Wave Dominated Deltas
Rio Grande - TST 2 and TST 3



Tst 2A and 3 are interpreted as wave-dominated deltas from their seismic reflection configurations, isochron contour patterns, elongate geometries, and location on the outer shelf during a sea-level rise. The elongate geometry of this type of delta is produced by high wave energy that reworks delta front sediments into shoreline attached beach ridges. The upper portions of the prograding clinoform reflection configurations is interpreted as an amalgamation of beach ridges, while the lower portions are interpreted as distal bar and prodelta deposits.




seismic data
isopach maps


TST 2A Overview


Main Characteristics
Width (km)
x
Length (km)		 Thickness (ms) Shape Reflection
Configuration		 Bounding
Surfaces		 Lithology Subbottom
Depth (m)
30 x 35 20 elongate
mound		 complex sigmoid
oblique		 top - base of either
Tst3 or Tst4
base - ts		 none 50-110


Depositional Interpretation
Interpretation Sediment
Volume (km3)		 Timing (ybp) Deposition Rate
per 1000 yrs		 Sea Level Eustatic vs
Climatic
wave-dominated
delta		 11.2 <11,000
to
>5,000		 6.86 km3 rising climatic/
sediment supply


Sediment Yields
Volume = (4/3)*(Each isochron is divided into a series of spheroids whose volume is then summed (a * b* c, where a,b,c are radii).
total volume (km3) deposition timing sediment yield (km3)
per 10000 yrs
11.20



TST 3 Overview


Main Characteristics
Width (km)
x
Length (km)		 Thickness (ms) Shape Reflection
Configuration		 Bounding
Surfaces		 Lithology Subbottom
Depth (m)
40 x 4-17 20 elongate
mound		 sigmoid oblique
tangential		 top - TST 4
base - ts or ts-2sb		 none 70-130


Depositional Interpretation
Interpretation Sediment
Volume (km3)		 Timing (ybp) Deposition Rate
per 1000 yrs		 Sea Level Eustatic vs
Climatic
wave-dominated
delta		 2.31 <11,000
to
5,000		 6.86 km3 rising climatic/
sediment supply


Sediment Yields
Volume = (4/3)*(Each isochron is divided into a series of spheroids whose volume is then summed (a * b* c, where a,b,c are radii).
total volume (km3) deposition timing sediment yield (km3)
per 10000 yrs
2.31 6000 6.86



Gulf Bottom Imagemap

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