Macdonald Transcript, stbd. Observer 25 Feb 99

 

0856 starting two 360º spins to calibrate magnetometer.

0945 on bottom, age 2 sheets and lobates; a few pillows a minute ago.

0945-58 getting trimmed.

2608m, 112º, underway, age 2.5 sheet flows.

Stopped for rock sample 1 in age 2.5 sheets and lobates.

1008 underway 112º, 2610m, age 2.5 sheets

1011 111º, 2608m, age 2 pillows, glassy buds; a transition from age 2.5 sheets and lobates to age 2 pillows.

1014 113º, 2603m, age 1.5-2 pillows; going now to age 1 pillows

1015 contact age 1.5-2 pillows/ age 0.5-1 pillows, occasional kipukas of the older stuff. Continuous veneer of sediment on older stuff, spotty on older.

2592m, 112º, looking for sample in new stuff, age 1/2 to 1 pillows, looks like all new stuff now.

age .5 pillows, jet black glassy buds, hydrothermal sediment. About to stop for our second rock sample.

1023 2691m, stopped for rock sample 2, in age .5 pillows, about 50 m past the contact into the youngest stuff.

1034 swinging around and heading off from rock sample station 2;

114º, 2588m, underway, solidly age 1/2 pillows.

age 1/2 lobates with skylights.

multiple collapses in lobates, and spaghetti worms on top of the lobates.

1042 stopped for rock sample station 3 in age 1/2 lobates with spaghetti worms abundant.

1056 108º, 2586m, underway, age 1/2 lobates, must be near a hydrothermal area based on all the hydrothermal sediment and material in water column.

1058 lots of empty mussel shells, most are still brown but some are white; lots of skylights in the age .5 lobates and many anemones.

1100 020º for a short ways, exploring this extensive mussel field ~100m in length, but all are dead.

1101 back to 110º, 2587 m age 1/2 lobates still.

1102 2587m, 110º, transition from lobates to pillow lavas still age 1/2, might be nearing the flow front of this youngest flow.

106º, 2484m, Age 1/2 or 1 lobates? Sheet flows on port side (Blee)

1106 2586m, stopped for rock sample station 4 in age 1/2 to 1 pillow lavas.

1124 done with rock sample station 4,

110º, 2595m+5m alt= 2600m, definitely on older age 1 pillows here,

1132 heading 194, 2599m, age 1 pillow lavas, glassy buds but not as glassy as the age 1/2 pillows.

1134 2596m, 194º, age 1 pillows and lobates.

195º, 2594m, still age 1 pillows

2595m, 192º, age 1 pillows

1139 2594m, still age 1 pillows as we approach crest of this pillow ridge

1142 age 1 pillows and lobates

1143 2584m age 1 lobates with a few pillows, crossed a collapse area floored with folded sheet flows which may have been age 1/2

1144 230º, age 1 lobates along the crest of this ridge, 2584m

1146 2585m, 232º, age 1 pillows,

1149 2588m, 246º, age 1 lobates and pillows, broken old mussel shells, old serpulids and mussel shells on port side.

1152 c/c 220º, age 1 lobates

1153 on new flow, age 1/2 pillows with jet black glassy buds; so the contact between age 1/2 and 1 seems to follow about 5m downhill from the crest of this ridge on the west side.

1156 235º, 2589m, age 1/2 pillows and lobates, local collapses and skylights. I think we are still near the contact. Splotches of sediment on flat surfaces, big shrimp.

1159 —09 2588m, touring lava lake on various courses; flying into large N-S collapse trough, age 1/2 lobates at top, lobate debris in floor which is ~5m deep, bathtub rings along lava lake edges, caves and tunnels which reach back at least 10 m ( as far as one can see) , water is turbid, spaghetti worms on the rim of this collapsed lava lake. Looks like a two-story collapse, ie, there are pillars on top of a lava floor which itself is supported by pillars below. Lots of ~5m high pillars.

1210 rock sample 5 taken from ledge of lava lake, age 1/2 lobates.

1212 underway west over to next linear collapse seen on dsl 120 side scan

1213 2587m, 200º, flying over edge of collapsed lava lake, lava lake renmants and pillars, now going south along this linear collapse lava lake, 6-7m deep floored by lobate and sheet flow rubble, turbid water, another collapse on top of a collapse as seen earlier. The lava lake edge is very sinuous and tunnels reach back under the edge as far as you can see.

1217 still in collapsed lava lake, age 1/2 lobates on top, sheet flows beneath.

big remnant recently collapsed into floor, brittle star

240º, leaving collapse lava lake area. Age 1/2 sheets and lobates.

Small skylights in age 1/2 lobates.

240º, 2588m, age 1/2 lobates, coming up on edge of another large collapsed lava lake also seen on dsl 120 record. 2588m 240º,

large caves, skylights, bathtub rings, lobate rubble in floor; we continue on 240º but the linear collapse continues to the S.

1231 age 1/2 lobates, back to the edge of a lava lake, have been for the last 3 min on Blee’s side.

2590m, 238º, age 1/2 lobates west of lava lake,

still age 1/2 lobates, spinning to left, 081 to check if Blee sees the older stuff

still age 1/2; nice shot of a "ghost shark", Cindy says this is the first sighting in the Pacific! Formerly known to be only in N Atlantic. It is a very primitive sort of "proto-shark". It may also be a rattail.

2593m, 272º, I think we are in the contact region where at 1/2 and 1 pillows are interfingered.

2595m, heading W, definitely age 1 pillow lavas, have crossed the contact. Lots of black glassy buds, but the black glass on the pillow surfaces has all sluffed off.

2598m, 274º, looking for sample of old stuff,

1244-1300 stopped for rock sample 6, 2602m.

1301 underway SE 133º, 2597m, age 1 pillows

1303 another ghost shark or rattail

may be back on age 1/2 pillows, but not sure, probably that transition zone again. 132º, 2597m

definitely see age 1/2 pillows sitting on top of greyer age 1 pillows and lobates. We are at the contact here.

134º, 2594m, definitely on age 1/2 here

1311 most definitely age 1/2 lobates and some folded sheet flows. Black glassy skin is continuous on surfaces, sediment occurs in distinctive patches.

1312 back over collapsed lava lake. flying into large N-S collapse trough, age 1/2 lobates at top, lobate debris in floor which is ~5m deep, bathtub rings along lava lake edges, caves and tunnels which reach back at least 10 m ( as far as one can see)

1314 another big collapse lava lake. flying into large N-S collapse trough, age 1/2 lobates at top, lobate debris in floor which is ~5m deep, bathtub rings along lava lake edges, caves and tunnels which reach back at least 10 m ( as far as one can see) beautiful cylindrical lava pillar 5 m high. Lots of pillars! Mesotech shows lava lake is 8 m deep here.

1317 purple sea cucumber floats by as we pass over east edge of lava lake going east.

1321 2587m, 109º, age 1/2-1 pillows and lobates ; looks more like age 1 here, may be in transition zone.

1324 2585, 108º, still in transition zone 1/2-1 age pillows, looks solidly age 1 pillows now.

1325 changing course to SW to head to waypt 8 skipping 6 and 7 because the contact appears to be further west than thought.

1330 age 1 lobates2586m, heading 222

2585, heading 223 age 1 lobates and pillows

1337 back in age 1/2 youngest flow, skylights, spaghetti worms,

—46 dumbo octopus, cephalopod, spotted right in front of us. 2m across!

1347 2588, 222º, age 1 pillows

2588, 222º, contact with age 1/2 lobates and sheet flows.

Skylight in age 1/2 lobates, splotchy sediment cover, some spaghetti worms. Within the age 1/2 there’s some even glassier blacker almost age zero stuff.

222º, 2588m age 1/2 lobates

222º, 2588m at edge of collapsed lava lake, age 1/2 lobate pillows at top, lobate rubble in floor.

turning to 270 to cross lava lake and look for sample

folded jet black sheet in floor of lava lake resurfacing the lobate rubble, right next to it is a flat sheet flow with a very thin veneer of sediment, it could be slightly older?

Stopped for sample 7 of that folded sheet flow.

underway west crossing edge of lava lake onto lobate lavas age 1/2, pillars, 2589m, yellow hydrothermal staining in crevices

age 1/2 lobates 224º, 2589m

1408 crossing back into lava lake, going west then turn south. The edges are floored by lobate rubble, the middle is resurfaced by age 1/2 sheet flow which is unbroken. The lake is ~5m deep and ~20m wide. Many lava pillars also ~5m high.

1410 2593m, heading generally S, age 1/2 folded and jumbled sheet flows in center of floor, lobate rubble at edges, pillars.

1412 more of the same, the center of the collapsed lava lake looks like a lava channel with jumbled sheet flow levees, and flat sheet flow along the middle.

1416 stopping for few minutes for power check.

1421 coming back over east edge of lava lake. Some turbid water, fish, once again the edges are floored by lobate rubble, the middle is resurfaced by age 1/2 sheet flow which is unbroken. The lake is ~5m deep and ~20m wide. Many lava pillars also ~5m high; the center of the collapsed lava lake looks like a lava channel with jumbled sheet flow levees, and flat sheet flow along the middle.

going down middle of collapsed lava lake, mesotech shows it is 24m wide here, this matches the dsl 120 side scan perfectly. Less deep 4-6m.

out of collapse on stbd side, age 1/2 lobates, then back along edge.

2591m 182º, following edge of lava lake, just east of it. Age 1/2 lobates, crabs, spaghetti worms.

1428 25590m, 160º, big caves heading E-W beneath rim of lava lake. Lots of pillars. Flat sheet flows covered with hydrothermal sediments, again a folded sheet flow 1/2 age. Stopping for sample, 2594 at floor of collapse.

rock sample 8 of folded sheet floor from floor of lava channel within lava lake age 1/2.

1454 leaving station, heading 175. In lava lake.

1457 lots of pillars and remnants

1459 heading west now, back into another collapse, then over and out.

1501 mostly age 1/2 lobates and pillows, a few older age 1 pillows here and there.

1502 in a transition region with both age 1/2 and age 1 lobates and pillows.

1505 all age 1 pillows now. This contact shows up nicely on the dsl120 side scan records!

1407 looking for sample in age 1 pillows.

1515 2605m, rock sample 9, chunk of age 1 pillows. Coming up.

Magnetometer calibration spins at ~1000m on way up.

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