Day 31: September 14, 2007 Salta to San Carlos
Trip Start Aug 15, 2007
202Trip End Mar 01, 2008
Map your own trip!
Show trip route
After doing my regular morning thing, I made sure Elena was up and the two of us packed our clothes into my green bag for our weekend field excursion to the Valle Calchaquí. I went to the office and upload the morning's writing to my blog. Claudia arrived a little after 10:00 with Matías. We loaded up the truck. Toyo had checked out the drill but we almost left it behind anyhow. Fortunately, Hector Quiroga spotted it in the deposito and brought it down just as we were getting in to leave.
It was very hazy as we left Salta and headed south on Ruta 68. Tuity and family had other things that needed to be done so they elected to follow us later in the afternoon. Feeling no rush to get to San Carlos, Claudia offered to make a detour so Elena could see the large reservoir at Cabra Corral. I had only been there once, in 1989, so I was happy to go. We turned east at Coronel Moldes. I had mentioned that I wanted to collect some stromatolites for the Brevard collection. Claudia, as usual, knew right where to go. Our first stop was to look at some stromatolites that approach a meter in diameter, rivaling the largest I had seen, the famous Ordovician stromatolites near Saratoga Springs, NY. The stromatolites of Salta Province are Maastrichtian (Late Cretaceous) and are found in the Yacoraite Formation. Not feeling up to lugging a meter-wide specimen back to Brevard, we pressed on to the far side of the bridge and looked in the large roadcut. We quickly found some that are only a few cm across, not nearly as impressive but easily portable.
We returned to the highway and continued south past Alemanía where Claudia and I first worked together, in 1989, when she was a senior at UNSa. We entered the Quebrada de las Conchas with its steep red walls of Cretaceous and Paleogene rift-filling strata. Elena was quite impressed. The ~65 km route through the canyon is loaded with beautiful vistas. We stopped at La Garganta del Diablo (Devil's Throat) and walked up to the steep 5 m slope that blocks easy entrance. Matías went over it but Elena was not wearing the right shoes to get up it. I knew that the next stop was just as good so I didn't even try to cross it.
About a kilometer down the road is El Amfiteátro (The Amphitheatre) which has a flat, sandy entrance. Both features are short narrow canyons that lead back into wide, round amphitheatres cut by waterfalls that are now usually dry. The headwalls of both must be at least 200 m high if not higher.
The Quebrada de las Conchas becomes the Quebrada de Cafayate as the road continues upstream to the south. The strata on both sides of the canyon exhibit faults, unconformities, folds, and facies changes. It is quite spectacular. Eventually, we reached the gravel road that cuts across the Valle Calchaquí to San Carlos.
San Carlos is a fairly typical small rural town. Like most towns in Latin America, it is laid out on a grid with the central plaza that houses the church, municipal offices, and some businesses. I stayed in a house a couple of blocks off of the square for a night in 1994. Claudia had reservations at a very nice hostería call La Casa de los Vientos (House of the Winds). It is run by an impressive woman named Sonia. Elena and I had a very nice room. My bed was on a raised platform and hers was in its own little alcove. We unloaded our luggage and then hopped back in the truck. Claudia wanted to show me the section she had targeted for study. We drove the 10 km gravel road west of town to the farming hamlet of San Lucas. I was surprised to see solar cells and solar water panels on the school.
We could see the excellent exposures in the Río San Lucas below. It is a wide, dry riverbed. Our plan was to gain access to the riverbed and drive back to the outcrops. With Claudia at the wheel, we got into riverbed in the Proterozoic metamorphic rocks and drove downstream in 4WD for a few hundred meters into the Paleogene strata before the boulders became too densely packed to easily pass. We were still at least a kilometer above the Neogene strata we wanted to study. She turned the truck around and we returned to San Lucas to see if we could hire a man with a mule to haul the water we would need to keep our drill bits cool as we drill our samples. Unfortunately, there didn't seem to be any pack animals in the town. As dusk fell, we headed back to San Carlos and passed a few burros, noting where they were for our return in the morning. Tuity and the others called as we drove down the road. They were just reaching the San Carlos "exit".
We met at the hotel and gathered in the dining room for tea and crackers. Sonia asked if we were affiliated with a mining company because if we were, she didn't want us there. Apparently, there is a huge local anti-mining movement. It is mainly a water issue. Water is precious in this arid agricultural region. The boom in uranium exploration in the surrounding mountains has everyone worried that a mine would use up precious water resources and contaminate the remaining part.
To overcome the water problem at the sample site, Tuity suggested that we hire a couple of local teenagers to haul water from the vehicle to the sample sites. Sonia called around and found us two guys, Ishmael and Oscar who agreed to meet us at 8:00 the following morning and work for 50 pesos/day.
We stood around outside before going to dinner, looking at the stars from the courtyard. Even with the lights of the hostería around us, the Milky Way was clearly visible. Around 9:00 we all piled into Tuity's Land Cruiser and went to a small restaurant on the central plaza. It was nothing fancy but very typical. I had a milanesa napolitana and Elena had fried meat empanadas. We returned to the hotel around 10:30. Elena asked me for the key but I told her I had left the room unlocked-most places around the valley don't even have locks. It's a pretty safe place. We looked at the stars for awhile from out in the parking area which was darker than the courtyard and went to bed.
Where I stayed
Casa de los Vientos