Swamped in saltwater
© Bryan W. Jones

Fast cars make, and break, speed records on the flat, barren, dazzling white raceway at Utah’s Bonneville Salt Flats. The first record was set in 1914 at 141 mph, and there have been many since, including one in 1970 by the rocket-propelled Blue Flame, traveling at 622.4 mph. In 2006 a diesel engine traveling at 350.092 mph broke another record.

The long, flat straightaway and smooth surface are the speedway’s draws. Almost its entire surface, 90%, is made of common table salt, deposited millions of years ago in the nearby mountains when Utah was covered by a shallow sea. Some 15,000 years ago, rivers dissolved some of the salt and carried it into Lake Bonneville, a glacial lake once as large as Lake Michigan, and 1000 feet deep. Although Lake Bonneville has now drained away, (leaving the Great Salt Lake) the salt remains, in some spots, almost five feet thick. Groundwater continues to flow in, bringing more. Each year, the water floods the surface and then evaporates, coating the raceway with a fresh, smooth layer of salt.

Dry land may seem as if it is terra firma, but the salt flats are on the move. The Bonneville Salt Flats are part of the Great Basin, which began forming in the western United States some 17 million years ago as North America drifted west, colliding against seafloor from the Pacific. As the San Andreas Fault lengthens, tearing rock from California and sending it north, the Great Basin widens, creating the vast, flat, open space that attracts high speed auto racers.

In 1846, the Donner-Reed pioneers, seeking a short-cut to California, crossed the flats. Traveling much more slowly than today’s racers, they met with tragic result. Their route, along what was known as the Hastings Cutoff, cost them both time and provisions. Where their wagons were mired in mud just below the salt, the wheel tracks can still be seen today. Their late start and difficult passage brought the party into the mountains at the onset of winter. Trapped for months on a snowy pass on Truckee Lake, they desperately resorted to cannibalism, forced to eat their deceased to avoid dying from starvation.

References and more information

Donner-Reed Story
http://www.nps.gov/cali/historyculture/donner-reed_story.htm

Horseshoe crabs, with their armored shells, spike-like tails, and antediluvian appearance, look as if they’re relics from the past. “Living fossils,” they roamed the sea’s shallow coast long before dinosaurs arrived on land. The oldest known horseshoe crab fossils were thought to date from 350 million years ago, until paleontologists began studying two new, and unexpectedly rich, fossil sites. An artist discovered one site: prospecting for rock flat enough for his painting, he accidentally turned up a fossil eurypterid, or sea scorpion.

Earth’s fossil record is scant, accounting for only a tiny percentage of the hundreds of millions of species of plants and animals that have lived here. Mudslides, or ash from erupting volcanoes, or in this case, highly saline water devoid of oxygen, can create spectacular fossil sites. These sites preserve soft tissue of animals that would otherwise be eaten by scavengers or decomposed by bacteria. Lagerstätten, as the sites are known, offer an extraordinary window into the distant past.

Two Lagerstätten in Manitoba contain fossils of earth’s oldest horseshoe crab. One site is in a cove on Hudson Bay outside Churchill, and the other among jack pines near William Lake, a five hour drive north of Winnipeg. Its founders named the animal Lunataspis aurora, “crescent moon shield of dawn,” for the crescent shape of its large, shield-like body and for its appearance much closer to the dawn of animal life than scientists previously understood.

Luna lived in lagoons and tidal flats of a tropical sea that once covered much of North America, a sea full of coral and sea lilies, fierce, coiled cephalopods, sea scorpions, and giant trilobites. Many animals from these ancient times are now extinct, but horseshoe crabs endure: the 445 millionyearold Luna is strikingly similar to its modern descendant Limulus.

Spawning horseshoe crabs, Delaware Bay
© Jay Fleming

p.s. Stay tuned! Even older horseshoe crabs have been reported from the rocky desert of Morocco, in rocks that once belonged to the sea. Ancient seafloor is still revealing the secrets of earth’s history.

References and more information

Paleontologist Graham Young of the Manitoba Museum’s blog on the discovery of Luna
http://ancientshore.com/2009/02/06/catching-a-crab/

A climber scales a piece of ancient seafloor in Utah’s Wasatch Mountains
© Andrew Burr

Utah’s Wasatch Mountains, more than five hundred miles from the ocean and five thousand feet above sea level, are remnants of ancient seafloor that record the ebb and flow of the planet’s early tides.

Some 750 million years ago, the ancient continent of Rodinia was breaking up while the Pacific Ocean basin was forming. Nevada was located along the coast. The sea and its tides reached inland, just outside what is now Salt Lake City.

Today, the steep cliffs of Big Cottonwood Canyon hold the record of those ancient tides. Within huge slabs of shale that once belonged to the ocean, alternating layers of sand and silt mark the turning tides (silt was dropped at slack tide, sand when water flowed more forcefully).

The passage of the moon around the earth and the earth around the sun dictate the rhythms of tides. Those rhythms recorded in Big Cottonwood Canyon suggest that when the ocean lapped on the shore of now land-locked Utah, the days were 25% shorter – 18 hours instead of 24!

References and more information

Bugden, Miriam. Geologic Journey Through the Central Wasatch Range. Utah Geological and Mineral Survey http://geology.utah.gov/online/pdf/pi-09.pdf
Utah Geological Survey
http://geology.utah.gov/geo_guides/c_wasatch/index.php

Sugarloaf Cove, Schroeder, Minnesota, on the North Shore of Lake Superior
© CK Sandberg 2009

The Great Lakes hold 90% of the fresh surface water in the U.S. It’s enough to put the lower continental U. S. under nine and a half feet of water.

Great Lakes water supports agriculture and industry, and supplies drinking water for the 33 million people living in the region. Each year, the lakes lose water – through evaporation, as water is removed for human use, and as it drains out from one lake to the next, and out through the Gulf of St. Lawrence into the sea. Each year, it is replenished. The water that refills the Great Lakes comes from a great distance. Evaporated from the Gulf of Mexico and adjacent Atlantic, it is blown in moisture-laden wind and storms 1000 miles to fall in the Great Lakes as rain and snow.

If things had gone differently, the Great Lakes might have been part of a large ocean. Over one billion years ago, heat rising from inside the earth stretched, thinned, and cracked the landscape around what is now Lake Superior, threatening to tear the terrain apart. The tear is known as the Keweenawan or MidContinent Rift. Some 22 million years of volcanic eruptions never widened the crack enough to let in the sea, or make Duluth a seaport, but the tremendous outpouring and subsequent sinking of volcanic rock – 10 miles thick in some places – sculpted the bowl that today holds Lake Superior. You can see evidence of the volcanoes that nearly tore the continent in two in the lava rock at Sugarloaf Cove on the north shore of Lake Superior in Minnesota.

References and more information

Sugarloaf Cove - The North Shore Stewardship Associations
http://www.sugarloafnorthshore.org/index.html

In 1970, artist Robert Smithson built an enormous spiral jetty at Rozel Point on Gunnison Bay in Utah’s Great Salt Lake. Some 1500 feet long and 15 feet wide, it disappeared when lake waters rose, remaining submerged for 20 years. When it reappeared, its black boulders were encrusted with salt.

About Spiral Jetty, Smithson wrote that he felt like a “paleontologist, sorting out glimpses of a world not yet together, a land that has yet to come to completion, a span of time unfinished…”

Millions of years ago, a shallow ocean repeatedly covered what is now Utah. Its waters are gone, but some salt remained locked in rocks deposited from those ancient times. Rivers began dissolving the salt, carrying it into Lake Bonneville, a once enormous lake which, when it shrank, left behind Utah’s Great Salt Lake. Today, some of its salt has crystallized on the boulders of Spiral Jetty.

The boulders themselves - 6650 tons of black, volcanic basalt – mark a different chapter in Utah’s geologic history. Earth’s continents are moving. North America slowly drifts west, colliding with the floor of the Pacific Ocean. The San Andreas Fault tears rock from California and pushes it north, sending Los Angeles toward San Francisco. Utah is being stretched. Dr. William Hammond from the Nevada Bureau of Mines and Geology reports that the distance between Salt Lake City and Reno, Nevada is increasing by about ¼ of an inch a year. As earth’s outer layer is stretched and thinned, molten rock from deep within the mantle erupts on the surface. From those volcanoes came the rock that Smithson used to build Spiral Jetty.

The artist died in 1973, but his sculpture is still there, recording the mutability of Utah’s landscape.

References and more information

Hintze, L. F. and B. J. Kowallis. 2009. Geologic History of Utah. Brigham Young University Geology Studies Special Publication 9, 225 pp.

Any child who has read Holling Clancy Holling’s Paddle-to-the-Sea knows we are connected to the ocean even if we can’t see it. In this beloved children’s book first published in 1941 but still in print, an Indian boy living in the Canadian wilderness near Lake Nipigon carves a canoe and a paddler. When he hears the cry of wild geese returning at the end of winter, he places Paddle-to-the-Sea on a snowy hill behind his home, facing south.

As the sun warms, Paddle-to-the-Sea begins his journey, carried by melting snow into a brook and then a river, and then into the rough waters of Lake Superior. Lake Superior is 600 feet above sea level; each of the Great Lakes is a little lower. Paddle-to-the-Sea drifts from one lake into the next, narrowly escaping a saw mill, and catching a ride in a container ship carrying iron ore mined from the nearby mountains. This iron, from Michigan’s Marquette Iron Range, the world’s richest iron mine, fueled the Industrial Revolution in the U. S. The iron was precipitated into the ocean and then raised into mountains almost two billion years ago.

Paddle-to-the-Sea floats along eddies and currents from Lake Michigan into Lake Huron. He passes the steel mills of Lake Erie, and plunges over Niagara Falls into Lake Ontario. Three years and several thousand miles later, he reaches the mouth of the St. Lawrence and the open ocean.

Beautifully drawn maps detail the watery life-line between the Nipigon River and the ocean. If the earth continues to warm, water levels in the Great Lakes will drop. Tiny Paddle-to-the-Sea might make the long journey, but the shallower water may inhibit large cargo ships that ply the waters of the Great Lakes today.

References and more information

Holling, Clancy Holling. 1941. Paddle-to-the-Sea. Boston: Houghton-Mifflin.

Great Lakes cross-section profile
http://www.epa.gov/glnpo/atlas/index.html

Iron formation in the ocean
Smithsonian Ocean: Our Water Our World
http://www.dnr.state.mn.us/snas/naturalhistory.html

Climate change and the Great Lakes
http://online.nwf.org/site/DocServer/Climate_Change_and_Great_Lakes_Water_Resources_Report_FI.pdf?docID=2442
http://www.usgcrp.gov/usgcrp/nacc/education/greatlakes/greatlakes-edu-3.htm
http://sitemaker.umich.edu/scavia/files/how-global-warming-report-08_final.pdf

While washing dishes at a friend’s cottage in Northport, on Lake Michigan, I noticed strange rocks on the window sill above the sink. They looked like coral, odd for a cottage on a freshwater lake. My host explained, “Oh, these are Petoskey stones, Michigan’s state rock. Our beach is full of them.” Later that afternoon, while down at the beach, I was stunned to find stone after stone marking the presence of ancient sea life.

Petoskey stones are remnants of once extensive coral reefs. Some 350 million years ago, during the Devonian Age, these reefs edged a large shallow sea covering what is now Michigan. When the sea retreated, the reefs remained. Petoskey stones contain fossils of a tabulate coral, Hexagonaria percarinata, now extinct. When glaciers covered Michigan, moving ice broke apart the fossil reefs, rounding the stones, and delivering them to the beaches of Traverse Bay, where they are found today.

References and more information

Paleontology portal
http://www.paleoportal.org/index.php?globalnav=time_space&sectionnav=period&period_id=13

Maya Lin’s new sculpture, located in an 11-acre pasture at the Storm King Art Center in Mountainville, New York, consists of long rows of undulating dirt and grass “waves,” each 10 - 15 feet high. The Wavefield both evokes the feeling and scale of ocean swells far offshore, and at the same time echoes the surrounding hills.

Made of land, it represents water, while the nearby hills are made of land that actually was once part of the sea. These hills, the Hudson Highlands, are the deep core of the Appalachians. More than one billion years old, they were built from an ocean basin that existed long before the Atlantic, and long before the Atlantic’s predecessor, Iapetus. When an ancient continent, Rodinia (”motherland” in Russian) was built, these mountains were raised.

Andy Goldsworthy
Storm King Wall, 1997-98
Fieldstone
Approx. 5 x 2,278 feet
Site-specific sculpture created for Storm King Art Center, Mountainville, New York
Photo: Jerry L. Thompson
© Storm King Art Center, Mountainville, New York
© Andy Goldsworthy, Courtesy Galerie Lelong, New York

Glaciers broke up and scoured pieces of bedrock from the hills, making the 1,579 tons of field stone that went into Andy Goldsworthy’s wall, not far from Lin’s Wavefield. The wall, 2, 278 feet long, threads through the trees, dips down to a pond, then rises on the other side across a pasture toward the busy New York State Thruway, carrying in its rock the region’s oceanic origin.

References and more information

Andy Goldworthy’s Wall – Storm King Art Center
http://www.stormking.org/AndyGoldsworthy.html
http://www.nytimes.com/2000/10/08/nyregion/a-grand-creation-that-crosses-a-road.html?scp=5&sq=andy%20goldsworthy%20and%20storm%20king&st=cse