Goulburn Valley U3A



This is just a small sample of what is being produced each month




Meredith Arnold.  2018


We had spent the early part of the day enjoying the glorious sunshine, a cooling sea breeze, and seeing the sights on offer at Mandurah, mingling amongst tanned and sun burned tourists, happy families, and holiday makers strolling along the quays and marinas at the western end of the estuary.

Colourful signs and banners were spread here and there along the jetties, all promoting the many activities available in this area of spectacular waterways.  With so many attractions and adventures to choose from we decided the best option was a lengthy dolphin cruise offering a seafood lunch, good coffee, guaranteed dolphin sighting, and whale watching during the spring and early summer season.

One solitary shiny dolphin lazily making it's way along the shoreline heading towards the open sea was our only sighting for the day, but our skipper expertly positioned the boat for cameras and phones to capture the precious moment.

Lunch was delivered on board when we moored at a busy marina crowded with noisy restaurants, so it was very relaxing to set off again to enjoy a leisurely meal cruising under expansive bridges overhead, and making our way along networks of canals where luxurious multi storeyed homes, all with wide frontages, manicured gardens, and luxury boats moored at private jetties contrasted dramatically with country living as we know it.

Perfume point, a low sandy outcrop where the odour of colonies of seabirds hangs heavily in the air, and wafts inland at times of strong breezes was our turning point to begin a slow sunny trip back to where we boarded.

Needing to make the best use of our remaining time we headed to the visitor centre nearby to check out more local colour.

"You'll want to see the thrombolites of course, they are at Lake Clifton on your way home" the busy volunteer behind the counter had replied with an indifferent wave of her hand directing us toward rows of stands stretching the full length of the room.  This strange and interesting information was intriguing.  What on earth were thrombolites?  We located the glossy folded brochure.

Living Fossils.  The most primitive life form on earth, dating back 3500 million years, predating plants, dinosaurs, and man.  Living rock, to be found in only a handful of places on the planet, and located south of Mandurah at Lake Clifton where the 6 kilometre x 120 metre reef is the largest in the southern hemisphere.  The unexpected details had surprised and astounded us as we read them, and the photographs showed a mass of rounded lumps that were not easy to discern.  We left Mandurah and drove south prepared to be amazed.

Dense coastal scrub edged the highway where a road sign indicated we should turn to the right toward the lake.  Tall Tuart trees poked through the under growth of peppermint eucalypts. Their creamy summer gum blossom looked like newly shorn fuzzy fleece scattered across each canopy.  We found parking at the end of the bush track where helpful instructions on the first of several signposts warned us of the dangers of leaving valuables in unlocked cars, and that Australian snakes can be venomous.

We read a detailed fascinating explanation on the formation of thrombolites, rock like structures a result of the activity of single celled bacteria, micro organisms called microbialites, among the first creatures on earth to produce oxygen, thereby making all subsequent life possible, then we continued on to the strongly built boardwalk stretching ahead over boggy ground.  A swamp, and limestone bedrock are usual where this rare and ancient process occurs.

A wide jetty led us over the sandy shoreline of the long shallow lake, land locked, but still 30 percent salt water and home to huge black bream, tolerant of both salt and fresh water, with some living 20 to 30 years thanks to the prohibition of fishing in 1996, and also, the location of the unique living fossils we had travelled to see.

A community of humble rounded scone like structures lay just beneath or breached the surface of the moving water as far as the eye could see along the shallows.  Limestone coloured porous rocks resembling swirled discoloured meringues lay baking in the sun above the waterline.  The wind had become strong in this open area, agitating the surface of the lake into choppy currents and whipping up white frothing foam which blew back and forth then snagged in drifts against the rough thrombolites.

A couple with a wire coated, keen eyed, red setter laughed to each other and teased  the dog in German, as he lurched forward to catch the flying foam, then  propped  in stiff legged confusion as it changed direction and blew wildly and unpredictably, including directly at him in attack.

We joined the strangely quiet groups of people gathered here and there along the railings on the jetty and stared down at the puzzling circles of stone below, simple evidence of a time when life dawned on earth.  A span of time so great it presents a difficult challenge to neatly file the knowledge of it into a comfortable niche of understanding.

We travel to far away places at great expense to visit the ruins and wonders of the ancient world.  We marvel as new discoveries of the evolution of man stretch back even further in time than previously known, and yet all of our prehistory pales into insignificance against these thousands of millions of years.

Yes we were glad to have seen the thrombolites at Lake Clifton, a place where time passes daily and yet stands still.


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