L08_Sedimentary_Rocks_Chemical_Weathering

Quartz sio2 hard tough very low chemical solubility

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: reac<on is rela<vely slow the reac<on products need to migrate away from the surface so that fresh mineral is exposed for addi<onal weathering (for example, the green copper oxide ‘pa<na’ on copper roofs retards subsequent oxida<ve weathering of the copper) mineral with cleavage planes. these are defined by the arrangement of atoms in the mineral (the larce structure) and may create weaknesses along which the mineral can fracture the fractured mineral has a far higher surface area to volume ra<o, thus increasing the poten<al for chemical weathering In a basic sense, soils are simply high- surface- area mixtures of minerals. The high surface area aids the chemical extrac<on of nutrients by plant roots, fungi hyphae, etc. Very few organisms can extract sufficient nutrients from unbroken rock surfaces (e.g., lichen). Most require ‘pre- digested’ rock, aka ‘soil’ soil profile schema<c lichen growing on rock surface In addi<on, soils have very high CO2 levels due to biological ac<vity Soils: commonly a few thousand ppm CO2, versus 400 ppm in the atmosphere! Which minerals are the most resistant to physical and chemical weathering? This is a ques<on that we can ask Mother Nature What do we find at the ends of very long river systems? (consider the river system as a factory of physical and chemical weathering) Con<nental Shelves are largely composed of sedimentary residues of physical and chemical weathering minerals/rocks that survive the transit (i.e., that survive prolonged physica...
View Full Document

Ask a homework question - tutors are online