Lithophone: Basalt of Amboy
A long time ago
An outcrop bears evidence of the earth’s past offsprings, some not only dead but extinct. The creature’s soft parts had decomposed long ago. Some of its bones, too, sank in torrential sandstorms and later bonded with minerals, composing a fine layer of rock. Onto this rock bed piles up new deposits, one event after another, until finally a tall barrier grows between those alive and the remains of the time unknown.
Even further back
A glittering pool of zooplankton rushes down the throat of a hungry mollusk. The planktons don’t know yet how to steer away from a predator. They only drift. Down to the bottom they go, past the point even light can’t pass. They fall onto the floor in their thousands, like snow, folding on top of one another. These bodies, each no larger than a hair’s breadth, make up the ocean floor.The floor grinds against another. Tension between these contiguous plates builds up. Friction causes heat, and heat boils the magma, which finally erupts, cracks the crust open. When the shattering and spewing stops, the last wisp of smoke unveils the basaltic field. An otherworldly quiet hangs in the air still hot. Right then, a pair of gerbils climb to the sunken hilltop. I clambered over the talus slope. I severed the bulbous rocks off its face with a chisel and a hammer. The stones collected from this site were then pierced with metal rods and hung, elevated from the ground. Otherwise, the piezo mics inserted inside the stones will pick up even the minute vibration on the surface they sit atop. When the arduino-powered "arm" (essentially a salvaged clock hammer piece joined at the top of the stepper motor shaft ) hits, the stone lets out a cry. It tells a story of its viscous past. The lava used to drip down the slope. Now, it is no longer moving. The stone's face is a witness to the threshold in time: between lava gushing forth and coming to a halt, quicker than one giant stride of a hiker.
Microscopic images reveal porosity of the stones. These cavities, known as "vesicles," were created by trapped air bubbles. They tell us that the molten lava cooled rapidly, as soon as it shot up above the surface. Often these basalt cavities are home to microbes. The porosity allows for fluid migration and basalt contains high level of nutrients—a gram of rock enough to feed millions—making it an ideal environment for tiny endoliths. For this very reason, vesicular basalt on Martian crust is considered one of the most likely places to find evidence of life outside earth.