Study of
Sediment Waves Formation and Morphology in Turbidite Systems from Physical
Modelling Perspective
Del Rey, Antonio Cosme1,
Rafael Manica2, Rogério Dornelles Maestri2, Ana Luiza de
Oliveira Borges2, Adriano R. Viana3 (1) Petrobras -
Petroleo Brasileiro S.A, Vitoria, Brazil (2) Universidade Federal do Rio Grande
do Sul, Porto Alegre, Brazil (3) Petrobras, Rio de Janeiro, Brazil
The study of sediment wave generation and
morphology in turbidite systems has been highlighted in some recent papers;
however the study in laboratory concerning these sedimentary structures hasn't
been discussing a lot. Thus, this work aims presents the results of twelve
simulations in a small-scale physical simulation comparing the sediment waves
generated in laboratory with natural turbidite systems through seismic data and
outcrops studies. In order to achieve this objective, an ancient turbidity
system of Eastern Brazilian continental margin was selected as prototype for
flume experiments. Its natural complex geometry was substituted by simplified
geometry (straight channel and basin) and then, this new topography was
implanted inside the small-scale model. The simulations showed the sediment
wave formation along the channel. Bedforms sequence was identified ranging from
linear to linguoid-type ripples. It was also observed a cross-correlation
between wave length and amplitude of these bedforms, however different flow
conditions cause changes in their geometry. On the overbank zone of the
channel, the deposits present ripples with the same direction as the flow
(downstream direction) while in the basin, the sediment wave present elongate
shape and perpendicular direction instead. The sedimentary structures generated
in these experiments were identified and compared with different seismic data
of recent turbidite system in the East Brazilian continental margin as well as
with natural outcrops observed in the Brushy Canyon Fm (TX, USA), Itajaí Basin
(SC, Brazil) and Almada Basin (BA, Brazil). The results of these three approaches
are discussed.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California