『Abstract
Models of Thermal Emission Spectrometer (TES) data suggest that
poorly-crystalline weathering products allophane and aluminosilicate
gel occur in several low-albedo regions of Mars. The presence
of allophane in TES models indicates that the martian surface
experienced low-temperature chemical weathering at low water-to-rock
ratios and mildly acidic to neutral pH on regional scales. The
allophane and gel may be ancient and preserved by a persistently
dry martian climate. Alternatively, evidence for recent ground
ice in these regions suggests that pedogenic processes causing
the formation of poorly-crystalline aluminosilicates could be
late Amazonian in age and may be active today. While previous
models have suggested that global-scale acidic weathering has
occurred on Mars for the past 3.5 billion years, the presence
of allophane indicates that acidic weathering was not occurring
in these low-albedo regions and that mildly acidic to neutral
weathering has been an important regional-scale weathering process
on the martian surface.』
Introduction
Methods
TIR spectra of allophane
Regional TES models
Discussion
Acknowledgments
References cited