Significance of Helena and Aurora Range
Helena and Aurora Range, Bungalbin has been referred to as UNIQUE, the "Jewel in the Crown", the MOST SIGNIFICANT BIF Range in the Yilgarn, PRISTINE and INTACT -
Some FACTS and FIGURES to support these claims are given below
LOCATION OF BIF (Banded Ironstone Formation) RANGES IN THE YILGARN (The orange rectangle indicates the Regional Study Area defined for the J5 and Bungalbin East Iron Ore proposal PER (Public Environmental Review))
WITHIN THE GREAT WESTERN WOODLANDS and COOLGARDIE BIOREGION there are six HIGHLY SIGNIFICANT Banded Ironstone Formation (BIF) ranges (based on landform and conservation values).
- Koolyanobbing Range (mined since 1960s)
- Mt Jackson Range (mined since 2004)
- Windarling Range (mined since 2004)
- Die Hardy Range (minimal exploration)
- Mt Manning Range (minimal exploration)
- Helena and Aurora Range (mine proposal referred to EPA and being assessed)
HELENA AND AURORA RANGE, BUNGALBIN, IS THE MOST SIGNIFICANT OF THESE SIX BIF RANGES - see Landform, Flora and Fauna values below.
Only three of these six HIGHLY SIGNIFICANT BIF RANGES are currently INTACT* and near PRISTINE.
- Helena and Aurora Range
- Mt Manning Range
- Die Hardy Range.
These three ranges are also the only Highly Significant BIF ranges in the Great Western Woodlands (and Regional Study Area identified in the PER of the J5 and Bungalbin East Iron Ore mine proposal).
Other, INTACT BIF ranges within the region and Great Western Woodlands include:
- Hunt Range
- Dryandra Range
- Lake Giles Range
- Evanston Range.
They are low lying, and although of great consevation value in themselves, do not have the same high landform or flora conservation values of Helena and Aurora Range, Mt Manning Range or Die Hardy Range.
* ‘INTACT’ refers to a BIF range that has not been mined (i.e. sections of the range removed) and has had minimal exploration activity (i.e. drill pads and tracks cut in to the hill slopes).
Landform, flora and fauna values are intrinsically linked
The greater the landform values - the greater the flora and fauna conservation values.
The main range of Helena and Aurora has some of the highest landform values in the region. The main range is 12km long, lies in a south-east to north-west direction, and has slopes that rise 200m above the surrounding plains, attain heights of 685m to 704m AHD, are convoluted, and support large BIF outcrops.
- The BIF outcrops of Helena and Aurora Range support two endemic rare plant species (other BIF ranges support just the one endemic rare plant species on their BIF outcropping or none at all).
- There are four endemic plant species on the main range of Helena and Aurora – all described as “ironstone loving”; all listed as Threatened. They don’t grow anywhere else in the world. (Other BIF ranges have just the one endemic species or none at all.)
- The BIF slopes of Helena and Aurora's main range support stands of 15m to 30m high White Gums, Eucalyptus capillosa subsp capillosa, (absent from slopes of smaller BIF ranges though they can grow near the base).
- The large BIF outcropping provides nest sites for Little Woodswallow and Peregrine Falcon.
- The southern slopes provide refuge areas for fauna - with their higher water infiltration rates, higher water availability, cooler ambient, surface and soil temperatures, and denser vegetation.
- The larger the BIF range the greater the size and significance of the refuge area.
- The greater the height and length of the BIF range the larger the population of Dryandra arborea (restricted to BIF landforms) it supports, an important food plant to honeyeaters, parrots, Western Pygmy Possum and insects.