Posted by: paulgarner | July 23, 2010

New Hance Trail, Chino Wash…then back to SLC

Slow internet connections have meant that I haven’t been able to update the blog since Monday evening, so here’s a round up of what we’ve been doing over the last few days.

On Tuesday the weather forecast said there was only a 30% chance of rain. But the thunderstorm that broke over us as we were making our way along the New Hance Trail in Grand Canyon apparently didn’t know that. The New Hance Trail is not one of the tourist trails. It’s steeper, more rugged and in places somewhat hazardous. Our party set off on Tuesday morning to hike the trail to the boundary between the Hermit Formation and the Coconino Sandstone, with the intention of measuring the section and mapping out the bounding surfaces between the Coconino cross-bed sets on the way up. Our hike down was fairly uneventful, and we had superb views of the Great Unconformity separating the Precambrian and Phanerozoic strata in the bottom of the canyon as we rested before heading back towards the rim.

But before we had made much progress back up the trail, the thunder and lightning descended and the rain came down in buckets and we were forced to take shelter, such as it was, beneath some rocks. The lightning appeared to be striking quite close by and the thunder was awesome as it echoed around us, amplified by the canyon walls which acted like gigantic sounding boards. It was quite an experience. After some time the rain did start to ease and we were able to resume our work and complete the tasks we’d set ourselves. The photo shows the canyon after the storm. In fact, one of the beneficial effects of the rain was that we hiked to the rim in much cooler temperatures than would have been usual at this time of year. So all’s well that ends well.

Tuesday night was spent in Seligman, along “historic Route 66”, and then on Wednesday morning we set out to study some more Coconino exposures. Unfortunately, we discovered that one of the sites we wanted to visit – Picacho Butte – was no longer accessible. Since our last visit, the entrance road had been fenced off. That was a real shame, because last year we found some interesting things at Picacho Butte that we wanted to follow up. “Plan B” was to measure a section of Coconino Sandstone at Chino Wash, along with another series of strikes and dips. Leonard Brand also showed us many more vertebrate tracks in the Coconino on a nearby hillside (see photo). Once our work there was finished, we said goodbye to Leonard and his students and John Whitmore, Ray Strom and I travelled on to Mesquite in Nevada.

Today we made the long journey from Mesquite back to Salt Lake City for our flights tomorrow morning. I’m heading back to Cedarville with John Whitmore before the biology/geology conference in Georgia next week. En route to SLC we briefly stopped to take a look at some exposures of the Aztec Sandstone, a Navajo Sandstone equivalent in Arizona, as well as taking a photo or two of the shorelines of ancient Lake Bonneville, the giant precursor to the modern Great Salt Lake, as we came to the Wasatch Mountains. The photo to the left shows some of the bagged samples we collected on this trip, as we sorted through them in our hotel room this evening. There’s a lot of work now to be done in studying these samples and the other data we collected. Keep watching this space!

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