『Abstract
The development and aftermath of a snowball Earth during Precambrian
time still raise questions, particularly the process involved
in the deposition of the associated cap carbonates and the time
required for the Earth to return to more stable and less extreme
climatic conditions. We present numerical simulation modeling
the chemical weathering of regolith exposed to a CO2-rich
atmosphere after deglaciation. We consider the effects to a CO2-rich atmosphere after deglaciation. We consider
the effects of an early cation-proton exchange reaction that promotes
fast initial dissolution of the regolith, a reaction often omitted
in the modeling approach but one that becomes particularly important
under acidic conditions and in environments where glacial erosion
can substantially refresh the rock surfaces. Calculations show
that this dissolution step may contribute significantly to the
riverine ionic input and may promote the deposition of thick cap
carbonates over a short period of time. The long-term weathering
of the regolith becomes predominant, representing an efficient
way of removing atmospheric CO2 over periods
ranging from tens to hundreds of thousands of years, depending
on the grain size of the regolith material.』
Introduction
Methodology: Numerical modeling and input parameters
Mineralogy
Reaction kinetics
Water-rock ratio and runoff
Results: Timing of weathering and CO2 budget
Discussion: Implications for cap carbonate deposition
Conclusions
Acknowledgments
References cited