November Outing Report - Glen Lomond Conservation Park, 03 November 2024

Hell Hole Falls with columnar basalt. 

Adapted from the TFNC December newsletter reports of M. Compton and B. Gundry

Our outing was a special day, one seemingly suspended in a kind of dreamtime. It was a glorious spring day in which to have an almost “Hanging Rock” timeless experience in Glen Lomond Conservation Park at the southern end of the escarpment.

We are all used to the indications of serious volcanic activity in the Toowoomba vicinity, especially obviously so with the flat-topped cone of Tabletop. But how about the other way round - a reverse cone down into the earth? For our November excursion we visited the very impressive mouth of a volcano in this park at the south-east corner of the eastern range. Here, we stood at the edge of this geological phenomenon and gazed deep into the funnel created when the boiling magma blew out of the depths and into the air. Giant basalt columns line the sides of the mouth, while a modest creek has cut a “V” in one side, trickling over as Hell Hole Creek and making its way to join Flagstone Creek. The ancient history of the area is palpable, and its impressive grandeur makes a great impact. 

Close by is an open area of grassland about the size of a cricket ground, with shelter sheds. Of course, the field nats set themselves up very comfortably in one of these and proceeded to enjoy the day “spaced out” in a naturalist kind of way. 

Some members set off for the walk to a waterfall deep within the park, returning with enthusiastic reports of the experience, but saying quite honestly that it wasn’t an easy walk. 

The “falls” occurred over exposed, hexagonal columnar basalt and the scatter of rocks of the plunge pool were likewise of basalt, but there was some softer material which initially was thought of a type of tuff. On further investigation it was a mass of matted biotic materials. Where there is water, there will be a living response. Here, plants, living and dead, clung to the moist basalt, creating a matted vegetative layer, in places only half a centimetre thick, but the more central masses may have been 10-20 centimetres thick. The entire mass was about 5-6 metres high at the apex and about three metres wide across the base. The entire moist biotic mass may have weighed over 1 tonne and looked something less than stable.

Meanwhile others, in the wont of Natters, scattered into the area adjacent to the shelter shed to enjoy their naturalizing.

Species List; Glen Lomond Park, Middle Ridge, Toowoomba (compiled by R. Hobson from members' observations)
Birds: Australian Brush-turkey, Wonga Pigeon, Crested Pigeon, Eastern Great Egret x 1 (overhead), Dollarbird, Peregrine Falcon x 1 (dead), Little Corella, Sulphur-crested Cockatoo, Rainbow Lorikeet, Scaly-breasted Lorikeet, Satin Bowerbird, White-throated Treecreeper, Superb Fairy-wren, Noisy Friarbird, Brown Honeyeater, Lewin’s Honeyeater, Noisy Miner, White-browed Scrubwren, Striated Thornbill, Black-faced Cuckoo-shrike, Common Cicadabird, Rufous Whistler, Grey Shrike-thrush, Eastern Whipbird, Pied Currawong, Australian Magpie, Spangled Drongo, Torresian Crow, Leaden Flycatcher, Eastern Yellow Robin, Mistletoebird, Silvereye Amphibians: Common Green Treefrog Litoria caerulea Reptiles (lizards): Scute-snouted Calyptotis Calyptotis scutirostrum, Lace Monitor Varanus varius Dragonflies and Damselflies: Australian Emperor Anax papuensis, Australian Emerald Hemicordulia australiae; Blue Skimmer Orthetrum caledonicum Grasshoppers and Crickets: Hedge Grasshopper Valanga irregularis, Field Cricket Teleogryllus commodus Cicadas: Black Tree Ticker Cicada Birrima varians Butterflies and Moths: Orchard Swallowtail Papilio a. aegeus, Chequered Swallowtail Papilio demoleus sthenelus, Dainty Swallowtail Papilio anactus, White Migrant Catopsilia pyranthe crokera, Yellow Migrant Catopsilia g. gorgophone, Caper White Belenois java teutonia, Scarlet Jezebel Delias a. argenthona, Lesser Wanderer Danaus petilia, Monarch Danaus plexippus, Common Crow Euploea corinna, Glasswing Acraea a. andromacha, Meadow Argus Junonia v. villida, Tailed Emperor Charaxes s. sempronius, Grey Ringlet Hypocysta pseudirius, Common Grass-blue Zizina otis labradus Beetles: a small green beetle Diphucephala sp. (very common esp. on Soap Tree Alphitonia excelsa) Ants: Giant Bull Ant Myrmecia gulosa, Green-head Ant Rhytidoponera metallica, Daemel’s Spiny Ant Polyrhachis daemeli, Southern Meat Ant Iridomyrmex purpureus