Saturday, May 29, 2010

Nats at the Quarry, May 2010

Nats at the quarry
Helidon Sandstone Industries (H.S.I.)

As I had long wanted to take the Field Nats to this place, it was gratifying to see such a large group turn up. We were informed that the sandstone deposit was originally a fresh water lake. Approximately 40 million years ago during the Jurassic Period, massive volcanic activity and earthquakes formed the sandstone deposit. Most of the earth that was dumped on top of this deposit compressed the sand in the lake into sandstone rock. This earth has since weathered away leaving only about half a metre of cover over the sandstone.

We began the morning by all travelling in a group higher up the pro-perty to view the revegetation of the bushland and the present extraction sites. What a difference there was between the moonscape of present or recently mined areas and revegetated early mined spots.

After morning tea near Lump Lake, we split into two groups. Lesley lead a group of bird watchers back up the top, while the rest of us made our way up the base of the gorge where black cockatoos, spiders and a great close-up view of a beautiful Evening Brown Butterfly took out interest. The group then met again to hear Greg, our minder from H.S.I. explain the differences in the quality of rock sites we had seen and the different methods of extraction. He then showed us the amazing cutting machines involved and explained that they are now the only sandstone site to process the rock entirely in Australia, as most is being sent 'raw 'to China for processing. I think everyone was impressed with the finished product, with the 'lolly' stone being the crowd favourite. Tricia

Quite a crowd

Quarrying, er …. Birding in the Helidon Hills – 09 May 2010

Some of the group decided to retrace their steps to do some birding in the heavier wooded gullies. There were plenty to see; Weebills, Buff-rumped Thornbills, a juvenile Golden Whistler, and White-throated, Striped, Yellow-faced and Fuscous Honeyeaters all fossicking in amongst the saplings. Across the track on the way down to the rock face were a number of spiders’ webs. The largest being the Golden Orb Nephila edulis with the golden silk shining in the sunlight. The female was very obvious in the centre and in one web we saw the small male on the outer edges. Sharing these webs were some Dew Drop Spiders Argyrodes antipodianus. Another spider to catch our attention was the Jewel Spider Austracantha minax. After morning tea a small group went birding on one of the ridges while others went exploring the little gorge. The ridges were found to be more interesting for the botany than the birds, and Al showed us a Copper-tailed Skink Ctenotus taeniolatus.
Bird List: Helidon: White-throated Gerygone, Buff-rumped Thornbill, Weebill, Spotted Pardalote, Striated Pardalote, Yellow-faced Honeyeater, Fuscous Honeyeater, Brown Honeyeater, White-throated Honeyeater, Striped Honeyeater, Pied Butcherbird, Australian Magpie, Golden Whistler, Grey Fantail, Jacky Winter, Willie Wagtail, Eastern Yellow Robin. Lake Apex, Gatton: Pacific Black Duck, Australasian Grebe, Australian White Ibis, Royal Spoonbill, Dusky Moorhen, Noisy Miner, Torresian Crow. Lake Galletly and Lake Lenor, Gatton Campus: Magpie Goose, Plumed Whistling-Duck, Pink-eared Duck, Grey Teal, Pacific Black Duck, Australasian Grebe, Little Black Cormorant, Australian White Ibis, Purple Swamphen, Dusky Moorhen, Crested Pigeon, Laughing Kookaburra, Sacred Kingfisher, Superb Fairy-wren, Noisy Miner, Brown Honeyeater, Striped Honeyeater, Black-faced Cuckoo-shrike, Grey Butcherbird, Pied Butcherbird, Willie Wagtail, Torresian Crow, Magpie-lark, Welcome Swallow. 38 species

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