Micromorphology and Stable-Isotope Geochemistry of Historical Pedogenic Siderite Formed in PAH-Contaminated Alluvial Clay Soils, Tennessee, USA

Micromorphology and Stable-Isotope Geochemistry of Historical Pedogenic Siderite Formed in PAH-Contaminated Alluvial Clay Soils, Tennessee, USA

  • Post by:
  • November 20, 2018
  • Comments off

Alluvial clay soil samples from six boreholes advanced to depths of 400–450 cm (top of limestone bedrock) from the Chattanooga Coke Plant (CCP) site were examined micromorphologically and geochemically in order to determine if pedogenic siderite (FeCO3) was present and whether siderite occurrence was related to organic contaminant distribution. Samples from shallow depths were generally more heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) than those at greater depth. The upper 1 m in most boreholes consisted of mixtures of anthropogenically remolded clay soil fill containing coal clinker, cinder grains, and limestone gravel; most layers of coarse fill were impregnated with creosote and coal tar. Most undisturbed soil (below 1 m depth) consisted of highly structured clays exhibiting fine subangular blocky ped structures, as well as redox-related features. Pedogenic siderite was …

Categories: