Signature of non-locality in depositional systems: Implications for modeling and interpretation of stratigraphic records

sadhospitalMechanics

Feb 22, 2014 (3 years and 3 months ago)

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Signature of non
-
locality in depositional systems: Implications for modeling and
interpretation of stratigraphic records


Vamsi Ganti, Kyle Straub, Efi Foufoula
-
Georgiou and Mark Meerschaert



Compensational stacking which is defined as the tendency of sed
iment transport
processes to fill
-
in topographic lows through deposition is a concept widely used in the
interpretation of the stratigraphic records. Recently, a new metric called the
“compensation index” was proposed to quantify the degree of compensation
al stacking in
any depositional system and power
-
law trends were used to describe the decrease in
standard deviation of sedimentation/subsidence with increasing averaging distance. An
explanation of the observed power
-
law trends was given in terms of the c
orrelation
between elevation increments in time. In this work, we present a possibility of an
alternative explanation for the observed power
-
law trends using high temporal resolution
data for a delta in an experimental basin undergoing relative subsidence.

We demonstrate
that heavy
-
tailed distributions for periods of non
-
sedimentation and magnitudes of
sedimentation events can lead to the observed phenomenon with the compensation index
dependent on the tail
-
index of the two distributions. Further, we show
that a truncated
Pareto distribution and a stable density provide a good fit for the densities of periods of
non
-
sedimentation and magnitudes of sedimentation in the experimental basin. Finally,
implications of the experimentally observed heavy
-
tails are d
iscussed in the context of
developing transport models in depositional systems.