Supervisory Soil Scientist, Rocky Mountain Forest and Range Experiment Station, Tempe, Arizona; and Soil Microbiologist, Pacific Southwest Forest and Range Experiment Station, Glendora, California. The weathering of parent rock may be an important source of some nutrients. The rates of weathering of the different parent rock materials vary and affect the inherent fertility and productivity of a...

Chemical weathering of silicate rocks on continents acts as a major sink for atmospheric carbon dioxide and has played an important role in the evolution of the Earth's climate. However, the magnitude and the nature of the links between weathering and climate are still under debate. In particular, the timescale over which chemical weathering may respond to climate change is yet to be constraine...

[1] Numerical models of bedrock valley development generally do not include weathering explicitly. Nevertheless, weathering is an essential process that acts in concert with the transport of loose debris by seepage and runoff to form many bedrock valleys. Here we propose a numerical model for bedrock valley development that explicitly distinguishes weathering and the transport of loose debris a...

In acidic forest soils, availability of inorganic nutrients is a tree-growth-limiting factor. A hypothesis to explain sustainable forest development proposes that tree roots select soil microbes involved in central biogeochemical processes, such as mineral weathering, that may contribute to nutrient mobilization and tree nutrition. Here we showed, by combining soil analyses with cultivation-dep...

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 ...

Papers published in Hydrology and Earth System Sciences Discussions are under open-access review for the journal Hydrology and Earth System Sciences Abstract Major environmental stressors of boreal and sub-arctic rivers are hydrological changes and global warming and both factors will significantly influence the future evolution of the river chemistry in high latitudes. We tested the hypothesis...

The halogen concentrations of a number of Martian meteorites vary significantly, with larger variations observed in I/Cl compared to Br/Cl. One striking feature is the high I/Cl ratios associated with those meteorites found in Antarctica. Removal of low temperature, superficial contamination does not significantly reduce the I/Cl ratio [1], indicating that processing in Antarctica is responsibl...

Common naturally occurring orthosilicates can be grouped into those in which the major non-tetrahedral cations are (1) FeII and/or Mg, plus or minus Al (olivine, pyralspite garnets, staurolite); (2) Al (Al2SiO5 polymorphs), or (3) Zr. Feand Mg-bearing orthosilicates have the weakest bonds between non-tetrahedral cations and structural oxygen (M-O bonds), and zircon the strongest, with Al-O bond...

Chemical weathering rates and erosion rates of granitic till in northern Sweden have been estimated. The present-day chemical weathering rate is compared with the long-term average weathering rate since the last deglaciation approximately 8,700 years ago. Also, the present-day release rates of major and trace elements due to chemical weathering are compared with the mobility of these elements i...

Space weathering causes the change in optical properties, such as darkening, reddening, and decrease of absorption depths of the planetary surfaces. Two competing processes have been proposed so far as the main mechanism of such space weathering; hydrogen irradiation by solar wind and bombardment of micrometeorites. We use the new data set obtained by Spectral Profiler (SP) onboard SELENE/Kaguy...