Jin et al., 2011

Paper/Book

Opening the "Black Box": Water Chemistry Reveals Hydrological Controls on Weathering in the Susquehanna Shale Hills Critical Zone Observatory.

Jin, L., Andrews, D.M., Holmes, G.H., Lin, H., and Brantley, S.L. (2011)
Vadose Zone Journal 10:928-942,  

Abstract

We investigated variations of Mg concentration, δD and δO in precipitation, soil water along a planar hillslope, groundwater, and first-order stream water at the Susquehanna Shale Hills Critical Zone Observatory (SSHO). Water flows vertically in the unsaturated zone of the hillslope, but hydrological saturation periodically causes lateral flow along interfaces of permeability contrast between the A–B and B–C soil horizons. Changes in soil water Mg concentration respond to hydrological changes and are ultimately controlled by the kinetics of clay mineral dissolution, but are buffered by the soil exchange capacity. Clay dissolution predominantly occurs within the A and B horizons, and Mg released from these zones of “low-flow” diffuses or flows into the “high-flow” zones at horizon interfaces. The Mg concentrations are low in these high-flow zones because fresher (younger) water flows in through macropores. The amplitude of seasonal variations in water isotopes (data from 2008–2010) decreases in the following order: precipitation (δD: 286‰) >> soil water (δD: 86‰) > shallow groundwater (δD: 26‰), indicating water becomes progressively older along the flowpath. Fractures and preferential high-flow paths make the watershed hydrologically responsive: the average time water stays in the shallow subsurface is inferred to be <2 yr. The stream water chemistry is affected by inputs of old groundwater that is relatively high in Mg concentration but relatively limited in range in δD, as well as by inputs from young soil water that is relatively low in Mg concentration with a wide range in δD. The relative contributions of these two sources to the stream change seasonally.

Citation

Jin, L., Andrews, D.M., Holmes, G.H., Lin, H., and Brantley, S.L. (2011): Opening the "Black Box": Water Chemistry Reveals Hydrological Controls on Weathering in the Susquehanna Shale Hills Critical Zone Observatory . Vadose Zone Journal 10:928-942, . DOI: 10.2136/vzj2010.0133

This Paper/Book acknowledges NSF CZO grant support.


Associated Data

Shale Hills - Groundwater Chemistry (2008-2010)
3 components    Susquehanna Shale Hills Critical Zone Observatory    Water Chemistry, Hydrology    Brantley, Susan L.; Duffy, Christopher, J.

Shale Hills - Hydropedologic Properties, Air Temperature (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties, Electrical Conductivity (2009-2013)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties, Matric Potential - 253 Probes (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties, Matric Potential - MPS Probes (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties, Precipitation (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology, Climatology / Meteorology    Lin, Henry

Shale Hills - Hydropedologic Properties, Soil Moisture (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties, Soil Temperature (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties - Real Dielectric Constant (2010-2011)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties - Imaginary Dielectric Constant (2010-2011)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Hydropedologic Properties - Water Table (2007-2014)
1 components    Susquehanna Shale Hills Critical Zone Observatory    Soil Science / Pedology    Lin, Henry

Shale Hills - Soil Porewater Chemistry (2006-2011)
6 components    Susquehanna Shale Hills Critical Zone Observatory    Biogeochemistry, Water Chemistry, Hydrology    Brantley, Susan L.; Duffy, Christopher J.

Shale Hills - Stream Water Chemistry (2006-2010)
5 components    Susquehanna Shale Hills Critical Zone Observatory    Biogeochemistry, Water Chemistry, Hydrology    Brantley, Susan L.; Duffy, Christopher, J.