A Life Full of Zeros: A Perspective on Human and Geologic Time

Some perspective on time. It's one of the more difficult concepts to get across in a geology education simply because the numbers lie at the very edge of comprehension. So here is a brief demonstration:

The first part is my own, but it was very much inspired by the latter part that is borrowed from Historical Geology - the Free Textbook for College-Level Geology Classes. I deeply appreciate the work that has been done to make classes more accessible to low-income students.

Imagine the years of your life as a bunch of zeros. Don't think of your life as a zero, just use them as a way of counting! So, we'll say that the average age of a college student is in the range of 20 to 30 years:

0000000000 0000000000 0000000000

Think of all that you have accomplished in that time! You've had an entire childhood, you've matured to an adult, you've navigated 13 years of elementary, junior high, and senior high school. You've maybe accomplished a few years of college, and you've perhaps held a job for several years. Some of you may be raising your own children.  You've accomplished a lot!

That's me in 1980 working on my Senior Thesis, aged 23 zeros...

So what lies ahead? We cannot know what time we have in life, and for some it will be cut short. We have goals and aspirations, the things we want to experience, the things we want to accomplish. How much time do we have? The average life span these days is around 75-85 years. How does that look in zeros? Here's 80 of them:

0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000

That's quite a few! Seems like plenty of time to plan for graduate school, or starting a career, or starting a family, raising children, and if you are idealistic, enough time to change the world in some positive way. Some of us look at this string of zeros and imagine how many are ahead of us, and some of us look at how many of those zeros we have already checked off, and some are looking at the relative few that are left. All of us no doubt see different things as we count of our potential lifetime. 

But how does our potential lifetime stack up to human history? This is where it gets sort of interesting. World War One ended just over 100 years ago. There are still several thousand people in the world who were alive when that war ended:

0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000

The California Gold Rush began in 1848:

0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 00

The Declaration of Independence was signed in 1776:

0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000

The Roman Empire was at its zenith about 2,000 years ago:

0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000

So here's the thing. You can still see your potential lifetime in comparison to much of the human history. Most of human civilization is encompassed by 8,000 or so zeros, and if I put all of them up, you could see your lifetime as a small, but still a visible part of the human adventure.

But now it gets weird. When we think of geologic time and the history of planet Earth, things get crazy really quick. Look at the 2,000 zeros above, and multiply it by six; 12,000 years. If you were to step outside here in California's Central Valley where I live, you would see grazing horses, camels, Columbian mammoths, and gigantic ground sloths. You would encounter predators like Saber-tooth Cats and Short-faced Bears, 50% bigger than grizzlies. They only went extinct 10,000-11,000 years ago. Humans saw and dealt with them.

Short-faced Bear at the Fossil Discovery Center, Madera, CA

But geologic time is a whole different ballgame. The ice age that ended just 12,000 years ago began some 2 million years ago.

The dinosaurs went extinct about 66 million years ago.

The dinosaurs arose around 220 million years ago.

A Mosasaur, a sea-going reptile from the time of the Dinosaurs

Complex life, i.e. swimming things with eyes, brains and nervous systems appeared about 545 million years ago.

What happens when we try printing up enough zeros to account for these vast numbers, and what happens to the significance of your life as a result? For that, I turn to the Historical Geology Textbook for College-level Geology Classes, referenced at the top of the post:

Have a look at the image below, which illustrates 5,000 individual zeros.

There are 5,000 zeros on this page. 

0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000 0000000000

How many copies of this image (or sheets of paper) would you need to print to reach a total of a million zeros?  

1,000,000 / 5,000 = 200 sheets of paper

Now, how many copies would you need to print to reach one-billion zeros?

1,000,000,000 / 5,000 = 200,000 sheets of paper

The Earth is 4,566,000,000 years old. How many copies would you need to print to cover the age of the Earth with each year represented by 1 zero?

4,566,000,000 / 5000 = 913,200 sheets of paper

Copy paper is bundled by 500 sheets. This is called a ream of paper. How many reams of paper would you need to replicate the age of the Earth?

913,200 / 500 = 1,826 reams of paper

Typically there are 6 reams of paper per box, that makes 304 boxes of copy paper just to print out the number of zeros in the age of the Earth. 

That is a long time… 

If you are having trouble imagining 304 boxes of paper, when we moved the department a few years ago, we had 200+ boxes stacked in our lab. Here they are...

It's an aside, but it recalls to me a favorite quote that I start many of my classes with: 

“After sleeping through a hundred million centuries we have finally opened our eyes on a sumptuous planet, sparkling with color, bountiful with life. Within decades we must close our eyes again. Isn’t it a noble, an enlightened way of spending our brief time in the sun, to work at understanding the universe and how we have come to wake up in it? This is how I answer when I am asked—as I am surprisingly often—why I bother to get up in the mornings.” Richard Dawkins

The Hawai'i That Was: Why Should We Care?

Lapakahi State Park on the Big Island is the remains of an ancient fishing village that was occupied for hundreds of years. Not a single plant in the picture is native to Hawai'i.

In a lot of ways, a post like this is how one might wrap up a series. The problem is that I can't say exactly where we will be or what we will have discovered by the time I've determined that this blog series is completed! I can certainly talk about why I had the idea, and maybe I'll find some guidance as we move forward in this exploration.

I can say that Hawai'i is very special to me. California is far and away the most interesting place in the world, what with the Sierra Nevada, the coasts, the deserts and all the other fascinating landscapes, but Hawai'i to me is an incredible place that I am privileged to visit only on special occasions. There are so many mysteries on the islands that I haven't had the time to explore. But there is something more. There is a sense of wildness about the place that I don't feel often in my many travels.

The Ha'upu Range. Kaua'i can certainly look foreboding from some directions.

I think it has to do the isolation and remoteness of the place. The Hawaiian Islands were among the last, if not the last significant landmasses to be colonized by human beings in the world. It's been only a few dozen generations that it was the last wild place on the planet,  It has been significantly altered by human activity, but there are still remnants of that primeval world that still exist today. You will never find it in a high-rise hotel at Waikiki, but the pieces are there if you know where to look.

An 'Apapane, one of the few native Hawaiian birds that is not in imminent danger of extinction.

At the same time there is a newness about the Hawaiian Islands. Not a single piece of land in the eight major islands is older than 6 million years. Essentially all of the Big Island is less than a million years old. There is a lava flow near my home in California. It erupted 9-10 million years ago, and while it has been altered by erosion, it still looks relatively "recent". And yet in the time since that lava flow in California, eight major islands grew, reached great heights, and then eroded. Literally thousands of species of plants and animals evolved in that short period of time. Many existed for a time, and then went extinct, sometimes by the hand of humans, and sometimes not.

Pu'uhonua o Honaunau, the place of refuge. If you violated kapu, you had a chance at life if you could make it here.

There are really two Hawaiian Islands that were: the islands before the Polynesians, and the islands of the Polynesians. They were then changed forever in 1778 when Captain Cook "discovered" the islands and their people. The changes in the intervening 238 years have been mostly catastrophic, both for the natural landscape and for the Native Hawaiians. It's only been in the last few decades that people have tried to recover pieces of the past before they were completely gone.

'Ahu'ena Heiau, the last "palace" of King Kamehameha in 1819. It's now surrounded by the bustling city of Kona, with luaus next door two nights a week!

We learn from history. We are often far too ignorant of our dependence on the land and resources, and forget that they can be abused and wasted. All human societies alter the landscapes that they occupy to increase their chances for survival, and some are more successful than others. The Polynesians who discovered the islands brought with them plants and animals they knew would insure their future, and for more than a thousand years they lived within the limits of the land. That is no longer the case today. Meeting the needs of 1.4 million people on the islands requires a huge amount of energy. Can you imagine the chaos if the ship and plane traffic were disrupted for any length of time?

So Hawai'i is beautiful. But it is also a living laboratory that has much to tell us about geology, ecology, evolution, and anthropology. And that is why we were there for much of the last two weeks, students of geology and archaeology, learning what we could in the short time that we had. The story of our journey begins in the next post.

Yosemite and a Sense of Scale (scroll down for the better pictures!)

A few weeks ago I had 'dinner' at the Mountain Room at the Yosemite Lodge (on my budget, dinner amounts to the French Onion Soup), and the maitre d', having been properly tipped, gave us the best seats in the restaurant for viewing the beautiful cliffs of Yosemite Valley.

Oh, the picture above isn't the view we had. It was 9:30 PM on a moonless light and we couldn't see a thing. But on our trip this week, I scooted around the corner and found what view we would have had from our table. That's the top of a booming Yosemite Falls a little to the left, and Yosemite Point on the right. The spire called the Lost Arrow is just left of center. I mentioned some of the geological background of Lost Arrow a while back.

I zoomed in a little bit to get a shot without the distraction of the roofs of buildings and to get a nice framing effect with the greenery. It's a beautiful and unique cliff that is sometimes overshadowed by the presence of nearby Yosemite Falls.

Lost Arrow is a destination for many rock climbers, so I zoomed in even more to see if anyone was around There seemed to be a dot of a person on the summit of the Lost Arrow, and three or four people standing at Yosemite Point, behind the fence up there. What a view they must have had on this sparkling June day!

As I stared through the camera lens, I started to realize once again the sheer scale of a place like Yosemite Valley. There is a difference of 3,000 feet between the point and the valley floor. People fade into insignificance against such cliffs (I explored this idea last Christmas at the Grand Canyon).

Can we use a scene like this as a way of understanding the immensity of geologic time? Maybe. It's a difficult concept. We geologists toss about ages in the millions and billions of years, and sometimes those numbers lose meaning, just like when a politician talks about spending in the millions, billions or trillions of dollars. I mean, really, what the difference? An 'm' replaced by a 'b' or 'tr'. Until the bill comes in.

The world has been around a long time. If the climber at the top of the Lost Arrow is six feet tall, his or her height is equal to 0.002 of the height of the cliff. If we think of the height of that person as representing a human lifetime of 100 years, the cliff represents 50,000 years. A goodly sum of years, certainly. There were essentially modern humans on the planet then, but many things would have been different; no cities, no agriculture, for instance, and there were a lot of strange animals in the world who are no longer with us: woolly mammoths, mastodons, sabertooth cats, and giant ground sloths. The last pulse of the ice age glaciers would still lie in the future, and the floor of Yosemite Valley may well have been a lake.

But 50,000 years is a small increment of time in geology. It is but 1/20th of a million years. The oldest glaciers coursed through Yosemite around a million years ago. If a human standing on the rim of the canyon represented a human life compared to a million years, Yosemite Valley would be 60,000 feet deep, essentially the difference between the top of Mount Everest and deepest trenches of the ocean floors.

Geological time certainly doesn't stop there. The granitic rocks that form the spectacular cliffs of Yosemite Valley cooled from molten magma around 85 to 120 million years ago. Round off to 100 million: if the person standing on the rim of this canyon represents a human life, the canyon of 100 million years would be 1,135 miles deep. That's more than a quarter of the way to the center of the Earth.

The oldest rocks in the Yosemite region, metamorphic rocks that once lay on the floor of the Pacific Ocean thousands of miles from California, date from around 500 million years ago. Our metaphorical canyon would now be 5,675 miles deep, which would be a real trick, since our planet is just 8,000 miles in diameter.

The oldest rocks in the world are just over four billion years old, and the planet formed 4.6 billion years ago. I don't know how to represent such numbers! But you could take a look at the next photo zooming in on Lost Arrow...how many people were climbing it on Tuesday (click on the photo to find out)?

UPDATE: I shouldn't say "I don't know how to represent such numbers", I should say, "It's late and I can't think anymore". If this cliff represents 4.6 billion years (the age of the earth), each foot represents about 1.5 million years, each inch equals about 128,000 years, so a human lifetime of a century would be about 1/1,280 of an inch.

Fading Into Insignificance: Mather Point, Grand Canyon National Park

In geology, scale is everything. We have a hard time understanding the meaning of a million or billion years when our own personal experience extends across only a few decades. A place like the Grand Canyon seems immutable and unchangeable in a human time frame, but it is simply spectacular what can happen on a time scale of five or six million years. An entire gorge, one of the largest on the planet, can be produced by nothing more than a river flowing and gravity pulling rocks from cliffs. A zoom lens can serve as a metaphor for human existence in the midst of deep time.

It has been my experience that when I look upon a scene of such grandeur, my mind is not fully capable of taking in the true scale of the canyon. The vastness of the scene has been shrunk to a single image in the back of my eye, and my ego makes me much larger in relation to the canyon in front of me. One way to gain a truer sense of scale is to hike the canyon. Nothing drives home the depth of the gorge more than trying to walk back out. It looks a LOT bigger when you stand at the bottom and look up!

On the other hand, one can stand on the rim with a camera, and see what happens to people scaled to the immensity of the canyon. I stood this morning at Mather Point and snapped a shot of people enjoying the view (above).

I was actually some distance away, using a 30x zoom, so I back out to 15x or so, and a strip of the Kiabab Limestone becomes visible. The rock is a mixture of limestone and sandstone that formed in a shallow sea in Permian time, around 250 million years ago.

Zooming out to 7x or so, the cliff grows in size, and the tourists are shrinking into insignificance. The cliff they are standing on is a few hundred feet high, but the real news here is the far rim of the gorge. Do you see the double layer of light colored rock separated by a forested slope? That thin whitish strip across the top is the same Kaibab Limestone! It is one of the thinner layers that makes up the cliffs of the Grand Canyon.

I was about a quarter of a mile away from the people at the viewpoint, and without a zoom they are practically invisible on the upper left. The canyon is ten miles wide, and more than a mile deep. We humans are mere insects in the face of such immensity. The existence of human civilization over the past few thousand years fades into an equal insignificance over the immensity of geologic time. The rocks in the deepest part of the canyon are more than 1.7 billion years old!

I want to pay a compliment to the National Park Service. I was most pleasantly surprised when we arrived at Mather Point this morning. For years, Mather Point was the spot where the majority of visitors saw the Grand Canyon for the first time. There was a crowded parking lot, always noisy, always kind of trashy. It got worse when the NPS completed the new visitor center a few years ago, because Mather was the closest parking lot and consequently the competition for parking spots increased. It was an untenable situation.

When got there today, we discovered a new parking lot and a realigned highway that diverted traffic away from the rim (completed in November). One could park at the visitor center, and take a two minute stroll to see the canyon for the first time. No trash, no noise, just a beautiful rim walk with the silent immensity of the canyon, and the occasional croak of a raven. The people I saw looked reverent instead of hassled. It was a moment of rediscovery, and I want to thank the park service for a job well done.

Time Almost Not Beyond Imagining: Recent Volcanism on the Colorado Plateau and Deep Time

1.15 million years ago, a massive explosion shook the New Mexico landscape, and some sixty cubic miles of ash shot into the atmosphere in a catastrophic rhyolite caldera eruption. The collapse of the magma chamber produced the Valles (Jemez) Caldera. Some of the ash traveled as far east as Iowa, but most of it was dumped on the flanks of the volcano in layers hundreds of feet thick. It was so hot upon landing that the material fused back together into a solid light-colored rock called welded tuff. Smaller eruptions followed, the most recent around 50,000 years ago. Erosion has been eating away at the margins of the caldera, forming a number of deep canyons (see this map of the caldera). One of these canyons is called Frijoles, the "Canyon of the Beans".

Tucked away in Frijoles Canyon one of the more interesting national monuments in the park system: Bandelier. It preserves the remains of an Ancestral Pueblo village that was built nearby and sometimes right into the welded tuff generated by the Jemez Caldera eruption. It is a fascinating place to explore. Although humans had passed through the region for portions of the previous 10,000 years, the village was built around 1150 AD and abandoned about 1600 AD.

A couple of divergent thoughts crossed my mind when I was considering a post on Bandelier National Monument. They had to do with deep time, and the wanderings of people. Wanderings takes up the next post. Here, I wanted to provide a bit of perspective about geologic time.

A thousand years seems a long time to the casual tourist wandering through these very ancient dwellings. We can feel a connection to these people sometimes as we look at the drawings they made on the rock, or the personal improvements in the living spaces in the rock rooms of the village built into the cliff. And yet they seem far removed by time. The year 1600 seems impossibly distant to our daily lives.

Still, there were (and actually still are) people in my life who were personally acquainted with Civil War veterans. And those veterans would have known people whose lives reached into the 1700's. Two or three degrees of separation...it isn't that far back is it? We can perhaps visualize that kind of time if we work at it.

But 1.15 million years? Even though we have actually covered 2 billion years in this series on the Colorado Plateau, I sometimes find even a million years difficult to comprehend. One million. One thousand thousand. The entire history of Bandelier's village, from construction to abandonment to tourist destination could be repeated 1,000 times to reach the time when the volcano exploded. And beyond that: the history would have to be repeated 65,000 times to reach the time when the dinosaurs disappeared, and more than 200,000 to reach the time when dinosaurs first appeared. And they appeared relatively late in Earth's history.

Deep time is one of the four great discoveries that mark the biggest advances of my science, that of geology: the others were the principles of uniformitarianism, evolution, and plate tectonics. The first two are largely credited to one man, James Hutton, and evolution is credited to Alfred Wallace and Charles Darwin, although others were involved. Plate tectonics was the discovery of dozens, even hundreds of researchers, although Alfred Wegener is given credit for kick-starting the idea though sheer stubbornness (I guess this should give the Alfreds of the world some hope!).

Bandelier National Monument is a fascinating and scenic place to wander. The top photo is of a kiva set in a high alcove in the upper canyon. Getting to it requires an acrophobic climb up some high ladders and narrow trails. The rocks of the canyon walls are full of holes caused by cavernous weathering of the relatively soft rock. Along the canyon floor, the Puebloans scraped and scooped out the rock to make their living spaces larger and more comfortable. I will have some more photos of the ruins in my next post. Camping and other facilities (mostly built by the CCC in the 1930's) are available.

Time Beyond Imagining

Still decompressing after a "long" trip of two weeks through geologic time on the Colorado Plateau. It is always difficult to comprehend the contrast between the hours and days of one's human existence with the millions and billions of years that characterize the geologic history of our planet and Universe. I expect to follow this theme in my blogs for a few days as I sift through the pictures of our journey.

The unusual view above comes courtesy of astronomical lunar cycles and Landscape Arch in Arches National Park. The arch has an opening nearly as long as a football field, and is only 6 feet or so across at the thinnest point. It is rather a wonder that the span still stands, and the future prognosis of the arch is probably measureable in human, not geologic, terms. A large chunk fell from the span around 1991.

The arches in the park are formed in the Slickrock Member of the Jurassic Entrada Sandstone. The unit has been pushed upwards by bodies of mobile salt from the late Paleozoic Paradox Basin. The upward pressure in the salt anticline has fractured and jointed the sandstone into a series of "fins", long narrow walls of rock. The base of the fins lie in the Dewey Bridge member of the Entrada (or Carmel), which is easily eroded, allowing a small window to form at the base of the fin. Chunks of rock fall from the window, until an arch develops. There are hundreds in the park.