Archaeological Investigations of the Quebrada Manga, Peru

December 31, 2007 Expeditions 2007

Archaeological Exploration of the Cotahuasi Highlands, Southern Peru

Kurt Rademaker (CCI), David Reid (Anthropology Dept.)

Project setup. Kurt writes:

Before Dave and I can even think about the canyon survey itself, we have to deal with some serious logistical issues. We are setting out to spend three weeks backpacking and documenting archaeological sites within a 100 km-long canyon beginning near sea level and finishing at ~3,800 m above sea level (masl). Although we have been studying GoogleEarth, topo maps, air photos, and ASTER satellite images in preparation for the trip, we really have no idea what this canyon is like. There are some roads or footpaths that access the canyon at intermediate points along the route, but are they passable? Will there be water flowing in the quebrada while we are there? Is the canyon even a viable route from the coast into the highlands? It is difficult to know what challenges lie ahead, yet finding out the answers to these questions is really what the trip is all about.

As the only substantiated link between specific Pacific coast and Andean highland locales in the Terminal Pleistocene, the Quebrada Jaguay-Alca link provides a unique opportunity to learn how the high Andes were first explored and settled. We are putting ourselves into an archaeological simulation of sorts, seeing what the environment is like and what resources are available along a coast-highland altitudinal transect corresponding to the Quebrada Manga route. The Quebrada Manga is the optimal route in terms of shortest distance, but was it the route actually used by Paleoindians 13,000-11,000 years ago?

The first major issue turns out to be water, or the serious lack of it. As we travel by bus along the Panamerican highway from Lima to Arequipa, we see to our great dismay that there is no water flowing in the lower quebrada bed. This, combined with the 90o F temperatures typical at the coast this time of year, tells me that we can’t count on there being any water in the canyon at all. An adult hiking in rugged desert terrain such as this needs to drink several liters of water per day, and Dave and I plan on being in the canyon for about 20 days – that’s a lot of water, way more than either of us will be able to carry. We will have to cache food and water at regular intervals along the canyon route so that as we move along we will reach new supplies. This means that before we can begin the canyon survey itself, we need to spend about a week putting in food and water caches, and for this purpose we hire a 4×4 from our good friend Saúl Cerón at Inca Tours Peru, an outfitter in Arequipa. So after a trip to the local grocery store in Camana, we load the 4×4 full of food and about 60 5-liter jugs of water! Now we just hope we can access the canyon with the truck. Our topo map shows several roads or trails which access the canyon from modern highways to the south and east along the route. This should be simple, right? Wrong!!!

Whether the modern irrigation of the coastal plain west of Camana has accelerated sand dune formation, or whether the constant onshore winds have always caused these dunes to form, dune fields and erosion of the coastal hills have swallowed up the roads leading inland from the coast. We try lead after lead, asking locals, only to find that none of the roads shown on the topo map now exist. This is bad, for if we cannot drive into the canyon to put in caches, we will have to backpack them in many kilometers over very rugged, sandy desert hills. One evening we are able to follow a rough, narrow road inland for several miles, only to find that dunes are overtaking this route as well. We get out shovels and clear the road of sand, proceed for a kilometer or so, then we are stopped once again by another sand dune. We work into the night, digging out the road by the headlights of our 4×4, make it further inland, but just as it seems we have broken through, we encounter larger and larger impasses. Finally, it seems futile. Exhausted and defeated, we make camp in the roadbed. Though we have worked for hours to get inland, we can still hear the sound of ocean waves rolling in the distance.

The next day is better. We discover a good unimproved road leading inland from the Camana city dump, and though we get the vehicle stuck in one stretch of deep, fine volcanic ash deposits, we are able to chock the wheels with rocks and use our shovels to work the vehicle through. This road gets us about 35 km inland and connects us to a small homestead situated near a permanent spring within the Quebrada Manga – an oasis! Following the quebrada bed north from this place, we place a second water cache at the 50 km mark. Two caches down! Caching food and water is not an easy process – we have to be wary of animals that will steal our food or cattle that may trample and break our precious water jugs. We also do not want to take the chance that people will find our supplies and take them, so the best strategy is to bury the caches in an out-of-the-way place and collect GPS coordinates so we can be sure of finding our caches when we come back through this way on the survey.

The next day we drive back out of the Manga Canyon to the coast, head east along the Panamerican highway, and head up the massive Majes canyon toward the highland village of Chuquibamba, our endpoint for the Manga survey. We try in vain to find a road that will access the Quebrada Manga some 15-20 km to the west, but only footpaths head that way. Water is readily available in this part of the highlands, and the frequent Andean rains at higher elevations during this time of year should eliminate the need for us to cache water. We backpack our food supplies west from Chuquibamba following a section of an Inka road, and hide a cache under a rock overhang in a small tributary canyon before heading back to Chuquibamba and arriving after dark. We would later refer to our long backpacking day as the “Chuquibamba Death March”! No matter – with the hard part over, we now had all our supplies in place and we were ready to head back to the coast and get dropped off to start the survey.

The Coast to the Oasis. Kurt writes:

Our first week of survey has been incredibly productive. We have discovered dozens of new sites in the coastal and lomas ecozones. The sites in the coastal zone are all shell middens, many of which contain artifacts made of Alca obsidian and petrified wood from higher elevations. These sites are either small camps or processing locales up to 400 m elevation. Lomas sites have locally occurring lithic artifacts, as well as ground stone tools, likely used to process seeds, roots, or other plant materials. The many sites in the lomas zone between 400 and 1,100 m elevation suggests that this ecozone was much more productive in the past than it is today. Recent deforestation and overgrazing by livestock has sadly resulted in a profound degradation of this environment. Protected examples of lomas vegetation can be found in the Lachay reserve north of Lima, and perhaps this area once looked like Lachay. Beyond the upper elevation limit of the lomas along the canyon rim is absolute desert. Not a stick of vegetation or a single animal can be found, except for vultures that circle me while I am walking through this moonscape. Not surprisingly, there are no archaeological sites up here on the canyon rim.

Six hundred meters below within the canyon are small springs and riparian zones. We follow the quebrada north as far as we can, but eventually it becomes a slot canyon with steep, high bedrock ledges and deep pools, impassable without technical canyoneering equipment. Travel along the canyon floor to the highlands is impossible, and although travel is much easier along the canyon rims, there are no sources of water or plant or animal resources, and the terrain is rugged.

To continue our survey work northward to Chuquibamba, David and I cross to a neighboring canyon and then descend back to the Quebrada Manga at the Chagenoc oasis, thrilled to break into our first cache of goodies. In the next few days we discover and map the extent of petrified wood deposits accessed by the inhabitants of Quebrada Jaguay. Not bad for the first half of the survey – over the next week and a half we will explore another 50 km of beautiful canyon country.

Highland Rains. David writes:

The past few days we’ve seen dark ominous clouds roll over us seeking higher elevations. The night before leaving Chagenoc, we were told by the old man who lodged at the orchard not to camp so close to the dry river bed; that the smoothed cobbles and boulders would soon awake with rushing water so strong it would carry us off with all our gear.

When we left the settlement, setting off for our camp 15 km away we understood. I was walking alone in the middle of the river bed when I looked up and in the daze of the desert sun saw a mass of brown coming straight at me. At first in complete surprise, I realized this was the outcome of the dark clouds, the head of the reawakened river. For part of the next week we had to wade through the reactivated river, crisscrossing to newer terraces, camping out of reach of the flowing waters that will regenerate the canyon vegetation and the small orchard of fruit trees the old man resides in.

Petroglyphs. David writes:

During the morning, as we waded through the reactivated river, we had renewed excitement knowing our focus of the day. Heading back to camp the previous evening, Kurt discovered a large boulder engraved with intricate carvings or “petroglyphs,” a form of rock art. Throughout the morning we identified more than 20 boulders with petroglyphs. The images included geometrical shapes, zig-zags, llamas, birds, pumas, snakes, foxes, human figures, and faces. Although the rock art probably dates to only the past few thousand years, the discovery of this site is quite important in regional contexts. Future investigations of the petroglyphs and the people who created them will be pursued in coming months

The Inka Tambo. David writes:

For the past week we’ve been making our way into the highlands surveying the canyon rim towards the settlement of Llacas. Most of the day we spend walking along a road of smoothed flagstones, indiscernible from most of the other rocks except that they are worn white. This white road is testament of the first statehood to unite most of the lands of the Andes, the Inkan Empire. We know we are not the first travelers along this canyon as the path we follow was smoothed by ancient peoples, countless llama trains bringing goods from the coast to the highlands, Inkan armies and messengers, and today the few farmers and llama herders that live in the local canyons around springs and wells.

Before the project began, back in the Andean Archaeology Lab in Orono, we traced our route using the program GoogleEarth. From the satellite images we located large rectangular structures and corrals on top of the canyon near Llacas. Our Inka road was leading us to it. The day we were close to our third supply cache, we finally came across the structures. The series of lodging rooms, storage houses and corrals is what is called an Inkan tambo. Tambos can be found along Inka roads in modern-day Peru, Bolivia, Chile and Colombia, and served as administrative and military centers for the Inkan Empire.

Descent to Chuquibamba. David writes:

The two days before leaving the canyons, we were finally hit by rain. We were in a side quebrada exploring rock shelters, as the desert rain fell and made the once dry rocks sheen and glow in the sunlight. We soon realized the difficulties the rains created as the small quebradas we were exploring became roaring impassible rapids and waterfalls. Since our only water source was the roaring streams, our water for the rest of the project was filled with thick brown and black sediment. We had to let the water sit overnight to let the sediment sink to the bottom, then begin the long process of filtering the water numerous times using a t-shirt, and boiling the water over our small camp stove.

It was still raining on our last day in the canyons, yet we still had a morning of survey work to be happy about. On our way to the town of Chuquibamba, we explored a set of rock shelters set in one great ridge. Unfortunately, the preservation of the shelter floors makes it unlikely any evidence of Paleoindians would be preserved if they indeed utilized the rock shelters. Instead, evidence on the surface of the sites included ceramics of the local Chuquibamba Culture and the subsequent Inkan influence.

The rest of the day we hiked closer and closer to civilization, the town of Chuquibamba. Going down the ancient paths and switchbacks from the canyon rim to the town was a surreal experience as a mist and fog set in among the large cacti that hugged the slopes. The obscuring fog made it impossible to see more than ten meters ahead, yet from below we heard traditional Andean music floating up from the town assuring a hot meal and comfortable bed after weeks in the desert canyons and highland pampas.

Project Summary

Our experience traveling through this canyon suggests that the Quebrada Manga was not an ideal travel route from the coast to the highlands for the early settlers of southern Peru. We could never have known this without on-the-ground exploration of the Manga canyon, and this finding is actually quite significant. The route from the Terminal Pleistocene coastal site Quebrada Jaguay to the highland Alca obsidian source probably followed the massive Majes canyon to the east – a longer route, but a well-watered, resource-rich valley.

Short-distance moves from Quebrada Jaguay into the lomas zones were probably designed to take advantage of valuable plant resources and to hunt deer, camelids, and other fauna. Our identification of relict Caesalpinia spinosa tree stumps (Dillon, personal communication) suggests that until recent overgrazing and deforestation, the coastal hills were covered by a lomas woodland. Paleoindians probably found these coastal hills to be a lush, productive zone relative to today’s degraded environment.

Longer-distance moves from the Quebrada Jaguay locale to the Majes valley to the east probably brought early inhabitants within the zone where petrified wood crops out. The Majes valley would have afforded year-round fresh water, freshwater prawns, fish, and other fauna, and tuna (Opuntia sp.) and other fruits. Tuna seeds, as well as freshwater prawn shells, have been identified within strata at Quebrada Jaguay, lending support to this idea. Recently, we have used GIS to model a least-cost path between Quebrada Jaguay and the Alca obsidian source, and the path follows the Majes canyon north, passes west of Chuquibamba, and continues over the highland plateau between the Coropuna and Solimana ice caps. Ongoing archaeological work along this modeled least-cost path will be aimed at discovering additional Paleoindian sites in the various ecozones so that we can better understand the mobility, settlement patterns, and environmental adaptations of some of South America’s earliest settlers.