Day 157: January 19, 2008 Comodoro Rivadavia
Trip Start
Aug 15, 2007
1
160
202
Trip End
Mar 01, 2008
Comodoro Rivadavia,
Argentina
Saturday, January 19, 2008
I slept in until 9:00; I needed it! After breakfast, I called Dubrovnik Rent-a-Car and rented a Ford Fiesta for two days for $75/day but I can only drive it for 150 km/day without paying extra. Fortunately, I shouldn't need any more than that.
I found an internet place near the hotel and uploaded my entries and fotos for the past couple of days. The travelpod.com site has now accepted about 15 of my fotos for featuring, at some point, on their web page. When I finished, I also called my parents. Only my father was there, my mother being out with my brother who is visiting from the Boston area.
I left the hotel in the afternoon and drove down to the beautiful beach at the funky resort town of Rada Tilly, 14 km south of Comodoro, to look at the section exposed in the cliff there. It is pretty impressive but, as I knew, far too steep to sample it there. That's okay, though. I discovered yesterday that the area was recently made into a provincial park so the paperwork that would be necessary to work there would probably delay sampling there by decades. I drove up to the top of the cliffs for amazing views north and south along the coastline.
A good portion of my field time in Patagonia is spent trying to figure out how to sample in the flat-lying strata, a new experience for me. In northern Argentina and Bolivia, the strata are all tilted so that all I need to do is walk along a stream that cuts through them. I never have to climb. The lowest tilt I've ever worked in was in the Campo de Talampaya, in La Rioja province, where the strata dipped just 6°. That required a 15 km traverse to collect from the 2100 m-thick section but no climbing. Here, however, if there is any dip, it is measured in a fraction of a degree, the traverse would be hundreds of kilometers long unless I can find places where I can access the strata safely. Since the Patagonian sandy soil is too porous for much surface runoff, there are no streambeds that cut through the strata. This limits sampling to places where trails or roads cut across the flat beds or places where nature has provided access.
From the clifftop, I could see the strata I was standing on stretching far to the south, exposed in lower cliffs than those at Rada Tilly. I decided to head south to find the exposures I had seen from the bus yesterday.
After crossing from Chubut back into Santa Cruz province, I drove for 15 or so kilometers before coming to a beach that had a sand dune plastered against the cliff. A camping area is next to the dune, right on the beach. It looks like the lowest 20-30 meters can be approached from there. Heading back toward Rada Tilly, there are two roadcuts that will add another 50-75 m to the section. Already, this section is much thicker than the one we sampled at Pescazaike. In 1998, with the DuPont geologists, we took the road westward which climbs through to the top of the major mesta that is at the top of Rada Tilly. Tomorrow, I will take that road again to determine if sampling the roadcuts along the way will be feasible. As I recall, there are a lot of them so a fairly complete section, up to 300 m thick may be possible. We won't have enough time to do it all this year but we can probably put a good dent in it if the rocks cooperate.
I returned to the hotel around 6:00 and putzed around until I got hungry. I didn't feel like going back to the place where I was ignored most of the time last night. I just missed the bus into the city center so I ended up eating what was probably the world's worst hamburger at the YPF station around the corner. It looked poisonous and it was, as I discovered about two hours later when I returned to the hotel after another hour at the internet place. I read the Buenos Aires paper and saw that River beat Racing last night 2-0. Elena will be happy to hear that.
While at the internet locutorio, I firmed up a vehicle and room reservation in Punta Arenas for when Liz arrives. I will try to go up to Puerto Madryn on Monday to see my travel agent friend, Angel Mansilla, if he is there. If he isn't, I'm not sure what I'll do until Will arrives but something will turn up, it always does. A trip to Puerto Madryn will give me a chance to look at the strata north of Comodoro although, as I recall, the Tertiary is not exposed for awhile because there is a thick pile of Mesozoic volcanic rocks but certainly, the Peninsula Valdez, near Puerto Madryn, is all Tertiary.
I returned to the hotel and made arrangements to stay for a third night. Then, I wrote before going to bed.
