Geology Through the Radio - A Horse With No Name

America's "A Horse With No Name" is one of my favorite examples of Geology Through the Radio, because it isn't what you would expect.

A Horse with No Name

On the first part of the journey

I was looking at all the life

There were plants and birds and rocks and things

There was sand and hills and rings

The first thing I met was a fly with a buzz

And the sky with no clouds

The heat was hot and the ground was dry

But the air was full of sound

I've been through the desert on a horse with no name

It felt good to be out of the rain

In the desert you can't remember your name

'Cause there ain't no one for to give you no pain

La la la la la la...

After two days in the desert sun

My skin began to turn red

And after three days in the desert fun

I was looking at a river bed

And the story it told of a river that flowed

Made me sad to think it was dead

You see I've been through the desert on a horse with no name

It felt good to be out of the rain

In the desert you can't remember your name

'Cause there ain't no one for to give you no pain

La la la la la la...

After nine days I let the horse run free

'Cause the desert had turned to sea

There were plants and birds and rocks and things

There was sand and hills and rings

The ocean is a desert with its life underground

And a perfect disguise above

Under the cities lies a heart made of ground

But the humans will give no love

You see I've been through the desert on a horse with no name

It felt good to be out of the rain

In the desert you can't remember your name

'Cause there ain't no one for to give you no pain

La la la la la la...

Geology

While not explicitly "geological", I have always found the lyrics in "A Horse With No Name" to be reminiscent of a major geological event. When looked at the course of the song, the rider starts off in the desert, however by the ninth day "the desert had turned to [the] sea". When a land surface that is subaerial eventually gets covered over with the ocean, this is known as a transgressive sequence. 

Figure 1: Transgressive sequence. Image courtesy of SEPM. 

As you can see in Figure 1 above, the desert/beach in Image A is eventually overrun by the ocean/sea in Image B. There are two possible methods for this to happen. One is that the land surface could be slowly sinking in relation to sea level. This can actually be witnessed today in areas along the coasts where the weight of the sediment, or even buildings, slowly lowers the surface elevation, such is in the case of New York City or Venice. The other is that sea level is rising in relation to the land surface. This can also be witness today with the continued melting of the polar glaciers due to climate change and a quickly warming planet, this melting ice can be seen to raise sea level over time. There is also a third possibility, which is a combination of the two events occurring. 

As the sea level rises in relation to the land and inundates the surface, eventually the sediment that is deposited will change. As we can see in Figure 1 above and Figure 2 below, the surface sediment for a desert or a beach would typically be sand. Once the land is inundated, that sand would shift to clay or mud as the water levels progressively got deeper and further away from the shoreline. Eventually the water would be deep enough with the shoreline far enough away that most sand and mud/clay would get deposited closer to shore, leaving only the deposits from the dead animal life as it built up over time. These dead organisms, formed mostly from calcite shells, would be compacted and lithified (turned into a rock), over time. These rocks are mostly a variety of limestone, which is identified by the blue brick pattern seen in the figures above and below. 

Figure 2: A simplified example of a transgressive sequence in the rock record. 

This pattern can also be seen in the rock record. If we were to see the rocks sitting on the side of the road, what is known as an outcrop (Figure 2), they would generally have the pattern of sandstone on the bottom representing the beach or desert. Siltstone above that, which is a smaller sediment size typical of the just offshore environment. Then mudstone or shale, a rock typically of fine layers of clay sized particles that is even further off shore. So in this instance as the water level deepens, the shoreline is shifting away from this location. And finally on top is the limestone, where we have reached a far enough distance from the shore that particle sediment (like sand and mud) is limited. 

There is one major point of interest between a real life transgressive sequence and the song, and that is a matter of time scale. A true transgressive sequence like this would typically take hundreds of thousands to millions of years to fully inundate a desert like environment, however in the song it only takes nine days. So, while it is a cool comparison to a real life geological event, it does need to be taken with a grain of salt. 

Possible Educational Questions to Ask

1. What are the environments mentioned in the song?

2. What types of conditions does the song use to define these environments?

3. Does this match what is geologically used to define the environments?

4. What did the singer of the song find on the 3rd day, and do you think you could see this feature in the desert? 

5. What is the geological term for the change in environment described in the song (“desert had turned to the sea”)?

6. What are the two (tectonic) possibilities to explain how this could happen?

7. The song states that “after 9 days…the desert had turned to sea”. Assuming a really fast time period for this to happen is 100,000 yrs. How much faster is this event that the band America described in the song?

8. “The ocean is a desert with its life underground”. Now assuming they meant underwater, do you agree with this statement? Why or why not?

You can see the rest of the Geology Through the Radio postings on my website.