the Yangtze [ Hu et al , 1982; Chen et al , 2002], and the Nile [ Kempe , 1983; Dekov et al , 1997]. Unfortunately, most studies cover a relatively short period (typically a couple of years) and are only able to account for seasonal climatic and biotic fluctuations.…”

A hydrologic assessment of a saline‐spring fen in the Athabasca oil sands region, Alberta, Canada – a potential analogue for oil sands reclamation

“…Na and Cl dominated the ground and surface waters within the fen, consistent with other springs in the AOSR connected to regional aquifers found within subcropping Devonian‐aged carbonate and Cretaceous formations (Hitchon et al ., ; Grasby, ). Salinity (EC, Cl − , and Na + , Table ) was markedly higher than other natural‐saline wetlands observed in the region (Purdy et al ., ; Trites and Bayley, ,).…”

“…Saline marshes and peatlands are also common throughout North America's interior, such as within the Great Plains region, where salts accumulate over many years within regional and local discharge zones (Harvey et al ., ; van der Kamp and Hayashi, ; Heagle et al ., ). In northern Alberta, saline‐spring wetlands are often found close to or along major river systems, where groundwater discharges to the surface through subcropping or exposed Paleozoic rocks (Hitchon et al ., ; Timoney and Lee, ; Grasby, ; Jasechko et al ., ). In some cases, these wetlands can be found far removed from riverbanks, as was observed by Wells and Price (in review), where a low flow discharge wetland received its salts from a near‐surface aquifer.…”