USC Dana and David Dornsife College of Letters, Arts & Sciences > Blog

August 12, 2014

Last day in the field

Filed under: Andean Fossil Hunt — Kathleen Ritterbush @ 9:10 pm

Monday Aug 11, midnight, Junin Province, Peruvian Andes

The blog won’t load but this is the last dispatch from the field anyway. We worked a long and successful day, then spent the night packing all our rocks and gear back up for the long journey home. Tomorrow our driver will take us in the truck back to Lima, and the next day we have our flights booked at midnight. We’ll go to Houston together, then on to Austin, Los Angeles, and Chicago for Joyce, Dave, and I respectively.

Today we returned to a field site we worked last Tuesday. This time Joyce and I had all day to work the site in detail, and we spent half the day pouring over about 50 feet thick of rock. By lunch time I was very satisfied that we’d observed several important details that fit logically into a new overall framework for how glassy chert rocks and limey carbonate rocks can fit together. After lunch we tried to casually walk out and observe several hundred feet of rock in a succession, but we met two challenges – too many faults, and too much chert. I’m making it my business to determine how the glassy chert rocks fit into the environmental puzzle, and when they are indicative of siliceous sponge activity in ancient habitats. By 3 pm we were overwhelmed with the extent and complexity of the day’s project.


We spent the morning looking carefully at these layers of rocks. Each little bed of rock at Joyce’s feet, and extending into the little cliffs behind her on the hillside, represent some amount of sand, mud, and animal and microbial fossil parts that accumulated on the seafloor in the time of the dinosaurs. The particular size of the mud or sand grains, the particular size of the fossil shells, tells us about the water speed and depth in their habitat. Unfortunately, in the field we can only observe certain large-scale features. So we spent hours testing, rejecting, and refining interpretations of how the rocks came to look the way they do now. We can test these hypotheses by making microscope slides from the rocks, and looking more closely at the relationships between microscopic animal parts and other seafloor materials.

So, with an hour or two left to work, I moved us to a different outcrop with a little alcove of mud and silt rocks, where last week I found a few ammonites. We spent the remaining hours of our field time patiently chisling and tapping and splitting rocks. We found dozens of ammonites, and I’m flying home with the best specimens to try to identify more specifically in which geological time interval our rocks formed. Joyce declared that this was a pretty anticlimactic end to our long adventure, but in the end I was the one to call it quits and tell her to stop getting fossils, because it was going to get dark.

Such contrasts! The red and white staff here is one meter thick, and each stripe is about the size of my hand. Each of these tiny layers of rock also represents some amount of sand and mud that accumulated on the seafloor during the time of the dinosaurs. Compared to the photo above, these layers are much thinner and much more easily covered up by vegetation. These rocks represent a very different habitat from the rocks that are more cliff-forming. Yet we spent about two hours on this exact spot. This time we were not photographing the rocks themselves, but splitting open small hand-samples to find ammonites.

Such contrasts! The red and white staff here is one meter thick, and each stripe is about the size of my hand. Each of these tiny layers of rock also represents some amount of sand and mud that accumulated on the seafloor during the time of the dinosaurs. Compared to the photo above, these layers are much thinner and much more easily covered up by vegetation. These rocks represent a very different habitat from the rocks that are more cliff-forming. Yet we spent about two hours on this exact spot. This time we were not photographing the rocks themselves, but splitting open small hand-samples to find ammonites.

We have more work ahead in Lima, but a bit less than originally planned, so we hope to hit the town and have a beer to celebrate a long, challenging, adventurous, intellectually exhausting field endeavor.

August 10, 2014

Phase 3: jigsaw puzzles and small victories

Filed under: Andean Fossil Hunt,Guess the Fossil! — Kathleen Ritterbush @ 5:13 pm

6:45 pm

Huge success today. If we had the energy Joyce and I would have done one of those jumping high-fives with the sunset behind us on the mountain top, like in the closing credits in a movie. BUT, as it happened we were hustling down a pretty steep slope, trying not to fall into any giant holes or off any cliffs, and it was just beginning to rain. So imagine that we high fived while jumping in the air, and add a llama, and that about sums it up.

Today we worked in a rural area beside a rushing river and grazing lands. This is one of my favorite field sites but it’s a MONSTER. The whole interval I’ve been interested is a pack of rocks about 140 meters thick, and the Earth Life Transitions team is increasingly interested in another 50 meters of rock below that. Now these are layers of mud and sand and animal shells that once accumulated on the seafloor, but now they’re shoved up onto mountains in the darned Andes. They’ve been heated, folded, bent and broken, faulted and eroded by rivers and rain. We want to observe the rock beds in the right order, as they once accumulated near a beach. BUT, the closer we look, the more we see that each chunk of rock is broken into it’s own little tower. A 10 foot tower of mud rocks here, a 15 foot tower of glassy rocks there, a few feet of sandy rocks exposed between the grasses over there. So we climbed a few big hills, and we tried to put the jigsaw puzzle pieces together.

Rock availability differs, and it effects how we are able to look for clues to past habitat conditions. At this field area there is way more vegetation, but at least the rocks in this photo, from a relatively large block of rock between faults, was easier to piece together than the morning's work.

Rock availability differs, and it effects how we are able to look for clues to past habitat conditions. This field area is only at about 15000 feet, so it has more vegetation that covers hillsides. Instead of cliffs, in some places we get small glimpses of the rocks and we need to piece those together. But at least in the hillside photographed here, the rocks are not separated by major faults, so the task this afternoon was more simple than the morning chore of clamoring between major fault-displaced cliff-sides.

Last year I came here and spent about a week with another geology team identifying these rock puzzle pieces, deciding how they ought to fit together, then measuring their total thickness and noting their general contents. Mud, glassy cherts, sands, silts, etc. I took a sample every 10 feet or so to make a microscope slide, and spent the year pouring over those results. Armed with more information from the microscopic view of the rocks and fossils, and from the synthesis of this site compared to others, Joyce and I came back today to pour very carefully over each pack of rocks and to make detailed observations of clues to the depositional energy. If sands in a rock show tiny beds that cross back and forth and cut each other off, they were interacting with fast-moving sea water. If fine carbonate muds accumulated tiny milimeter thick layers gradually, making a laminated rock, this happened in quiet, slow moving water. Now, quiet water can exist in shallow settings, like lagoons, or in deep settings, farther from the coastline. It is our job to figure out the approximate habitat that formed the rocks, and that fostered the associated fossils.

I tried yesterday to post a photo of a fossil, but hilariously none of my photos of fossils would be recognizable. There is so much lichen and shadow and gunk on the rocks, and in most cases the fossils we’re considering are just broken shell pieces or microscopic. I’m most interested here in fossil sponges, but the sponges usually explode into tiny glass needles that litter the seafloor, so to tell for sure I need to look in a microscope months after leaving the field.

Well today I got two good bits on news on that front. I got a photo of a fossil some folks at home might actually recognize! AND after finding a likely candidate rock, I split open a chunk of chert with my sledge hammer and looked with my 10x hand lens – behold, sponge spicultes from their tiny exploded bodies, right there in the rock. Joyce could see them with the naked eye. She found this really impressive and I felt proud that my fossils aren’t, you know, totally illusions.

Photos and more accounts of the day will follow after dinner! Time for water and soup and photo uploads.

Hasta luego!

10:20 pm

Oh man, this is why it’s so hard to run a blog on these trips. Dinner, a shower, skyping with family, and now I’ve got to type the field notes for tomorrow’s destination. But I’ll add some photos once I upload them from my camera. Onward and upward! One more field day!

Guess the fossil

Ok, readers, I finally find time to upload a fossil image for you. Do you recognize what marine animal left this structure behind for use to find hundreds of million years later? Answer in the comments, facebook, or twitter @NerdFever.

June 25, 2013

Hot chocolate at the top of the world

Filed under: Andean Fossil Hunt — admin @ 8:50 pm

Tuesday 6/25/13
10:40 pm


It doesn't count if boards aren't missing

It doesn’t count if boards aren’t missing

obligatory rushing river in a canyon deep below

obligatory rushing river in a canyon deep below

Silvia en la Selva

Silvia en la Selva

a wire and wood plank bridge across a river in the jungle near the mine

a wire and wood plank bridge across a river in the jungle near the mine

This is a plunging anticline. The rocks should be in flat layers, but the layers are folded up like a burrito. Truck for scale.

This is a plunging anticline. The rocks should be in flat layers, but the layers are folded up like a burrito. Truck for scale.

Not a bad place to wait two hours for the road to open.

Not a bad place to wait two hours for the road to open.

a mile long line of cars waits for the road to reopen after a surprise that it will be underconstruction, along with the only other two exits from this region, for the next 6 months.

a mile long line of cars waits for the road to reopen after a surprise that it will be underconstruction, along with the only other two exits from this region, for the next 6 months.

Silvia said it's not a vicuna, because the ears are too long. Who are you mystery 4th ungulate!?

Silvia said it’s not a vicuna, because the ears are too long. Who are you mystery 4th ungulate!?

The truck to pick us up from the mountaintop field site was late, and it was getting cold. Etewhaldo suggested we hide from the cold inside one of the miner’s quarters. I thought they were all abandoned. There’s a cluster of maybe four or five buildings the size of mobile homes, each devided into little offices or dormatories, here on the top of the mountain. We’re about 2500 meters up, I checked the schematic of the mine. Yesterday, inside the mine, we were at about 1700 meters. My ears have been busy with popping. A clearing near the top of the mountain contains a big earthmover, the abandoned offices, and a lonely guard tower where a very official and fairly whistful young guy is in charge of checking the names of everyone who comes and goes, appearing suddenly in big 4×4 trucks and disappearing just as suddenly. He doesn’t have a computer, even though that’s where the best internet is (AHAH!) due to a huge aentena. And he doesn’t even appear to be allowed a book or magazine. As Silvia and Etewhaldo and I wait for our truck, now 10 minutes late, I tell them in Spanish about firewatch towers. As an adolescent I felt a whistful romance for firewatch towers in the wildernesses of the west, where a person might spend 4 months alone, watching the forrest, with only a radio and books and an imagination. I was convinced I’d be a famous writer if I could just get a summer job in a firewatch tower. Ed Abbey, Jack Keruac I think… good writers needed to have such experiences. As I explained this to the other two, I noticed the quiet guard peering through the window listening intently to my broken Spanglish, with his bare desk and clean reflective vest, and a sad expression. Etewhaldo found some cookies and candies in his pack for us, and I joked with Silvia that this was dinner. Getting cold, he led us to one of the abandoned buildings to shelter from the wind, as our car apparently wasn’t even on route yet.

The day was a bit of a bust scientifically but not bad all and all. Sort of like a rain day. In the morning Etewhaldo wasn’t at the mine offices to meet us. In fact the whole geology department was closed and locked. Apparently the two preppy guys my age I noticed at the cafeteria last night, sitting apart in colored polo shirts and looking nothing like locals or miners – are the grandsons of the owning family. They popped in for a surprise visit, and this took the geologists away from their other work. So for the morning Silvia and I had an office day. It was good luck, as it took a long time to correctly package all the samples from yesterday’s mining adventure. It was so loud, and so hard to communicate, that the numbing on the samples and the symbols on the mine schematic didn’t match. I figured it out, made notes, wrapped the mudstones in paper and plastic, labeling the samples inside and out, trying to protect against breakage in the bouncy truck. We’ll see how well I did.

I was almost done when the guy from the core warehouse came up asking if we had photos that might reference some markers in the core series. Long story, but the entire sequence was destroyed after we left. It boggles the mind. At least I got descent photos. I spent the next hour making him a massive photomerge in photoshop. Such a shame.

After lunch Etewhaldo came back and took us again above the clouds. He’d had a crew clear off part of a road cut so we could better see the rocks. We asked for about 4 meters. When we arrived, in unusually hot sunny weather, carrying all my junk (bastante equipaje) the roadcut was cleared by about 40 meters! Machete-d leaves and branches all around, and there the rocks we came to see. We looked and sampled and discussed. I felt bad about the plants, but the jungle grows really fast. Its very strange becoming a geologist after being a biologist. Particularly, as a paleontologist, I think in VERY long timescales. I brought screens for the light for photography. I’ve been lugging them around (they’re lightweight but awkwardly shaped and bulky) for days and people keep asking why I have them. Today they worked great; they can mellow the shadows of a bright sunny day into the even light of a late cloudy afternoon. The only problem was refolding the large screens into small circles, which had the three of us laughing and trying again and again. It was a good toy for three grown scientists to feel silly.

After the first road cut we went around the back of the peak, along a road that’s been out of service for some years after a small rockslide. The jungle was so thick you wouldn’t imagine cars once drove there. And the rocks above, with a fabulous overhang, and vines and water dripping down on us… sadly, the wrong rocks. These were the same we contemplated from above on Sunday, and now that we were seeing our destination, it was not quite the horizon we wanted.

And so, with evening coming on, we returned to the guard tower to await our truck. We tried to get into one of the little rooms. Rather than abandoned, inside there were several sleeping mats, a hotplate with pots, and small stores of peppers and food about. Just as soon as we pulled the string on the lock and it broke, the three miners came out of the jungle in their orange jumpsuits. Amusing awkwardness ensued as we explained we busted their lock on accident, but also Etewhaldo harangued them about their machete job above. So these were the guys who cleared the roadcut for us! And now after a long day they wanted to get out of the cold and we had to figure out how to break into the last not-so-abandoned room on the mountaintop.

We kept thinking our truck was arriving, but it was other trucks bringing other workers. They come and go in day and night shifts; the mine never sleeps. Eventually Etewhaldo and Silvia and I set up in an abandoned office to wait out the cold as the workers got into their house and started some cooking. They offered to have us over for dinner but we couldn’t eat into their stores when there was cafeteria food waiting for us below. Inside the office, two large desks, and a bookshelf were covered with dust. On one shelf were the largest moths I’ve ever seen in the wild, and a stack of forgotten accident prevention forms. The miners came by with some hot water and mugs and powders for coffee and hot cocoa. We thanked them and made hot drinks and continued telling stories. In the jungle Etewhaldo told us of his friend who got lost for an hour after taking a five minute pee break on the river bank during a boat trip. The jungle can be dangerous. I told about a winter evening when the metro rail was delayed an hour, so Amir and I huddled in a glass elevator at the elevated station. We spent an hour making friends in the elevator, going up and down, up and down, each time greeting the new member of the society of people waiting for a train that wouldn’t come. A drunk guy drove onto the tracks, and the city needed to cut the power. I was able to tell it mostly in Spanish. It really bothers me when I am lagging in following funny conversations.

The sun set was amazing, in billows of dark clouds marching from over the series of peaks separating us from Lima. Home for Silvia, who misses her husband and teenage son, though she really loves getting into the field. I took some photos. The miners teased the guard to pose for my photos, so he struck one like the construction worker in YMCA.

It was dark by the time we made it down to the main offices, and busses were arriving with nightshift workers. Busses and busses. It’s been really interesting getting so see what life is like here, and getting to know the geologsits. After dinner, Etewhaldo came to our casita to see some slides, and we must have shown him an hour of geology presentations. The poor guy watched half of my dissertation defense. In a sense we’ve done this visit in reverse, explaining why we’re here at the end. But he’s even more interested now, and we’re gradually widening our sphere of people with information to share about our investigation. I was really pleased that he knows Julio, from the mining company that hosted us last year, and who we will see again next week. I showed him thin sections of the microscopic view of a sponge that Julio found.

On our drive we saw two armadillos, and on the basketball court there were bats chasing bugs in the evening. It will be strange to leave the jungle, and head to the snowy peaks tomorrow. But it will be reallllllly nice, hopefully, to see some darned fossils. I don’t know, the next site is also a mine. We’ll see. Either way…

Winter is coming.

June 24, 2013

Deep in a mine, deep back in time

Filed under: Andean Fossil Hunt — admin @ 7:55 pm

Monday June 24
9:30 pm
Another wild day of adventure in the jungle.


Sampling rocks from the walls of the mine

Sampling rocks from the walls of the mine


I spent the morning deep underground, and deep back in time. I’ve got a schematic of the mine that shows how deep down we were, and how far from an exit, but I haven’t read the specifics yet. In particular, I avoided reading this while actually in the mine.


These dark mudstones record the slow accumulation of marine sediments

These dark mudstones record the slow accumulation of marine sediments


At the moment I’m interested in a series of black shales between fifty and two hundred meters thick, laid down some time in the Early Jurassic sea. Shales weather into mud, so in the jungle, farm, high plains, or mountains, they’re not well enough exposed to examine the conditions of the sedimentary environment. But underground, in a freshly cut tunnel through the mines, the rocks are as fresh, complete, and well exposed as one could dream about. We got a quick look yesterday, and made arrangements to spend the this morning taking samples.

The idea was that I would measure the section and mark the sampling sites with red paint, then the team would follow behind and make the samples. Taking samples requires time and caution. The rock needs to be selected from the correct level, with a piece likely to show sedimentary or fossil features. The piece needs to be labeled with a number, a location, a date, etc.

It was dark, and LOUD. We sloshed through water up to our boots, and searched for signs both geological and man-made on the walls of the tunnel. We could have been in the middle of the world. It was actually a huge relief that every 20 minutes or so a truck or huge earthmover would drive through. We’d stand along the walls or in an alcove to let it pass. Very strange to me was when individual miners would pass by on foot. A point of light in the distance would materialize into a person who, after brief greetings, would continue down the impossibly dark long tunnel in the other direction.

Every time miners came by they approached us, shook hands, exchanged greetings and questions. In general people here are very big on introductions. People will stop what their doing in an office, walk across the room, shake my hand, exchange greetings, then go back to work. Its awkward for me that the standard greeting with women is a little cheek touch, without actually kissing, but making kind of a kissing sound. I’m just too uptight and American to do this with total strangers. Guys seem to recognize this, but they don’t want to be rude either. Ever experience that encounter where one person moves in for a hug and the other for a handshake? Same thing, only more awkward. Anyway, in the mine there’s no kissing, haha, but certainly lots of handshaking. I think maybe spending one’s day in the dark and noisey and challenging depths makes human contact all the more vital and welcome.

It was an adventurous experience and a scientifically challenging one. We used all of our heads to compare the schematics with what we saw in the rocks and with our expectations. In the abstract we conceive of sediments deposited over time slowly in a marine environment. This turns into rock and we can, 200 million years later, sample those same sediments for chemical signs of life and environmental conditions. But a lot went on in those two hundred million years. Building the Andes, for example. And these rocks are smack in the middle of it. This introduces breaks and faults in the rocks, fluids that burn through and bring new minerals, ore deposits, and destructive forces that change the chemistry completely.


Those aren't fossils! Carbonate sediments in this rock core are scrambled with minerals added by hydrothermal fluids. Sometimes this adds ore, which is why there's a mine here.

Those aren’t fossils! Carbonate sediments (dark grey) in this rock core are scrambled with minerals added by hydrothermal fluids. Sometimes this adds ore, which is why there’s a mine here.


The sampling was altogether a success, followed by a lunch on patio overhanging the jungle. Pear juice, empenadas, and as always soup, rice, potatoes, and meat.

The warehouse for cores of rock sampled from the mountains and mines.

The warehouse for cores of rock sampled from the mountains and mines.


After lunch I got another treat: the core warehouse. This is where they store all the cylindrical tubes of rock taken with a large drill. From the surface down, or from the mine up, a huge machine can drill out a tube of rock tens of meters long. This can expose the transitions between bodies of rock. The miners keep a huge stock of these to look for valuable ore. For me, they laid out several meters of core that form an example of the contact between two important units. One is terrifically altered, making it promising for mining. The other, my black shale, is fairly intact. An afternoon of photographing and observing, followed by the bouncy ride back to the housing units.



Home sweet home in the jungle mining enclave

Home sweet home in the jungle mining enclave

They’re putting us up in this lovely house on a property like an old resort. I went for a walk around sunset to look at the jungle. Along the drive from the mine there’s a rope and wood plank swinging bridge high across a rushing river. More than anything I want to walk across it, and indulge my millionth Indiana Jones experience. But, like examining bats caught in my corridor or identifying the butterflies, crossing rope bridges is not what I came here to do. All in due time.

At dinner we sat with some miners and talked about sports and politics. It was good practice for my Spanish which is still very inadequate to hold a conversation. There are just too many holes in my vocabulary. But already I’m doing better than last year, and I’ve only been in the mountains two days. Let’s see how I’m doing in two more weeks.

Thanks all for following! Tomorrow night we move to a different mine, and I may or may not have internet. Hasta luego!

June 23, 2013

Jurassic in the Jungle

Filed under: Andean Fossil Hunt — admin @ 5:06 pm

Sunday, 6/22, 6:30 pm
A white knuckle day of adventure, some of which I’m not even at liberty to share. Spent the day shouting expletives in my brain, but saying little. In the morning we drove up the steepest cliffs at the top of the jungle peaks, into the clouds, and hiked around to look for the rocks we seek. No sponges here; I’m searching for the rocks deposited at the same time as the sponges, but in places the sponges were not dominating. This way I hope to compare and contrast, and to construct an interpretation of how widespread the sponge phenomenon was.

The drivers here are CAVALIER. Holy #$%^. Sheer cliffs, thousands of feet down, barreling up mountains sides, but slowing, perfectly, expertly, each time we encounter a tiny bit of water, or an oncoming vehicle. Yesterday on the drive up into the Andes and down the rainy side (was that only yesterday!?) the whole transit requires passing massive transport trucks going 5 mph. But, oh, 1/8 attempts, we’d have to duck back behind the truck because there’s another vehicle oncoming. Every driver just takes this in stride. Almost the only honking I encounter in the highlands is the friendly greeting or safety honk when taking hairpin blind turns. Holy crap there were so many hairpin blind turns today. And the gigantic trucks coming out of mines and tunnels unexpectedly on one-car-width roads…

A mine abandoned after a landslide shows fresh rock exposed at the tops of the jungle peaks on the eastern and rainy side of the Andes in Central Peru.

A mine abandoned after a landslide shows fresh rock exposed at the tops of the jungle peaks on the eastern and rainy side of the Andes in Central Peru.



Walking was tough for the first 10 minutes. Up a hill, following acclimated Peruvians, with my weak lungs and brand-new-out-of-the-box steel toed boots that don’t quite fit. I purchased them the last day in LA, east of downtown, between two doctors appointments, on late notice they were required. Can’t complain. If some rocks go sliding I don’t want broken toes.

Tiny yellow orchids. Vibrant purple flowers. Butterflies I didn’t have time to watch closely enough to see all their damned colors. Rocks. Bastante rockas. Rocks in the trail, rocks hidden by thick jungle vines and a foot of moss and soil. Rocks exposed in giant patches of bare vertical cliffs on the mountain tops, or Better, or worse, depending on when you’re there, gigantic patches of fresh rock exposed by massive landslides. Walking down the first mountain peak, through narrow passages in thick jungle, suddenly there was a little shrine set in the vine-choked cliff-face. A shrine with the long bones and skull of two humans. Very old, found here when the mine was first explored. Now they are set in this little shrine, with candles and what not, and the site is named after them. The first ones. The mine site is named the first.

It’s been such an amazing day. Decked out in miner’s attire; they lent us clothes. Steel toed rubber boots, thick pants and overshirt, hard hat. After an hour or so of security clearance, we went outside for a Sunday event of flag saluting. Two men operated a PA and microphone, and we stood in rank with about 25 miners to take turns listening to announcements, saluting the flag, and singing the national anthem. I wished I’d known so I could practice. As it was I got enough looks for being a female – curious looks. I didn’t want to be rude by laughing out loud when two miners in hard hats approached to present the flags – goose stepping the whole way. It was just so goofy and serious and corporate and spirited, all together in the gathering mists of this mountain top jungle, that I had to bite my lip hard to keep from laughing. Three miners were given the honor of hoisting the flags, and one made a speech. Tomorrow is a day to honor workers of the countryside, and from what I could tell he made a moving declaration about his family, the value of the land, and the labor we must not take for granted. Finally it was all abruptly over, and Silvia and I were introduced to the head honcho of the site. He had an expression that he didn’t find our work interesting, but he didn’t seem to doubt that his geologists did. And they do. That’s been the best part.


Mists and rocks along the narrow paths at the edge of the mountain peaks

Mists and rocks along the narrow paths at the edge of the mountain peaks

I’ve been treated like a total expert and professional. The geology team hosting us spent a half hour laying out maps and schematics of the mines, geology, and region. They gave their analysis and opinions, then listed to our questions. Together we decided what sites to visit today. It was completely crazy. From the top of the mountain to its Moria-esque forbidden inner roots; on this trip we get to see everything from the rocks at the surface to cores from the lowest reaches. By the end of the day I was up to my rubber boot tops in water, following two men I could barely understand, past the blaring sound of a ventilation system, into the terrifying but spectacular unknown. This is exactly what I came for, and so much more!

Now a shower, and dinner, and organization of the day’s photos. Thanks for following!

Up the Andes, but still in the central time zone and Cenozoic.

Filed under: Andean Fossil Hunt — admin @ 5:06 pm

Saturday, 6/21
A long day. We packed the truck in Lima about 8am, and arrived at our first major destination about 5pm. Now it’s about 9:15, and once again almost time for bed.


I really love Peru. I feel very comfortable here. Largely Silvia is responsible for that. She’s made expert arrangements with geologists and companies, with the truck rental, etc. I get odd looks from many people, I guess because my blonde hair is fairly out of the ordinary, and I’m not generally on a tourists’ corridor nor am I traveling like one. That’s just as well; I’m not a tourist. After a second glance at me people just go about their business. A lot of workers seem surprised to see me in a mining truck, but they’ve all behaved very politely and respectfully. Silvia says, though it’s changing, that there are still pervasive issues of machismo and dismissal of women in mining and geology fields which are mostly populated by male workers. Around Lima I saw plenty of women in blue color positions; collecting garbage, unloading trucks. Riding from the airport the first night, I saw a female traffic cop who stood in front of a speeding bus, and when it finally halted right in front of her, she banged on the window and gave the driver hell for disobeying her directions. Geology and mining is interesting because it’s parts manual labor and parts intellectual. Silvia is very highly respected by all the senior mining personnel. She told me tonight that when she first came to this mine, as an 18 year old college student, her group drove all night to reach it, only to be told at the entrance that women were not permitted within the mine. A fellow female student told the mining employee, “That’s your rule, so it’s your problem, not mine!” As a compromise, the company finally allowed them inside, but only dressed in baggy men’s clothes, so as not to distract the miners. She said afterwards the miners laughed with them that it was still apparent what was happening. It’s good to see how far things have come. Already tonight our presence has raised some eyebrows, but everyone’s been very polite.


This is a motorcycle with a flimsy cover and rear wheels, like a disel rickshaw. In the back you'd see the Andean foothills if you could see anything but smog.

This is a motorcycle with a flimsy cover and rear wheels, like a disel rickshaw. In the back you’d see the Andean foothills if you could see anything but smog.

The road was long. Up the mountain. Up, up, up, up. I would have slept but the geology is too exciting, and the motion of the truck to bouncy. Up up up the mountain. People live all along the roadside, in small rooms built of hollow bricks, disastrous conditions in even a moderate earthquake. We passed the family trout farms, that use the water flowing along the deep valley by the road, in little carved out ponds on the steep cliffsides. By the time we made it up and over the highest peaks, I was so hungry I ate almost a whole grilled trout.

Homes and businesses and towns spring up alongside the main road into the Andes from Lima

Homes and businesses and towns spring up alongside the main road into the Andes from Lima


Snow on the peaks at the top  of the Andes here, near one of the sponge destinations. This time we drove on, headed for the far and rainy side.

Snow on the peaks at the top of the Andes here, near one of the sponge destinations. This time we drove on, headed for the far and rainy side.

After lunch we were disappointed to find that a main road was closed, so we needed to go around by an unpaved way, adding an hour to our already fairly delayed trip. But what a drive! Winding winding winding down the mountain, across the high planes, down into the jungle on the rainy side of things. Today I saw the biggest chickens I’ve ever seen, a few hundred lanky cruising dogs, hundreds of sheep, one llama, and also one of the nation’s signature birds: the freaking enormous hummingbird. I’ll have to check with Dave or the internet. This thing was the size of a parrot, but with a wide red tail and hovering in the damned air like a helicopter. I’m used to it out of their thimble sized friends, but this thing was huge.


The church and courtyard of a mining village on the high plains.

The church and courtyard of a mining village on the high plains.

People live on the sides of the road up the mountain, and in the high planes there are mining villages, each with a large church and courtyard at the center of dormitory style housing and sprawls of brick shacks. Down lower on the wetter side the fertile valleys were filled with terraced gardens with livestock and adobe houses. We passed two villages large enough to host active soccer games. Then down, along a rushing series of rivers, with constant water falls crossing the road and a big rainbow in the cloud-adorned sky, into the jungle. We were barreling down these unpaved roads, and now and then would stop to ask directions to our destination. Finally, in what seemed like the fifth tiny cluster of buildings in the middle of the lowering and narrowing jungle, at 5 pm Silvia announced, “We’re here!”


Mixed brick and adobe houses of villages on the high plains, as we made our circuitous way to the jungle.

Mixed brick and adobe houses of villages on the high plains, as we made our circuitous way to the jungle.

It was anticlimactic. An hour and a half of paperwork, medical checks, hard hat issue, showing our documents. We wanted to give a presentation to the geologists about what I’m looking for, but it will have to wait til morning. Finally we headed up a hill to the little cluster of smurf village accomodations, which are really quite nice. For dinner at 7:30 we had Chifa in the cafeteria – that’s a cafeteria’s version of Peru’s version of Chinese food. It was actually pretty good. Sweet tamerind sauce on meat and veggies with rice. The climactic scenes of Con Air was on in the dining hall, and I enjoyed explaining the plot to Silvia. After dinner we spoke a while – or rather she did – with a geologist colleague. I can follow conversations and generally understand 50-90% of what’s said, depending on who’s talking. Siliva and I have been taking turns speaking English and Spanish, and mostly she’s speaking English. I don’t know if its more for my benefit or for her to practice. She’s terrifically fluent but doesn’t get to use it as often as German. Its hard brain work, searching for words. So now I’m ready for bed. We thought we’d see some rocks this afternoon, but so it goes. I’d rather see them in the right context. One of the geologists we bumped into during dinner is fairly confident we can see the contacts I want, so I’m excited about the morning.


La Selva. The Jungle.

La Selva. The Jungle.

We don’t have internet until they configure our laptops somehow at the main office. Silvia let me borrow her phone and I sent text messages to my husband and sister, asking them both to update my parents, who would win the gold if worrying were an Olympic sport.

We’ll see what rocks I get in the morning. Can’t wait.

August 14, 2012

!No quiero a salir!

Filed under: Andean Fossil Hunt — admin @ 8:29 pm

[I don't want to leave!]

A tremendous day to end a tremendous field session!  Again, I am blown away.  By the rocks themselves and our luck to find their fossils, by my incredible new geology friends, by the whole adventure of it all.  I could not have imagined a better trip.

We have enough exciting fossils and rocks to publish a new interpretation of this sequence, and to reveal important events following the mass extinction.  We went far beyond the fundamental questions I posed in my proposals.  And, we have a mind-boggling collection of fun challenges for the future.

We went to the site by the farm today, and the farmer indeed left the gate unlocked for us.  Almost no fossils to see there, but plenty of sedimentary structures.  When the waves interact with bits of sand and shell on the seafloor, they can leave lasting marks in the rocks.  200,000,000 years later, I’m interpreting these layers of sand and shell and muck to determine the history of the environment where our animals lived.

A key challenge of this expedition is tackling several different field sites.  This way, we can see the conditions in different parts of the environment that simultaneously recorded responses to the mass extinction.

The last site of the trip was spectacular, and the highest elevation, in the Sierra Nevada range.  I’d been marginally interested after a preliminary scout session on Saturday.  Then, yesterday morning Julio brought me cores from Sierra Nevada, and I knew I wanted to see it with my last remaining half day.

WOW.  So many fossils, so many peculiar associations.  In fact, these rocks looked most like my material from Nevada.  I spent three hard years banging my head (well, my rock hammer) against those rocks before finding their secret of sponges.  Now, it seems like Mission: Impossible Fossil is my specialty.  This afternoon, I was looking at rocks equally frustrating.  I’m riveted!

A crucial skill in geology is reconstructing the history of a pile of rocks.  Fossils are great, but they can only inform us about mass extinction ecology – specific animals at a specific time – if we can organize the rocks into relation with others.  If we can discover the correct stratigraphic order, the correct sequence of the rocks, then we have a guide.  Sure, rocks are often stacked on top of each other.  But what about when they point straight at the sky? Or when they twirl around and flop over on themselves.  Picture a gigantic taco shell made of 40-foot thick rock. That’s what I saw today.

Over lunch – fried trout from tiny family farms – Julio and I talked about jobs and vacations and vocation. He’s an exploration geologist.  His life, like mine, is full of daily mysteries, and mysteries that take years to tackle.  He’s been looking at this taco shell of rock for six years.

Today we searched for and found fossils.  Together we collected notes, photos, observations, and samples for microscopic analysis.  Raul is stellar at finding fossils, it turns out, and chiseled out a half dozen for me while I photographed those too tough to remove.

We were at close to 14000 feet of elevation today.  Conveniently, the site led to a steep slope with a road at the bottom, so the drivers pulled the trucks around and then met us half way.  Easy!  Still I got winded – glad I ran all those stairs back in LA.

Dark clouds moved in and the cold sharpened in a persistent wind.  Julio and Armando and I agreed it was time to go, and we were only half way down the slope.  Wouldn’t you know, we kept sighting more fossils all the way down.  We kept agreeing to leave, then finding something too good to pass up – just a photo! Just a photo.  Finally, it started snowing.  Snowing.  OK, OK, now I will get off the rocks.

There was just a bit of snow but it was already five, and Raul would have to drive in the dark on the windy roads down to his valley hometown  In the lessening light and sprinkling snow, I gathered all my samples, exchanged contact info, goodbyes and hugs all around.  Man I hate to leave these rocks. I hate to leave this countryside and I hate to leave these damn fine geologists.  But everybody’s got other fish to fry, and I have a hunch I’ll be back.



August 13, 2012

surprise and sheep

Filed under: Andean Fossil Hunt — admin @ 7:59 pm

Today began with the most fantastic surprise. Julio brought me CORES!


Wild rocks are big, and messy, and plants grow on them and sheep make messes on them (especially here!) and they tend to fall apart.  So if a company or academic group has money and wants to know more about rocks, they take a core. Picture putting a straw into the rocks, holding your thumb over the top, and pulling it out. It’s exactly like that!  Only it costs at least ten thousand dollars and half the time everything in the tube breaks.


I thought Julio said he’d bring me photographs of some kind of holes from one of our field sites. No.  He brought me these rock cores from inside the earth, totally perfect clean rocks, of exactly what I’m looking at here in the mountains. We poured water on them to make the fossils clear. Julio had looked through photos to decide which cores from the company collections might interest me most.  He chose wisely. They were amazing!  They contained diffinitive evidence of some of the phenoms we’re chasing – the mass extinction, the impact on local rock development, the rise of sponges.


The rest of the day was a bit of a struggle.  I was again managing a team, with so many language limitations, and so many ambitions. I feel exactly like this on every trip.  If I only had one more week, one more day, one more hour.


I was working, balancing time limits, detailed notes, vertical relief.  Meanwhile the geologists above me were scaling the cliffs like eagles.  That’s when I shot this video.  This is how I feel all day every day out here.  Outwardly, it’s business business business, but inside, I am shouting this:


As a grad student, I have to select a set of problems I can handle now, and accumulate interesting investigations for the future.  Dave says, “Those are projects for you future master’s students.” He’s right.


Today I needed to work with finality. Measure, sample, select, choose.  Though I’ve got this great team, I can only be in one spot at a time. When should I take the photos I need? Should I take them now with the sun casting shadows or wait for the perfect diffused cloudy light? Should I call one objective a bust and move on to the next?

But as I joked repeatedly to my team today, I’d take the whole mountain if I could, and I never want to leave.


We worked our tails off, ate lunch, worked again.  I managed to explain the American adage, “I’ll work when I’m dead”, which we all thought was ridiculous.  I told the geologists that since they work so efficiently, they could take the precision attack jobs, and I’d take the careful plodding thoughtful musing jobs.


In the end, we got it all done.  Well, whatever we didn’t get is fruit for another trip, another team, geology students from the university in Lima.  I finally agreed to leave and go back to the trucks, but then I heard hammering.  Sure enough, the guys were trying to sample some more.  Again I agreed to leave twenty minutes later, and again, I heard more hammering behind me.  Good geologists never want to leave the outcrop.

So it was almost sunset when we left. Everyday we pass through this flock once or twice, with the shepherd and her sheep dog and puppy.  But today, on the road, we saw two little lost lambs all alone.

little lost lambs sm


August 12, 2012

Cultural notes about the high Andes

Filed under: Andean Fossil Hunt — admin @ 5:10 pm

Today we saw VICUNAs!!!!! My ungulate triumvirate is complete!  Llamas and alpacas are pack livestock native to Peru and derived from the wild – and still present – vicuna. Our driver Raul said we would see them and we did!


Our field site sandwiches a colonial complex of ore processing and livestock and living areas, all built hundreds of years ago.  I’ll be looking for sponges then think, Oh, Damn, this is man-made! And find myself walking on a wall hundreds of years old.  I mean, to me, that’s not much time.  But my dad will be impressed.  See the group photo in the last post.

Our driver is from this little mountain town that has the only hotels and his grandparents still live here.  Seriously – he saw them on the road tonight when we arrived in town and he stopped to chat a moment.  They live in the Andeanas – the terraced slopes of the high plateau where the Incas developed agriculture.  When the Spanish asked about the mountains, and pointed, the locals answered, “Andeanas”.  They grow a ton of flowers to send to Lima, but they’re also used for an annual Easter festival here in town.  Raul told us all about it.  Now that he knows we enjoy cultural information, and that my Spanish is improving so I understand more – he’s been very informative.

Other fun things right near our rocks  – cows at pasture across the river, sheep together with their human shepherds and sheep dogs – real sheep dogs!  Most dogs are mutts here.  And people gathering grains.  Raul explained but I understood nothing until he said, “cervesa”.  Ahah! Hops!

La Equipa de Sueños! [the dream team]

Filed under: Andean Fossil Hunt — admin @ 5:09 pm


I am just speechless.  This is the craziest, most fortuitous, most amazing field trip.  WOW.


Fossils.  Tons of fossils.  Ammonites, sponges, bivalves – everything a girl could want, if she lived in the earliest Jurassic ocean.  WOW.


And my team.  My team!  Spectatular geologists.  Really amazing.  Even the drivers, curious, hard working, eager to join in, made important finds.  Really amazing.


First I asked the geologists what they wanted to do for the day.  They said, of course, to help me.  This is amazing because Dave and I thought, look, this mining company is sending “an assistant” with us to keep an eye on us.  That’s handy, so we don’t get in trouble with the police or locals or anybody.  But instead we got two professional exploration geologists, and their driver who is super helpful but I don’t know his official vocation.  I don’t know if the head geologist assigned the second geologist with us or if he asked.  Either way, it’s spectacular.


In the morning, I spent the better part of an hour explaining my plan and answering questions.  First, I gave them printed explanations of my sequence of rocks in Nevada, then took them on a photo tour of my site’s best sponge fossils on my laptop.  After that, I showed them photos of microscope slides – both of my Nevada sponges and from Dra. Rosas’ slides from the rocks on which we sat.   then I laid out my plan for how we could all explore the rocks, and what specific priorities to look for.  I did this entirely in Spanish, asking for words by description in Spanish and with a couple written down in my notes.  It was exhilarating,


More exhilarating was the fact that they TOTALLY understood what the hell I was saying.  I don’t mean just the words – and Julio, who speaks some English, helped to explain concepts for me.  Even when I speak in Spanish, and I think in Spanish, I have English ways of constructing sentences and thoughts.  Anyway, they didn’t understand just the gist or just what to look for.  They totally get why I’m here.  They get that this mass extinction completely changed the world, and the changes explain these totally frustrating wierdnesses about their valuable rocks.  And they totally want to help, to discover for themselves the answers, and to learn how to see and interpret fossils and sediments.

At lunch, we sat by the river.  Everyone brought too much food but it was delicious.  After lunch we compared notes on our findings.  Wow!  Three teams, working totally independently, ended up observing almost the exact same package of rocks, and reported very similar findings.  A few pseudofossils, but I was able to explain these well enough without letting anybody down too hard.


After lunch I walked through each of their findings.  Incredible.  I showed them which parts are valuable, and which are not related to life 200,000,000 years ago.  There’s a lot in a rock that didn’t happen then.  And I think they saw more of how I prioritize and sort fossils and sediments of importance.


When we were done, we decided to explore more, with the last hour of the day.  We went to the roadside to look for ammonoids.  Again, we split up, and again we found the same stuff.  But bringing together these different observations, comparing them, seeing how the rocks connect – I mean PHYSICALLY connect – this is amazing.  This is worth a dozen days in the field.  More.


It take SO MUCH TIME to go through rocks, to learn what’s important, to decide where to search.  Even though I know what we’re looking for, here’s an example.  I had a lousy morning.  I was on one side of the creek and ruins, and my rocks were ok but a bit busted and too much caked on dirty caliche to see much.  If I were alone here, I’d be discouraged after that.  I would take another look across the creek, see some of the observations these guys made – but we had six people pouring all over these rocks today.  The synthesis makes those six observations WAY more than the sum of their parts.  We became a team of people, each with the experience of six people.  It sounds silly but knowledge is like this. It’s fractal.


So at the end of the day we found the most unexpected jackpot.  I came here looking for sponges.  We found those yesterday.  Then I wanted a model for how the sponges lived in their environment and the changes in it – we got that during the morning and afternoon.  Then, in the very last hour of the day, we got this surprise bonus.  Ammonites.  Ammonites tell you what was swimming or drifting in the water above the seafloor.  They also tell you time.  Ammonites come and go.  They evolve fast, spread around the world, and go extinct quickly too.  With ammonites, we can zero in on where in time our sponges are, our environments are – all of it.  Dra. Rosas will be so thrilled.  During her dissertation she found maybe two in this particular rock unit.  Other visiting scientists she speaks of found one, another a handful.  Today, in the last hour, we got a dozen.  And of course more fossils between the ammonites to help us learn more.  Totally incredible.


Tomorrow: measurements, collections, observations.  What an incedible find such work.  Julio asked me if I was going to see Cuzco, and when I said no, he asked don’t I ever go on vacation.  Now, when he and I are walking sheep trails between fossils on these steep mountainsides, I point to the river and views and say, “Vacaciones!” and he laughs.


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