The assessment of chemical weathering rates within an upland catchment in north‐east Scotland

Abstract

A study has been made of weathering in Glendye, an upland catchement of heather moorland underlain mainly by granite with some gneiss in north-east Scotland. The concentrations of a range of elements and ions in precipitation and river water were measured over a twelvemonth period. The total input and output of each element or ion was calculated. The resulting balances show net outputs of all species except hydrogen ion. Large net outputs of silicon (38.5 kg ha-' a-') and bicarbonate (48 kg ha-' a-I) indicate considerable chemical weathering. A large net output of chloride (32 kg ha-' a-') indicates the importance of dry deposition of oceanic aerosols. When this is allowed for the rate of output of elements due to weathering is:These results were compared with the abundance of elements in bedrock and differential weathering ratios calculated. These are compared with data from the Hubbard Brook study in New Hampshire. In both cases calcium is by far the most mobile element. The relative importance of the atmosphere and of chemical weathering as sources of each element was calculated, and the results compared with those of a study at Wet Sleddale in the Lake District. Similar patterns emerge in both cases.

Impact of soil and groundwater heterogeneity on surface water chemistry in an upland catchment

“…Several of the subcatchments showed considerable differences in flux values from the overall system, Taken from 1999 to 2000 weekly data for Glen Dye (AEA Technology plc), except for DOC and DIC (Dawson, 2000) and Si (Reid et al, 1981). suggesting considerable heterogeneity at smaller scales.…”

“…Concentrations of DOC, DIC and Si were not measured at the Glen Dye monitoring site and deposition values for C were calculated using concentrations from a year-long study by Dawson (2000) and for Si using concentrations reported by Reid et al (1981), both collected from measurements in Glen Dye. Concentrations for each weekly period were multiplied by the corresponding precipitation volume at the Allt Roy site over the same period as for stream solute loads, summed and scaled to the catchment area.…”

“…Insights in the exports of inorganic solutes have been gained from catchment budget studies in the UK (e.g. Reid et al, 1981;Thornton, 2001), the USA and Canada (e.g. Furman et al, 1998;Watmough and Dillon, 2003) and other parts of Europe (e.g.…”

Controls of concentration and loadings of major ions in a stream draining intermediate igneous rocks

“…Calcium, magnesium, and bicarbonate were all present at very substantially greater concentrations than those in streams draining acid rocks, five to ten times the values quoted for a granite/gneiss catchment in northeast Scotland (Reid et al, 1981).…”

Relationships among dissolved organic matter, iron, and discharge in a moorland stream

“…Reid et al (1981a) commented on increased iron levels near the peak of summer floods. However, the mechanisms in this latter case were different, since Reid et a/.…”