Feb. 15, 1999
Transcript of Bill Ryan (Starboard Observer)
[This is based on real-time audio recordings of port hole observations and subsequent modifications that have been richly-supplemented by a review of all of the videotape and the navigated track]
09:35 2638 270 Landed on the bottom on a smooth sheet flow.
The terrain around is heavily sedimented. Age 2.5 of Ken
Macdonald. The sub dorps over a west-facing cliff onto a terrace
containing a few large bulbous pillow lavas. All the interstitial
spaces between the pillows are filled with and are interconnected
09:37 2646 264 We begin to get underway towards Way Point 2 and soon cross a surface of large tabular slabs broken from a very smooth (sheet) flow. Some slabs are titled and jut up from the surface having been ripped up and carried along in the flow.
09:38 2647 265 This is indeed a very smooth sheet flow whose surface ta\exture is obscured to a significant degree by the thick and pervasice sediment cover.
09:39 2647 265 The surface has been smoothered by the sediment since it was broken up into slabs. Looks like a sidewalk pavement under and inch or two of fresh snow. No bare slabs or loose talus is visible right now.
09:40 2646 268 Arriving at Rock Sample Station # 1. Tabular slabs seen from the starboard viewport, pillows from port viewport. Sample taken from a pillow bud. The scene transitions into lobates along vwith fewer and fewer pillows, all the morphology of the same age and probably bthe same flow unit.
09:44 2646 247 Underway and crossing heavily-sedimented pillows and lobate flows (Age 2.5). Then rising in water to get a transponder fix. Pillows seen below in the SIT camera.
09:46 2646 256 Up in water at an altitude of 14 meters. Bottom temporarily out of sight. A good cfix is obtained for our starting point.
09:47 2646 261 SIT camera showing heavily sedimented pilllow lavas on broad pillow mounds.
09:49 2655 295 Over a west-facing escarpment cut into the pillow lavas
09:50 2653 265 Ribbed and striated pillows cut by a narrow fissure and then becoming mixed with smooth lobate flows.
09:51 2665 266 Over another west-facing cliff onto more pillows and lobates.
09:52 2649 264 Over this cliff onto angular talus ramping up against its base.
09:53 2656 266 Can't see bottom except via the SIT camera. Powering down.
09:55 2681 261 Bottom coming into view as a mixture ofpillow lava and elongated pillows.
09:56 2682 263 Over another west-facing scarp about 5-7 m high, talus at its base consisting of angular blocks and truncated and broken round pillow heads and trunks.
09:57 2681 265 Up and over a small ~5-meter high east-facing cliff onto a terrain of elongated pillow lavas. Less sediment than before. Age 2.0. Elogated pillows have a l:d ration of 4 to 6. and appear to flow northward.
09:58 2677 265 Dominately pillows with minor lobate flows. Two small fault-generated steps down to the west in succession.
09:59 2678 266 Crossing a narrow (1-m wide) fissure cutting through pillows at the base of the second step down.
10:00 2689 263 A thin (0.5-m wide) fissure cutting the pillows. More lobates now and fewer pillows.
10:01 2690 266 Passing onto smooth lobates cracked open on their top surface to expose white \hydrothemal staining on the broken facets. The roof rock of these lobates is thick (estimated 15 cm). Populated by anenomes Age 2.0.
10:02 2690 265 These lobates appear to have less sediment cover than the pillows just passed. Age <2.0. Some folded and wrinkled sheet flow among the lobates. Crossing a small west-facing cliff.
10:03 2691 290 Stopping for Rock Sample # 2 from the rim of a 1-m wide fissure striking parallel to the roughly N-S valley trend. Very little sediment in this fissure. The talus present is extremely fresh. While sampling I can observe bedded lavas of 20cm to 2 m thickness in the wall of this fissure. They appear to be truncated lobates and pillows.
10:16 2690 017 Finishing the sampling, turning CCW over sedimented lobate flows.
10:18 2689 266 Crossing these lobate flow occasionally interspersed with bulbous pillows\; some of the pillow heads have open skylights.
10:19 2690 263 More lobates and then signs of talus. We are approching a wall. Then ascending this wall only to drop over a deep 2m wide fissure cut into the lobates and revealing bedded lavas in its wall.
10:20 2687 265 Another thin fissure and more talus, leading onto a 20-meter high, steep, east-facing escarpment bounding the west edge of the central valley floor.
10:21 2686 266 Talus contains many tabular slabs thought to be fragments of lobate roof rock as well as blocky pieces and round trunks of pillows display radial fractures. Talus is very fresh without any traces of sediment.
10:22 2686 266 Climbing this talus ramp with some signs of low remperature hydrothermal biology. Up three small scarps easch separated from the next by very narrow benches. Massive flows and thin bedded lavas observed in the direct bedrock outcrop in the wall. Climbing up its steep face for an altutude of 11 meters.
10:23 2679 265 Reaching lobate flows at the top rim. Age 2.0. Then over a thin spur and down 5 meters to another bench. This latter bench is cut by N-S thin fissures running through lobates of Age 2.5.
10:24 2668 264 Descending a narrow ramp of talus.
10:25 2671 265 Very smooth and heaviliy sediments lavas whose surface texture is hidden by the sediment cover. Some lobate flows have shattered but as yet uncollapsed roofs.
10:26 2676 257 Some minor collapse pits in these lobates and shattered roof rock. Age 2.5.
10:27 2673 258 Lobates, small collapses and pillars. Massive rock with columnalr jointing in the wall of a track-normal fissure.
10:28 2671 259 Collapsed lobate lavas with a heavy coating of brown to orange hydrothermal sediment among old and extinct chimneys and degraded edifices. Some chimneys have half a dozen separate spires. Umber color to the sediment. Lava surfaces no longer visible. We are down in a lartge collapse depression. Bottom looks lumpy. Age 2.5 and locally 3.0 in the areas of thick sediment of hydrothermal origin.
10:30 2667 256 All the volcanic relief is presumambly buried under the thick blanket of hthe ydrothermal sedimentary materials and precipitates.
10:31 2666 257 Extinct sulfide mounds, and an enormous sulfide chimney.
10:32 2667 261 Tabular and smooth lavas cut by a narrow but deep fissure.
10:33 2663 260 Heaviliy sedimented smooth sheet flows and very smooth lobate flows beneath the significant sediment cover.
1034 2662 259 Talus leading to a 12 m high wall directly in front of and fracing us.Talus is sloping away to the starboard side. Loose tabular fragment of presummable lobate roof-rock.
10:35 2659 260 Climbing the wall. Cross a narrow N-S fissure and back onto smooth flows cut by more fissures.
10:36 2650 261 More talus and shattered rock, broken pillow heads and trunks and thin tabular slabs. Up a big wall in front of us revealing in its face not only massive and bedded pillow lavas, but truncated thin sheet flows, and lense-scaped lobated flows all truncated and exposed by faulting. The lobates are commonly empty.
10:37 2647 258 Reach top of this wall, populated by lobates. The altimeter in the stern of Alvin registers 14 meters. Lobates are smooth and heaviliy sedimented. Age 3.0. Cross small fissure 1 m wide.
10:38 2634 260 Another valley-parallel and 2-m wide fissure cutting the lobate surface. Talus on its floor. Thin layers of bedded sheet flow exposed in the fissure wall. Lobates are the stratigraphically highest rock on the wall. Another fissure and then over a cliff.
10:39 2632 260 SIT camera shows talus at the base of a giant collapse depression, eight meters below us. The floor of this depression is populated with tall and perfectly vertical pillars standing among lumpy sulfide mounds. Large extinct sulfide chimneys.
10:41 2640 260 Passingby a 9-m tall and dead chimney on the floor of this collapse depression. The lobate flows around it are very heavily sedimented.
10:42 2640 250 Crossing a 1-m wide fissure on floor of this deepression. Sediment cover is impressively continuous and thick. Age 3.0. Stepping over a west-facing escarpment dropping down 8 m onto faulted pillow lavas with large (>1m) diameter bulobous heads and heaviliy sedimented.
10:44 2647 260 Pillow terrain on floor of the giant depression, densely fractured. Wall directly in front of us whose presence is manifested by a ramp of angular and blocky talus with hydrothermal staining on broken facets. Talus here is extremely fresh, no sediment dusting at all.
10:45 2647 259 Preparing to motor up the east-favcing wall. As we do so, massive rock faces come into view as the bedrock outcrop appears interbedded with thiner (20-40 cm thick) strata that look like truncated pillows and lobates. Reaching the top of a 15-meter ascent, we find the rim to be heavily sedimented lobates of Age 3.0.
10:46 2629 260 Cross a N-S running fissure in a generally flat terrain of lobate flows, with huge pockets of sediment between the individul lobate tongues.
10:47 2629 261 The smooth flat and practically featureless terrain is cut by thin (< 0.5 m wide) fissures running though an almost 100% sediment cover. The occasional rock exposure is lobate flow and very sparce pillows.
10:48 2629 257 Pass what looks like an Alvin drop weight dusted with sediment lying on lobate flows and elongated pillows. All depressions between the pillows are filled and linked together. Age 3.0.
10:50 2629 242 Arrive at Way Point 2 and begin turn CCW to Way Point 3. Very smooth lobate flows transitioning to sheet flows whose surface texture can not be recognized because of the thick sediment cover.
10:52 2629 182 Still turning to come steady on a SE track and moving slowly over smooth low-relief lobates and sheets with small collapse features such as skylights.
10:55 2629 113 Turn completed and now dropping off a 14-meter high east (valley) facing cliff. SIT camera shows angular talus at the base of the cliff spilling onto a fissured pillow lava terrain.
10:57 2647 112 When arriving on the floor beyond the base of the cliff, the fissured pillows have now transitioned into fissured lobate flows and they make a smooth and nearly flat substrate. The sediment cover here is less than at the top of the cliff just descended. Age 2.5.
10:58 2643 122 Beginning to hunt for Rock Sample 3. Finding a suitable sample becomes difficult and time consuming.
11:09 2642 328 Turning slowly CW to a fissure in the lobate to find a way to pry off the surficial flow. Lobates transition to folded sheet flows and back to lobates.
11:14 2642 277 Sample taken.
11:17 2643 186 Turning back towards Way Point 3 and underway.
11:18 2641 111 Crossing a N-S oriented fissure cutting though these lobate flows.
11:19 2640 110 Traversing another fissure. Some lobate surfaces display small collapse features with 1-m wide skylights through the roof rock which reveal them to be >1 m thick and now mostly empty conduits.
11:20 2640 112 Another narrow (0.5 m wide) valley-parallel fissure. and over an east-facing cliff. SIT camera slows talus at the base of a 10-meter high vertical face. Talus is angular blocks and tabular slabs.
11:21 2651 111 Bottom comes into sight through the porthole. Heavily sedimented and thinly-fissured lobates with small collapse pits and fractured and sagging roof rock.
11:22 2654 108 A narrow ~N-S fissure followed soon by a second fissure, both oriented in the same direction.
11:23 2656 114 Very smmoth lava surface that is probably sheet flow.
11:24 2659 114 Passing over and thne motoring down a 5-m high east-facing cliff oriented parallel to the trend of the valley (graben). Rubble at its base.
11:25 2664 114 Settling down on shattered lobates with small (<2m dia) roof collapses and cut by narrow (0.5 m wide) fissures. Talus has poured into this fissure from the cliff just passed.
11:26 2661 113 Floor below us is now mostly lobates as we njow fly over and motor down another 8-m high east-facing cliff to arrive in a narrow N-S depression.
11:27 2675 112 Its floor of broken but very smooth sheet flow is densely fissured. Truncated thin sheet flows are exposed in the vertical face of the fissure walls. More than 6 thin fissures are crossed in rapid succession ,all cut deeply into these flat sheet flows.
11:28 2676 113 Reach a talus ramp at the bounding west-facing and 6-meter high wall of the narrow N-S depression. The talus is mostly thin tabular material, presumably shed from outcropping sheet flows in the escarpment that now looms dead ahead of the sub. The talus is quite fresh with only a thin but uniform dusting of sediment.
11:29 2677 113 More talus now containing some pillow fragments displaying the typical radial fracture patterns on the cut faces.
11:30 275 113 Arriving at the west-facing wall. Sulfide chimneys populate the talus ramp at its base. Start to climb the cliff. End of video Tape 1.
11:31 2668 112 Over this rampart and down onto the floor of the axial depression. Lots of talus now heavily coated with brown to ocher-colored hydrothermal sediment.
11:32 2676 115 Extensive sulfide mounds, all extinct, some broken and degraded. Shattered ores are yellow-stained. Cross a thin fissure near the base of an east-facing valley-floor bounding wall. Talus is found in a fissure, presumably shed from wall since it contains broken pillow fragments.
11:33 2573 114 Crossing the contact from the base of talus ramp onto the external terrain of large bulbous pillows and elongated pillows. This is the youngest lava (non-taus) terrain we have seen. Age 1.5.
11:34 2681 114 Pillows everywhere. Some are superficially cracked and reveal yellow hydrothermal staining on the crack walls. Minor sediment betweem the pillows.
11:35 2680 111 Slowing to search for a location to sample these pillows.
11:36 2679 109 Stop in a patch of elongated pillows with buds. Much less sediment here on these axial floor pillows than anythingwe have seen before. A constructional terrain with very little tectonic disruption. Rock Sample 4.
11:41 2676 113 Underway across this constructional pillow lava substrate.
11:42 2676 116 No interstitial sediment in pockets between the pillow heads and tubes. Pillows are ribbed and striated. Surface texture clearly visible with only a thin dusting of sediment.
11:43 2676 116 Briefly stop to look closely at these pillow-skin textures and then back underway across the pillows at a slow speed. Cross a large (2-m wide) fissure cutting N-S through the pillow lava mound.
11:44 2676 116 Large (>1m dia) pillow heads not strongly tectonized by valley-parallel-cutting fissures. Some fissures display small (1-m amplitude) throws.
11:45 2675 115 Pillows become elongated and appear to have flowed down a slight incline to the east. Good pictures of the elongated fabrics on the SIT camera. Age 1.5.
11:46 2679 116 Pillows end in lobates that are slighltly more heavily sedimented (Age 2.5). Sulfide stain is observed on this sediment. Many small fissures cutting through the lobates. Looked like the pillow mound just cross has buried some of these fissures and thus represents a distinctly younger stage in the evolutrion of the valley (graben).
11:48 2678 115 Smooth lobate flows extending eastward to be onlapped by a talus ramp coming from the east-bounding wall. Anemomes, fish and crabs of a presumed low temperature hydrothermal diffuse vent nearby. Talus is angular, blocky and rather fresh-looking.
11:49 2679 115 Starting to climb this poorly-sorted talus incline.
11:50 2670 116 Motoring up the 16 meter high wall abovev the talus ramp and observing bedded lavas both thin and massive (with columnar-like jointing) in the bedrock exposures. Lobate flows cap the rim of this escarpment. Hydrothermal staining on some facets exposed on the wall. A small valley-parallel fissure cuts the lobates a meter or so in (eastward) from the valley rim. We then discover that this rim is a down-dropped sliver and that behind it this fissure opens upwards to be the continuation of the wall. Some talus shed from the higher wall has scattering into this fissure (an opening of the cliff-face by a valley-parallel joint).
11:52 2663 116 More bedrock comes into view in the wall. Again its is both horizontal and somewhat rythmically bedded spaced by massive layers several meters thick with clean flat partings. Layered pillow truncations in the outcrop.
11:53 2665 117 Approaching now the real top of this west-facing wall
11:54 2662 151 Lobates occur again right at the rim. Altimeter displays 19 meters down to the inner valley floor as the sub crests the rim. We stop at the top for Rock Sample 5 in these bedded lobates which pass transitionally into folded sheet flows.
11:55 2662 150 Maneuving to pluck off a digit from the lobates.
11:56 2661 158 Sample taken. These flows are rather heavily dusted with sediment Age 2.5.
11:58 2647 158 Underway crossing this terrain of lobate flows and subsequently rising up a precipituous 14-meter high west-facing cliff that makes the highest rampart of the inner valley wall.
11:59 2649 119 Heavily sedimented (age 2.5) lobates at the top with some scattered pillow lavas.
12:00 2648 117 Pillows becoming more abundant, heavily sedimented, pockets between adjacent pillows are fully interconnected.
12:01 2646 117 Cross a fissure perpendicular to the sub's track (~N-S). Now there are vast pockets of sediment between the lava bedforms.
12:02 2647 117 Becoming more and more pillowed at the expense of the lobate flows.
12:03 2649 119 Another N-S fissure cutting through a predominately pillow lava terrain. Bottom drops away into an 8-meter deep N-S trough (tiny graben) bounded by steep scarps. Large fragments of pillow lava (heads and trunks) scatter its floor along with more tabular talus. Talus of all sizes from baseball to basket ball to garbage can. The wall ahead as it is climbed reveals bedded outcrop and is capped by heavily sedimented pillow lavas. None are observed as flowing down the scarp.
12:04 2643 117 At top the pillows are mostly elongated into tubes with a 4:1 to 6:1 aspect ratio (l:d) oriented to the east.
12:05 2643 119 Cross ~N-S ridges and troughs that look like small horsts and grabens each with 2-4 m of relief and a few meters across the tops and bottoms. This faulting cuts and offsets (vertically) the elongated pillows and tubes. The terrain appears to have received a little more sediment. Some lobates encountered have small skylight windows and cracked roof rook. Looking in these portals shows the lobate flow to be <1 m deep and mostly void. Last fault encountered is an 8-meter step up onto what I presume to be the high rim of the east wall of the valley.
12:06 2643 119 Shattered lobate roof rock, sometimes collapsed into pits, mostly still intact as roof material but slightly sagged. Approaching Age 3.0 up here on the rim.
12:07 2640 131 Large collapse pit, >5 meters in diameter. Fallen roof rock of lobate flows scattered on its floor. The period of collapse is old bhecause the debris on the floor is heavily sedimented.
12:08 2643 128 Cross sa mall fissure incised into a terrain 90% covered by sediment. Then another fissure or alternately a mini horst & graben structure with 3 to 4 meter amplitude of the fault throws.
12:09 2644 134 Another wide fissure. All the talus in this region is very fresh-looking with only the slightest sediment dusting. The fissure is disecting lobate flows.
12:10 2640 133 Very smooth and flat lava terrain whose texture can not be discriminated due to the thick sediment cover. Cross over an east-facing scarp 6-m high and down into either a wide fissure or another mini grabem. The floorof the narrow depression is scattered with talus that has less sediment cover than the rim. Cross this talus and then up onto a bench.
12:11 2643 133 A complex terrain of spurs and troughs that might be faulted crustal slivers or very wide and shallow fissures. The host terrain is lobate lava. Talus is present only in the immediate vicinity of the steep scarps.
12:12 2641 148 Shattered lobate flows and some collapse pits, seen from a high altitude of 8 m as we fly over the up & down landscape. Slowing to look for a suitable sample site for Rock Sample 6. Pass onto folded sheets and snuggle up to the rim of a very wide (>2m) and deep (>8m) fissure with verticle sides.
12:13 2640 150 With SIT camera we look down on the talus below us that has fallen into this fissure and from the port hole out onto the bedded bedrock exposed in its wall. The talus contains both angular blocks and round fragments of presumed pillow heads or truncks shed from the wall.
12:17 2645 155 The sample is obtained from the exposure right at the rim at the far side (east) of the fissure. The more we look, the more it appears that it might be an exposed lava tube opening to the west.
12:20 2645 156 Underway and turning CW to the south west to Way Point 4. Crossing another large fissure or more likely, a collapsed tube and several other collapse pits in a host of lobate lava.
12:24 2640 237 Over a 6-m drop off and into one of these pits whose floor is littered with talus.
12:25 2638 238 The terrain outside the depressions becomes predominately pillow lava, still Age 3.0. Pillows are also in the floor of the depressions and lobates around the rims.
12:27 2642 235 Another large collapse depression in the lobates with quite fresh roof-rock and talus on its floor. (The colllapse seems to have been much more recent than when the lavas erupted).
12:28 2641 237 Without dropping into these depressions, we continue to the SW and cross shattered lobate lava whose surface texture is obscured by the thick (1cm) sediment cover. All the subtle relief is hidden. In the scene 90% of the region is sedimented, 10% is rock exposure.
12:29 2638 237 Cross over a large west-facing escarpment 15-meters in relief. The SIT camera shows a talus ramp at its base. Altimeter reaches 19 m as we park at the top with the stern of Alvin hanging out over the cliff. The rim is lobate flows.
12:32 2655 238 The down-dropped block (in a relative sense) comes into view and is also lobate lava upon which the fresh (sediment free) talus is scattered. This is the base of the outer East Wall of the valley. The lobates are sedimented with an estimated Age of 2.5. It is clearly a younger terrain than that of the rim area and theEast wall summit area, but not by much. The lobates display small skylights that show its roof rock to very very thin (<5cm).
12:33 2657 237 A collapse pit in the lobates scattered with sediment-free, shattered and tabular roof-rock and fresh blocky talus.
12:34 2656 236 Bedded lavas are seen in the walls of the depression that appears to be about 5-m deep. Large pillow heads and trucks have broken off the walls and are scattered on the floor among the roof-rock.
12:35 2650 237 Continuing over the uncollapsed lobate terrain .
12:36 2652 237 Crossing a fissure about 2-m wide and nearly filled with fresh talus.
12:37 2652 238 Back onto intact and heavily sedimented lobate flows, then skirting some small collapses occupied the same fresh talus as before. These collapses or fissures also contain bedrock outcrop in their walls. Then climbing a small N-S trending and east-facing fault scarp whose base is lined by talus. Bedrock outcrop in its wall and sheet flows and lobates on its rim.
12:38 2652 237 More mini horst and graben looking terrain of verticle but low relief (<4 m) ridges and troughs cut into the predominately lobated lava terrain.
12:39 2648 237 The up & down trip continues as if it is a series of successive wide fissures each accompanied by modest vertical displacement, again all incised into and offsetting a lobated lava surface of Age 2.0.
12:40 2648 239 Over a very large west-facing cliff bounding the inner rift valley that initially drops 10 meters onto a narrow bench of the same shattered lobate flows.
12:42 2661 238 Blocky talus on this bench.
12:43 2664 237 Motoring down the cliff that is directly behind us. Altimeter is 9 m, but as we go over the next step of the cliff, the bottom falls away by 30 meters down an almost vertical escarpment.
12:44 2684 236 Still motoring down, altitude is 16 m.
12:45 2696 237 Botttom coming into view as we prepare to land in the inner rift. Pillows and tubes seen in the SIT camera strewn with blocky talus. Sediment cover much reduced from that existing on the top of the escatpment.
12:46 2694 238 Rising onto a small mound in the center of the inner valley floor composed of much younger pillow lavas. Age 1.5.
12:47 2691 300 Turning CW and looking for a place to sample this pillow terrain. The pillows and minor lobates here are colonoized by anenomes. Rock Sample 7.
13:01 2692 334 After much struggle, a sample is successfully obtained and secure in the basket. Back underway to Way Point 4.
13:02 2706 286 Descending off the pillow mound in the center of the inner valley onto a surface of lobate lavas cut by very deep fissures and with small collapse pits and dusted with more sediment that the pillows behind us. Age 2.0.
13:03 2692 260 Lobate lava fairly heaviliy sedimented here in the "moat" along the base of the west wall of the inner rift valley.
13:04 2692 242 Lobates flowing westward into this moat and cross-cut by thin fissures and cracks displaying white and yellow hydrothermal staining.
13:05 2693 241 The lobate surface here is quite smooth with tongues clearly elongated and headed westward as the floor deepens in the direction of travel.
13:06 2694 241 Lobates transitioning into elogated pillows as the "moat" right at the foot of vthe bounding wall is approached. Sudden apprearance of talus from the steep eastward-facing wall straight ahead. The talus is extremely fresh, with no sediment dusting at all. Hydrothermal staining in local regions of the talus.
13:07 2698 243 More talus and rocky talus accompanied by chutes of glassy gravel and sand (presumsably derived from the glassy rinds of thelavas exposed in the wall ahead). Chutes in the talus ramp that we are just climbing with concentrations of very black gravel and sand.
13:08 2694 241 Beginning to motor up this cliff. Above the talus ramp of 4-meters height is a massive bedrock outcrop on a vertical face. Reach a narrow bench some 7 m above the foot bof this wall. The bench is strewn with talus. Now climbing another vertical face directly above this bench.
13:09 2682 241 Altimeter registers 11 meters as the cliff faces reeveals masasive outcrop on sheer joint surfaces. No forward progess.
13:10 2682 276 Altimeter is now 18 meters as we still motor up this escarpment to another narrow bench cut by a fissure. This is a sliver of the rock face that has not yet detached along valley-parallel joint planes. Talus in this fissure has been shed from the 15 meters of cliff face still above us.
13:11 2667 328 Reach the top and arrive on a lobate surface immediately cut by cliff-face parallel and narrow fisures. (Are these futher slices of the crust pealing away from the cliff on joint planes?) The lobate surface immediately out of the inner valley is regionally flat yet is populated with large local collapse pits and depressions with 2 to 4 meters of relief from rim to floor. Can see a small and extinct hydrothermal chimney in the very first pit as I stare through its skylight opening.
13:12 2668 293 Momentarly stop to look into a collapsed lobate and see very thinnly layered rock (2-cm bedding thickness) which looks much more like successive sheet flows that have moved through a subsurface tube rather than bathtub rings. The lobate rim that wraps these strata is about 10 cm thick and in cross-sectioon looks like spary calcite. Its circumference is folded in spots and not at all circular.
13:13 2669 265 An excellent look into another collapse opening in the lobate surface.It is littered with former tabular roof rock that is now extensively shattered and scattered.
13:14 2668 255 Stopped at a pillar to sample the lobate surface that makes up its top. Rock sample 8.
13:16 2669 260 Back underway over another collapse pit in the lobate terrain. Relief just 2 to 3 meters maximum.
13:17 2666 225 Another pillar in this depression with "bathtub" rings surrounded by rubble that looks like extensively shattered former, and thin roof rock. The scattered rocks in the depressions have less sediment dusting than the lobate sufaces which hosts the pits.
13:18 2666 211 More views of the talus in these depressions and clues to how it has been shattered into small fist-sized fragments and not large tabular slabs.
13:19 2668 213 Down in a collapsed depression with lots of former roof rock and small pillars.
13:20 2669 211 The shattered rock all around suggests that the roof had once been extremely fragile (possibly very thin or extensively fractured before collapse).
13:21 2668 210 Another collapse hole in the lobate surface and more shattered roof rocks as debris on its floor.
13:22 2669 210 Crossing an extemsive areas of shattered roof rock among the pillars. Impressed by its small size (more like cobbles than boulders). Hydrothermal staining on the debris and some hints of vent fauna (fish and anenomes).
13:23 2668 209 Flying 5 to 6 meters above these shattered lobates as the port-side observer describes a large pillar with bathtub rings. Then up on to the non-collapsed lobate lavas that are extensively cracked but still form a more or less intact surface. The cracks form polygon shaped patterns simiar in desugn to the plates on the back of a turtle.
13:24 2667 211 More collapsed regions, more rock scattered on their floors, and an extinct hydrothermal mound with discolored sediment around its base (orange, yellow and white). Then back up onto the lobate surface and down into another pit (all with the eyeballs as the sub stays high and flies more or less at a constant depth).
13:25 2667 208 Shattered roof rock as we reach Way Point 4 and turn CCW to Way Point 5 located to the southeast.
13:26 2668 146 Moving now in rapid succession from one pit to another with only small regions of intact roof. The relief of the pits continues to be only a couple of meters. Some of the pieces of roof rock scattered on the floor are 10 cm in thickness, others are <5cm. Slab after slab is observed in this quire wild scene of "destruction".
13:27 2668 147 The scattered roof rock continues across a depression floor as I look into cavities in its wall. It is as if a large percentage of this subsurface landscape had been hollow and only supported by pillars and narrow buttresses with vast amounts of the locality subsequently collapsed. The young (sediment free) nature of the debris on the floor in contrast to the sedimented intact lobate suggests that the devestation took place long after the initial lava eruption that produced the lobates surface and its honeycombed interior.
13:28 2669 144 Animals of a nearby hydrothermal low temperature vent area and sulfide sediment among degraded extinct sulfide chimneys in one of these collapse depressions. The overlay of sediment on the collapsed roof rock suggests that the hydrothermal activity postdates the collapse.
13:29 2666 144 A greater concentration of anenomes, crabs and suspended mater in the water.
13:30 2666 144 Crossing now a huge (15 meter-deep) collapse depression as its talus-littered bottom falls away out of sight.
13:31 2673 177 Crabs, polycheat worms, fish, and heavy concentrations of hydrothermal sediment all around us while we motor down to the bottom.
13:32 2681 257 Altitude is 11 meters nd we abort the attempt to drive to the floor of this deep chasm, but instead fly over it. Its walls lined with talus are almost white from the attached tiny polycheats. We can see diffuse flow coming out of the rubble. Crabs everywhere by the hundreds amassing around extinct chimneys and all across the debris surface.
13:35 2668 152 After a lot of maneuvering high off the bottom to get to its margin, we see more vent fauna in patchy concentrations.
13:36 2673 154 We realize that we are on an east dipping steep slope leading to the inner valey floor. The SIT camera shows this to be scattered talus and rubble. Some patches of folded sheet flows and more talus as if the flows in the past had poured down this pre-existing slope.
13:38 2688 145 Still descending this slope across the talus surface .
13:39 2697 148 Rapidly descending the slope leading into the inner valley floor and now observing that in places through the talus there are now elongated pillows that flowed down hill to the east.They transition with lobates that have long east-directed tongues and are intact and untectonized. Age 2.0.
13:40 2697 148 Having arrived on the inner valley floor of smooth lobates with lots of fresh digits we decide to stop to take Rock sample 9.This fresher-looking smooth lobate flow in the axis of the graben has an age of 1.5. It takes much maneuvering and time to find a protrusion to sample with the manipulator arm.
13:43 2694 186 Much turning at a creeping spped over the lobates and transitional elongated pillows.
13:46 2695 163 Low relief tongues on the lobates as we still hunt for a sample that can be plucked off the lava surface. Then we clearly see the fresher lobates that have flowed around older higher standing pillows which have a distinctly thicker dusting of sediment caught in their ribs and striations.
13:48 2695 170 Stopped.
13:50 2694 108 Moved again very slowly over to a narrow fissure and see signs that the lobate lavas had poured into this opening.
13:55 2693 183 Finally sample a bud from the lobate surface.
13:57 2693 184 Underway and turning CCW back to a southeast heading to Way Poiint 5. Cross a narrow N-S fissure as the lobates transition back into pillow lavas of a comparable age. The pillows are elongate as the valley floor slighly deepens eastward from a very low relief central mound just sampled. .
13:58 2694 153 The lobates and elongated pillows are cut by a N-S valley-parallel thin fissure. For the most part this is a tectonically undisrupted terrain.
13:59 2693 151 Lobates become quite smooth with long tongues.
14:00 2692 151 Another narrow but very deep clean fissure as the lobates transition to folded sheet flow of Age 2.0.
14:01 2690 151 Encountering the west-facing wall of the inner valley on the valley's east side. It rises in a moderately steep but not precipitous slope. Talus at the base.
14:03 2686 150 Climbing over pieces of broken pillow lava and the shattered skin of lobate flows.
14:04 2684 148 Continuing to climb this ramp and across a fissure.
14:05 2681 150 The talus passes upslope into elongated west-directed pillow lavas and tubes that are split apart with white hydrothermal staining in the cracks. A valley-parallel fissure cuts these pillows. The latter have clearly flowed down hill towards the valley floor.
14:06 2680 146 Cross another N-S fissure 2-m wide and very deep. Bedrock is observed to outcrop on its vertical wall. Can not see to the bottom of this clean cleft. Then followed by another fissure of the same valley-parallel tectonic trend.
14:07 2680 150 The sub is now high above the bottom as the east-ascending ramp is being scaled. Its leads directly on to a near-vertical cliff.
14:08 2681 148 Cross another deep and wide fissure on the way vto the cliff and encounter the bedrock outcrop in the shear west-facing wall. Motor 10 meters up this cliff to its top.
14:09 2670 150 Stop at the rim to sample slabs of sheet flow in place as the topmost strata. Rock Sample 10.
14:19 2670 347 In basket as the sub gets underway. Cross a fissure in lobate terrain still of age 2.0. Moving very slowly. Bedrock outcrop in the wall of this fissure.
14:22 2671 005 As the sub spins CW it crosses slowly over a gaint valley-parallel fissure. The bottom drops away 15 meters in this black hole. The walls are vertical as we both peer down with the aid of the SIT camera to talus in its floor. The walls are masaive bedrock cleaning cut by a joint surface. As we cross this cleft and are now heading SE, the east rim is again lobate flows.
14:25 2681 121 Back on course to Way :Point 5 while re-crossing this same cleft and then on to a lobate surface at the far rim. The lobates momentarily transition into folded and smooth sheet flows.
14:26 2670 121 Then back into smooth lobates which once again are intermixed with sheet flow.
14:27 2669 121 Small open trap doors in the lobates showing them to be mostly void. The surfaces are cracked and sometimes shattered.
14:28 2669 119 Onto a talus ramp and then quickly climbing the rest of the east wall. One sees in the outcrop a superb view of truncated pillows and bedded lavas. The talus here is very fresh with no sediment dusting.
14:29 2657 122 As we rise 25 meters up this face to its crest there is much bedrock exposed through patches of the fresh talus. We encounter a spur that is a thin sliver that has detached everc so slighly from the east wall along a valley parallel joint plane. We head up and over this spurs and arrive on a heavily-sedimented and mixed lobate and sheet lava terrain. Age 2.5.
14:30 2646 118 The SIT camera shows talus 7 meters below us as we look down into a depression scattered with talus.
14:33 2656 082 The terrain below is now pillow and lobates of Age 3.0 as we move on eastward away from the belt of talus.
14:34 2656 081 The lobates are cracked and greatly obscured under a think layer of sediment. We stop to sample from the rim of a valley-parallel fissure. Rock Sample 11.
14:37 2654 356 As the pilot announces that we are "almost out of juice" we encounter severely degraded knobs of former hydrothermal chimnies surrounded by thick hydtrothermal sediments. Not wanting to sample altered rock, the sub maneuvers away from tgis area back onto the lobate surface with occasional pillows.
14:40 2655 171 Heading very slowly south we cross pillows and lobates intermixed with each other and decide to hunt for a digit on a pillow. This terrain is age 2.5.
14:46 2655 138 Sample is in the basket.
14:48 2655 135 Weights away as we begin our trip back the surface. Thank you Bob Waters for the hard work in so successfully sampling these deleciate rocks.