<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Velbel, M.A.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Weathering and pedogenesis at the watershed scale:  some recent lessons from studies of acid-deposition effects.</style></title><secondary-title><style face="normal" font="default" size="100%">Chemical Geology 107: 337-339</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">CWT</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1993</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://cwt33.ecology.uga.edu/publications/343.pdf</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Geochemical mass balance is commonly used to calculate mineral weathering rates. Such studies invariably find higher present-day rates and generally conclude that the higher rates are a consequence of recent environmental acidification.  However, because the residual solids which are the basis of the long-term estimate are time-integrated accumulations of weathering products, it may be inappropriate to compare short-term rates from solute input-output budgets with0long-term rates from bulk profile chemistry. There are disparities in both the time-scales over which the two methods measure rates, and the volume fraction of the regolith being sampled. Soils better integrate time; solute budgets better integrate space.</style></abstract><accession-num><style face="normal" font="default" size="100%">LTER.1993-80763</style></accession-num></record></records></xml>