COMPARATIVE ASSESSMENT OF SOIL WEATHERING RATESIN THE LANDSCAPES OF THE NORTHERN SLOPEOF THE KHAMAR-DABAN RIDGE
M.Yu. Semenov, G.P. Sandimirova*, I.V. Korovyakova, E.S. Troitskaya,T.I. Khramtsova**, and T.V. Donskaya**
Limnological Institute, Siberian Branch of the RAS, 3 ul. Ulan-Batorskaya, Irkutsk, 664033, Russia
* Institute of Geochemistry, Siberian Branch of the RAS, 1a ul. Favorskogo, Irkutsk, 664033, Russia
** Institute of the Earth's Crust, Siberian Branch of the RAS, 128 ul. Lermontova, Irkutsk, 664033, Russia
Keywords: Soil, weathering rate, runoff, removal, Sr isotopes, ratio, mineralogical composition
Pages: 50-59
Abstract
Determination of the soil weathering rate plays an important role in estimation of the stability of terrestrial ecosystems because weathering is the major source of matter in ecosystem. This work was aimed at elaborating a technique for comparative evaluation of the rates of weathering in small areas making up a single landscape-geochemical system. The studies were carried out in the basin of the Pereemnaya River. The present-day and the average historical weathering rates were estimated. Data on the ion runoff show that the contributions of different areas of the water catchment basin are unequal. For the total content of Ca2+, Mg2+, K+, and Na+, the weathering rates calculated using the balance method vary from 1.1 to 5.4 keq·ha-1·yr-1. The weathering rates calculated from the isotopic composition of Sr are nearly the same (1.6-5.2 keq
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