Jl. Urai et A. Feenstra, Weakening associated with the diaspore-corundum dehydration reaction in metabauxites: an example from Naxos (Greece), J STRUC GEO, 23(6-7), 2001, pp. 941-950
Metabauxite lenses embedded in marble on Naxos consist of diasporites below
the 420 degreesC isograd, and dehydrate into corundum-rich rocks with incr
easing grades of metamorphism. While the diasporites are essentially undefo
rmed, the corundum-rich rocks are strongly deformed, even though both diasp
orites and corundum-rich rocks are much stronger than the surrounding inten
sely deformed marbles. The observed structures can be explained as an effec
t of high fluid pressures during the prograde diaspore-corundum dehydration
reaction, which causes dramatic temporary weakening of the metabauxites (t
o a strength comparable to that of the surrounding deforming marbles). Defo
rmation of the metabauxite is thus largely restricted to the time span the
phase transformation occurred, allowing the dehydrating bauxite mass to def
orm together with the surrounding marbles. (C) 2001 Elsevier Science Ltd. A
ll rights reserved.