Tony Coates, Jeremy Jackson
NPR/NGS Radio Expeditions
26 Mar 1995
- Rio Yape
- 8.06841 -77.31982
- SONY TCD-D7
- Sennheiser MKH 30
- Sennheiser MKH 40
Stereo=1; Decoded MS stereo; Sennheiser MKH40 Cardioid Mid Mic and MKH30 Bidirectional Side Mic
DARIEN Logs Dat #4
MS -stereo --Sennheiser 40 & 30
0:01:45 - 11:33 ****Preparing to leave from Union Choco ...Boat revs up motor and takes off.....3 good boat passes (second one is distorted, 3rd one too), SS: need to take all of the above and make one good boat scene:
revving the engine, taking off in the dugout canoe, steaming upriver no need to find a fade point
12:41 AC: This is the second day of our exploration. We've come up the river today by boat -5 kilometers upriver from the village where we stayed, and we've come to the mouth of another small river, the Capite, a village of Indians, the Wunan. We've stopped here at a little place where some people are working on some boats, look like dugouts, look at the map see where we are and what's going to happen today.
13:30 TC: Both a problem and an advantage is the fact that the river is extremely low, even for the dry season this an extremely dry, dry season; and as a result we have difficulty getting around in the rivers even the main arteries, the main roads for the Embera in the Darien. We're going to take a little bit of an advantage in that we've noticed coming up several exposures of sediments that might contain fossils that are above water today, whereas they would never have normally been above water before and we've never seen them before...so we'll take a look at those on the way back. So basically we'll work our way slowly down the river stopping at a number of exposures and discussing what we find there and implications for our interpretation of the geological history of the Darien. Biff Bermingham will collect fish from this river to compare with those he's been collecting in other rivers, and he will be trying to work out the consequences of the geological evolution to the migration of fresh water fish through the river basins of the Darien. 15:04
*** 25:30 -35:00 FX Canoe drifting downriver no motor
FX -Drifting down river by dugout canoe -with no motor ....Leo: audio landscape.... Most of it with kids swimming in the river. Good where boat is rubbing against the bottom, and the boatman is poling.... one place where a fly goes by, then sound of oar pushing against the rocky bottom of the river.... (before kids go swimming close by -then Leo turns the perspective -baby begins crying..... Gets good with more of rushing river sound, poling, less swimming kids -more birdy, (then no good..... leo chatting)
Get out of the dugouts .....scientists at work in the field FX -*** 37:20 -37:32 hammering (Very short but good hammering) AC -You just picked up a log like section and it split into 10 pieces.... JJ and TC: It's no good....water gets in and eats away fossils ..... . TC: So the whole point of doing a river is....a river is rapidly eroding through whatever the bedrock is, and that's your best chance of finding fresh stuff.....but even then it doesn't always work.
AC: It's in a process of destruction....which exposes stuff you want to get, but as it's doing it, it's further destroying it. TC: We're looking for a strange balance. As you can see, we've come up with great difficulty, when the river is very low, but that gives us the maximum amount of exposure of the sediments we're looking for; so ironically the most difficult time to do it logistically is the best time geologically. If the rock is too far above the river, never inundated and eroded, it will almost certainly have gone. And under the water, it's the freshest, but we can't get to it. So we need something that's between the high and the low stands of the dry and the wet seasons where it's sufficiently eroded to be fresh ....when you hit that you get rich faunas ... if you're lucky.
JJ: Also these little holes....shrimp and crayfish burrow in.....
TC: Two phases of the activity: 1) The orientation and unraveling of the 3-dimensional geometry of the rocks so that I sort them out chronologically...that can be still done perfectly well here...you can see there's a very nice sandstone bed that runs all along the way dipping to the river. I will do my routine things, like measuring the dips and characterizing these sediments and they'll take their place in the sequence of observations that will orient the rocks, and then every so often, we hit the bonanza of the fossils as well, and that's when we get the biological information JJ: Then we know where we are in the sequence but he does what he does everywhere we stop. (40:48)
45:01 -FX: Walking/splashing through the water.... to shore; Then Tony says off mic a bit: Jeremy, is my hammer there? AC: It's in the floor of the boat. TC: The eternal curse of the geologist, where is my hammer...... 45:37 ....plus more splashing.... to 45:52
46:20 TC: You can see things have probably changed around in that the dip is different and the sediments are different....they're pretty weathered.... we'll just scavenge a bit.... see if there's something to collect...... I'm going to do the routine things, measure the dip and get the orientation for the usual purposes, and we look to see if there's anything fossiliferous here..... (gets very windy 47:40)
48:22 JJ: Nada, nada .....And places are fresh too, where I broke it off it's nice and dark gray..... it's very coarse, and we were here before and took a microsample, didn't collect any fossils ...this is showing lower down, nothing there.....
49:03 AC: How common is it for you to find people living right above the place where you want to collect?
* JJ: Almost everywhere, and that little boy as he was walking down and I said good morning to him said, 'oh those are the people who are looking for little snails......caracolitos.....AC: so you're known on this river.... JJ: I guess so..... I suppose it's a novel thing to see people arrive in a boat and run around like little children looking for snail shells... (49:36)and of course, where there are some ...people help...etc.
51:13: It's easy to do it here....n the main highway....as saw yesterday difficult in small rivers...have the collection of Axel Olson......
(52:09) "la-ha" .......and the word for an outcrop is a floramiento.....but no one here would understand that......AC: talking about learning the right words and how this has helped you....
*53:08 TC: It'a also true that the Embera of all the indigenous peoples of Panama are the most observant and the most precise in describing both the species of birds and fish and wildlife, and surprisingly the are equally precise about telling us where fossiliferous deposits were. 53:30
53:56 AC: Do you know how they explain the presence of fossilized shells? There's freshwater aquatic life in the river.....
*JJ: First time went to an Embera village.....................the head man understood instantly what we were looking for ... and when I went into a little spiel to explain this area had been underwater and that was why there were shells in the sediments it was obvious that if there were marine shells of the type that one would find at the beach, it was logical that this material had once been under the sea.....not difficult for him to understand.....and when he explained...that was clearly accepted. (55:06)
57:06 AC: There's a lot of strata in this outcropping, and it's very thin layers like a crepe....how much age in a yard of that material? TC: One of the things that go on in the bottom of the sea is that animals that live within the sediment are often very active and they burrow both to make places to live and they feed off the organic matter that's within the sediment, so when we come along as geologists and look at it years later, if you see a massive unstratified sequence, you'll often find within them the mollusks are disoriented, they've often come apart in different.....and they're not in any position that relates to their living positions, and the sediment itself has a mottled convoluted perturbed texture and if it's well preserved you can see the shapes of the burrows and if you're a marine biologist who knows the infaunal (?), the animals who live within the sediment, whether they be worms or mollusks, or crabs you can actually identify the species of infaunal animal just from the shapes and the characteristics of their burrows; now for them to be able to live like that, they can't be being permanently and rapidly buried they need a certain stability for that to occur.....what we're looking at here is a series of rapidly laminated sediments, which means the currents
......as look across whole exposure, it's one continuous laminated set of sands ... and that suggests to us that this has been rapidly deposited --it's accumulated rapidly and infaunal animals have not been able to get established, so though it looks an impressive pile of sediments that might represent a very long time, it's probably deposited in a relatively short amount of time very rapidly.... so suggests geologically speaking not much time represented here..... 100 or 50,000 years...........
JJ: ......There are surely a few shells scattered through this outcrop, we're not seeing any of them because of weathering and alteration, and also because of dilution.....For me the ideal situation is a place where deposition stopped or was slow so that conditions were favorable and the organisms are concentrated in the sediment.
1:01:09 TC: One of the advantages of paleontology over biology is the fact that if you get a slowly deposited set of sediments, the sample of the fauna that you get is time-averaged over a significant chunk of time....you therefore get accumulated a wide diversity of those organisms, and a biologist who goes out even every year and collects in one spot is still sampling a smaller array of those samples....and so a good fossil horizon is a time-average sample as if you'd been there hundreds of years and waited for them all to accumulate....... 1:02:00
1:05:49 END DAT #4