Rarotonga Fieldwork Day 1

Programming three tied gauges at 30 second intervals, one to stay on land, two to go in the water. Maybe one of the harbor and one, hopefully today. Near the beach.

One tide gauge set inside house number five up high.

Taking a tour with Roger right after we got in? Um, took us down to a beach where we walked through. Um. A fully sort of intact. Coral reef. That. Sits above a sort of tabular bench that maybe the early Holocene. High stands, maybe a meter meter and a half above the Lagoon. Interesting, the Lagoon is. Uh, potentially. Flooded entirely by wave action, so the water level is not actually representative of means sea level. Something we want to think about with our tie gauges.

The South Point. Um, we parked at the end of a little road that came off the main road with Roger. And just walking around. It's another sort of beautiful, intact Reef. So much choral diversity. Everywhere you look is a coral likely and growth position. But within a few meters. Five species, easily identifiable. Again, like the other location. There is a lower bench. Kind of half a meter above the Lagoon. Maybe the? Corals in that lower bench look a bit more like breccia, but from standing far away and sort of looking at them. Uh, they're sort of things that look like possum Opera. These sort of branching? Towards corals that are growing in a distribution. Every two meters or so away from each other. Similar how we see we saw in Hawaii in the Lagoon itself, so I don't know if this is. Different sea level high staff is an early Holocene, or is it all part of the same Macataya? Likely less interglacial sequence. Uh, there's no obvious internal stratigraphy of the reef and sort of just quick glance. And the top is just as diverse as the bottom.

To add to that last note in a few places. Now, I've seen this Coral, an incredibly small corallites. So, it's weather is looking very smooth. It kind of stands out with respect to the rest of the outcrop. Um. It reminds me. Of Palmata. The way Palmetto looks in outcrop. I'm curious if that will be a good Target for dating.

Just snapped a photo of one of these upward branching. I'm calling pasta law for a type corals. Like sticking up out of the vegetation at the top of the makatea. It really seems like. As far as I can see upwards, there's a change in like the kind of. Uh, Coral are the kind of limestone that we're looking at. No obvious change in species or. Into Rubble.

The lower surface is sort of polished. It's kind of a braided and smoothed in places. And I sort of suspect it's just from sand seasonally. It was storms sort of moving in and out. Roger had mentioned that there are times of the year. Where sand builds up down here in times of the year. Where it gets. Pulled back out to see.

Move to the leeward side. And stopped at a small pocket Beach. Uh, the same sort of reef structure above, but really good examples of tabular class Beach Rock. Thrown up on top of each other. Thrown up into a modern beach. Mixed with classes of Boulders from. The older wreath.

Tide gauge attached to a rock at the harbor. The Rock has a small white float. Um, it's in the middle of a sand patch on the right side of the harbor as you're coming down the road facing the ocean. Uh, we plan to. Measure the height of the concrete and the offset with the top of the water and use that with a tide gauge measurement to get mean tide level, we'll re-measure the concrete anytime we pass through here over the next five days.

Previous plan for measuring the tide gauge to the water height to the concrete height doesn't really work because the water height moves, and we don't have the exact. Timing the 30-second interval of the tide gauge, so we don't want to introduce that extra uncertainty. So, Roger's going to get in the water. We're actually going to measure the position of the tide gauge up to the top of the concrete, where we'll measure our GPS point. Okay, so?

Plan for when we come back might be to attach a weight on a string and lower the weight down from the wall until it hits the tide gauge, and then we'll pull in the string marking where it was at the concrete, and then we'll actually just measure the length of the string and see how that compares to Roger's measurement in the water.

Roger got in the water and we measured directly from the tide gauge to the base of the concrete. It's a harbor. Um, the first time we did it. We got three meters and 32 centimeters the second time we did it. We got three meters and 31 and a half centimeters. Uh, it was two meter full ruler sighted to the wall with Roger in the water. And then measure down from the top. With Roger putting his finger on this side, it's spots. It was 68 and 68 and a half. Um, that was the additional measurement onto the two meters. The ruler wasn't inverse, so this is where the 132 or 131 and a half comes from.

Right now, the tie gauge, I mean, sorry. The satellite is set with zero pole offset the GPS. We're going to keep that the entire time. Ultimately, everything will get referenced back to the water level from the tide gauges. Um. Where this may be an issue is if we have the? Gps, measuring someone else's control point. We need to remember that we did not put the offset of the antenna. Into the measurement before we compare. So, if we're suddenly two meters? Too high, then it's just the offset.

It's really important. We don't change that over the trip, so if suddenly everything seems too high or too low, we need to. See if someone programmed an offset in their phone.

After a successful meeting with the mayor with a very warm and welcoming. Are the deputy mayor? Roger took us down to matai. We sat as a team and sort of discussed some of the observations and game plan for the day. Uh, waves are very rough and. Uh. They actually crash pretty high up on the beach, so almost lost some bags. The plan right now is to sort of walk the outcrop and try and identify some of the features that Woodroffe. Mention just two different layers a sand sheet between them and at the same time. Also, get everyone a chance to sort of figure out what kinds of corals we're seeing. What kinds of different fossils? Um, to build some observational basis for the rest of the trip.

Observation of a coral. And sort of the upper part of its high near the walk, the entrance near the road. Take. I took a picture with my. Tg5. And. The corallites sort of grow upwards in a feather pattern. Uh. You know, maybe a millimeter to half a millimeter apart? It kind of looks like a Diploria-like coral when I see it from from end on. So some kind of brain coral. Pattern to the ridges between four lights.

The lower part of this unit. Uh, is dominated with a branching Coral that I'll describe now. The branches are. Maybe a centimeter? At at maximum should? Diameter. The colonies can be several meters across in growth position. I took a picture with. Uh, with my tg5. Uh, with a ruler showing that. Um, the corallites themselves. When you see the branches head on you, it looks like a bunch of tiny little rings. There, maybe? Two millimeters across very evenly spaced. I can't quite tell if they have the characteristic end on corallite that you would see in a Acropora. But some kind of upward branching. Colonial Coral definitely in situ! Um, and can be quite large.

Still describing that last Coral. As I stepped back, I realized that the colony is actually. Uh, maybe tens of meters across. It extends all the way down the beach. Um, as. One massive Colony. Uh, and I took another picture, and that only covers about half of it. There's more that extends down towards the beach.

Still describing that same Coral. I don't know if it's a different Colony. But um, the other side of the groove. There's another massive colony of the same kind of coral looks the same, same upward branching.

I'm looking at two new corals in a unit above the large branching Network. I took a bunch of pictures of these corals. They're side by side, which helps. Sort of key in on the observational differences. The one on the right? Sort of, uh? Circular, maybe 70 millimeters, 0.7 centimeter. corallite Chambers. All sort of lined up like a bunch of circles next to each other, like a honeycomb. And in cross section, you can see. Uh, a pretty distinct vertical. Uh, Network separating this sort of little horizontal Chambers. Coral is in growth position. Next to it is a coral with extremely small. Uh, kind of the same pattern, so we have these. Vertical. Rides with. Horizontal. Chambers, but everything's just much smaller when you look in Dawn. You can see that same sort of a bunch of circles next to each other honeycomb, but these are about a millimeter. Maybe two millimeters in diameter? The smaller corallite Coral. Weather is very sort of smoothly to touch. There's the other one is a lot more. Some holes of jaggedness coming out of the rock.

The smooth Coral seems to sort of wrap around. little nubs of high topography, maybe encrusting along the side. So also. At least in the location I just photographed. Really heavily. Punctured by Christmas tree worm. Or some other kind of attaching. Organism took a bunch of pictures of these holes that sort of penetrate through the coral. Maybe at the top of some of these, there are. Uh, sort of big encruster colonies. Lots of super dense carbonate cement and. Just kind of looks like a jumbled mess. Uh, reminds me of things that we saw in the Barbados Reef.

The upper part of this outcrop is, I mean, almost everything is Coral. It all seems like part of the framework. A lot of this really small, corallite Coral. I just took another picture. Of this side-by-side relationship with the other sort of larger honeycomb Coral. The honeycomb Coral. Is maybe in this case, 40 centimeters across, and I've seen a lot of similar sizes. Um, but it's sort of sitting in many, many meters of this finer. coral, where you can't really see where it starts and ends.

There's another Coral here that has. This sort of um? Honeycomb type look this? Circular circles next to circles. Uh, but in this case, the corallites if I'm using that word right, or maybe three millimeters across. So, it's this. Intermediate between the really large ones that I previously talked about and the extremely fine grained coral mass that makes up most of the outcrop.

In general, the coral I just described is smaller, so I see it in patches of 10 to 20 centimeters at a time.

Pretty consistent feature of the outcrop in general. Is that the? Branching, large framework corals I talked about early on. I'm not really present in this upper unit. It could be that they were only present in that initial Groove that we walked down. And maybe in another Groove. I would see them again, but I see them every time I get down towards the beach. And when I'm up a meter to, I don't really see them very much.

Just took a picture of another Diploria-like coral. I think it's very similar to the one I first described. The weathering is a little bit different here. I may want to check in photos if the. Scale is the same sort of the the size of the chambers of the. Um, width of the corallites as the one I described and photographed earlier.

I'm trying to see a few pockets of the branching Coral or at least something that looks very similar to it higher up, but they're not the massive colonies that I saw below. Just took a picture of one that sort of angled away from the beach today. But the whole colony itself is maybe 40 centimeters wide at the at the widest.

I'm taking a close look at. Coral that looks a lot like the one that I've been calling the smooth coral. Uh, maybe this is just a different weathering pattern or expression. I just took a few photos where you can really see. These sort of circular? corallites walls. Uh, kind of poking out with sort of a positive relief. I can't quite tell if this is the same just sort of the top end view of the one that looks incredibly fine from the side.

At the same location as you go down. Towards the beach. We find the same massive colonies many, many meters across the branching corals. So it doesn't seem like it's necessarily connected. The groove we were in, and it might be sort of a vertical or lateral position of the reef.

A bit higher up here. There is another. Branching Coral. I think it's distinct from the one below. Because it has this sort of half centimeter width to the branches. The actual texture of the coral is reminiscent of the smooth one, so there's this very small corallites. It have sort of a positive relief relationship with the structure. The Colony itself is only about 10 to 15 centimeters across. Just photographed it.

Just photographed an interesting sort of modern feature. I'm sitting in a pile of sand that was likely pushed up. Recent storm or large waves? And it's sitting in a little pocket. And along the walls, where you can clearly see the the sand is deflated a little bit. There's very distinct tannish cement along the walls. You've seen this in other places where sand sort of sits on Limestone, and it accumulates rain, water, or sea spray, and then you get this sort of heavy cementation at that contact.

Just photographed a view in a little Gully where there are breccia clasts that really appear to be part of the old outcrop, but it's actually quite, um. Possible that this has been cemented in relatively recently.

Photograph of Billy taking notes. With giant waves crashing in the background in the South Point of ATU in the distance.

I have been looking for, but haven't seen much evidence of coralline algae or green algae. Um, either I'm missing it. I don't know exactly what I'm looking for, or it's not here the same way that. I saw it snorkeling the other day.

Another photograph of the smaller branching Coral, one with the smaller branches and the texture that is reminiscent of the. Coral that I've been calling the smooth coral. It's surrounded by a bunch of Diploria-like coral and some of the smooth core itself.

A few more photos taken of the large Colonial branching Coral at the bottom. Upon close inspection is very likely. It's the same as the tiny ones. The small 10 centimeter wide colonies from above. It's the same sort of positive relief. Very, very fine structure. And just depending on weathering. Sometimes the branch is like half a centimeter, and sometimes they look a little bit wider. Could be that it's two very similar species, the ones wider and one's thinner. It's hard to tell.

This lower branching units lower/seaward. Upwards, transitioning slash landwards transitioning into. More of the Diploria-like coral and smooth, large encrusting corals. This General stratigraphic pattern holds all the way out to here. I've got to turn back towards. Where we started. I haven't seen any kind of clear Horizon or. Um, Hiatus or sand layer that separates the two. Elevation of that contact does seem to vary, maybe at least like a meter. All right, we'll have a better since, uh, when we map it out with photogrammetry.

My interpretation of this region is that basically, we're standing on the MIS 5e equivalent of what the slope would look like today, where the waves are crashing. The top is mostly. framework boulders of coral, just all growing on top of each other and then deeper into the slope. You start transitioning into these large networks of corals much the way in the Caribbean we might see. Mostly Staghorn Coral at The Reef Crest and a lot of Stony Coral transitioning down into. Elkhorn Coral Circle. I don't think I'd stay home and stuff there, but so if a corn has lowered down. And Armada higher up. Nothing like the Palmata in the upper part here. Um, I don't really see any branching corals, and I wonder if that's just the wave energy the environment's too high? It was a very high storm side of the island. Is the Rough Side today. It's likely the rough side in the past.

Large Diploria-like coral block up on the road, just photographed likely was very close to here in its original position. Probably this boulder's been moved a little bit, and it's really massive, so. You know, an excavator that made the road might have moved a couple meters, but it doesn't seem like something that could be transported up here. There are other corals in the photograph. I mean, there's the sort of larger honeycomb Coral as well as potentially some branching corals that look sort of like finger Coral. Maybe the same as the branching coral we've seen everywhere else here, but? Uh, this is way up on the road elevation's quite high. Potentially in situ. Just good to have for some context.

Directly across the road from it is a similar piece, so unless in constructing the. They move two pieces of the same stuff into the same place. Um, seems that there's a chance that. We're actually at the road still within the reframework.

Just flew HS101. This is the matai section. We set out a bunch of gcps, collected some Coral samples from both Horizons. Uh, flew the Drone. Around 49 feet up. Uh, one pass. Sort of across the outcrop in sort of the orthogonal to the ocean. Direction. A second pass at a high angle, kind of flying over the ocean, looking back at the outcrops. Um, lower, maybe 20 feet 25 feet, and then a third pass really high at 150 feet. Uh, parallel to the shore.

Also note the first battery, which was the Lamont battery, worked just fine. The second battery I put in, which is one that I brought from UVic. Uh, it went in and looks like it has full charge. When I tried to take off the Drone, it said battery. Um, battery malfunctional. There's a cell broken. Take it in for repair, so I'll mark that one as not capable. The next battery I put in was fine. I don't know yet about the last battery.

HS101, gcp3.

HS101 gcp5.

HS101 sample a?

HS101, gcp7, and Sample B.

HS101, sample C.

HS101 sample D?

HS101 gcp1.

HS101 gcp12.

HS101 sample e?

HS101 gcp4.

HS101, sample G up on the road, maybe? Only in the last pass of the Drone flight Boulder that may or may not be in situ. Similar to the boulders that I described earlier when walking on the road.

HS101 sample F also on the road, also part of. Boulders that may or may not be in situ, but very likely still in situ, just with Road kind of piled around them.

We're still wondering whether or not the road is actually around the elevation of Woodroffe sand layer. Just behind the road. There's a hill covered in vegetation. That's another at least six meters higher than we are. Um, so we might try to bushwhack in and check it out.

The topography I noted before is actually just the canopy, so we walked through. The scrub, and then it actually opens up underneath. And it turns out that the small vegetation near the shore when it gets away from the shore actually becomes quite tall trees.

HS102. Is that Tuaroa? A little walk down from HS101. The waves are really crashing, so we're gonna stay pretty close to where the road comes through. We can't quite work our way up and down the outcrop, uh, without risking ourselves. Um. The geology, the the Rocks themselves. We have sort of the same diversity of five or six main Coral species. A lot of the? Um. One. We were calling the smooth coral or. Uh, that I described earlier. That's probably a Porites lobata-like coral. Not the same. Obvious thickets of branching Coral below. Um, there is a table. Maybe an erosional Terrace that's just a little bit above the Lagoon? Um. Sort of sticks out a bit. That'll try to get in the Drone photographs if the rain lets up here. Uh, we're gonna just work this out pretty quickly to get some ages and some elevation measurements so that we can compare to Woodroffe.

Photograph of what kind of looks like a pipe more upward branching, large coral with one to two millimeter size, corallites with very thick thick, all right. So we're looking for another.

Describing a coral that I don't think we saw very much of, if at all, at HS101. So, at HS102. Sort of. This upward branching makes me like organ or pipe more corals with. There's several centimeter wide. Uh, vertical columns. I think they're weathering out. I think it was like a pipe that was that wide, with some gaps between them. The corallites themselves, sort of, make up the walls of those columns, and the corallites are only about a millimeter or two millimeters wide.

The width of these colonies. These pipe morph colonies in some places here are over meter, maybe?

There seems to be a tabular or encrusting form of a coral here with a very, very small, corallite. Uh, took a few pictures. Um, showing one of these tabs. It's kind of wavy and undulating and has. Clear boreholes through it. Uh, it's sort of sitting on top of colonies of other corals. And maybe it represents the end of coral growth of this spot. Also seems like there's a breccia immediately above it, so maybe this is the contact between framework and infill?

HS102, the weather is not cooperating with us. We're not going to fly the Drone. Or really take pictures with the Nikon. It's a little too dangerous to work with some around the outcrop, with big waves crashing on it. So, we're gonna just put the GPS on the coral samples. Maybe make some measurements kind of high up at the top of the makatea and call it a day for h102 Tuaroa Beach.

HS102 sample a brain coral?

HS102, sample B, also a large Diploria-like coral.

HS102, sample C. Uh, it's not a Diploria-like coral. It looks more like, what maybe Porites lobata-like coral? Or the smooth coral.

Hs102d. Also Diploria-like coral.

There's a path down here to the water and rocks that are quite nicely exposed. The topography a little bit smoother overall than HS101 and 102. But still a lot of framework Coral all throughout the same sort of bench that maybe? The possible Holocene erosional feature is present.

The first stop is at Cook's Landing or Oravari Beach. Woodroffe has noted that there are sheets of sand that sit on top of in situ reef here so we're starting to look for that. I'm just sort of observing the lower reef unit right now and there's really really beautiful example of brain coral that then gets colonized by an encruster that then has a branching coral growing out of the encrusting coral and more branching corals to the side and then it all gets covered sort of in reef rubble and sand and you've got to take a few photographs.

The pockets are layers full of sand and plasts. They're not continuous horizontally, sort of at one stratigraphic horizon. They seem to be patches. And the sand itself is quite coarse and very angular. A lot of flat sort of tabular pieces of sand that I'm kind of assuming are actually like algal fronds or some kind of algal blades. It may be a little under a millimeter thick and two or three millimeters long.

The coarse sand sheets do show some evidence of ripples. We have cross beds and sort of tabular sets of 10-15 centimeters. Sort of sitting in a lens. Not a lot of cross bedding, but in some places it sort of sticks out.

It does seem like the branching corals can get transported in whatever environment this is without breaking up too much. Just took a photo of two that appeared to be upside down floating in a sea of sand.

Stepping back from maybe 20 meters from the wall, you'll get a nice perspective of this sort of undulating framework reef surface that then gets covered in this really coarse and sometimes cross-bedded sand. There are even like little pockets for the sand sort of filling in the topography of the coral reef. And in those pockets you see more cross-bedded and then you go up into this maybe one and a half meter thick block of sand that's kind of sitting as one sort of table, not a lot of cross-bed, it's quite massive.

Just snapped a photograph of that relationship I was just describing but up close where you can see almost a meter of positive topography on the reef and the sand is sort of draping and unlapping it on both sides.

It's clear towards the top of this sand layer that corals re-colonize the surface. I just took a picture of some massive 1 to 2 meter large stony corals, even with some sort of branching and pipe morphs on top. What are they sitting on? They seem to be sitting right on that sand surface of that bridge. So, the possible interpretation is that somewhere in sort of a low point on the reef, where you dump a bunch of sand, maybe on a cyclone, it gets colonized first by encrusters that make a hard ground, and then the corals come in after and we establish the surface.

The coral rubble and sand layer persists well into the jungle away from the coast. It doesn't weather as nicely, but it seems like the same environment.

I walk north to another beach. It's unclear. I didn't see anything distinct from where we were at Cook's Landing and Cook's Landing at the best outcrop. So we'll probably work over there and maybe skip from there back up to the harbor later today.

HS103 Cook's Landing summary observations. The lower few meters is mostly a coral reef framework, high diversity similar to what we've seen at other sites, lots of stony corals and branching corals and brain corals. The top of that surface has a considerable amount of topography with growth position corals on the top surface and then get buried in a sometimes massive, sometimes cross-bedded coarse and angular sandstone with increasing amounts of coral clasts and breccia blocks as you work your way up. So it's quite sandy right on the contact and then it becomes more coral filled upwards. After about a meter and a half or two meters you start to get growth position corals within the matrix of that sand sheet. So it's sort of hard to imagine what that environment is. Maybe it's a little bit more like a lagoon where the corals are able to establish themselves on a hard ground around the sand and then they grow for as long as they can before they get buried again. There's still a lot of sand laterally from these growth position corals. There's no obvious top to the section walking up into the woods. It seems like a lot of the same stuff as far as we can see up to the elevation of the road. No clear change in context.

Interpretation note, the topography near the coastline is incredibly rugged. This could be modern erosion, but once you get up into the jungle, it's extremely flat. So one thing that might be possible is that we're actually looking at the edge of the reflat and the jungle itself is the reflat, but we can't really see it because it's buried in soil.

HS103 drone flight took about 75% of the battery just finished.

Really stunning view of burrowed crossbed sitting on top of mountains of coral. Just really well exposed here.

HS103 GCP8.

HS103 brain coral sample potentially not in growth position does not yet have a letter.

HS103 GCP4.

HS103 GCP7.

HS103 green coral sample potentially. I think I saw people working here clearly examples but removed the bag is gone. Check with others.

First unknown sample at HS103 will be D as in dog.

Standing at HS103 sample B.

HS103 GCP3.

HS103 sample C, varieties.

Second unknown sample was B.

HS103 GCP5.

HS104 is Tangeroa, or the harbor. One of the walls was excavated only two years ago. This was a really nice natural experiment in preservation. Preparing this wall to the older walls, the way that the corals and organisms that have encrusted and colonized the corals. The way that they look and show up in the algorithms can be different. The fresh faces in some ways are actually harder to see. Sort of coral textures and corallites, but it's easier to see things like Christmas tree worms, giant clouds, and crusty places.

Of fresh? Sitting on top of patches of sand? Direction of the coral fragments. Really looks like a mess. Hard to tell how much it is. It's all kind of connected enough that you can't be just a pile of. Um, the encrusters extend along Horizons, not flat Horizons, but? This is my vertical Horizons for many meters, suggesting that there's some coherence to the entire. System and above the encrusters. There are these delicates or ring coralline algae. Um, and then pour sound.

HS104. The lower part of the outcrop definitely has more large Coral colonies, likely all of them institute high Coral diversity. The upper part, which looks like the jumbleness. My vision or my conversation is actually at any point in time. This was a hard surface. A piece of rubble falls off or gets trapped here and pretty quickly. Razors and encrusters different organs. It's kind of cemented in place and the reason I'm saying, that is, I actually see lots of delicate algal material and. Very small, delicate corals seem to just be part of this jumble without getting fractured or fragmented. So, if I have a couple meters of accumulation, you know, maybe adjacent to higher parts of the reef or just sitting on top of? A happy part of these have died out here. There are some larger corals in this upper part. Um, sometimes up to a meter or two across. But they're less common than down below where it's almost the entire outcrop. It's very likely this is exactly what we were looking at over at HS103. But. The fresh face, let's see. It's sort of in a new way. It's not the same sort of sand layers we saw in HS103, so it's a little less Sandy.

HS104, the harbor. I flew the drone without the ruler out. So we just have to rely on the scale of the drone points.

HS-104B.

HS104 GCP5.

HS104 GCP5.

HS104 sample D.

HS104 GCP7.

HS104 GCP8.

HS104 GCP8.

HS104 GCP.

The Makatea higher in the jungle, so inland. Still clearly is marine, they're coral fragments. It's so weathered that it's really hard to see much, but when you break open pieces you can see that there are shells and corals and maybe some sand. It's so heavily recrystallized that on the inside you mostly just see crystals. But if you really look closely at the weathered surface and a few places you can see corallites sort of standing out. There's no obvious notch or sort of feature on the front end of this higher Makatea to suggest that what the relationship is with the units that we've been studying closer to the coast.

Drove a road from town to the northeast, right at the end, stopped at the landing. Very steep path down to the water, but it's accessible. Massive framework coral reef with huge Porites. I'll take a photo here in just a second. And additionally, along the coastline, there's a notch, sort of three, maybe one to three meters high, that maybe the early Holocene high stand, we've seen sort of the same elevation in quite a few places. The landing is called Tarapaku.

Two photographs. The first is of the massive Porites colony. The top of it is colonized by encrusters, full of borings. They create these sort of crinkly laminations and sort of go around the entire coral colony. And then above you have sort of platey thick encrusters and branching coral, smaller stony corals. But up to the right there's another large colony. This just feels like a massive framework reef with some really large and happy corals. Second photograph with Billy for scale shows the notch that I mentioned that maybe early Holocene. It could be an erosional feature. You can see it down the coast in a few places and I'll try and capture it with the drone so we can really test whether that elevation matches the tables that we've seen in other places. This is a good site to collect maybe a GPS point along the modern notch. If the GPS will be able to sort of see the atlas configuration from this cliff face.

A few underwater photos I just snapped of three corals that started growing on the reef flat or the back reef flat, whatever we're calling it, sort of a very flat elevation table, sort of surrounds up to you. I wonder if there's some kind of varieties. They're very fine, small corallites.

capturing a bunch of photos of the reef flat including really spectacular microatolls and Halimeda and a whole bunch of species probably some of the Pocillopora but I'll just have to try to identify them after looking at the photos later.

Tilly asked a great question about the paleo environment and we looked at the ground we're standing on which is actually full of grains and shells that broke out up into coral and sand but it's hard as a rock so it really seems like this surface probably just fills up to the lowest water level and stays here and the corals are all short-lived, they die, they roll around, they get cemented pretty fast and reflected on whether the environment we're looking at in the reef yesterday at the harbor whether or not that surface could have accumulated in a much the same way like at any point in time it was all hard because cementation happened so fast.

The flat microatolls in this reef flat, actually an excellent sea level indicator. And hypothetically we would see them in our crop just like we had at the harbor. At the harbor we never saw that growth form or that context of the corals. But we should keep our eye out in that kind of environment where you have high coral diversity, sand. And if suddenly we see a bunch of corals growing horizontally and they're not very tall, then we might actually be at sea level. So maybe we don't need a beach in Phanestra to get a precise sea level indicator here in the Cook Islands as I was sort of pessimistically thinking yesterday. If we can find the right morphology of coral in the upper unit, then we might actually also be exactly what we need.

This site is HS106. The stop at the Ha'ai Makatea yesterday. The old stuff is HS105.

While it's hard to tell, there are corals even high up along the vegetated part of HS106.

HS106 GCP7.

HS106 GCP5.

HS106 GCP1.

HS106 GCP3.

HS106 GCP4.

HS106 summary. Lower down, large intact, very large meter scale, corals. Many photographs early on from here from the site. In the higher part it's a lot like the harbor. We have smaller corals, encrusters, all kinds of sort of reef framework material, but nothing, no really large colony, so we see a lot of our still sub-meter scale corals. We poked around in the very job trying to find evidence of any kind of flat, micro-atoll style growth patterns, but haven't seen that.

Last GCP at HS106, the GCP was collected before the point was taken. We've tried to get it about in the right spot, but it might be a little bit off. Just keep that in mind when doing the photogrammetry. Maybe you need to untoggle the final GCP using the time-step with the GPS.

It was the GCP near the ruler.

A quick stop in the woods to see a boulder that we could see from the road walked out to the cliffs and sort of at a place where the shelf is basically even with the cliffs and you can see these nice sort of constructional terraces where the waves crash much like what I've seen in Barbados and a few other places with highway energy right up against the tidal notch. I took a photo deep water right off to the north a very flat top to the unit and a wide sort of open plain flat shelf so it's just this narrow little bit here that doesn't have much of a shelf.

Looking down from the cliff onto the shelf, you can see very very large coral colonies. Green and yellow and brown and red. Tens of meters of cross.

From the road stop I walked north to where you can see a very broad exposure of the reef flat, the back reef flat and then there's really large microatolls that you can see from the top. They really stand out, they're beautiful. No clear way down. There was a rope tied off so maybe people climbed down but it seems a little unsafe even with this relatively mild waves today. The cliff face is really impressive just a shear drop all the way across.

The top of the cliff as far as the eye can see in this direction is just as flat as can be which really suggests that that might be the paleo re-flat.

HS107 Tarua T-U-R-U-A. First sense is that this is the flat table that we were looking at from earlier this morning. It obviously has more topography when we're standing on it but a lot of corals, fairly large corals, very steep cliff, not a lot of access down to the water.

Large in situ giant clams.

After walking HS107, just some observations, lots of articulated tridacnid giant clams. Other bivalves and gastropods are certainly abundant. Tons of coral, really all the species and types we've seen so far, even different forms, are all in situ, often sort of meter scale clumps of stony corals separated by these little canyons or valleys that run towards the ocean. There are corals that are sort of lined up with that same orientation. So something Billy called pseudo-palmata because of how it grows seems to be lined up in the same orientation as these little gullies. At the gullies, there's a lot of breccia and sort of corals that seem to be growing into the gullies which suggest that perhaps they're primary, so primary topography on this old surface. Of course they could be modern and just falling in place and cementing. It's hard to distinguish the two. The way that this outcrop weather is really spectacular. You can really see all of the features of the corals. It's pretty tough on the boots though.

HS107 GCP7.

HS107 GCP5.

Scratch that seven samples collected.

Three samples collected.

HS107 GCP7.

and a clam shell for Daryl Kaufman.

Before we started, Wanna said we should collect less samples and then she collected seven samples totaling 5,000 kilograms.

HS107 GCP.

HS107 GCP4.

HS107 sample B.

HS107 GCP.

HS107 sample C.

Take a quick trip up to the quarry. The road is blocked by a gate with a lock, but we had permission to go in so we went around on the right side. Pretty heavily recrystallized, sort of all the way up and down, lots of flowstone and sort of the deepest part of the hole. Very large brown, probably calcite crystals. Throughout the rest of the stratigraphy, even though it's really heavily recrystallized, it almost looks like a white micrite. When you get your eye in, you can start to see lots of reef texture and corals. I just took a few photos of a coral up close.

Stopped at the 5e record slash Holocene record on Rarotonga. Nothing really surprising. The corals look pretty banged up like the Gischler paper said. Slow tide so we can get out and walk on the flat. Not seeing anything in growth position or in situ. It's really hard to tell the surfaces very weather. Not some great coral, maybe 30cm, 40cm size blocks. Not sure if they're in situ, they're probably rubble.

Very large corals in the tidal range. They get hard to imagine this as entirely rubble. They could be early Holocene. Again, no clear in situ corals. Took a few photos of the organisms sort of on the surface of the probably vermetid constructional terrace but the flat low low tide mark.

There is a prominent notch, it's probably the modern notch, not even a Holocene one. It really seems like we're here right at low tide.

Photographs of Jacky standing above some upward cupping forms that maybe growth position corals hard to tell but certainly something interesting about the way the rock is weather.

A bunch of photographs of the green algae, how they made a type and a finer one. Some circular organisms that I think are probably some kind of an anemone, they're just in the closed up state. And then out towards where the waves crashed, sort of orange, brown color is some kind of plant or algae. The utility had brought a piece from a Tarapaku landing. We looked at before it and this seems to be the organism that lives in the edge of the foreground here in the Mississippi.

A conspicuous upward branch in coral is that one of our suggests of a big in situ.

photograph of an encrusting coral exposed at low tide today which probably isn't even lowest tide of the year. It's sort of remarkable that these organisms can sustain themselves in these varieties.

Photograph of water draining off of the? Anyways, I took some photos of the. Water running off as waves, similar to what we've seen in India. So, it makes me wonder that. If this was a stormier environment which you have essentially deeper channels here?

A few more photographs of corals that I have decided to make their home here in this sometimes exposed and never buried the environment.

There's a boulder perched on this flat. I wonder what kind of storm I brought back.

It really seems like there's just too many upward branching corals in this unit for it not to be some kind of in-situ reef slash reef hardground system.

A bunch of photographs of worm tubes, sort of at the bottom of the tidal launch. Likely some kind of vermetid.

A little higher up in that tidal notch, there are some kind of chitons smaller and a bit more cone-shaped than the ones we see in the Caribbean.

I can't quite make out exactly what I'm looking at, but when you step back from the tidal notch, there's this sort of light and dark banding. Makes these scalloped or circular shapes. The white up close is clearly some kind of cement or fine calcium carbonate. The dark, you can sort of see the grain texture of the underlying rock. Maybe these are some kind of feeding traces or something else that I should have with the organos that live here in the tidal zone. I don't see it any higher.

Photographs show some large brain corals. Unsure if they're in growth position or in situ. Associated with the coral sort of around the outcrop here there are a lot of these. I don't know like tabular and a flat maybe four or five centimeters thick plates. It's not exactly clear what they are. The carbonate doesn't weather very nicely and I don't have the hammer but they are at least reminiscent of some of the encrusters. The things that we've been calling encrusters in other locations.

Close-up photograph of one of these tabular blocks does show that there are corallites.

Roger Creel stands on the tidal bench looking at potential MIS-5E outcrop here on the road.

Hard to tell without a hammer and looking really closely with a hand lens, but it really doesn't seem like this outcrop has much sand suggesting that we're likely closer to the wave break. The corals are small enough that it doesn't feel like something we'd be seeing off the edge of the shelf, like the lower parts on Atiu, where we have really large corals, which is probably deeper water. This feels like a really shallow outcrop in encrusters and sparse corals that are probably in the position that they grew in. It's too high to be early Holocene. It really feels like it has to be a MIS 5e.

been looking pretty hard for coralline algae or other sort of delicate coral organisms and I just don't see it maybe broken up bits of it but nothing that seems in situ.

Upward branching corals seemingly in growth position are abundant throughout the outcrop.

There's definitely some sand in the system. Just took a photograph of clear crossbedding up above the tidal zone. Roger points out that this is quite reminiscent of Cook's Landing and I agree with that. The paleo environment. Sand here and there, a few crossbeds, but probably at any point in time this was a pretty hard surface. You could walk on without sand moving around. The corals and the encrusters are just doing whatever they can with the tiny bit of accommodation space they have.

Worth noting, discussion with Billy and Roger about the origins of the lower bench. We seem to quite like the idea that maybe that actually is the early Holocene. It could be in the right spot. That would support the idea that the outcrop is MIS 5e. But Billy challenged me on why I think it's 5E and other than elevation and context, which is, you know, guesses at best. I said, well, because it looks like shit. So maybe that's not the best conclusion, the best observation.

Double check the timing of the tide. If we're actually standing here at low tide then this notch could be modern but if we're standing near a mid to high tide it's very likely this is the Holocene notch sitting in a MIS 5e outcrop.

The code is 2015.

Rocks are stored in Locker 90. When you pay they give you a code and a locker.

They actually only charge us 7 per day.

Drop truck off on Friday around 8.30 a.m. at Pickering Motors and then they will give us a ride over the airport.

Perch beach rock just above the tidal flat and the harbor likely early Holocene. Closer to the harbor, it's across the large colonies of Branch and Coral. Suggesting that that's MIS 5e. The two are sort of sitting right on top of the trail here.

photograph of a coral at least pointing upwards maybe in situ on what's probably the 5E flat.

Second interpretation here that seems more likely is that the whole sequence is conformable. It's Holocene, early Holocene flat, then just kind of sideways transitions into a beach. Just a photograph, kind of a gal ashore with a little bit of sand left. You can see that sand trover hanging out into the spot. Just imagining that what you're standing on is the early Holocene movement. Let's see how this should look.

The photograph of the nearly two-year diameter branch and coral colony in this lower early all-in-tidal flat or fringing tidal flat.

We decided to place the tide gauge in the harbor but on the far side where there's a shallow bank We'll walk and put it into one of the holes in the bank and attach it to a rock and then measure the tide gates directly with the GPS.

Tide gauge placed in the water, a couple photos of it.

The road is a little bit rough but we can get to the end after the shipwreck with this high clearance truck.

Towards the end of the road there is a place to back the truck in so you can turn around.

Finally at the end of the road looking at the outcrop. Maybe 10 meters above sea level above the bench. Just an incredibly dense reef network. Probably more coral diversity and density than anything we saw at H2. The outcrop is full of these channels that run to the sea. So you can see it's really nice and satellite imagery. And I just took a photograph of the coral that tends to colonize the inside of the channel. It lines itself up oriented direction towards the sea. So they sort of form these linear ridges towards the sea. They sit mostly in the lows in the edge or sides of the channels. And branching corals tend to populate most of the top of the little ridges.

This site will be HS109.

Four photographs just show the quick survey of the diversity of the coral species in about a one-year radius.

Overall, this outcrop feels deeper than a lot of the environments we looked at on the end. And I say that because I'm not seeing thick sort of encrusters and worms and bores, the things that sort of colonize the coral. We're not happy. Something that we would see quite often in the back reach. There it really is, just coral on coral on coral on coral. No sand either. At least not clearly. Large amounts of sand.

A couple of photographs of stunning upward branching coral colonies that line the front slope. This is where I need to slow the line.

A nice rainbow marks the equation.

photograph of Billy and Roger standing on the next cliff above the coastal cliff and there's two faults or at least cracks through the rock sort of pointing up at them those cracks may be the large linear features you can see from up above in the drone.

The unit just above the road is a heavily recrystallized grainstone.

HS109, six coral samples and a Tridacna which was labeled C.

HS109 GCP3.

HS109 GCP7.

HS109 GCP5.

HS109 GCP1.

Each has 109 keys in pieces.

Photo caption, the team is searching for more coral inland at the base of the next cliff in a very sharp terrain.

HS109G sample.

Beach access at Araoa.

The walk down to Araoa beach goes to a narrow slot in the coastal 5e outcrop. The outcrop itself is full of very large spectacular corals. It's a large coral framework reef so much what we've seen before. As you get closer to the water you start to see things within the sort of sea cave slash cave erosion of the cliffs that look like Holocene corals and sands. They come up to maybe a meter and a half or two meters including lots of varieties. Kind of seem like they're stuck on top of the sort of reddish cave cement flowstone.

photograph of a drilled Porites in this sort of notch cave rising.

Porites really high up sort of in the cave proper probably four meters maybe three meters above the ocean today still kind of has this relationship that suggests it could be filling in the cave but I'm starting to doubt that it's Holocene maybe this is just a funny weathering feature to to to follow me problem.

Two photographs of a course sort of plating grainstone that's sort of at eye level near the top of the cave part of the Aroa outcrop.

Roger standing on sand and grainstone just not lithified yet and at his shoulder level behind him is the grainstone that I just photographed. So I do wonder how much would it take for that surface to just be a few meters higher.

It really seems like the sequence of events here. The cliff must have formed, followed by a low-stand tree where you could make the cave, maybe it doesn't have to be that low. And then you've filled in the cave slash, a rosional feature with more corals in sand. The options are the cliff is 5E, the cave happens during the time between 5E and the Holocene, and all the infill is Holocene. The challenge with that is that the sand and corals go pretty high. The other option is that the cliff is actually an older interglacial and the infill would then be 5E. And a third option would be that all this could somehow happen within 5E. So you have a high stand, you form the reef, you drop the sea level, form the cave, you bring sea level back up within 5E, and flood the cave and grow some more corals. The drilled coral that I took a photograph of is likely Gischler's 125,000 year old coral at 2.5 meters. If that is true, then the infill is 5E, which sort of rules out the Holocene version of this story.

Jacky points out that a possible explanation is that the coral that was dated or drilled fell into the cave off of the wall and then got cemented in place which would allow the young age in what's actually a Holocene deposit.

The darker patch of coral in the photograph may be the early Holocene, a tiny little reef that persisted behind its big boulder.

This unit has abundant upward branch and corals and flat-lying sort of plating and cresting corals.

The drone flying strategy at HS110 will be first to do a simple pass of the front face where most of the GCPs are. Then I'll try to do a more complicated pass in the cave where I'll walk with the drone to make sure that I don't hit anything.

The sampling strategy here is to collect a few pieces from the front, maybe even this really Holocene patch that I photographed earlier, and then work our way both up and back into this access point. We'll test some of the various hypotheses we've discussed so far. Wanna might also take a sample of the coral that's already been drilled so we can see if we get 125 for that sample.

Drone flight complete. Did a couple passes on the outer wall and the beach landing and then spent quite a bit of time trying to get at least the lower part of the cave but the upper part where I think the last sample comes from will it's just not constrainable with a drone. I used about one and two-thirds batteries.

HS110GCP3.

HS110GCP7.

HS110 is locally known as ARA-OA. A-R-A-O-A.

HS110 sample B.

HS110 sample A.

HS110GCP5.

HS110GCP12.

HS110, not GCP, sample C. It's the same sample that was drilled previously.

HS110 sample E as an elephant.

HS-110 GCP-1.

HS-110 two high samples, one through what looks like it may be a Porites that has a core that has been drilled sort of in the growth direction. That took a photo of that. And then a second sample that came from the very large brain coral sort of around the backside. So, that's it. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide. I'm going to go back to the next slide.

Photograph of Jacky with the chisel about to take another sample of a brain coral that's somewhere between E and the two samples like previously mentioned that we're higher up.

Second type gauge measurement after lunch.

Billy Manson GPS while the crew finishes dinner at the harbor. Not dinner lunch at the harbor.

HS-111 Ivirua follow the road through town and then there's a small turn to the left. It's a little bit steep right when you turn down to come off the makatea and the road is pretty smooth again. Park at the end of the road there's a ladder and steep slot canyon through the high cliff down to a beautiful flat full of tons of small, what looked like micro atoll from above. I took a few photos of that and a few photos of the access point.

First impressions of the outcrop is that it's. Um. Framework Reef. I walked over a bunch of in-situ growth position, large corals very reminiscent of one of the early stops on. Uh, at you.