Alvin Dive 3361

Time Heading Depth Comments

0843 180 1500 start maggie calibration spin
0922 069 2630 on the bottom, fairly old, well-sedimented curtain folded sheet flows. Settling down to take a sample
0926 108 2636 still looking for a sample amongst the AGE 3 curtain-folded sheet flow. No glass on the flow, and deep pockets of sediment amongst the folds.
X:-632 Y:-10931
0930 105 2637 Under way after taking Sample 1 X:-626 Y:-10922
0933 268 2633 Wrinkled and folded sheet flows have barely discernable morphology in the heavy sediment cover. Still well to the East of the axis. Transition right here to pillows, some elongate, that appear to be flowing in SE direction.
0936 268 2620 Pillow decorated with a lot of buds. Meter-scale rounded pillows, and 5-10cm long buds. Interpillow sediment, clearly AGE 3.
0938 270 2620 Really thick sediment cover with some bulbous pillows, and either sheet flow folds or drained pillow rims sticking out.
0940 275 2618 Contact - very abrupt Age 1-1.5 now
Much younger pillows, with breadcrust texture, and few buds. Glass on the crust of the pillows, and in buds. Interpillow sediment pockets exist but not everywhere. Stopping for Sample 2.
942 358 2619 parked and taking sample 2
0945 270 2617 just underway after taking sample 2, to the West of the young to old contact is more sediment, but then back into Age 1-1.5 pillows. Thick with 10-20cm long glass buds.
0949 276 2599 Pillows are large here (>2m), and incresasing budded.
0951 278 2586 Pillows, but getting increasingly glassy
0953 275 2582 Lobates with intact glass, and small round patches of sediment. Characteristic of the Age 0.5-1 Aldo Lake lava flow. X:-1334 Y:-10992
0959 015 2582 Sample 3 among the very flat AGE 1 lobate flow at the axis. Lobate still has the mottled appearance given by little thin patches of sediment.
1002 278 2581 under way after taking sample 3 more of intermingled Pillow and Lobate flow, but still AGE 1.
X: -1445 Y:-10988
1005 286 2590 transition back into flattened pillow terrain. Pillows not as glassy as those lobates, but it's unclear whether this pillow flow is really another flow than the lobate flow at the axis
1008 284 2604 lobate to pillow flow, not as glassy, AGE 1.5-2. Still abundant buds on the pillows
1010 277 2601 Headed upslope again through pillows (<1m size) with buds. These pillows have no glass except on infrequent buds. Pillows are mostly rounded, but some are elongate 1-2m downslope (E).
X:-1883 Y:-10125

1013 spinning 2589 summit on the West side of axis. Pillows from apparently the same flow as composing the rest of this mound. A few more buds up here possibly. Will collect Sample 4
1019 070 2589 Under way after collecting Sample 4 from the summit of this axial pillow mound.
1022 072 2585 Another local high in this pillow mound, still in the pillows comprising the pillow mound.
X:-1847 Y:-10900
1025 070 2582 Still in pillows that look like the ones on the pillow mound, but there are thick pockets of interpillow sediment here Age 2.5-3.
-1670 -10825
1028 fissures, 2 about 20cm wide, in a Lobate flow,
1029 074 2583 meter-wide fissure, with contact to very glassy Age 0.5-1 lobate flow just on the East of this fissure, will stop for Sample 5
X:-1547 Y:-10778
1035 250 under way after taking Sample 5, double back to look at contact between age 0.5-1 lobate flow and age 2 pillows
Contact is at X:-1543 Y;-10777
1037 068 2584 back on original track, just passed sampling station 5 in the age 0.5-1 lobates
1039 068 2581 still in the age 0.5-1 lobate, with the mottled sediment/ crust of glassy appearance
1040 064 2581 Spagetti Worms and local collapses of individual lobes in the Age 0.5-1 lobate flow
1042 070 2581 Deep collapse off to the STBD, can just barely see across it, depth 3-4m. Collapse floor is rubble, walls are selvages and hollow caves. Roof is young lobates.
1045 109 - Picked off Sample 6, a piece of the lobate forming the roof of this collapse pit. Dozens of selvages on the walls, and lopped-off pillar in the floor of the pit. Pillar is only 1-2m high, but top is gone. X:-1388 Y:-10723
1048 068 2580 Out of the collapse, still flying over the Age 0.5-1 lobate flow. Intermingled pillows with a lot of buds.
1049 072 2577 Coming up on a local high. Mainly pillows now, with some hydrothermal staining on the rinds.
1051 072 2582 In pillows with buds and almost no glassy rinds left.
X:-1223 Y:-10668
1054 320 2583 just came about and headed to next waypoint. Still within the pillows with no glass and many buds. Lack of interpillow sediment pockets suggests these are not really off-axis AGE 1.5-2.
X: -1181 Y: -10601
1057 332 2576 Thick patches of orange-colored hydrothermal sediment in the older pillow area. Mainly pillows about 1m in diameter. X:-1218 Y:-10555
1058 333 2580 Crossed over the contact with non-glassy unornamented older pillows and the youngest lobate flow. Lobes are fairly small (<1m) and uncollapsed. Hydrothermal sediment has gone away.

1101 342 2580 Spaghetti Worms, glassy lobates locally collapsed with hydrothermal sediments thinly covering the glass.
1103 270 2581 In Age 1 glassy lobates mottled with sediment pockets.
1106 274 2585 Lobates and pillows intermingled, still same relative age, 0.5-1.
1109 080 2587 Over the contact with an older pillow-lobate unit. Contact between an AGE 2 pillow-lobate flow and the AGE 0.5-1 intermingled lobate-pillow flow that is the youngest age.
1110 two extinct hydothermal sulfide chimneys, just on the younger side of the age contact. One chimney has only one spire, other has 4+ spires, both are ~5m tall. On the Age 0.5-1 lobate flow, not on any apparent fissure
1116 061 2583 flying over Age 0.5-1 lobate, just after stopping at the extinct chimneys. Lots of local meter-scale collapses of a few 10's cm depth.
1118 061 2583 intermingled Age 0.5-1 lobate-pillow flow. Thick ornamentation on the pillows in this local patch. Lobates have 2-3 m wide lobes.
1123 356 2581 Big collapses 4-5m deep and >20m wide within the Age 0.5-1 lobate flow. Dozens of selvages form the walls of the collapse, and hollow caves also extend away from the area where the roof has collapsed. Crossing over several collapses.
1126 358 2583 This collapse is floored with sheet flow not rubble. Looks longitudinally striated for the most part, but with islands of jumbled sheets in the center of the flow. These collapses form a series of pukas in the DSL-120 sidescan imagery.
1136 005 2582 Heading up and back out of a collapse after sampling a fold within the curtain-folded sheet flow at the base of the puka. Sample 7.
-1338 -10101
1139 000 2584 Age 0.5-1 lobate-pillow intermingled area. Local collapses a few m's wide and 1 lobe deep (10's of cm). No sign of "older" seafloor kipuka seen in the 1996 Argo survey.
1142 006 2584 No collapses here, but still in the Age 0.5-1 lobate
X:-1350 Y:-9844
1145 010 2587 Left the lobates behind, in an area of fairly young pillows, no sign of age contact. Pillows are bulbous meter-scale and thickly ornamented by glassy buds.
1148 Lobates with heavier sediment cover Age 1.5+
Sample 8
1151 320 2591 underway after taking Sample 8, at the contact with the older lobate-pillow flow, and the Age 0.5-1 lobate of the axis. Older flow has well-decorated pillows with glassy buds, but no glassy rind left. Lobates are bulbous, too.
1158 345 2608 In the Age 1.5-2 pillows, pillows are 1-3m diameter, mostly not elongate. Now turning to head East again.

 

1205 092 2600 Crossed the contact again with Age 0.5-1 intermingled lobate-pillow to East and Age 2 pillows to the West.
-1274 -9417
1216 Just underway after taking Sample 9, within the younger pillow flow. Flying over small pillows and bulbous lobates, not as much ornamentation on the pillows as on most of the other flows in this area.
1220 073 2587 Age 0.5-1 lobates
1222 085 2581 White staining in the cracks in the intermingled Age 0.5-1 lobate
1225 072 2578 left most of the lobates behind, flying over bulbous pillows now. Not a different flow just different morphology.
1227 071 2573 Skylight-like collapses in intermingled pillow-lobate of Age 0.5-1. Little collapses 2m diameter, but >3m deep. Spaghetti Worms.
1229 2572 Flow direction in Age 0.5-1 lobates due East.
1231 077 2576 Coming over an abrupt drop off in pillow terrain. Drop was 6m high, but still in Age 2 pillows.
1234 341 2585 Stopping for Sample 10 in relatively older pillow flow in a drop off on the eastern side of the East ridge on the axis.
1255 076 2586 Under way after taking Sample 10 - a bud from the older looking pillow flow. Might be age 1.5, still glassier than the really old stuff called as contacts previously. Might just be the flow front of the Age 0.5-1 lobate flow. Mostly in elongate pillows.
1258 076 2598 Old pillows and intermingled lobates, we will come about to a westerly heading as lava is fairly well-sedimented now, and we haven't crossed an abrupt age contact beyond the one at 12:31
1302 281 2592 in meter-size pillow, white staining in some of the cracks, a few buds but otherwise no glass. Elongate pillows rarely seen, but when visible indicate flow still to ENE
1305 283 2576 meter-scale pillows with lots of buds
1307 283 2572 crossed contact between Age 0.5-1 lobate to the West and older pillows on the East side. The Age 0.5-1 lobate has collapsed lobes and Spaghetti Worms.
1309 281 2571 Age 0.5-1 lobate, fairly flat meter-scale lobes. This is what we've begun to recognize as most recent axial lava
1317 284 2574 under way after taking Sample 11
Age 0.5-1 lobate toe
1322 284 2595 Entered into older pillows, no glassy rinds left, but there are a few glass buds on every pillow. Sediment not very thick, no accumulated sediment pockets.
1326 287 2603 Drop-off, 4-5m high, floored primarily with rubble. Walls are selvages, so this is a volcanic collapse pit.
1332 090 2601 under way after taking Sample 12
a piece of lobate crust near the top of the crater in the pillow mound seen in DSL-120 sidescan.
X:-1378 Y:-8971

1335 092 2602 lobates lightly dusted with sediment cover the top plateau on the pillow mound
1340 stopping for Sample 13
from the base of the pillow mound on the western side of the pillow mound
1347 090 underway after taking a sample from the toe of one of these meter-size pillows. The toes sort of grade into being lobates in and of themselves.
X:-1184 Y:-9840
1350 089 2589 Just East of the contact Age 0.5-1 pillows with lots of buds and 10cm size ornamentation. Some glassy rind left on these pillows.
1355 090 2572 flow morphology transition from pillow to the West and lobates on the eastern side of the morphology contact. All within the Age 0.5-1 lava flow at the axis
1357 085 2570 Spaghetti Worms and a line of 3 selvaged collapse pits with a pillar (top broken off) in one and all floored by rubble. The line is on an E-W trend (sub heading), but each collapse is about 10m diameter, and uncertain, <3m depth.
1401 049 2572 Age 0.5-1 lobate, meter-size lobes, and a very gradual transition to pillow-lobate intermingled flow.
1414 048 2598 Age 0.5-1 lobate flow with a few small pillows
1416 116 2598 Looks like this is an older pillow flow. Still has some glassy buds ornamenting the pillows, but very little glassy rind present. Sediment dusting over the entire surface of the rocks.
1423 055 2598 Sample 14
lobate flow to the East of the axis. Lobates are broad to fairly bulbous here, but appear older than the youngest lavas. These lobates are dusted with sediment, Age 2?
1428 315 2596 finished sampling 14, end of Alvin Dive 3361.