Landscapes evolve in response to external forces, such as tectonics and climate, that influence surface processes of erosion and weathering. Internal feedbacks between erosion and weathering also play an integral role in regulating the landscapes response. Our understanding of these internal and external feedbacks is limited to a handful of field-based studies, only a few of which have explicit...

Transport and retention of colloid tracers were evaluated in standard petrographic thin sections, prepared from saprolite (Cr horizons) formed from fractured sedimentary rocks, using epi-fluorescence microscopy. Thin sections prepared from dismantled hydrogeological columns revealed four domains of macropores with apparent apertures ranging from 1 to 500 Am. Colloid retention occurred within bo...

The objective of this study was to experimentally determine the influence of pore structure on the transport and dissolution of trichloroethylene (TCE) in clay-rich saprolite. In order to simulate a "spill," pure-phase TCE containing a water-insoluble fluorescent dye was injected into two heterogeneous 24-cm-diameter by 37-cm-long undisturbed columns of water-saturated saprolite. TCE entry occu...

soil using Cl as a tracer in a 5 mM solution of CaCl2. The AEC ranged from 0.01 to 1.86 cmolc kg 1 with an Many studies have shown that subsoils in the Piedmont region of average value of 0.68 cmolc kg 1. Retardation coeffithe southeastern USA have anion exchange capacity (AEC) and can adsorb anions such as nitrate (NO 3 ). Groundwater discharging to cients were determined from the BTC data and...

In the mountainous Rio Icacos watershed in northeastern Puerto Rico, quartz diorite bedrock weathers spheroidally, producing a 0.2–2 m thick zone of partially weathered rock layers ( 2.5 cm thickness each) called rindlets, which form concentric layers around corestones. Spheroidal fracturing has been modeled to occur when a weathering reaction with a positive DV of reaction builds up elastic st...

Groundwater flow in sedimentary rock saprolite, and in soils derived from this material, is strongly influenced by sedimentary layering and fractures inherited from the parent bedrock. The main objectives of this study were to determine whether parent bedrock lithology and infilling of fractures and other macropores with pedogenically derived clays and Fe/Mn oxides also play major roles in cont...

Saprolite, weathered bedrock, is being used to dispose of domestic sewage through septic system drainfields, but the thickness saprolite needed remove biological contaminants unknown for most saprolites. This study developed and tested a simple method estimating below drainlines filter E. coli from wastewater using estimates volume pores that are smaller than length coliform (≤10 μm). Particle ...

The chemical, morphological and mineralogical properties of two Enon sandy loam (fine, mixed, thermic Ultic Hapludalfs) soilsaprolite profiles, one formed on gabbro and the other on metagabbro, are compared. Clay skins are scarce and stress cutans common in the argillic horizons of these soils. Iron-manganese concretions are concentrated in soil horizons immediately above the argillic horizons....

Landslides associated with hillside cuttings in igneous rock saprolites are a serious natural hazard in Hong Kong and have been extensively studied by government agencies and local universities for many years from the perspective of soil and rock engineering. A review of the case studies for some major landslides, especially deep-seated landslides, shows certain puzzling features. First, a numb...