Time expressed in years before present day.

~2,000,000,000: Paleoproterozoic era, possibly during the Orosirian Period. Sediments are laid down in a shallow sea teeming with the newly evolved Cyanophyta, or blue-green algae.

~1,700,000,000: Probably during the Stratherian period, after the evolution of multicellular life, intense heat and pressure cook the above sediments into metamorphic rock, the Vishnu Schist. Intrusions of volcanic rock, the Zoroaster Granite, occur at about this time.

~1,200,000,000: During the Stenian period, as the supercontinent Rodinia is assembling, a layer of dolomite sediments out atop the Vishnu schist and Zoroaster granite. This will be called the Bass Limestone. After a relatively brief period of time, perhaps only a few million years, the sea from which the Bass Limestone was deposited recedes, and river deltas along the advancing shore lay down mud, silt, and sand that will become the Hakatai shale. These wetlands are home to stromatolites, large reef-like structures made by colonial cyanobacteria. The Hakatai emerges above sea level, is eroded away in part along with any overlying layers, and then re-submerged, after which sands are deposited —these will become the Shinumo Quartzite — and then tidal flat sediments upon the sands, which become the Dox Formation.

~1,100,000,000: A series of volcanic eruptions cover the area in basalt up to 1,000 feet thick. This will be called the Cardenas Basalt.

~1,050,000,000: After the Cardenas Basalt (and the rocks below it) is uplifted and eroded, shallow marine sand accumulates in some places: the Nankoweap Formation.

~1,000,000,000: For the next 175 million years, the sea advances and retreats. As it does so, it lays down alternating layers of coarse (delta or near-shore) sediments, and finer (deeper-water) sediments. These become, in order of decreasing age, the Galeros, Kwagunt, and Sixtymile formations.

~800,000,000: Tectonic faulting activity breaks up the landscape, creating fault-block mountain ranges and tilting all the strata from the Bass Limestone to the Sixtymile Formation to about 15 degrees from the horizontal. A hundred million years or more of erosion commences, in most places removing all trace of the Nankoweap through Sixtymile formations, in some places scraping the earth clean down to the Vishnu Schist.

~550,000,000: The region is once again slowly submerged in ocean water. This ocean water now has multicellular animals living in it, some of them, such as trilobites, brachiopods, and crinoids, with hard shells. As the shore advances over the landscape the Tapeats Sandstone is laid down, consisting of coarse beach sand and conglomerated cobbles.

~530,000,000: Shallow seas deposit silt, which will become the Bright Angel Shale.

~516,000,000: The sea is deeper now, and deep-water calcium carbonate precipitate accumulates on the sea floor, which will fuse into the Muav Limestone. For more than 150 million years afterward, any sediment laid down on top of the Muav Limestone will be eroded away — if any is in fact laid down, which we do not know.

~350,000,000: Water erodes channels in the top of the Muav Limestone, and this water is rich in calcium, likely from dissolving the Muav. Some of that calcium is left behind as precipitate. It forms the Temple Butte Limestone.

~330,000,000: The area is now near the equator. A shallow tropical sea teeming with Devonian animals and aquatic plants covers the land. Thick layers of limestone and dolomite are deposited on the floor of this sea, entombing and fossilizing many of its inhabitants. This will become the Redwall Formation.

~325,000,000: Tidal estuaries deposit mud and silt, which becomes the Surprise Canyon Shale. This rock is friable, and all but a very small amount of it is eroded away over the next fifty million years.

~285,000,000: Shallow estuaries and tidal flats cover the land. The sediments laid down in them become shales, siltstones, and limestones. Some of the layers — collectively known as the Supai Group — contain fossils of early amphibians and reptiles.

~265,000,000: After another dry period in which rock layers are eroded, the water returns: riparian wetlands in a generally arid climate deposit a torte of mud, silt, and rust in many thin layers. This will become the Hermit Shale.

~260,000,000: Chronic drought hits the area, and the landscape becomes a desert of pure quartz sand, which becomes the 600-foot-thick Coconino Sandstone.

~251,700,000: In an event perhaps related to the chronic drought, almost all life on Earth dies.

~250,000,000: Surprise! The sea comes back, comparatively devoid of living things. As it advances and recedes, occasionally leaving behind chemical-rich lagoons of water to dry out and leave their dissolved salts behind, layers of sand and calcinated silt and gypsum are deposited atop the Coconino sands to become the Toroweap Formation. Starting at about this time, braided coastal rivers deposit thick layers of silt and sand, the Moenkopi Formation, all of which will then be eroded away — at least in the area we’re discussing.

~225,000,000: Another sea, or series of seas. These deposit calcium carbonate, which will become the Kaibab Limestone, some of the youngest rock in the area. But not the very youngest.

~75,000,000: After being walked all over by dinosaurs for 155 million years, the land begins to rise up. It is the start of the Laramide Orogeny, which may or may not have anything to do with the Farallon Plate subducting under the North American Plate at the latter plate’s western edge, which is now along North America’s west coast, in Utah. For whatever reason, the whole countryside starts to lift up into the air.

~35,000,000: Another pulse of uplift. Watercourses in the area respond by digging deeper.

~5,300,000: Geologists will disagree in the early 21st century as to what happens now. Some will say that the Hualapai drainage system, digging ever deeper and eastward into the Kaibab Plateau, breaks through into the drainage system of the Ancestral Colorado, which until now had flowed southeastward into a lake basin. The opening up of the Gulf of California by the San Andreas Fault likely plays a role, as the Hualapai had also formerly drained into a lake basin. The lowering of the watershed’s bottom end to sea level greatly increases the cutting power of the river. Other geologists will maintain that stream capture alone could not produce the landscape of the 21st Century, and that the lake the Ancestral Colorado fed probably overflows into the Hualapai’s drainage. Either way, a catastrophic flood takes place, and the carving of the Grand Canyon begins in earnest.

~3,000,000: The climate gets wetter during the Pleistocene, and more water cuts the Canyon more deeply.

~1,800,000: Volcanoes erupt, forming the youngest rock in the Grand Canyon. The eruptions dam the river at least a dozen times over the next 1.4 million years, causing gigantic reservoirs to form. Some of the lava dams are 1,000 feet high, with the full force of the Colorado flowing over them in impossibly huge waterfalls as it cuts troughs through them. The Canyon reaches nearly its current depth about now.

~10,500: There are definitely people passing through here by now. How long they’ve been doing so we don’t know.

~4,000: There are definitely people living here year ‘round by now.

~1,200: The Ancestral Puebloan people build remarkable and sturdy edifices in the area.

138: John Wesley Powell rafts the Colorado through the Canyon singlehanded.

113: Much land around the Grand Canyon is declared a preserve by President Benjamin Harrison.

99: Grand Canyon National Monument is established by Theodore Roosevelt.

88: Grand Canyon National Park is signed into existence by Woodrow Wilson.

40: My friend Dave prevents the building of two dams within the Canyon.

6: President George W. Bush, an avowed fundamentalist Christian and smirking denier of scientific fact, is sworn into office.

3: The National Park Service approves the gift-shop sale of a book claiming the Canyon is just 6,010 years old while denying other new books shelf space. Park Service brass stonewalls in defense of the decision, despite sharp criticism from the non-ignorant community, until the present day.

2: I trace the delicate outline of a crinoid stem in a block of Redwall Limestone that has fallen a few hundred feet from its place of origin, far above the trail. It exists, for now, until the wind and water break it and it runs out to the fetid water of Lake Mead to add its silt to the reservoir. A million of its compatriots are still encased in the rock above. I look for the mold, the negative impression of the stem where the rock has split, and find it. The texture of the living crinoid is pressed into the rock, a Devonian cuneiform, and a far more hallowed scripture than any ever written by the hand of humans.

27 thoughts on “Timeline

  1. Hank Fox

    Ah. I wondered about the “singlehanded” too.

    (Spoiler: For those of you not in the know, Civil War veteran Major John Wesley Powell was a bit of a grandstander, and played heavily in his own accounts of the first expedition down the canyon – thus he “singlehandedly

  2. Rob G

    <i>…and a far more hallowed scripture than any ever written by the hand of humans</i>

    Well, except for the Major Matt Mason Big Little Book.

  3. Rob G

    the geology will long out last the humanity and the dieties.

    I suspect the Atkins Dieties will outlive even the Grand Canyon.

  4. Charles

    I liked the Powell joke too.  Good one!

    So many, many people worked so hard to do the fieldwork necessary to develop that time line.  I can only begin to imagine how they felt upon seeing crap like that in the bookstore and knowing that people will say, “Well, it must be true, I bought the book in the official bookstore.”

  5. E-lad

    If all that stuff washed out of the grand canyon, why is there no delta at the river’s mouth?

  6. Rob G

    Well, I saw this sentence

    Prior to the mid 20th century, the Colorado River Delta provided a rich estuarine marshland that is now essentially desiccated, but nonetheless is an important ecological resource.


    Truly, Google and Wikipedia are miraculous.

  7. kathy a

    so—if it was created just 6,000 years ago and its past is not acknowledged, the grand canyon is pretty much just a big piece of southwestern art?

    i am wondering now if things are this bad for science at other big national parks.  it is hard to imagine yosemite’s bookstore and signage pulling off the same kind of thing, if only because it would be noticed immediately—there is a far greater educated population within driving distance, i think.  but i don’t know.

    good quick search, rob.

  8. Jim in STL

    Chris, Great job. 

    To add a spatial dimension to the great timeline that you’ve laid out I’d add that the Grand Canyon Supergroup (GCSG), prior to ~800,000,000 and the tilting, was one of a series of sedimentary basins recording tectonic activity all along the western margin of Laurentia (pre-Bush dynasty USA) that would provide that base for much of the most beautiful landscapes that we enjoy today. 

    This older period, middle-to paleo-Proterozoic (after about the 800,000,000-year mark I refer to all the rocks as modern), is a time of radically different continental configuration that included either Siberia, Australia or S. China (or some combination thereof) as our western neighboring continental mass, sans California, Oregon & Washington -since this is still debated I guess the ID/Creationist crowd can claim this as new territory if they want.  In addition to the very very impressive Grand Canyon (GCSG and the overlying modern rocks), I highly recommend some driving/hiking time in the Sierra Ancha Mtns, east of Phoenix, to explore some of the beautiful remnants of the Apache Group rocks (neo Proterozoic).  Or, my favorite, the Belt Supegroup rocks (middle Proterozoic) of Montana (Big & Little Belt Mtns, Glacier NP).

    The geological evidence on this and other continents regarding the age and development of the earth is staggering and cannot be undone by the ID/creationists -somewhere, someone will be the guardian of this information.  It’s through the efforts, such as your writing, of the science/reality based community that the US doesn’t loose its rightful place to ramain one of the guardians of the scientific story of the these treasures.  And, for that I’d like to say thanks to you and those who come to your blog that keep the good fight going.

    I hope you don’t mind but I included a link in my URL below that has a pretty good map -pre California. 

    Thanks again,

  9. Chris Clarke

    Lives in San Francisco, bashes Bush—shocking.

    Linked by PZ, get careless, petty tangential comment from thoughtless conservative troll who ignores the post’s main point—shocking.

    I’m not blaming PZ for that, of course. He’s afflicted way worse than I.

    Anyway and for what it’s worth, there are quite a number of Bush supporters in my neighborhood.

    Rob unsurprisingly beat me to the Delta answer, although he failed to cluck sufficiently at the sheer ignorance Young Earth Creationists flaunt. He also failed to mention the depth of sediments in the Lower Colorado River valley. Parker Dam, for instance, the world’s deepest, gooes through almost 300 feet of detritus before hittng bedrock, and it’s in a narrows where the sediment would have had a relatively tough time accumulating.

    And howdy to Jim in STL! Always nice to see you, and thanks for the URL.

  10. Kseniya

    Wonderful timeline, Chris, thank you.

    I didn’t know about the bookstore thing. Little bits of data like that don’t always make it up here to the People’s Republic.

    Kseniya (part-time Pharyngulite)

  11. Rob G

    he failed to cluck sufficiently at the sheer ignorance Young Earth Creationists flaunt.

    My supremely ironic use of the word miraculous left him in tears, I am sure. And I leave the geological details to people who like to show how cool they are.

  12. biosparite

    Actually the end-Permian extinctions have been attributed not to the desert conditions prevailing in the interior of Pangaea but to the horrendous effects of massive basalt outpourings in Asia. The latest wrinkle to this is that a large (500 kilometer) impact crater may have been located in Antartica under the ice that seems to be pretty much right on for creation at the same time. The issue is whether such an impact could send shock waves to the other side of the world and cause basalt eruptions through the effects of counter-coup. Permian paleogeography demonstrates the impact site and the basalt are antipodal with respect to each other. See the article in New Scientist on Antartic lakes below the ice surface. Publication date is around Dec. 8 or 18, 2006.

  13. Chris Clarke

    The words “related to” linking the desertification and the end-Permian were chosen deliberately, with the express intent of not implying causality. Though the case for the flood basalts as a cause is compelling, the jury’s still out. Peter D. Ward has an alternative mechanism in mind, which I describe here with links.

    In any event, a mass extinction of animals often means a mass extinction of plants, and extirpation of plants is functionally equivalent to desertification. Also of note are the braided coastal rivers contributing to strata after the end-Permian: braided rivers correlate with loss of vegetation in the watershed. (Fewer plants -> more erosion -> more sediment load -> braiding.)

  14. Bill Worzel

    I wonder about the Permian extinction. I have heard of a theory that a larger amount of gas percolated up from the ocean bottom as decaying sediment “turned” suddenly. Could a large asteroid strike cause a shockwave that could perturb ocean sediment in a nearby basin on such a scale to cause such a bubble to be released?

    Just a thought.


  15. Jamie

    No, Bill.  A large asteroid strike could not cause such a shockwave.  Only the first four Black Sabbath albums could do that.

  16. Dick Durata

    Chris, you might think to project your timeline into a purely speculative future. Will the Hoover and Glen Canyon dams last another six thousand years? (I don’t think so.) How will they fall? When will the NPS stop selling bullshit books? Before or after the Rapture?

  17. G. Tingey

    The one constant in this are the deliberate lies told by the christians.

    But, then they are religious believers, so you shouldn’t expect anything better …..

  18. Rob G

    G. Tingey, I think the number of deliberate liars among people who profess to be believers is fairly small. Most Creationists simply have larger, or more selective, blinkers than the rest of us (we all have them). And there are plenty of believers who don’t allow their beliefs to choke their knowledge.

  19. Rob G

    Hank, Richard Dawkins makes the same point as Sam Harris in The God Delusion, and adds that much of the problem lies in the indoctrination of children from an early age (there is a fascinating description of a survey done in Israel regarding children’s attitudes towards Joshua’s destruction of Jericho). “Well, duh”, you might say, but he’s the first prominent person I’m aware of who’s had the guts to call it child abuse.

    While religious “moderation” (frankly, I see nothing very moderate in believing in a Creator who meddles in our daily lives) does provide fertile soil and cover for extremists, there are plenty of religious people who actively oppose Creationism and other manifestations of dogma gone mad. Dawkins even speculates that many of these people are closet atheists, which I find reasonable given the widespread and often venomous hostility towards atheism (of Western countries, in the U.S. especially -could a self-proclaimed atheist become President?). I think this is changing, and that in the next couple of decades it will be OK for people to “come out”. Let’s hope it’s sooner.

  20. Rob G

    I am curious how a King James version of the bible…

    Well, it’s a bit cryptic, but I believe everything you need is right here.

  21. Trystero

    I’m told by the Moab locals that, if not the Grand Canyon itself, at least the canyon through which it flows in southern Utah was NOT “cut by water.”  Rather, the whole place sedimented on top of a salt dome.  N-million years ago, an underground river disolved enough of the salt that the layers above collapsed.  The Colorado merely followed the channel left by this collapse.