It took about an hour to go through Torréon. Unfortunately, it was rush hour. The going was slow and the traffic was horrendous. About twenty minutes after the van left Torréon, the air conditioner died, and the coolant transformed into gas and started to pour out of the vents inside the van. Miller said, “I guess we are going to have to live without an air conditioner for awhile. We’d better take a look under the hood.”
Miller raised the hood. Gary said, “My God, look at that! There is some sort of pulley embedded in the rubber insulation around the hood. Well, I guess the poor old air conditioner done committed suicide.”
Arturo said, “Let’s move on. We need to get to San Pedro del Gallo and start doing some fieldwork. I’ll drive.”
The van had just passed through the town of Mapimí when it just plain stopped for no apparent reason. Miller said with a look of measured disgust, “What in the hell is wrong now? Let’s take another look under the hood.”
At first, no one could see anything wrong with the engine. Then Felipe observed, “One of the belts is off its pulley. This old van doesn’t have a S-belt like the newer trucks and vans. It has several belts. It looks like the air conditioner part that got embedded in the rubber around the hood was part of the pulley that drives the air conditioner and the engine. The belt that drives the engine has slipped off what is left of the pulley. I believe the part that broke away housed the part of the pulley where the AC belt was attached. The AC belt must have totally disintegrated when the part flew off. Let’s see if we can put the engine belt back on what is left of its pulley and head back to Mapimí. Maybe we can find a mechanic that can fix this thing. The problem is that we’ll probably need a new part. It’s not likely that anyone is going to have a part for a van this old in Mapimí. We’ll probably have to go back to Torréon to get the vehicle fixed properly.”
Miller said, “Let’s see if we can get a temporary fix for the pulley in Mapimí. I still would like to get to San Pedro del Gallo today. It’s not very far off now. It’s probably an hour drive from Mapimí.”
The van made it back into town, and they found a mechanic who was willing to take a look at it. It seemed that everyone from blocks around the mechanic’s shop soon found out that the four gringos were geologists. It turned out that Mapimí was near several gold mines. Many Mexicans worked in the mines and, over the years, managed to collect a variety of minerals that were often hard to come by elsewhere in North America. In addition, the mine dumps were treasure troves for mineral collecting; even school kids sold minerals beside the road.
While the van was being repaired, a mineral vendor dragged Miller, Gary, and Arturo off to his house to view his mineral collection. Felipe stayed with the mechanic. The mineral vendor’s collection was spread out on numerous tables in a large interior open-air patio. All sorts of ore minerals were on display. His collection included such copper ore minerals as bright green malachite and blue azurite, as well as silver and gold ore. Many of the man’s specimens were of museum quality. Miller bought a beautiful specimen of twinned selenite crystals about eight inches in length and crossed in the form of an X.
Arturo said, “We’d better get back to the mechanic. I hope he fixed our belt problem. We need to take off for San Pedro.”
When they returned to the van again, they found that it was ready to go. The mechanic indicated that he could make no guarantees. He told the geologists that they would need to go to an AC repair shop in Torréon to get the job done properly. They would have the proper parts.
With the van repaired, the four geologists finally arrived at San Pedro del Gallo. Fortunately, the old dirt road, which was full of huge potholes and covered with coarse river gravel for long stretches at a time, had been covered with smooth black asphalt. In the old days, the trip south to San Pedro from the main road took over an hour. Now it only took a half an hour.
San Pedro del Gallo is the kind of town that Hollywood would love to photograph for a Mexican Western. As you approach the town from the north, the first thing you see is a picturesque white stucco Catholic church and a graveyard with a prominent mausoleum known as Puerto del Cielo to the west. The town is situated at the south end of a valley and flanked by a mountain called Cerro Volcan to the west and rolling hills to the east. A rich aquifer not far below the surface supplies the town with abundant water. Miller wondered why the aquifer wasn’t utilized more for agriculture. With the hot days and cool nights, this would seem to be an ideal area to grow grapes.
According to some of the locals, the town had been held hostage by a bunch of extortionists for a number of years, who made each citizen pay them a ransom. Finally, one of the more influential citizens, who had made good money working in the United States, reported the extortionists to President Salinas. Mexican Army Special Forces came in and cleaned up the town. The extortionists were packed off to a federal prison.
The last time Miller visited San Pedro del Gallo with several students, there was no airport. Now an airport had been carved out of the low hills to the northeast of town. Although the locals claimed this airport was built to allow Mexican dignitaries to visit the town, Miller suspected it was now being utilized by the drug lords.
By now it was about two in the afternoon, and Miller said with a worried look, “We’d better pick ourselves out a place to camp—one that’s well away from town. The fewer prying eyes around our campsite, the better.”
Felipe said, “Professor Miller, I’ve looked at the topographic map. There seems to be a pretty good place north of town next to a creek. You have to cross the creek to get there. However, most of the creeks are dry around here at this time of year. I would estimate that this place is about seven miles from San Pedro. There seem to be pretty good roads and jeep trails going in.”
“That sounds good. Let’s get after it. It will take at least a half an hour to set up camp. I would like to get a little fieldwork done before it turns dark. I’ll drive and you navigate. Hopefully we won’t get stuck in the sand somewhere.”
As they drove to the campsite, the geologists could see that Cerro Volcan formed an imposing ridge to the west. The campsite was just to the east of the northern end of Cerro Volcan.
Miller said, “After we set up camp, I suggest that we sample the north end of Cerro Volcan, where Burckhardt made his traverse in 1910. We ought to be able to sample the Zuloaga Limestone, the Santa Rosa Formation, and the base of the La Caja Formation. The La Caja Formation is closely related to the Taman and Pimienta Formations at Tamazunchale, but unlike these two formations, it contains abundant ammonites. So when we examine the La Caja—and, for that matter, the other formations—Garry, you and Felipe need to keep your eyes open for ammonites. These are absolutely critical in determining the age of the rocks. If you find one, put a sample bag under it exactly where you found it. We’ll then note the position of the ammonite specimens in our measured section. Arturo and I will collect samples for microfossils as we go along.” He looked around at the group. “Okay, let’s get started. It’s about 115 degrees Fahrenheit in the shade. I suggest that all of you tank up with Gatorade before we get started.”
The work proceeded efficiently. The geologists met their goal by about seven o'clock and returned to the campsite. They drank more Gatorade and had a few beers before they started preparing dinner with some kielbasa that was still frozen in the ice chest. The dry ice was now about gone, but still a few things remained frozen. Felipe and Gary dug a fire pit, filled it with charcoal saturated with lighter fluid, and plopped a grill over it. It took about twenty minutes for the charcoal to be reduced to the familiar orange glow that promised the fire was ready. Miller wrapped the kielbasa with some heavy-duty foil and placed it on the grill. Since it was still frozen, Miller figured it would take it about twenty minutes to cook. In the meantime, he opened cans of sauerkraut and German potatoes and heated their contents on the stove. While Miller tinkered with the sauerkraut and potatoes, Arturo unwrapped the sausage from the foil and placed it directly on the grill to brown. They didn’t have any salad makings, but some avocados doused with lime juice filled the void. A watermelon served for dessert.
After dinner, they tossed some dry firewood in the fire pit and made a dandy campfire. By now, the sun was setting behind Cerro Volcan and presented itself as a large orange ball. Parallel lines of clouds in the foreground alternated between stripes of white, pale orange, and deep orange. As the sun set, a mother coyote with some yapping pups lurked on the periphery of the campsite just beyond the surrounding ring of light. Gary tossed their visitors some leftovers from dinner and the yapping turned into growling as the pups fought for a bite of the goodies.
“It’s about time to turn in. Tomorrow is going to be a rough day. We need to finish up here and head on home.”
Gary asked, “Professor Miller, where are we going to start sampling tomorrow?”
“I plan to start work at an arroyo that runs from the south end of Cerro de La Cruz, or ‘Hill of the Cross.’ If you look at the topographic map, you’ll see that Cerro de La Cruz links up with the Cerro Volcan northwest of town. We ought to be able to sample all but the uppermost part of the La Caja Formation in the arroyo. The upper part of the La Caja is exposed on a hill at the cemetery west of town. You’ll see a place called Puerto del Cielo immediately to the east of the cemetery. This must be some sort of chapel or mausoleum. The contact between the La Caja and the overlying Chapulhuacan Limestone occurs here. There are also good exposures of the contact on another hill immediately north of the cemetery.”
Arturo said, “Before we start sampling the area near the cemetery, I think we need to tell the priest or someone else at the church what we are up to; otherwise, we may get some complaints from the locals. We don’t want to get arrested again.”