Melanges are found in over 70 countries, usually
in mountainous areas, near recent or ancient
tectonic subduction zones. The Franciscan
Complex of northern California is geologically
infamous for its many melanges.
There is a connection between Medley "and
"Melange": “medley” is an English word loosely
meaning “mixture”, for which the French is
“mélange”. The acute accent above the “e” in
mélange (pronounced "may-LAWN-juh") is often
neglected in the United States. It is acceptable to
pronounce melange as "mell-AHN-juh."
In 1919, the British geologist Edward Greenly first
described, as “autoclastic mélange”, the chaotic
Gwna Melange of Anglesey, in North Wales. The
details of melange formation are controversial:
there are over 2000 papers on the geologic
aspects of melanges but few address the
troublesome geotechnical aspects (Medley, 1994).
The geological literature of melanges is
complicated by many apparent synonyms for
melange fabrics, including: olistostromes, argille
scagliose (scaly clay), sedimentary chaos, mega-
breccia, chaotic structure, complex formations,
lenticular fabric, tectonic mixtures, friction carpets,
Varicolored Clays and wildflysch.
|Gwna Melange, North Wales.