2016-12-12 General Committee - Attachment 1 to Item 6 - Biodiversity Assessment Report

                                                   Noosa Biodiversity Plan – Biodiversity Assessment Report




(Department of Primary Industries (DPI), 1981). These old metamorphic rocks are described as Land
Zone 11 under the State Government RE classification system.

During the early to middle Triassic, the Kin Kin beds were intruded by the Woodum Granite, which now
form part of the Woondum Range that stretches north of Mount Cooroora. A much smaller, isolated
outcrop of another intrusive volcanic is the Cedar Creek Porphyry, which also occurs at Noosa Heads
(Shields, 1995). These old volcanic rocks are described as Land Zone 12.

Numerous igneous intrusions have also occurred across the shire since the Jurrasic period, which has
resulted in scattered and isolated peaks. Most prominent include Mount Cooroy, Mount Cooran, Mount
Cooroora, Mount Tinbeerwah and Mount Pinbarren (DPI, 1981). The remains of tertiary basaltic extrusion
also form Black Mountain and the Wahpunga Range just east of Kin Kin. These younger volcanic rocks
are described as Land Zone 8.

These volcanic geological formations have created the hilly undulating topography that dominates
approximately half of the Noosa Shire area, which includes Noosa’s highest point of 488m in the
Woondum National Park.

The extensive undulating and level plains, swamps and tidal flats of Noosa’s eastern coastal lowlands
have been formed by depositional processes since the late Triassic period. During the late Triassic period
and early Jurassic period, the deposition of coarse freshwater sediments from the granitic intrusions to
the west formed the Myrtle Creek sandstones in the eastern portion of the shire (DPI, 1981). These
sandstone rocks are described as land Zone 9-10.

In the more recent Tertiary geological period, clay, silt, sand and gravel have been deposited as alluvium
along all major streams across Noosa (Land Zone 3) while finer textured material has been deposited in
estuaries and lagoons adjacent to the sea (Land Zone 1). Older alluvial deposit that are now elevated
above the early Tertiary alluvium also form the plains and gently undulating rises along the Noosa
catchment floodplain (Land Zone 5). Fluctuations in sea level have probably resulted in intrusion of sea
water and possibly some marine deposition in these low-lying areas of Noosa (Shields, 1995). The low
sandstone hills and freshwater alluvium deposits in which the headwaters of the Noosa River originate
are situated at a lower elevation. This unusual formation has resulted in the development of the river’s
unique coastal lagoon system.

Bordering the coast line of the Noosa Shire are low hilly wave-deposited and windblown sand dunes. On
the northern section of the coast from 10 km north of Noosa River to the northern shire boundary, sand
dune crests rise from 75-200 m above sea level (Land Zone 2). The northern dunes consist of white and
iron-stained quartzose sand and local concentrations of heavy mineral sands, peat and sandrock (DPI,
1981). The sand dunes along the rest of the coast are below 75 m except for the area around Noosa Hill,
at the mouth of the Noosa River which rises to 147 m (DPI, 1981). Dunes further inland have become
stabilised by vegetation compared with the unstabilised frontal dunes (Shields, 1995).


2.4       O t he r e co s yst em t yp es & se rv i ce s
Other sources of biodiversity in Noosa include the subtropical marine and freshwater environments.
Within the shire this includes:

      •    Sandy and rocky beaches
      •    Intertidal rocky shores
      •    Nearshore fringing reefs
      •    Riverine seagrass beds
      •    Sheltered intertidal flats


  © ECO LOGICAL AUSTRALIA PTY LTD                                                                       19