Lithophone: Basalt of Amboy
"Instrument" made out of igneous rock pieces and arduino-powered arms
Google Earth, Amboy Crater, CA, 2020
A long time ago
An outcrop bears evidence of the earth’s past inhabitants; they are not just dead but dead dead—extinct.
Their soft parts had decomposed long ago. Their bones, ground and pulverized over time, bond with other minerals, composing a fine layer of rock.
Onto this bed, new matters pile up. One geological event marks, in vain, a rift in time.
Even further back
A school of zooplanktons drift into the predator's gaping mouth (a mollusk, most likely). Too primitive to care about anything, they don't steer away but run straight to the mollusk. Motor skill is not the only thing lacking in this organism; there is zero drive.
Down to the bottom they fall, past the point even light can’t pass. Like snow, they cover the floor in layers folding on top of another. The ocean floor is made of these bodies, each no larger than a hair’s breadth. It's hard to believe, but our belief matters little in the abyssal zone.
The ocean floor is neither smooth nor continuous. Tectonic plates grind against one another—tension builds up. Friction causes heat. Heat boils the magma, which finally erupts. The crust cracks open. When there's no more shattering and spewing, a wisp of smoke dissipates, unveiling an open field. An otherworldly quiet hangs in the air still hot. A pair of gerbils climb to the sunken top.
I chiseled at the bulbous handle. The girth wasn't impressive—I could grasp my fingers around its narrowest point—but it held onto the others so steadfastly that it seemed believably permanent.
The stones collected from the Amboy Crater were pierced with metal rods and hung to remove any surface vibration. When the arduino-powered rotating "arm" (i.e. a salvaged clock hammer piece joined at the top of the stepper motor shaft ) hits the piezo-embedded side, the stone sounds its unique tone. It tells a story of its viscous past.
The stone is the threshold in time. It lives in the moment of transition—lava gushing forth to lava solidifying—swifter than one big stride of a hiker.
Microscopic images show just how porose the samples are. These cavities, known as "vesicles," were created by trapped air bubbles. They evidence a big surprise: molten lava cools the second it spurts out into the open.
These basalt cavities are home to many microbes. Porosity allows for fluid migration. As a result, basalt contains high level of nutrients, making it an ideal environment for tiny endoliths. (A gram of rock is enough to feed million microbes.) For this very reason, vesicular basalt on Martian crust is considered one of the most likely places to find evidence of life outside earth.