William H. Calvin
UNIVERSITY OF WASHINGTON
SEATTLE, WASHINGTON 98195-1800 USA
This page is at http://WilliamCalvin.com/bk3/bk3day2.htm
|The River That Flows Uphill (Sierra Club Books 1987) is my river diary of a two-week whitewater trip through the bottom of the Grand Canyon, discussing everything from the Big Bang to the Big Brain. It became a bestseller in German translation in 1995.||AVAILABILITY limited; the US edition is now out of print. There are German and Dutch translations in print.
The River That Flows Uphill|
A Journey from the Big Bang
to the Big Brain
Copyright 1986 by William H. Calvin.
You may download this for personal reading but may not redistribute or archive without permission (exception: teachers should feel free to print out a chapter and photocopy it for students).
I DONT BELIEVE this place. Were hiking up North Canyon this morning, carved in the Supai sandstone behind our campsite. There are thousands of layers of Supai sandstone little more than an inch thick, and so the trail up the canyon has a series of little steps and, when a number of layers have been broken away together, big steps. There was recently a creek flowing down this canyon, as there are a number of pools of stagnant water which we walk around. Then there are steep jumbles of boulders blocking the path, rocks from the high cliffs carried down by a flash flood; they would have added to the rapid below if theyd been carried as far as the river. We climb up them, a knee here and an elbow there, sometimes gaining a handhold from a convenient tree growing in a crack. We meet up with dry waterfalls, where a resistant ledge of Supai forms a lip over which the creek sometimes pours. It is too high to climb, but there is a path around it to the right.
And the greenery it was pretty at Lees Ferry and along the river, but back here in the narrowing side canyon, the greenery is completely surrounded by red rock and so appears even greener than green. Good old color contrast, the reason why they stick blue labels on yellow bananas, to enhance the yellow. Well, here the red enhances the green. The view is truly spectacular. There are also some flying mammals flitting about probably brown bats who didnt get enough to eat during the night. Maybe the sandstorm was hard on the insect population.
The canyon walls are closing in as we hike higher. We circle some more pools, seeing our reflections superimposed on those of the red walls behind us. Then we hear the waterfall. And, as we round another little sculpted pool, there is the grotto. Little water is falling, but the graceful beauty of this place, carved by thousands of years of rushing water, leaves us breathless. The waterfall looks like a flower, almost an orchid with its tongue extending downward toward the luminous pool at its base. The colors well, the red shades into pastels and, as the water channel is approached, into silver and subtle grays through which the blue-and-white water flows peacefully. There is the grace of an oriental painting to this scene. Some of us wade up the pool to the gentle waterfall, to see if it is real.
Returning, I decide that I can get the best view from an elevated perch. So I begin climbing the Supai sandstone layers up a steep slope on the left wall of the saddle-like pass were standing in. Eventually I perch upright in a crack in the Supai, with a nice view of the sculpture. And with a view down the canyon toward the river. The little pool that we skirted just before arriving at the waterfalls pool now reflects the canyon wall beyond, deepening the red and orange colors. A willow tree is gracefully draped, arching over the little pool. Looking up to the distant Supai sandstone being reflected in the pool, I see a zone of fractured rock leading steeply up the wall of the side canyon. Like the saddle opening out into the grotto, it is probably a flexure, where great subterranean forces have twisted the Supai layers, the twists later exposed by erosion. So the orderly layers of Supai sandstone are broken by this flow of collapsing layers, only to again resume their order. The colors are red-orange, shading into pastels, at least in this morning light.
Then there is the problem of getting down, camera in hand. Going up, I just edged up the crack, but heading down is another matter, and I hesitate to just stride downhill, not trusting the traction of my still-wet shoes. So I sit down a lot, and finally make it to the bottom. I could have just run down and then up the other side while slowing down, reversing and coming back, but Im not that nimble-footed. I hear, however, that one of the boatmen loves to do exactly that for exercise. Jimmy, apparently, gets restless and runs up this canyon early in the morning by himself, does a series of back-and-forth runs across this U-shaped saddle (running up even higher than I carefully climbed) before reversing to run back down, and then runs back down the trail to the river. All before breakfast. Undoubtedly in his sandals. The boatman telling me all this claimed that Jimmy gets irascible if he doesnt get enough exercise.
No one, fortunately, was in any hurry to leave this place.
WEVE BEEN GETTING quite an introduction to the layers of the earth. As we float down the river, they rise up out of the water, Phoenix-like. First we see a little of the new layer at the waterline; ten minutes later, its taller than we are. Its like having a mountain range grow up around us. From the rim, of course, it looks different, more like a sunken mountain range the Paiute Indians called the Canyon "Kaibab," the "mountain-lying-down".
The Colorado Plateau may have been uplifted by lava welling up from the depths of the Earth, pushing up the Earths surface like a blister. The river cut down through this domed layer-cake like a meandering knife. Imagine a cake pan in the oven with a wavy, serrated knife suspended above it, the blade is just off-center and tilted slightly downhill. As the hot cake rises up around the knife, a canyon is formed to one side of the domes peak (the North Rim). In the case of the Colorado Plateau, the cake was cold and already layered when lava and continental drift helped push it up. And it rose anywhere from 1,500 to 4,000 meters (5,000 to 13,000 feet).
Starting back about the end of the Mesozoic (and the dinosaurs), there was a 20-million-year-long episode of rock-buckling and mountain uplifting called the Laramide Orogeny (no relation to orgy, someone explained orogeny is Greek for "mountain birth"). This produced all sorts of buckling and folding of the Earth, not to mention the Rocky Mountains. The Colorado Plateau itself was not unduly squashed except for some spectacular wrinkles such as the Waterpocket Fold up in Utah. Then, starting 20 million years ago, after things were quiet for awhile, the Miocene period saw the whole American Southwest stretched and torn apart.
While the river runs downhill, as rivers prefer to do, it seems an even steeper descent because of the doming. At Lees Ferry, we were at an altitude of 940 meters (3,107 feet) above sea level, standing on Kaibab Limestone. Only 70 river miles downstream from Lees Ferry, the layers have been pushed up more than one mile; the Kaibab also forms the top of the North Rim, at an elevation of 2,640 meters (8,800 feet). The plateau ascends 1,700 meters, the river descends about 140 meters in that 70-mile distance so it seems as if youre going downhill at a much faster rate than you really are. The doming presumably happened gradually, more slowly than the rate at which the rivers erosion could cut through the layers; usually, rivers go around mountains rather than through them.
Rock layers bent and folded? Yes indeed. They sometimes fracture, of course, and form cracks called fault lines. And when they slip and slide in those cracks, we feel earthquakes. There are several fault lines just downriver from here, and well see some really big ones later in the trip.
For now, though, back to the Kaibab Limestone. Not far below the Paria confluence, another, grayer layer could be seen in the ledge just above river level. Soon it too had grown tall; now its far above us. This Toroweap is a thin-layered limestone with some silty layers mixed into it.
Then, still further downstream, emerged a white sandstone, the Coconino. This layer formed from ancient sand dunes when it was above sea level; it then sank and later, about 250 million years ago, the Toroweap limestone was deposited, compressing the sand and cementing it together into sandstone. Sandstone forms more quickly than limestone, a meter being laid down in a mere 1,700 years by the wind, as compared to the 8,000 years it takes for the same thickness of limestone to be deposited underwater by little animals dying.
And then we got into the Hermit and Supai layers. The Hermit is a colorful, fine-bedded shale deposited along an ancient floodplain, while the Supai is a reddish, chunky layer of sandstone and siltstone. Siltstones and shale come from river deltas. When a river fans out, it slows down. And when it slows down, the dirt particles suspended in the water settle out, building up to about a meter thick within 3,300 years. The red color signifies that a lot of iron oxide, more familiarly known as rust, was carried by that ancient river, probably from the erosion of an inland mountain.
So these layers tell us that an ancient, rust-containing river delta that existed here was covered by sand dunes as the climate changed and dried up this area. The area then sank for some reason and became an ocean floor burial ground for microscopic animals. Then, much later, it arose to become land again. Most erosion takes place on land, and indeed there is very little left atop the Kaibab around here. We saw those more recent layers yesterday in the horseshoe behind Lees Ferry. At Zion National Park up in Utah, one can see 300 stories of more recent layers the bottom of Zion Canyon is the same Kaibab Limestone that forms the top layers of the Grand Canyon. But down here, those more recent layers atop the Kaibab have been eroded away by wind and rain. If this land sank again, the new layers formed atop the local Kaibab would conceal a 250-million-year gap of missing layers. There would be fish fossils and then, in the layer atop that, modern animals maybe even a hapless sailor or two. The geologists call such a discontinuity an "unconformity." The Canyon has many of them, but we usually cannot spot them.
"Just try adding up the expected depth of the Grand Canyon," Alan noted, "as if a meter depth formed every 8,000 years, and youll see that a lot of it must be missing. In fact, more than 95 percent of it. Were just sampling the history."
All this, just in the five layers of rock we face on the shadowed eastern wall of the Canyon. Five layers emerged yesterday in a mere eleven miles; if things kept going at that rate, wed run out of layers in another day or two. And be halfway to China soon afterwards. I assume the number of new layers per hour will not continue at its present rate.
NORTH CANYON RAPID was just downstream of our campsite. It is a rapid of which many rivers would be proud. On the Grand Canyon scale, it rates a 5, at least until the next flash flood moves those boulders down into the river. And sculpts the grotto a little more.
Planning ahead, were all wearing raingear for the next 10 miles of rapids. The Marble Canyon is still in shadow since it runs north-south and the sun is still in the east. It must only be nine oclock or so, yet it seems as weve had a half-days adventures already.
The Redwall layer rises quickly out of the river, or so it seems. Actually one has to watch carefully to spot the first little bit of it several miles below North Canyon. It appears on the left shore in the midst of a talus slope (talus, in this context, does not mean the iron man in Spensers Faerie Queene, nor the ankle bone in anatomy; in geologists and hikers vocabularies, talus is short for "a big pile of big rocks" fallen from above, the gravel of the giants). The talus covers up the Redwall for a while, then there is a Redwall section a half-story high standing there, like a section of stage backdrop. Then the rapids hit; this stretch of river is called the "Roaring Twenties" for a reason. So we were busy watching the rapids, or watching the bottom of the boat while bailing afterwards. Our boatman today is J.B. (also known as Jim Irving); he tried to get a lot of water into the boat, and even poured a 20-liter bucket of water over his seat and the silver-colored storage boxes, so that we could bail yesterdays sandstorm out of the boat. I spent a lot of time jumping up and down on the floor of the boat to stir up the sand before scooping with the bailer bucket.
At first, we didnt notice that the cliffs, which had grown several stories tall along the riverbanks, were no longer the familiar Supai. The red-orange color and regular layers are quite different from the Supais chocolate-red and chunky appearance. We suddenly realized that we were quickly getting deeper into the Redwall.
Almost immediately, we started seeing caves along both shores. They werent from the rivers carving but rather from erosion by underground water, trickling down from the North Rim snowmelts. Redwall tends to be sufficiently resistant that it channels groundwater sideways, making an underground lake. Where it pools is called the "water table." The moist limestone may form caves here and there where the Redwall is less resistant. Although some caves have almost round entrances, most have elongated horizontal openings little ledges with roofs. But we dont see much evidence of the seepage. As we roared through Cave Springs Rapid at Mile 25, I looked around for springs flowing out of the canyon walls but saw little sign of the greenery that is the tipoff of seepage, much less a flowing spring near the river. Then I had to bail again.
"Is the patch holding tight?", I shouted over to Alans boat.
"How," Laura Sirota replied, "could we possibly know with another rapid throwing water in, just when we finish bailing?"
RIVER MILES OR RIVER KILOMETERS? Someone suggested that river miles should be made metric, but that would be like moving the milestones on an old Roman road to correspond with modern measurement. And while 10 river miles are usually 16 kilometers long, mapmakers dont re-measure every time a new meander is cut or a sandbar is washed away, lengthening or shortening the river a little. So its all approximate anyway. Still, although there arent markers along the river calling off the passing miles, the guidebooks have them marked on the maps and aerial photos. They wouldnt be hard to change to metric, but map names like 140 Mile Canyon would also have to be corrected all over the Grand Canyon, not just along the river corridor. And someone points out that wed have to rename all the stretches of river like the Roaring Twenties and the Photogenic Fifties that incorporate mileage in their names, making them the Euphoric Eighties or some such name in metric. Ah, well, America needs one relic of the English system of measurement just for historical perspective well let it be the Grand Canyon river mileage. Generous of us, I know, but were enjoying ourselves immensely.
DESERT VARNISH is a dark stain that appears on the Supai and Redwall layers. Weve been noticing it as we float along. It looks like a black stain spilled down the face of the red rock, the sort of thing one sees on the outside of a paint can. Someone compares the sight to a painting, causing a cynic to comment that the painter had something in common with the one who did his house, leaving those black drip marks everywhere.
The drip marks occur because of dew and rain at night, or so the story goes. When the surface of the rock is wet, the water seeps down into the rock a little way, following the fine cracks. In this fashion it covers an enormous amount of surface area. The water also dissolves some of the minerals in the rock, such as manganese and iron. When the sun comes along the next day and warms the rock, the water on the surface evaporates and the water in the cracks wicks back up toward the surface, carrying the dissolved minerals along with it. When the water finally evaporates, the minerals are left on the rocks surface. There they oxidize into what we see as black varnish. Lichens like the moisture too, adding to the texture of the surface.
This cycle repeats itself after every rain, every dew. Gradually, a layer of oxide builds up where water has been draining before it evaporates. Thus the similarity to drip marks on the outside of a paint can.
There is no desert varnish on the Kaibab or Toroweap layers; they seem not to have the right stuff.
The scenery continues to be spectacular, even more impressive than yesterday because the Canyon is getting deeper. Its a good thing that I brought along waterproof geologists notebooks in which to write this diary. They conveniently fit inside my hat, one of the drier places so far. I seem to remember that Abraham Lincoln carried a whole file cabinet worth of papers inside his stovepipe hat.
Back to bailing.
THOUGH IT IS CALLED SHINUMO WASH on the maps, this place is most notable for the exquisite grotto Silver Grotto that lies just a short distance up the way. It takes more than a casual hike to reach it because the going is, shall we say, "interesting." The boatmen tell us that were in for something more like a climb, slide, and swim.
First to the serious business lunch. A boatman fills up two great cooler jugs with river water (its clear again, the red silt disappeared overnight), and measures out a few drops of liquid bleach into each. One is set aside as the water supply, but people are asked to wait a while for the chlorine to work. The other cooler jug gets an added ingredient a big can of lemonade mix is dumped in and stirred around. Both jugs are set atop overturned bailer buckets. In the meantime, two folding tables have been erected and a plastic tablecloth spread out, and cutting boards laid down after being washed in the soap bucket (two more buckets of river serve as a hand wash and rinse). Then the boatmen slice up tomatoes, onions, lettuce, cheese, and a few other things. Everyone awaits the official announcement, and then one has a choice: the long make-your-own-sandwich line or the short express line for fans of peanut-butter-and-jelly sandwiches (today we also have leftover pancakes from breakfast, on which one can spread jam). You can, of course, do one after the other, so I stand in the long line munching on a pancake sandwich. Seconds continue for some time, and there are cookies for dessert, even apples and oranges.
Lunch is a leisurely affair, and bird-watching is popular here. Eventually most of us head over to the cliff. Not everyone goes on every hike; people often elect to stay behind and lounge around the riverside. This hike in particular is advertised as "not for everyone" due to the climb and then several obligatory swims; indeed, most river trips dont stop at Silver Grotto. And because of the swimming, most people who do make the trip leave their cameras behind. However, my little palm-sized camera fits under my hat if I loosen the chin strap, so I plan to swim with my head above water.
The cliff is less than two stories high. We wouldnt have to climb it at all if the river were higher; we could step directly from the boat onto the tongue of the dry waterfall. At ordinary river levels, one has to ascend the cliff on the upriver side, about like trying to climb into an upstairs window, but with lots of natural handholds here and there.
It is a slow but relatively safe process, aided by spectators below pointing out the next grip or foothold, and, when one gets close to the top, by the strong arm of a boatman to help one make the last step. I discovered a little problem with my camera-carrying method: it is very disorienting to have your head weigh more than usual when climbing; it felt funny every time I bent my neck to look for another handhold. It probably wouldnt have bothered Abe Lincoln, but Im not in practice. I finally slid off my hat with one free hand, while midway up the rock face, and dropped both hat and camera down to Dan Hartline, who was waiting on the beach below.
Climbers arriving at the top of the cliff are greeted by several giant agave "century plants" which tower over everyone. I looked back down. Dan had stuck my camera in his pocket, the usual sensible place to carry it, and was wearing my hat as he effortlessly climbed the cliff.
Next, we hiked along a narrow ledge at the top of the cliff, leading into the canyon. The ledge got narrower and narrower, and we finally came to a lovely view of a pool several stories below. And a smooth, steep descent path to reach the pool. Someone has thoughtfully installed a permanent bolt anchor for a climbing rope here, and all one needs do to descend is to back oneself down the slope, letting out rope, and aided by suggestions of "stand up straighter" or "lean back further into the rope, itll hold you."
Once at the bottom, I re-installed my camera inside my hat and pulled the chin strap tight. Then we started wading our way up the pool; when the bottom dropped away, we swam a dozen strokes until we could get our footing at the end of the narrowing canyon. The next obstacle the canyon posed was a slick, one-story-high "V" groove which we climbed by wedging our bodies across the gap and wiggling sideways with our shoulder blades. At the top of the "V" groove we pushed off into a longer, deeper pool. Then, dripping wet, we climbed a series of thin Redwall ledges.
Hard work, but its spectacular. A bandshell-like cave rises above us in the Redwall. For about one story up from the flat floor, all is white, gray, and black horizontal stripes; the bandshell above is red, with some little vertical black stripes from desert varnish, and some touches of green from hardy desert plants that have found a cranny to root in one of them a maidenhair fern which cascades down a short distance. There is a small pool on the floor, and one story above it is an opening, into which a waterfall occasionally pours, though not today. Through the U-shaped opening I can see that the canyon takes a jog to the left, white walls opening into a large cave in which some dark greenery hangs. The white walls just beyond the opening have some faint red stripes. Above them is a dark gray wall with giant vertical red stripes, some obviously mud. Crowning the bandshell is Redwall colored by a deep red wash. But this highest red layer just to complement the contrasting horizontal black, gray, and white stripes of the lower walls of the bandshell, and the vertical red stripes of the white and gray backgrounds inside the opening is vertically striped with black desert varnish. It is quite a sight to behold as one arrives, dripping with water and sweat and perhaps feeling "it-better-be-worth-it after all-Ive-gone-through." This is the Silver Grotto.
Most of us sit comfortably on ledges on one or another of those black and white and gray layers around the edge of the bandshell. But an adventuresome few climb up into the U-shaped opening via a path from the left with foot- and handholds here and there. One hiker loses his balance and slides a half story down an unobstructed path into the deep pool below, swims to shore, and tries again. Those who make it disappear within.
There is not too much more to see, the climbers report on their return to the top of the waterfall, just the cave and a steep groove, left by another waterfall which there is no hope of climbing. Sounds nice to me maybe theyre just saying that so we wont feel bad. The climbers stand at the opening atop the ancient waterfall like orchestra conductors surveying the size of the audience (which is their nonchalant way of contemplating the path back down getting down is always harder than the ascent). Most abandon the idea of the path. Then they sit down and prepare themselves for the plunge into the pool. There are suggestions from the audience that they take the plunge.
A big frog is spotted climbing up the wall that rises out of the pool, resting comfortably between hops on unbelievable inclines. It is heading up toward the opening in a flanking move John DuBois suggests that its an "attack frog" coming to get the trespassers. To the cheering of the audience, the climbers slip and slide down into the frigid pool, swim ashore, then hurriedly haul themselves out so that they can run around the floor to warm up. The frog takes no notice of their passing.
We are in no hurry. The boatmen, once convinced that were too tired to try to imitate them, demonstrate that with enough speed, one can actually run around the wall above the pool. They race around, halfway up between the pool and the opening. It is indeed a banked turn, just as on a racecourse. A slow-motion movie would suggest that the boatmen had defied gravity, jogging at a 30° angle from the vertical. One after another, the boatmen zip around the horseshoe turn. None goes too slow, none slips. Good old centripetal force presses them into the wall, making their floppy sandals grip better. Thats cheating, we shout try going slower. But they know better. Then they run into the left approach but keep going upward, their speed actually carrying them up into the opening. We suggest they get down with a running start as well, but the course wont work in reverse.
The frog ignores them too. I sometimes think that frogs cant see people, that we dont exist in their world of flies and other frogs.
What a lovely spot for a concert. We understand that on one trip a year, a string quartet hauls their old instruments along in waterproof cases (the cello is the big problem the boatmen haul it up and float it across the pools on an air mattress), and give concerts along the river. The grotto at the end of the North Canyon hike would be a nice site too. Silver Grotto is perfect for music making. Today we have to imagine the music. There are special places in a desert broad swatches of red and black color with delicate green decoration, church-like acoustics, and an unearthly light and this is one of them.
Heading back down, there is a stunning view of the meandering path followed by the flash floods that have polished this silvery gray channel, beyond which we catch a glimpse of the Colorado River flowing along at an unseemingly hasty clip. Its backdrop is twenty stories of steep Redwall cliff on the far side of the river, capped by chocolate-red Supai chunks. The light from the Redwall is reflected in the pools we must swim through, and here and there a swimmer starts out, rippling the smooth orange waters. A magical place.
THE SWALLOWS SEEM TO WORK HARD for their living, gliding along just a hands-breadth above the surface of the water in search of insects. I havent even seen any insects, but the birds seem to find them. The swallows have to eat enough to support all that wing flapping. Between the swifts and swallows during the day and the bats during the night, there are few flying insects left to pester us. There are no mosquitos, not one, though high water may bring some. Perhaps we should train bats to follow us around back home.
Not unlike the bats, the violet-green swallows have a distinctive way of flapping their wings. Facing upwind in a mild breeze, they seem to stand still while they jack themselves straight up into the air, almost as if they were climbing an invisible ladder. When they are several stories high, they fold their wings, drop their noses and go into a stall, turn in the direction they want to go, extend their wings slightly into a swept-back V, then dive down with wings fully extended as they speed along the surface of the river, flapping vigorously again as they lose speed. Then they flap their way up to a childs height and dive for another minor sweep or two before climbing that tall ladder again. If they miss a choice morsel, they will turn into the wind, flap their way up a story or so while allowing themselves to be swept backwards, then dive again over the same spot on the river. In quieter moments, we hear their song, "Chit-chit-chit-wheet-wheet."
I wonder if theyre any more likely to notice us than the frog up at Silver Grotto? Or is the swallows world divided up into birds, food, probably cats, and "all others?"
FLYING CATS? Ive been teasing Dan Richard that even cats can fly. By parachute. Not as naturally as the spiders do, but at least all in the interests of ecology.
The Royal Air Force and the World Health Organization once parachuted domestic cats into remote villages in Borneo in which all the local cats had died, allowing a population explosion of rats (which are potential carriers of all sorts of nasty diseases such as typhus, leprosy, and plague). And why did all the native cats die? From the insecticide DDT, sprayed to eradicate malaria-carrying mosquitos (as many as 90 percent of the people suffered from malaria).
This is a sobering story that we professors tell biology classes to illustrate the importance of a food chain and its ecological interrelations. The mosquitos in the story were controlled by spraying the insides of village huts with DDT. Malaria was indeed eradicated. All seemed well until the thatched roofs of the huts began to collapse on their occupants. It seems that the thatch was being eaten by the larvae of a moth that was normally present in the hut roofs but never before in such numbers. Apparently theyd undergone a population explosion. The moths predator, a parasitic wasp, had also been killed off by the DDT, but the wasp larvae had had the sense not to eat DDT.
But still, what is the loss of a few thatched roofs compared to eradicating malaria? But there were further consequences the DDT was eaten by cockroaches, though not in great enough quantities, alas, to kill them. A little clue: DDT isnt broken down and excreted very well once its in, it cant get out. It just builds up. Not enough, however, to kill very many cockroaches.
Next, the DDT-laden cockroaches were eaten by the friendly neighborhood geckos, those lizards that walk across ceilings with their suction cup feet. Now a gecko has to eat a lot of cockroaches to make a living, and the DDT from the cockroaches accumulated in the bodies of the geckos until it reached concentrations an order of magnitude higher than in the cockroaches. But still not enough to kill the geckos.
The trouble was that a village cat ate lots of geckos in addition to an occasional rat. Hundreds of cats were therefore accumulating the DDT ingested by millions of cockroaches. And while the DDT concentrations were never high enough to kill very many cockroaches or geckos, they finally did become concentrated one order of magnitude too high and killed the cats. And saved the rats. And helped spread the other nasty diseases.
"Operation Cat Drop" eventually restored the cat population and eased the threat of plague. Ignorance is expensive. Just knowing that mosquitos spread malaria and that DDT kills mosquitos isnt sufficient youve got to understand what else will eat DDT, even in sublethal doses, and so on up the food chain.
The whole systems the thing. It is called ecology. Our agricultural/medical/industrial society is dumping all sorts of new chemicals into the environment, with little knowledge of what theyll do. The remedy if any isnt usually as simple as parachuting cats.
LIKE THE OTHER LIMESTONES such as the Kaibab top layer, Redwall is really a light creamy gray color. The red coloring is just a wash, an overlay from the Hermit and Supai layers atop the Redwall those former river deltas with all the rusty silt in them from ancient mountains. The red iron oxide washes down over the Redwall limestone, coating it with the lovely red so familiar to Grand Canyon visitors as they concentrate on the tallest steep cliffs inside the Canyon. Were privileged to see the original gray color wherever a stream has washed away the red coating, or wherever a slab of Redwall has recently fallen away, exposing the underlying colors. Therefore, we can spot sites of recent rockfall just by the patches of pale color amidst the red. In a while, the dripping rust will color these red too, healing the wound.
Where the red has been washed away by the spring floods of the untamed Colorado, the underlying color in this stretch of canyon alternates between a light and a dark gray. Standing by the river is a slab of fallen Redwall limestone, standing vertically like Ten Mile Rock did yesterday. It has alternating dark gray and white horizontal bands, but no red. It is squared off, almost as if a stonemason had been at work. Someone is reminded of the black-and-white banded architecture of Giottos Tower in Florence, and of his church in Siena, and I agree. A little bit of thirteenth century Italy, here in the bottom of the Grand Canyon. Art imitates nature but sight unseen?
WE PASSED A LOVELY CAMP on the right shore. As we zipped by, I thought that it was too bad we couldnt stop. But we stopped there after all; its just that the nice place to park at this campsite is downstream of the rapid. And so J.B. ran the rapid, then caught the back-eddy. We rode it back up to camp.
No sooner are the boats tied up than shouts of "Bag line!" are heard. The black rubber bags containing our gear are tossed by a boatman to the first person on the shore, who passes them along in bucket-brigade fashion. A pile of black bags forms back in the center of camp. As one boat is emptied, a new bag line forms at the next boat. And then everyone is free until dinner, free for bathing, napping, or exploring. We explore the camp, picking out nice sites to spread a sleeping bag. They are everywhere.
CLIMBING UP A CRACK in a three-story cliff of Redwall, I find a platform of eroding rock and debris from higher layers that didnt make it as far as the river. The platform extends for a mile along the right bank, and was home to the Anasazi. These Native Americans of a thousand years ago probably grew beans, corn, and squash in nearby South Canyon. And surely on the sand bars of the river, down where our tents are taking root. I wondered aloud about how many of our campsites are, in fact, old Indian camps. Probably most, said Subie.
The foundations and walls for a few small buildings remain up here; they probably built down near the river too, but floods have since erased the evidence. The northernmost ruin has a clever design, with a baffle protecting the front door, a wall keeping the north winds of winter from blowing into the room. The Anasazi must have been small, because someone as tall as I am would never have fit inside the one room except diagonally. Even assuming the short stature that poor diets cause, there would have been comfortable sleeping room for no more than two persons. Broken pottery and stone tools are laid out near each ruin; we pick them up and examine them carefully. As compared to tourists generally, river-runners and hikers rarely walk off with souvenirs. If this were the South Rim theyd be gone in a day not so much a matter of lesser virtue as of sheer numbers of visitors. Three million people come to see the Grand Canyon in some years, and 98 percent never get more than a few steps below the rim. Only one-half of one percent run the river, most during the April-to-October season.
At the junction of two paths was a large rock slab covered with desert varnish. At first I passed it by without a glance. Later I found that it had been decorated with quite a number of petroglyphs. These are like painted pictographs, except that they are pecked into the rock face. No one knows whether the Anasazi used this method because they didnt have enough colorful material for painting pictographs, or because they knew that designs etched into the rock would better survive the desert varnishing.
Many of the traditional Anasazi forms can be discerned on the slab, including near-replicas of the famous pair of spirals (one large, numbering seven turns, and one half-size with three turns) found at Chaco Canyon over in New Mexico which the ancient inhabitants used to track the 18.6-year lunar cycle, the equinoxes, and summer solstice. The spirals here couldnt have been used the same way, as there is nothing to create a shadow as at Chaco, but I presume the spirals were widely copied as magical symbols, decorating many local walls and rock slabs around the Colorado Plateau.
Another six stories up are a number of caves in the cliffs overlooking this three-story-high living platform, and the teenagers have been exploring them. The trail leads to a narrow crawl space. Jeremy DuBois tells me that from it, one can peer out of a hole to see far down a cliff into South Canyon below. Once, unfortunately, someone fell to his death from that hole, Alan tells me; mishaps involving river passengers (as opposed to ill-prepared hikers coming down from the rim) are fairly uncommon, particularly on the oar-powered trips on which there is an experienced boatman for every 3 or 4 passengers.
I can see where the local Giottos Tower came from: the entire Redwall cliff across the river is one alternating light and dark gray layer after another for over thirty stories up from the river, each layer about as far apart as the rungs of a ladder. The red Supai coating seems to have been washed away from an enormous expanse of flat cliff, perhaps by groundwater seeping out of the walls at some other time of the year (its dry now). There are also vertical cracks evidently made by water seepage and the white layers often bridge the gap where the darker layers above and below them have been eaten away, suggesting that the white layers are harder stuff, purer limestone. As a result, the cracks look like ladders, but they lead nowhere.
On this side of the river, the late afternoon bathers are out. There is a deep but protected channel leading upriver out of South Canyon, a nice place for a quick dip. Weve all collected a coating of alga from our swims back at Silver Grotto. We wash off, but no one stays in the frigid water for very long.
HOMINIDS GOT THE WANDERLUST about 1.5 million years ago. This topic came up after dinner when we got to talking about the Anasazi and the other natives of the Americas. Someone brought up the Bering Sea land bridge, and off we went.
Hominoids are the apes and the hominids. Hominids are us, our ancestors, and our cousins back to the time that we split off from the chimpanzees about 7 million years ago. Prior to 1.5 million years ago, the hominids apparently stayed put in Africa. Homo erectus, with its partly enlarged brain, spread out of Africa into Asia and later Europe. Homo sapiens was around by 100,000 years ago. Australia (which was joined with New Guinea during ice ages, when the drop in sea level connected them) and the Americas, however, seem to have waited a long time for human habitation. Only at about 50,000 years ago do traces of Homo sapiens appear in Australia. Perhaps boats were invented then, allowing the water barriers between the Earths land masses to be surmounted, though the Mediterranean islands were not inhabited until 13,000 years ago, the traditional time assigned to the invention of boats.
Anthropologists now think that water is not the barrier it was once thought to be. One can, after all, even walk on water in special circumstances. Traditionally, the peopling of the Americas has been attributed to the substantial lowering of sea level (by about thirty stories) by the last ice age, when the ancient pioneers could walk across the Bering Strait from Asia to Alaska. However, as Alaskan anthropologists note, anyone who thinks that the Bering Strait is a barrier simply hasnt been around during the wintertime. (They slyly suggest that the textbook myth about the Bering Strait is a fiction created by the summer tourists). Just as the Lapps conduct migrations across the ice-covered Baltic Sea between Sweden and Finland, so could anyone have strolled across the Bering Strait during the winter, ice age or not. The barrier would be getting from coastal Alaska down south to the main body of the continent; during an ice age, thats rough. Crashing surf and rugged headlands keep one from hiking down the coast. Glaciers kept anyone from using inland routes. About 13,000 to 14,000 years ago, as the most recent ice age was starting to melt off, a corridor opened from the Yukon down to Edmonton, Alberta, and so travel would have become much easier starting then. Certainly there are a number of Alaskan species of mammals, such as the grizzly bear, which suddenly make an appearance down south after that date.
Still, though, travelers could have come to the Americas before the last ice age got started if they had come by boat, anywhere along the coastline of North, Central, and South America, from Africa, Asia, or Europe. Any time they could have gotten the boats and brave sailors together. Present evidence suggests that this happened only in the days of modern-type Homo sapiens sapiens; Neanderthals had probably disappeared before the peopling of the Americas. The ages of properly excavated archaeological sites go back to 31,000 years ago in Brazil, 21,000 years in the eastern United States, and 14,000 years ago in Chile, although there are scattered claims of even older finds.
One of the California neurobiologists noted that there is a large human skull, arguably dated to the last ice age, that washed out of the cliff above the surfing beach at Del Mar, just north of San Diego; some archaeologists are trying, so the local joke goes, to locate his surfboard for tree-ring dating.
There is evidence that only a few small groups made it to the Americas, and that each then had a population explosion. All of the South American natives seem to fall into one group. The Inuits (Eskimos) and the Athapascans (Navajos, Utes, Apaches, and many of the west coast "Indians," as well as the groups between the Yukon and Lake Athabasca) constitute another. The rest of the North American Indians comprise a third group, though for most purposes they can be identified with the South American Indians. The groups are based not on cultural similarities but upon genetically coded traits, such as blood types, and are constantly being revised as new genes are analyzed. However, it is evident that, except for the late-arriving group of Eskimos and Athapascans, the natives of the Americas arent especially related to the peoples of northeastern Asia on the other side of the "Bering land bridge." Most Indian skull shapes are quite similar to the types found in China before the Classic Mongoloid type invaded China from the north about 15,000 years ago; the oldest Eskimo and Athapascan skulls are clearly Classic Mongoloid and more recent.
In the Southwest, there were paleo-Indians around hunting with Clovis point arrowheads 11,000 years ago (these characteristic arrowheads, found widely across North America, were named after the find at Clovis, New Mexico). Hereabouts, the archaic Indians periodically visited the Canyon about 4,000 years ago. In Stantons cave the big hole in the Redwall that we can see downstream in the fading daylight they left figurines made of willow branches. It wasnt until about A.D. 900, however, that they stayed in the Canyon long enough to bother building habitations, at least ones sturdy enough for the archaeologists to detect after a millennium.
The Indians had been around the Southwest long before that, irrigating crops at Mesa Verde by A.D. 600. They may have been distant relatives of the Meso-American Indians, who were building cities down in the Yucatan peninsula of Mexico by that time. The Anasazi, as the ancient Indians who lived around here are called, were hunter-gatherers who settled down; but not before they got some of their ideas about check dams, irrigation, stars, and agriculture from the Mayan civilizations down south, who were into empires in a big way by A.D. 600.
This makes the Americas extraordinarily interesting to anthropologists. We can stand here at South Canyon and see thousand-year-old relics of a Stone Age people including "soft" artifacts like baskets and sandals without all of the overlay of subsequent Bronze and Iron Age peoples, without the Greeks and then the Romans having built temples atop the site. Here one can study the fluctuations of climate in the thick and thin tree rings of long-surviving trees, see what the vicissitudes of rainfall did to the Anasazi population numbers, get some feeling for what it was like to live in a marginal situation out on the fringes of the main population, where every bit of cleverness counted. The Grand Canyons Anasazi are an anthropologists dream, giving an uncluttered view of a people not unlike those who were once on the cutting edge of human evolution.
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