『Abstract
　The complex weathering processes which govern the production of soil from bedrock have proven difficult to understand for many lithologies. Weathering of black shale is of particular interest because it releases organic carbon and heavy metals as solutes and therefore impacts the health of terrestrial and aquatic ecosystems. To understand black shale weathering, a geochemical survey was initiated for soils developed on shales of the Marcellus Formation at a zero-order catchment at a satellite site of the Susquehanna/Shale Hills Critical Zone Observatory located in Jackson Corner, Pennsylvania. This formation is an organic- and metal-rich, carbonaceous shale that underlies much of New York, Pennsylvania, Ohio and West Virginia. In this paper, we focus on the effects of weathering on variations of Cu isotopes in the shale. Cu concentration data for soil were normalized using Ti concentrations to document the mobility of Cu relative to bedrock. At both the ridgetop and valley floor, depletion profiles for Cu are documented in the soils. The Cu in the soils is depleted in ⁶⁵Cu (average δ⁶⁵Cu = -0.5‰±0.2) compared to the parent material (average δ⁶⁵Cu = 0.03‰±0.15). Consistent with loss of Cu from soils, the pore waters contain 10 ppb Cu on average and are enriched in the heavy isotope (average value δ⁶⁵Cu = 1.14‰±0.44). Rayleigh fractionation models using the concentration and isotope data of the soils are consistent with pyrite weathering and loss of Cu from the ridgetop, but downslope transport and Cu re-precipitation at the valley floor.

Keywords: Black shale; Weathering; Cu isotopes; Marcelllus shale』

1. Introduction
2. Methods
　2.1. Rock and soil sampling
　2.2. Porewater sampling
　2.3. Sample preparation
　2.4. Soil elemental analysis
　2.5. X-ray diffraction and SEM analysis
　2.6. Water chemistry analyses
　2.7. Copper isotope analysis
3. Results
　3.1. Soil, rock and pore water chemistry
　3.2. Rock and heavy mineral mineralogy
　3.3. Copper isotopes of soils, rocks and soil waters
4. Discussion
　4.1. Location of Cu in Marcellus shale
　4.2. Cu depletion in soil
　4.3. Cu isotopes
　4.4. Rayleigh models of the Cu concentration and isotope data during weathering
5. Conclusions
Acknowledgements
References