TY - JOUR
T1 - Geochemical evolution of the Critical Zone across variable time scales informs concentration-discharge relationships
T2 - Jemez River Basin Critical Zone Observatory
AU - McIntosh, Jennifer C.
AU - Schaumberg, Courtney
AU - Perdrial, Julia
AU - Harpold, Adrian
AU - Vázquez-Ortega, Angélica
AU - Rasmussen, Craig
AU - Vinson, David
AU - Zapata-Rios, Xavier
AU - Brooks, Paul D.
AU - Meixner, Thomas
AU - Pelletier, Jon
AU - Derry, Louis
AU - Chorover, Jon
N1 - Funding Information: Funding for this project was provided by the Catalina-Jemez Critical Zone Observatory (NSF EAR-0724958; EAR-1331408). Additional funding was provided by a Geological Society of America Student Research Grant to C. Porter (now C. Schaumberg). We thank Mary Kay Amistadi, Tim Corley, David Huckle, James Ray, David Bernard, Claire Tritz, Aidan lo Blum, David Renner, and Lauren Koch for assistance with lab analyses and fieldwork. Matej Durcik generated the GIS map figures and helped with data management. We appreciate comments by Sue Brantley and two anonymous reviewers that greatly improved the manuscript. Data used in the study can be obtained from the IEDA database (https://doi.org/10.1594/IEDA/100638; https://doi.org/10.1594/IEDA/100639), and Hydroshare (https://doi.org/10.4211/hs.28639de860f74340a 3549735abb7b0c6). Publisher Copyright: © 2017. American Geophysical Union. All Rights Reserved.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - This study investigates the influence of water, carbon, and energy fluxes on solute production and transport through the Jemez Critical Zone (CZ) and impacts on C-Q relationships over variable spatial and temporal scales. Chemical depletion-enrichment profiles of soils, combined with regolith thickness and groundwater data indicate the importance to stream hydrochemistry of incongruent dissolution of silicate minerals during deep bedrock weathering, which is primarily limited by water fluxes, in this highly fractured, young volcanic terrain. Under high flow conditions (e.g., spring snowmelt), wetting of soil and regolith surfaces and presence of organic acids promote mineral dissolution and provide a constant supply of base cations, Si, and DIC to soil water and groundwater. Mixing of waters from different hydrochemical reservoirs in the near stream environment during “wet” periods leads to the chemostatic behavior of DIC, base cations, and Si in stream flow. Metals transported by organic matter complexation (i.e., Ge, Al) and/or colloids (i.e., Al) during periods of soil saturation and lateral connectivity to the stream display a positive relationship with Q. Variable Si-Q relationships, under all but the highest flow conditions, can be explained by nonconservative transport and precipitation of clay minerals, which influences long versus short-term Si weathering fluxes. By combining measurements of the CZ obtained across different spatial and temporal scales, we were able to constrain weathering processes in different hydrological reservoirs that may be flushed to the stream during hydrologic events, thereby informing C-Q relationships.
AB - This study investigates the influence of water, carbon, and energy fluxes on solute production and transport through the Jemez Critical Zone (CZ) and impacts on C-Q relationships over variable spatial and temporal scales. Chemical depletion-enrichment profiles of soils, combined with regolith thickness and groundwater data indicate the importance to stream hydrochemistry of incongruent dissolution of silicate minerals during deep bedrock weathering, which is primarily limited by water fluxes, in this highly fractured, young volcanic terrain. Under high flow conditions (e.g., spring snowmelt), wetting of soil and regolith surfaces and presence of organic acids promote mineral dissolution and provide a constant supply of base cations, Si, and DIC to soil water and groundwater. Mixing of waters from different hydrochemical reservoirs in the near stream environment during “wet” periods leads to the chemostatic behavior of DIC, base cations, and Si in stream flow. Metals transported by organic matter complexation (i.e., Ge, Al) and/or colloids (i.e., Al) during periods of soil saturation and lateral connectivity to the stream display a positive relationship with Q. Variable Si-Q relationships, under all but the highest flow conditions, can be explained by nonconservative transport and precipitation of clay minerals, which influences long versus short-term Si weathering fluxes. By combining measurements of the CZ obtained across different spatial and temporal scales, we were able to constrain weathering processes in different hydrological reservoirs that may be flushed to the stream during hydrologic events, thereby informing C-Q relationships.
KW - concentration-discharge relationships
KW - soil water chemistry
KW - water quality
KW - weathering
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U2 - 10.1002/2016WR019712
DO - 10.1002/2016WR019712
M3 - Article
SN - 0043-1397
VL - 53
SP - 4169
EP - 4196
JO - Water Resources Research
JF - Water Resources Research
IS - 5
ER -