My experience is that these features are often found in suites. An
outcrop may have several unusual features that, in combination can
point to it being synsedimentary or a later structural. For example,
the little duplex shown in the first two photos could be either
(although the top and bottom boundaries look sedimentary), but if we
take into account that a few meters away we find these "balls" and
other like features, then is looks like the structure is
synsedimentary. That is not to say that there wasn't a slump (the
balls point in that direction) and that during the slump there was
slip on a bedding surface to cause the duplex. Strange things can
happen in poorly consolidated sediments in an active tectonic
environment.
Photos are from the Middle Miocene of the Western Foothills of
Taiwan, just north of the village of Gaoshing.
Cheers
Dennis
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Dr. Dennis Brown
Instituto de Ciencias de la Tierra "Jaume Almera"
c/Lluis Sole i Sabaris s/n
08028 Barcelona
Spain
Tel: 34 93 409 54 10
Fax: 34 93 411 00 12
e-mail: [log in to unmask]
http://wija.ija.csic.es/gt/dennisbrown/
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