Table T17.
Depths of basement
unit boundaries and within unit structural and lithologic characteristics based
on Formation MicroScanner data.
| Unit |
Rock
type |
Depth
to top
(mbsf) |
Thickness
(m) |
Recovered
in core
(m) |
Recovery
(%) |
| 1 |
Pillow
basalt |
235.8 |
4.6 |
3.52 |
77 |
| 1 |
Massive
basalt |
240.4 |
4.6 |
4.21 |
92 |
| 1 |
Pillow
basalt |
245.0 |
6.0 |
4.73 |
79 |
| 1 |
Basalt
+ sediments |
251.0 |
2.4 |
0 |
0 |
| 2 |
Sediments |
253.4 |
2.1 |
0 |
0 |
| 2 |
Pillow
basalt |
255.5 |
5.0 |
0 |
0 |
| 2 |
Massive
basalt |
260.5 |
1.3 |
0 |
0 |
| 2 |
Pillow
basalt |
261.8 |
10.9 |
1.27 |
12 |
| 3 |
Sediments |
272.7 |
2.4 |
0.03 |
1 |
| 3 |
Pillow
basalts |
275.1 |
7.9 |
3.41 |
43 |
| 4 |
Sediments |
283.0 |
1.3 |
1.00 |
77 |
| 5A |
Pillow
basalt |
284.3 |
1.7 |
0.78* |
46* |
| 5B |
Sediments |
286.0 |
2.0 |
0 |
0 |
| 5C |
Massive
basalt |
288.0 |
10.6 |
7.08* |
67* |
| 6 |
Sediments |
298.6 |
1.1 |
0.05 |
5 |
| 6 |
Massive
basalt |
299.7 |
1.3 |
0.59 |
45 |
| 6 |
Pillow
basalt |
301.0 |
14.0 |
9.22 |
66 |
| 6 |
Massive
basalt |
315.0 |
3.0 |
3.22 |
107 |
| 6 |
Pillow
basalt |
318.0 |
>5.0 |
3.36 |
<67 |
|
|
|
|
|
|
Notes: The location of
boundaries identified from FMS may change slightly with further data processing
post cruise. * = It is not clear if any of Subunit 5A was recovered. The
thickness calculated for Subunits 5A and 5C is based on the assumption that if
there is a break in the lava flow, it might be in Section 183-1140A-33R-1, 36-39
cm. The altered layer (orange color) suggests a separation of basement Unit 5
into Subunits 5A and 5C. For more details, see "Physical
Volcanology" and "Igneous
Petrology and Geochemistry".