–Carbon bound in gibbsite, collected from a residual weathering profile developed on a Paleozoic granite in the Georgia Piedmont, was examined for its C content and found to be geologically young. The study site, located at the Panola Mountain Research Watershed, has developed a granite–saprolite–soil regolith in which C-gibbsite model ages deep within the profile (C-horizon) average about 8000...

The authenticity of much of the stone-work along Queen’s Lane in central Oxford, UK presented an opportunity to produce a photographic survey from which a weathering index could be established. This represents a site-specific approach to devising a weathering form. Because it is photo-based, weathering forms are visible for comparison and classification purposes across disciplines. Limestone pe...

The degree of chemical weathering in soils increases with mean annual precipitation (P; mm) and mean annual temperature (T; C). We have quantified these relationships using a database of major-element chemical analyses of 126 North American soils. The most robust relationship found was between P and the chemical index of alteration without potash (CIA-K): with . Another strong relationship was ...

Despite evidence that weathering plays a role in forming intertidal, estuarine, and fluvial rock platforms, many publications uncritically refer to “wave-cut” or “stream-cut” rock platforms. The alternative explanations of chemical weathering and physical water erosion of rock platforms have been debated since 1839. Our new approach to this long-standing problem introduces data from fluvial as ...

A provenance study was conducted on the Mid-Proterozoic Newland Formation, in which petrographical features of sandstones and geochemical characteristics of shales were integrated to arrive at an internally consistent interpretation. Sandstones of the Newland Formation are typically arkosic sands and arkoses with very well rounded quartz and feldspar grains and only minor amounts of extrabasina...

Introduction: Orbiter and lander/rover studies of Mars' surface have identified and provided preliminary characterization of surficial materials including igne-ous and sedimentary rocks, possible volcaniclas-tic/pyroclastic rocks, and unconsolidated sediment. Some surfaces expose unaltered anhydrous silicates (militating against extensive interactions with water), but most results (including st...

Introduction: Spectroscopic observations offer the best means to evaluate chemical weathering on Mars at regional and global scales. Near-infrared (NIR) spectral data from OMEGA and CRISM have revealed hydrated minerals that indicate aqueous alteration, including different clay minerals [1-3], sulfates [1,4], silica [5], and carbonates [6], which are regionally localized across the Martian high...

A reaction set of possible mineral weathering reactions is proposed to explain observed cation and silica export for the Emerald Lake watershed, a small Sierra Nevada, California catchment. The reaction set was calculated through a stoichiometric mole-balance method, using a multiyear record of stream flow and snowpack chemical analyses and site-specific mineral compositions. Reaction-set calcu...

Sedimentary rocks are composed of detrital grains derived from source rocks, which are altered by chemical weathering, sorted during transport, and cemented during diagenesis. Fluvio-lacustrine sedimentary rocks of the Bradbury group, observed on the floor of Gale crater by the Curiosity rover during its first 860 sols, show trends in bulk chemistry that are consistent with sorting of mineral g...

To better understand the mechanisms that hydrological conditions control chemical weathering and carbon dynamics in the large rivers, we investigated hydrochemistry and carbon isotopic compositions of dissolved inorganic carbon (DIC) based on high-frequency sampling in the Wujiang River draining the carbonate area in southwestern China. Concentrations of major dissolved solute do not strictly f...