Today we entered Arizona, and passed the tiny hamlet of Fredonia. We saw the Kaibab National Forest, with the Kaibab Limestone bending around the Kaibab Monocline. Also, Louise talked about the Colorado Plateau and the Moenkopi Formation. Later we saw big folds in a north-south direction, about 60-70 Ma old, caused by the opening of the Atlantic at Greenland, resulting in the Laramide orogen. That's the only effect that orogen had on the stiff, unbendy Colorado Plaeau.

The road along the Vermillion Cliffs, part of the Grand Staircase of colourful Mesozoic strata, was truly spectacular. Red, white, yellow, brown and purple bands along steep cliffs overlooking the Colorado River, and erosion products in the form of giant boulders resting on tiny pillars of weaker material. It’s like some weird animated movie of another planet.

Then we crossed the Colorado River and entered the big Navajo Reservation. The Navajo is the largest Native Nation in the USA, some 160,000 to 200,000 souls, and many of them still adhere to the old ways. Every other homestead had a round hogan, the old Navajo house.

We had lunch a bit up the road to Glen Canyon Dam, where we sat down on basalt among cactuses. Louise talked some more about the Chinle Formation. After picnicking by the heavily trafficked road we rolled down the slope and looked at colourful sandstone and weird erosional forms. Then we drove down road 89 again and saw the Echo Monocline on the left. Next stop was at Cameron and at Chief Yellowhorse’s store, where they had a lot of Indian arts&crafts stuff. Finally a chance to do some serious tourist shopping; I came away with a really nice and expensive Pendleton blanket.

At last we reached Grand Canyon National Park and looked down in the largest ditch in the world. The colours--the depth--the distances--the crowds--the cold! There are several lookouts along the South Rim (and supermaket-size tourist traps) and we stopped at most of them, along with a busload of singing Italians and a herd of medical bikers.

The stratigraphy of the Canyon goes something like this: Starting at the bottom, the Inner Gorge is cut through Precambrian (1.8 Ga and younger) igneous, sedimentary and metamorphic rocks. The Cambrian Tapeats sandstone (brownish) overlies these unconformably. This is followed by the Bright Angel shale (green) and Muav limestone (green), reflecting a Cambrian transgression. The next unit is Devonian and called the Temple Butte Formation, but it is very thin here. It is overlain by the steep Redwall limestone (red). Then comes the Carboniferous Supai Group (red), with shales, siltstones, sandstones and limestones, evidence of repeated transgressions and regressions. Above this come the Permian Hermit shale (red), Coconino sandstone (white, steep, with impressive cross-beddings), Toroweap sandstone and limestone (white-ish), and Kaibab limestone (white). Thus the Permian saw a regression and then a general transgression.

The park itself is like a big city only with trees instead of houses. After our tents were raised at the camping ground, we drove to Market Plaza to buy food. The national park is situated between four Indian Reservation, the Navajo, Hopi, Hualapai and Havasupai, so the park employees were almost exclusively of Native stock.

After a cold night and an even colder morning we prepared to descend the Grand Canyon. The Bright Angel Trail on the South Rim winds and winds its way down from Permian to Cambrian layers. The total descent from top to bottom of the Canyon is 1.4 km and we were supposed to hike halfway down, to Plateau Point. We were given rock units to study on the way down, in groups of two.

Thomas and I looked at rock unit #2, the Toroweap limestone. Then we rushed on downwards, passing slow desdendants (haha) and wheezing ascenders, and taking care not to get trodden on by the passing mule teams and also not to fall off the edge. It took two hours to reach Plateau Point, where one looks down into the Inner Gorge (Precambrian), down to the Colorado River and its rafters. Here we had lunch, and could undress somewhat as we discussed our rock units and lookes at the ravens soaring in the updrafts. And then we had to walk back up again...

First it was hot and then, as the trail returned into the cliff shadow, I had to put on more and more clothing. Every fifteen minutes or so, or when the body signalled system shut-down imminent, I stopped for a rest and some water. Wheeze wheeze. Thomas caught up with me after a while and we made a team all the way up, getting passed by Johan and Pelle in Coconino. They were going like a steam train. At least there were no mules to get out of the way of, just their smelly waste products.

Useful things to bring on this hike: small backpack; layers of clothing and pants that can be turned into shorts; 2-3 liters of fluid (water and Cola); 2-3 energy bars; some fruit; a light lunch (e.g. beef jerky and some bread); baseball cap or hat; sunglasses; camera; really good shoes/boots that will not chafe the feet.

The whole day was used up for this little trip, we started at about 08.00 a.m. and returned to the Visitors’ Centre at about 05.00 p.m. after a 3-4hr march uphill. It was a fairly tired group that went to the Mather Campground to shower before a much needed dinner at the Grand Canyon centre. Boy did we sleep well in our damp and cold tents this night!

This night I discovered the Pendleton blanket is not only pretty but incredibly warm as well. Pity it couldn't keep my legs and back from getting really sore... This morning was very slow, because many of us were exhausted from the exercise the previous day. And we had to get up extra early to make it to Las Vegas in the afternoon.

The first site of the day was a basaltic cindercone volcano among the San Francisco Peaks, associated with the Basin and Range extension. There were pumice, lapilli and bombs to be collected. A herdlet of elk ran past the vans as we left. The time went on as we went west and north, looking at lava flows on Route 66. When we re-entered Nevada, Johan recalls some kind of dam structure which was named “Howard” something. Pelle remembers it as the Hoover Dam. It was quite big and Calle was not allowed to enter the visitors’ centre, perhaps because of the bomb he took from Therese at the cindercone. The dam is a big concrete wall set between ignimbrite cliffs seemingly held together by cobwebs of powerlines, and the top of it is one giant traffic jam. It is also featured in numerous movies.

Ahhh, Vegas... Glitter, neon, cars, noise, buffets, slots slots slots, shows... overwhelming but very much like a soap-bubble: all colourful exterior but no substance at all. Still, in the words of Xev, it's fun! Our little hotel the Howard Johnson Plaza was on the wrong side of the highway so we had to walk a mile or two to get to the Strip. These are the hotesl we visited:

• Excalibur--fantasy towers and medieval.

• New York New York--the whole town built up inside the building, plus a roller-coaster and NY skyline on the outside. The food was very expensive and too much (when it finally arrived).

• Caesar's Palace--quite fun but no gladiators, just pickpockets. Niclas left his wallet unguarded a second and eeeee-pfoo! it was gone.

• Westard-Ho--cheap 27oz. margaritas.

• Luxor--a giant black pyramid with Pharaohs strolling around the slot machines inside.

• Circus Circus--boring and bewildering, we had to be led out by an employee.

By that time it was 0400 and pretty much everything but the slots had been closed down since midnight. I thought Vegas was a city of sin and night turned into day... We took a taxi back from Circus Circus. The cabbie was a lot more impressed by our walking that distance than by the hike down and up the Grand Canyon. Well, you've got to get your priorities right!