Geoscience Reference
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to either side. For this first visit I avoid the restored telegraph station with its tiny museum and tea
shop, and head straight for the beach. I want to experience primordial Earth without a guide.
There's an empty car park of white sand, with wattles and low-slung saltbushes clinging to the
surrounding dunes, and a path threading through the bushes towards the sea. Though I've come to
find the world's simplest creatures, the complexities of life are everywhere. From one of the bushes
a chiming wedgebill incessantly reiterates its five-note melody. From another, a grey-crested pigeon
regards me unblinkingly. The shells of the beach crunch underfoot; they are tiny, bone-white, and per-
fectly formed, and the bivalves that grew them are eons of evolution ahead of the simple creatures that
I'm seeking. I step on to the boardwalk, which stretches like a pier out into the water. Each weathered
plank of wood contains row upon row of cells that once collaborated in a large, complex organism.
Signs on all sides show pictures of the slime creatures with smiley faces and cheery explanations of
their origin. Flies buzz infuriatingly around my head, landing on my face to drink from the corners of
my eyes. Black swifts swoop between the handrails, and butterflies the colour of honey, with white
and black tips to their wings. Time travel is harder than it looks. The modern world is right here even
in Hamelin Pool, and it's stubbornly refusing to leave.
I retreat to the telegraph station to plead with the ranger for permission to leave the boardwalk and
wade out into the pool. He hesitates and then relents. “Go along the beach to the left,” he says. “Don't
step on the mats. Be careful.” The mats he's talking about are one of the signs of primeval Earth. They
are slimy conglomerates of ancient cyanobacteria, and they grow painfully slowly. At the beginning
of the last century, horse-drawn wagons were backed into the sea over the mats, to unload boat cargo.
A hundred years later the tracks they left are still visible as bare patches in the thin black sludge. An
injudicious footprint here will last a long time. I promise to watch my step.
I return to the beach and this time walk carefully towards the water's edge. More striking than the
ubiquitous patches of sludgy, foul-smelling bacterial mats are the “living rocks” in between. These
strange denizens of Slimeworld are everywhere, an army of misshapen black cabbage heads marching
into the sea.
The ones highest up the shore are now nothing more than dead grey domes of rock, shaped like
clubs, perhaps a foot tall. They once bore microbial mats on their surfaces, but these have long since
shrivelled, abandoned by the receding water. Closer to the Pool's edge the domes are coated with black
stippling that will turn to dull olive green when the tide washes over them. Most of the stromatolites,
though, lie in the water, stretching out as far as I can see. Between them the sand is draped with black-
green mats of slime, and chequered with irregular patterns of sunlight as the waves ripple overhead. I
wade up to my knees among these strange formations, basking in the sunshine. There is nobody else
in sight.
The living rocks of Slimeworld are called “stromatolites”, a word that comes from the Greek
meaning “bed of rock”. Though the interior of the stromatolites is plain, hard rock, their outer layers
are spongy to the touch. Here on the surface is where the ancient microbes live. They're sun-worship-
pers: by day they draw themselves up to their full filamentous height—perhaps a thousandth of an
inch—soak up the sun, and make their food; by night they lie back down again. The water that sur-
rounds them is filled with fine sand and sediment stirred up by the waves. Gradually this sand rains
down on the organisms, and each night's bed is a fresh layer of incipient rock. The stromatolites are
inadvertent building sites; the sticky ooze that the organisms extrude acts as mortar and the sand acts
as bricks. Every day, as the microbes worm their way outward, another thin layer of rock is laid down
beneath them.
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