Table T1. Summary of seismic units and depth reflectors.
Plotted using velocity profile provided by downhole measurements
Plotted using assumed velocity profile
Reflector
Unit
Time
to top
(ms TWT)Assumed
velocity
(m/s)Depth to
reflector
(m)Thickness
(m)Cumulative thickness
(m)Character of reflections
within units
Seabed
0
60
R-1a
80
1510
60
69
Reflectors separate bundles of grouped waves
R-1b
170
1520
129
100
R-1c
300
1530
230
68
R-1d
387
1540
298
66
Faint reflectors; muddier subunit
A
364
364
South-migrating sediment waves
R-2a
470
1550
364
54
R-2b
523
1600
418
82
B
136
500
N-onlapping S-prograding and downlapping
R-3
580
1725
500
Paraconformity (onlaps north)
Depth drilled to 627 m
C
139
639
North-onlapping sediment prism
R-4
730
1750
639
Unconformity Y (Davey, 1977)
D
1069
1708
Postrift sedimentary cover
Basement
1485
2300
1708
Oceanic crust
Estimated thickness to basement: 1708 m
Reflector
Unit
Time
to top (ms TWT)
Assumed velocity (m/s)
Depth to reflector
(m)
Thickness (m)
Cumulative thickness
(m)
Character
Seabed
0
62
R-1a
80
1548
62
73
Reflectors separate bundles of grouped waves
R-1b
170
1591
135
109
R-1c
300
1629
244
74
R-1d
387
1645
318
72
Faint reflectors; muddier subunit
A
390
390
South-migrating sediment waves
R-2a
470
1660
390
57
R-2b
523
1710
447
54
B
111
501
N-onlapping S-prograding and downlapping
R-3
580
1728
501
Paraconformity (onlaps north)
Depth drilled to 627 m
C
130
631
North-onlapping sediment prism
R-4
730
1730
631
Unconformity Y (Davey, 1977)
D
1076
1708
Post-rift sedimentary cover
Basement
1485
2300
1708
Oceanic crust
Estimated thickness to basement: 1708 m
Note: Horizontal lines separate the main seismic units recognized. Italics indicate unconformities.