Aluminosilicates authigenic formation

SURDAM (R.C.) and PARKER (R.L.), 1972. Authigenic aluminosilicate minerals in the tuffaceous rock of the Green River Formation, Wyoming. Bull. Geol. Soc. Ame. fL3, 689-700. 

Allophane production. Allophane is a non-crystalline, hydrous aluminosilicate of highly variable composition, which forms as a common colloidal constituent of soils it may be an intermediate in the formation of some authigenic clay minerals. 

Both the tropical reverse weathering studies and the recent discovery of the process controlling opal diagenesis in surface sediments demonstrate the importance of rapid authigenic aluminosilicate formation in marine sediments. The focus is now back on determining the importance of these reactions in marine geochemical... 

The formation of such minerals and authigenic feldspar under highly saline conditions is sometimes termed reversed weathering. This is appropriate in the sense that ions weathered in other locations are thus incorporated into new minerals instead of flowing to the sea. The minerals formed, however, are considerably different from the original igneous aluminosilicates, although their chemical compositions may be similar. 

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