The nearest place to see California's oldest rock is around Mount Pinos, near Frazier Park west of the Grapevine on I-5. But you can touch a piece of the oldest rock on the whole planet much closer to the Bay Area. Photos by Andrew Alden

I'm glad to see that Ben Burress, my colleague at KQED QUEST, was open to the thrill of deep time as he laid hands on some of California's oldest rock in Death Valley.

When I went to geology school, back in the ice ages, I brought with me the same normal, healthy fascination with extreme age—geological age. At that time there was still a great deal of mystery about the earliest times. To me, the most mysterious thing you could call a rock was "Precambrian," that is, rock dating from the time before the earliest hard fossils appeared, marking the base of the Cambrian Period. Precambrian time amounts to four billion years, nine-tenths of all Earth history. Unlike familiar, fossil-studded post-Precambrian time (I know that's a weird term: geologists call it the Phanerozoic Eon), the Precambrian was an endless succession of enigmatic, mashed-up rocks. Their story wasn't really a story but a pile of hints and fragments—mountain ranges rising and eroding, continents merging and separating, just one damn thing after (or before?) another in the dimness of deep time.

We have a better picture of the Precambrian now, but really, it's still pretty blurry. If you look at the geologic time scale, you'll see that the Precambrian time divisions are set at arbitrary even numbers of years, not significant geologic events. In California, our oldest rocks all originated around 1700 million years ago in the Paleoproterozoic Era, and they all sit in the corner of the state outlined on this geologic map.

Precambrian rocks are shown as scattered patches of dark brown on this high-level geologic map of California. Click it to see it at 1000 pixels.

The outline marks a segment of the North American continent's ancient foundation—the craton—called Mojavia for the Mojave Desert. It's a pretty young part of the craton, and it's all we've got.

The oldest basement rocks of Mojavia are all highly altered—squeezed and stretched rocks classified as gneiss or schist. And they're still on the move today as plate-tectonic interactions are both stretching western North America apart and, in California, yanking it northward along the San Andreas fault system. Just as Sierran granite (shown in red) has been pulled all the way up to the Bay Area, so has a big chunk of Mojavia making up the San Gabriel Mountains.

The westernmost outlier of those Paleoproterozoic rocks crops out in the San Emigdio Range, which forms the rim of the Central Valley southwest of Bakersfield. The quickest way to see them is to turn west off of Interstate 5 toward Frazier Park, then drive up either Frazier Mountain or Mount Pinos (Cerro Noroeste is also possible if you're ambitious). The gneiss shown at the top of this post is on Mount Pinos. It was turned into gneiss around 1450 million years ago, but the rock originated as something else, probably a sandy mudstone, around 1700 million years ago (source, USGS OF-02-406).

Elsewhere in California, you can repeat Ben Burress's experience in Death Valley by walking up the canyon at Badwater, but a more interesting canyon hike with the same Paleoproterozoic rocks starts about 2 miles north of Badwater. And blogger Garry Hayes describes more Paleoproterozoic rocks in the San Gabriels.

The really old rocks in America are found in Wyoming and the states around Minnesota. They date from the Paleoarchean Era and are more than 3 billion years old. One example can be easily seen in Washington, D.C., in a prominent spot between the White House and the Washington Monument: the twin Haupt Fountains, each one made from a 55-ton slab of Montevideo Gneiss from Minnesota. At the time they were made, this was considered the oldest rock in the country.

The reddish, scrambled-looking Morton Gneiss is a popular stone for buildings and gravestones, and at 3524 million years of age it's considered to be the oldest bedrock in the United States. You could travel to Minnesota to see it (there's even an EarthCache for it west of Minneapolis), but don't bother—you probably have samples right in your own town. David B. Williams, author of Stories in Stone, calls it the country's most beautiful building stone.

Morton Gneiss in the Bank of Montreal building. Photo courtesy Jason Woodhead of Flickr under Creative commons license

But you can go older still. There's a Canadian rock from a spot in Labrador called Nuvvuagituq said to be 4.28 billion years old, but the date is still not settled. Today the Acasta Gneiss, also from northern Canada, is the world's oldest firmly dated rock at 4.03 billion years. You can see that one at Rocklin, just up the road. Go to the campus of Sierra College, on the south side, and locate the excellent Earth History Rock Walk.

There, among the assorted amazing and instructive boulders, is a nice chunk of Acasta Gneiss.

But whenever I want to experience the deepest possible deep time, I reach for a meteorite from my collection and lick it. Nearly every common meteorite is older than Earth itself.

Precambrian Noonday deposit in Mosaic Canyon, Death Valley

What's the oldest stuff you’ve ever seen, or better still, touched? Have you ever felt awe from contact with something of great antiquity? How old can stuff be? These are questions that have ravaged my mind since childhood.

I've always loved things of antiquity—antique objects, artifacts, fossils, and rocks. "Like." But what's that got to do with astronomy and space? Well, that's where all the oldest stuff originally comes from…but I'll get to that in a moment. First, an anecdote about old stuff.

In search of the oldest stuff, there I was at Badwater, in Death Valley, the lowest point in the continental US (the place where you crane your neck and strain your eyes to make out the words "Sea Level" on the sign waaaay up the cliff). Not far off, to the south, an alluvial fan slouched off into the salt pan, issuing from an unseen but obviously existent canyon in the mountains that make up the east wall of the valley.

I had learned at the visitor center that those mountains (the Black Mountains) are made of some very old rock: Precambrian rock that was originally laid down about 1.7 billion years ago!

So, up the alluvial fan I scramble, turn left, and up the deep, narrow canyon that the alluvium betrayed…

…to the base of a dry waterfall…

…to a wall of raw, exposed rock, the very bones of the Black Mountains…

…and reach out a hand, pressing palm and fingers firmly to the stuff.

Ahh….

1.7 billion years old; that rock I touched had been rock (albeit slowly transforming) for over a third of Earth's existence, and over a tenth the age of the universe itself. I don't know about you, but I find that awesome! And I had my hand right on it!

When we talk about the age of a rock, it is measured from the time the rock solidified ("aggregated"), either with the cooling of molten lava or magma, or the solidification of sediment. Finding really old rocks on Earth is complicated by weather and geologic processes, which continually transform, bury, and "disaggregate" them. Even so, very old rock can be found in certain places, like Greenland, Canada, Australia, and Africa. We're talking about ages between 2.5 and 3.8 billion years, and maybe more. I'd like to get my hand on some of that!

Get away from Earth and its rock-disaggregating processes and you can find some much older stuff. On the Moon, pretty much all of the material you find lying about is at least twice as old as that stuff I put my hand on at the base of the Black Mountains. On the Moon, significant surface activity (volcanism, bombardment by asteroids) ended some 3 billion years ago, and since then the crust has remained more or less unchanged, other than alterations caused by the occasional meteorite impact. The youngest rocks on the Moon are about the same age as most of the Earth's oldest stuff.

We even have a piece of that old stuff at Chabot: a chunk of 3.3 billion year old basalt brought back by Apollo 15 astronauts–and the only things that separate my hand from its speckly gray surface are two panes of glass and some nitrogen gas. Alas!

Get out to an asteroid or a comet and you may very well be setting foot on stuff that's over 4.5 billion years old, unchanged since the formation of our solar system! Within our solar system, that's about as old as stuff gets, but venture beyond it, perhaps to a planetary system that is older than ours, and you'll undoubtedly find older stuff! (This blog post is beginning to ring of George Carlin material.)

But what's the oldest stuff? I can't give you a rock of age beyond a certain point in time, because it took the early universe some time to develop the elements needed to build rocks-as-we-know-them, through nucleosynthesis in the cores of stars. Before that time, the only "stuff" around (at least that we would recognize as stuff; we won't go into dark stuff right now) was hydrogen and helium, which cannot by themselves a rock make.

But that primordial hydrogen and helium, the original building blocks of all material substances, has been around almost from the beginning of time, 13.7 billion years ago, soon after the Big Bang burst forth on the scene (whatever scene that may have been). Hydrogen, found in every water molecule in every glass of water you drink, in vast abundance within the oceans and waterways of the Earth, and through and through your own body, head to toe, is stuff we live and breathe, and is as old as the universe itself!

I don't know about you, but I find that spine-tingling.

Martian dunes, captured by NASA's Mars Reconnaissance Orbiter

The motor in question powers a fan in an exhibit built to demonstrate the physical processes of duning—the fluid transport and deposition of solid particulates into collections and patterns. The fan blows up a constant micro-gale within the exhibit enclosure, and visitors get to play Mother Nature by turning a handle and redirecting the wind. Meanwhile, a mass of tiny white glass beads is constantly whipped up into a fair recreation of a sand storm on planet Arakis….

After the chore of installing the new motor, I rewarded myself by enjoying the exhibit a bit. I piled up all of the sand on one side of the tank to see how the fan would redistribute it; I sent the wind from different directions, watching how the freshly blown grains were scattered across the pristine black undersurface; I placed all of the pyrite rocks, which serve as wind obstacles, in one pile. It was a lot of fun.

One thing I noticed that I hadn't paid much attention to in the past was how the dune actually moved, or migrated. Maybe I hadn't watched long enough before, or maybe it was easier to witness because I had stacked the deck by mounding the sand all in one corner, but it was fascinating to see the process.

On the windward side of the giant dune, the scouring wind picked up the sand and carried it racing to the top—slowly peeling away the front face of the dune. As soon as the sand-laden wind reached the crest and took a sudden turn downward, it was slowed a bit, becoming less able to support the sand grains, which then fell out onto the leeward side of the dune in a sandy-wind version of precipitation. The buildup of sand on the lee side eventually formed small avalanches that slid down the face in little dry floods.

In this fashion, the dune moved along, slowly being erased on its windward side and formed on the lee.

Almost coincidentally, a few days later I read a report from NASA about sand dunes on Mars. In some areas, dunes have been observed to migrate over time, while on others the patterns have remained stock-still—some of them for perhaps thousands of years, or longer.

So I had successfully created the right conditions for a migrating sand dune. What about static dunes? Well—I had noticed already that some of the pyrite rock obstacles that I placed in the sand stream formed small dunes in the wind-shadows of their leeward sides. The rocks weren't moving, and so the dunes they were nurturing and protecting remained in place.

Some of the static dune ripples observed in Meridiani Planum—where the rover Opportunity is exploring—have been explained as possibly being protected by the presence of "blueberries": tiny nodules of gray hematite that have eroded out of Martian rocks, but which themselves are erosion-resistant, and too large (1-3 millimeters) to be carried by the wind. The blueberries, as the explanation goes, embed in the sand and form a protective "armor" layer for the dune ripples, which remain safe and still in their lee.

Where else do we find dunes, other than Earth? Well, you need wind of sufficient strength and sand of sufficiently small size, for starters. We don't know about dunes on Venus; Venus has a thick enough atmosphere, but the winds may be too sluggish to whip up much of a sand storm. The only other object with a thick enough atmosphere and a solid surface is Saturn's moon Titan—and in fact we have pictures of Titanian dunes taken by Cassini.

Now I'm feeling that old itch to make another trip to my favorite place in the Solar System, Death Valley, to explore the macroscopic dunes of Stovepipe Wells . I'll send a postcard….

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Sand dunes near Stovepipe Wells, in Death Valley. Photo: Craig Miller.

Now, okay, "quiet" is a somewhat subjective thing. When I lived on the upper (way upper) west side of Manhattan in the 1980s, any interval without hearing a car alarm seemed like blessed relief. Quiet can be measured, of course, with sound pressure meters. Anything below about 40 decibels is pretty darn quiet for most people's purposes.

The National Park Service (NPS) says the quietest place it has yet measured is a spot in Great Sand Dunes National Park, where Vicki McCusker, who helps oversee the natural sounds program for the Park Service, says it was "bottoming out" their meters.

I've never been there but it's hard to imagine greater quietude than an afternoon I spent in Death Valley. Coincidentally this was also on a sand dune, near Stovepipe Wells. It was also Christmas Day, which kept the tourist traffic to a minimum. It was at a point in my life when I was in desperate need of some deep introspection, so I parked my car along Highway 190 and trekked into the dunes, found an accommodating slope and sat down. Occasionally a fly (or something) would buzz by. Other than that, the loudest thing was the buzzing in my own head, which I can only hope would've been inaudible to anyone with me.

It's interesting how, when things get really quiet, our bodies try to make up for it with ringing ears and internal chaos. The noted bioacoustician Bernie Krause talks about the time he and his wife, Kat were hosting guests from New York, who literally had to leave the Krause's semi-secluded Glen Ellen "sanctuary" because the night-time quiet was creeping them out.

I asked Krause what he could draw from that. "Well, it tells me that we’re more insane than I ever thought in the first place," he mused. "I mean, we’re definitely verging on pathological.  Because it’s exactly those kinds of sounds–the urban acoustic envelope in which we enfold ourselves–that kind of urban noise that’s driving up the numbers of prescriptions for Prozac."

Surveys of national park visitors would seem to bear that out.  In the early 1990s, NPS surveyed 15,000 visitors in 39 parks, about noise issues (NPS manages 391 "units" nationwide, 58 of which are designated as "parks"). More than nine out of ten visitors surveyed cited "enjoyment of natural quiet" as a reason for visiting. This survey provided some juice for the ongoing natural sounds program in the parks.

An open question is: where does it go from here? Much of the current effort in the parks appears to be geared toward developing "air tour management plans," a response to concerns that first arose over the increasingly crowded skies above the Grand Canyon. McCusker told me that while aircraft overflights are the most pervasive noise issue across the parks, the most common complaint is probably over loud motorcycles (note to "straight-pipe" Harley owners).

Krause, who conducted a year-long project documenting soundscapes in Sequoia-Kings Canyon National Park, hopes the research will also be used to develop new rules governing on-the-ground noise pollution. "If the parks can set aside places where people can go and hear the natural world as it is, at any season of the year, then that will be a really big benefit for visitors coming to the parks," he says. "Otherwise, you’re seeing the parks with the wrong soundtrack. It’s like watching Star Wars without a soundtrack."

So check out this four and a half minute “journey” I produced with Bernie Krause, founder of Wild Sanctuary. It takes you from the familiar cacophony of the urban soundscape to a serene spot in Sequoia Park.

QUEST on KQED Public Media.

Listen to the radio report, "Soundscapes of National Parks" online.

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Mockup of Phoenix (top) and 'Robinson Crusoe on Mars'
(bottom)—both set in Death Valley National Park…
Credit: NASA (top), Paramount Pictures (bottom)

This time the flavor of the day is the Phoenix Lander, courtesy of NASA, scheduled to land on May 25th at about 4:38 PM PDT. We'll be watching live NASA coverage of the landing at Chabot Space & Science Center that afternoon, if you'd care to join us…

Following somewhat in the footsteps of the Viking landers of the 1970s, Phoenix's primary mission is to look for evidence of life, or at least the chemical conditions that might be suitable for life to exist. The two Viking landers carried small chemical laboratories that analyzed soil samples scooped up from the surface, as does Phoenix.

While its mission parallels that of Viking, one big difference from Phoenix is its destination: the Northern Polar Ice Cap of Mars. The Vikings landed much farther south in the mid latitudes. Phoenix is targeting the ices of Mars' arctic region.

Growing up, one of my favorite sci-fi films was Robinson Crusoe on Mars. Made in 1964, the same year that Mariner 4, the first space probe to Mars, was launched, RCOM made a descent stab at imagining what it was like. So what if the main character walked around in apparent t-shirt weather and with sufficient atmospheric pressure to keep his blood from boilin–he still wore a respirator that doled out oxygen from an ever-dwindling supply tank, a nod to Mars' thin atmosphere.

A couple of other things our astronaut Robinson Crusoe found on that fictional Mars that we are now looking for on the real one: liquid water and life…Our hero found small caches of water (with the help of a monkey) in grottos between the rocks, and, lo and behold, living in that water was a vine-like life form with edible fruit or tubers. He even took a foot-trek, along with his guy Friday, to the polar ice cap…

(I also loved the film because some of its "Martian terrain" scenes were shot in my favorite spot on Earth, Death Valley…)

Though evidence of past liquid water action seems to be all about the planet, Phoenix certainly won't find any brooks or pools or grottos of spring water, owing at least in part to the frigid arctic region it will set feet on–an arctic zone on a world where the warmest temperatures in the tropics might reach levels of the coldest climates on Earth. What's important about landing on Mars' ice cap is that Phoenix is almost certain to dig up some water–albeit frozen.

And it is the chemical compounds either locked up in that ice or preserved by its proximity that Phoenix is interested in. (Similarly, climatologists on Earth study ice cores from Antarctica to analyze the trapped and preserved gases of Earth's atmosphere of past millennia.)

We wish Phoenix a happy landing, and look forward to the first images and discoveries from the Martian North Pole. And I'm fairly confident the epic polar adventure ahead won't resemble in the least another "great" film of 1964: Santa Claus Conquers the Martians….

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.

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The Milky Way in the skies of Death Valley's
Devil's Racetrack. Credit: Dan Duriscoe, U.S. National
Park ServiceI just got back from my semi-yearly pilgrimage to my favorite spot on Earth: Death Valley National Park. My main reasons for returning to this place again and again have mostly to do with hiking in the stunning natural beauty of the place, reconnecting with good times in my childhood, and reflecting spiritually on life, the Universe, and everything.

But, I can't go to a place like that and not feel more connected with outer space. Not only is the night sky a celestial spectacle–but it's darned cold there too, this time of year! Cold, like space. Each turn of the Earth through its own shadow is like a quick dip in the icy pool of space….

After twilight had faded, after the campfire had burned to embers–and as the frigid cold of the desert winter night started seeping through my layers of clothing–I lay down on the picnic bench and raised my binoculars to my eyes…

…and that's all I had to do. Arcing overhead was the section of the Milky Way around the constellations Cassiopeia, Perseus, Andromeda, Pegasus–a section of the sky rich in a variety of "deep sky" objects (objects typically only visible through binoculars or telescopes).

There was the Double Cluster in Perseus–a pair of "open" clusters of stars.

Open clusters are stars bound together gravitationally, still clinging to each other after their "group infancy" in the gaseous cloud that gave birth to them. Stars in these clusters are young–and because of their youth, open clusters often contain a number of large, bright, blue stars that shine brilliantly–but which have short life spans as stars go, being more prolific hydrogen-burners (gas guzzlers). (In a word, you can't find an old blue giant star.)

You can't avoid seeing open clusters in this region; the place is positively littered with them….

This is also where the famous Andromeda Galaxy can be found, in the constellation Andromeda (where else?). What's special about the Andromeda Galaxy? For one, it's the closest large galaxy to our own, as well as the most distant object in the Universe that can be seen with the unaided human eye (without telescopic help). Looking at the Andromeda is like looking through a peephole into the realm beyond our Milky Way…

I could go on and on yakking about what I got to see in the clear, dark Death Valley skies last week, so I'll have to stop myself now. Suffice to say that with a dark sky, a pair of binoculars, and a segment of the Milky Way in view, encountering the celestial wonders of the Universe in a very personal way is like shooting ducks in a barrel.

But don't let the light polluted skies of the Bay Area stop you from trying it from your own backyard; there's a lot to behold despite the city lights…

Benjamin Burress is a staff astronomer at The Chabot Space & Science Center in Oakland, CA.