Beez Neez now Chy Whella

The Blowhole

Big Bear and Pepe Millard

Tue 12 Jan 2016 23:47

The Blowhole

We left the Tessellated Pavement, headed south and stopped at the next lookout.

Our next stop was on the other side of Pirates Bay at the end of the promontory.

Closer, we could see local fishing boats.

We took the turning and promised ourselves if we were good tourists we could stop at Peters for an ice cream.

In the car park we saw the new verses the old number plates.

Our self-appointed guide clearly expected us to turn right and stamped his foot when we didn’t.

We walked a little way up the path and stood for ten minutes looking down at the Blowhole. Nothing major happened but it sounded good and we did get a minor splash just before we headed up the track to the Lookout.

Fossil Bay, the view to the right or further south.

The track went on a little further and gave a view to the left, in fact, across the bay to where we had been at the Tessellated Pavement.

Back to the first view to see if we could get any waves crashing, they had been out partying hard last night...... We watched for ten minutes and these are the best the waves had to offer, doesn’t bode well for anything spectacular back at the Blowhole.......

The track back had a turn to the right which took us to the other side of the Blowhole. We stood for a while but nothing mighty came in. So just little splashes from smallish waves.

The Blowhole, a former sea cave and tunnel, is an old blowhole. The roof at the rear of the tunnel collapsed to create a broad arch with a blowhole behind it. The Blowhole point was originally an unbroken line of cliffs of siltstone. This flat-lying rock was formed like a giant layer-cake when mud and silt were deposited on the sea floor about two hundred and seventy million years ago and compacted under the load of later sediment. Earth movement cracked the roof, creating vertical joints which enabled the sea to cut caves and tunnels into the cliffs. The Blowhole only lives up to its name when the seas are rough and in the right direction. Swells enter the tunnel and sea-spray and air are blasted through the funnel, creating an explosive effect in the small joints at the back of the inlet. When seas subside the Blowhole runs out of puff and it may then be described, although rarely, as ‘The Millpond’.

1. The Older Coastline. This is how the Blowhole Point may have looked at an earlier stage of cliff erosion before The Blowhole developed and Fossil Island was cut off to the north.

2. Erosion of a Coastline. As the sea level rose, the sea further eroded the shores of Pirates Bay, working on the vertical cracks [joints] and existing caves in the cliffs. Water pressure, sand and stones abraded the cliff base, causing rock slabs and boulders to beak loose. Gradually the cave, the entrance of the future blowhole, was enlarged, and the tunnel behind it lengthened.

3. An Unfinished Task. In the modern situation wave action has cut The Blowhole point into two sections. Over time The Blowhole will be lengthened and in a distant future its roof will collapse to form a gully. By then, especially if sea levels are higher, The Blowhole point will have become two islands, perhaps three, because there is already a gulch to the south of The Blowhole. The cliffs of those future islands will continue to erode until eventually The Blowhole will become little more than boulders, silt and sand.