Dry Tropics Biodiversity Group Inc.
(inform, educate, enthuse, implement)
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Wild Plant "Hot Spots":Alligator Ck | Town Common and Bald Rock | Mt. Stuart summit | Paluma "H Trail" | Running River | Quarantine Station | Rangeview Ranch | Saunder's Beach closed forest
Alligator Ck. Picnic Area walk:
Lists of plant species at "Allig. Ck. Hot Spots":visitor centre forest face |
Townsville Region Plant Hot Spots: by Russell Cumming and Doug Silke, copyright 17/4/99
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Map of the Alligator Ck. picnic area walks
General information about the Alligator Ck. picnic area walk
This area is a great example of three vegetation types, two are very common locally. The greatest diversity of any of our "Plant Hot Spot Areas" occurs in a very small area here, 40% of listed species here are seen at no other spots: 1. "Mid-high to tall small leaf (microphyll) closed forest with some deciduous emergents": is common throughout the area in protected gullies and rocky slopes that are protected from fire; many of the species here are very common and widespread locally in this vegetation type. 2. "River She-oak tall open forest": is common mostly along the more permanently wet creeks in the lower foothills, but most of the area's creeks cease flowing very early in the dry season. 3. "Gray Bloodwood, Poplar Gum, Moreton Bay Ash and Ironbark mid-high to tall woodland": covers the vast majority of the Townsville area. It covers most of the lowlands, foothills and extends into the upland slopes throughout the rain shadow drier Townsville area. Typically ironbark occurs on the foothill slopes. It grades from "woodland" into "forest", where other Eucalyptus spp. become more common, wherever the climate is wetter (and so at higher altitudes).
So how did the Mt. Elliot peaks form? Towards the end of the Julago Volcanics that formed Many Peaks Range (260 M years ago), many upwellings of molten rock occurred in the Townsville area, remaining perhaps a kilometer or two below the surface, the Julago Granitics. In part this upwelling happens because magma is lighter than the surrounding solid rock. These upwellings cooled as they rose towards the surface, solidified into granite and stopped rising. Cycles of erosion, exposure on the surface, reburrial under kilometres of sedimentation and volcanic debris, and more upwellings took place. The large mountains formed mostly during this mountain building period (but also earlier similar ones). Subsequently these mountains all eroded down to a very long lasting inland plain extending well out to sea, except Mt. Elliot's granite peak always protruded. Erosion by the sea during times of high sea levels (stable plain breakup 60 M years ago), and other lesser erosion processes removed the surrounding plain and exposed the granite peaks that you see today. Julago volcanic rocks, while softer, have persisted and remain alongside the granite in many places. The Mt. Elliot peaks are part of the Cape Bowling Green National Park that includes as a huge coastal belt to the south that contains many world renown freshwater wetland/mangrove/saltpan/old dune habitats. This area is largely inaccessible, but it's importance, most obviously for birds and fish habitats, ought not be ignored. Like the Town Common it is seriously affected by weeds. Sugar cane expansion has also had a significant effect. The outdoor display board near the shelter shed in the Alligator Creek picnic area explains much more.
Mt. Elliott by Tony Bean | to top |