Welcome to La-ne-Jeering / Mt. Langi Ghiran
The Langi Ghiran State Park is 14 km east of Ararat, Victoria. The park covers an area of 2695 ha. The park can be used for camping, walking and driving. It has steep granite peaks and gentle sloping open woodland sections.
The name Langi Ghiran is a corruption of "Lar-ne-jeering" in the language of the local Djab Wurrung people and means "Home of the Yellow-tailed Black Cockatoos".
Lar-ne-jeering is a place of cultural and spiritual significance to the Traditional Owners, the Djab Wurrung people. Ancient rock art and a rock shelter found along the 1.8km Langi Ghiran art walking track is a testament to their long history and enduring connection to Country.
Visitors to the park are asked to be respectful of these places.
Lar-ne-jeering ancient rock art
Soil/Landform Unit - Langi Ghiran ranges
- Granitic landscapes of the upper Wimmera River catchment are characterised by ridges, escarpments and mountains such as Mount Langi Ghiran. As part of the Dissected Western Uplands, the ranges are noted for the tors and boulders of granite outcrop that are frequent along with cliffs that rise above rock overhangs. Plateau remnants are preserved also on Mount Buangor with gentle slopes surrounded by steep granite margins. The granite of the ranges have developed sandy soils with weakly gradational to uniform profiles, along with yellow texture contrast soils that may become sodic lower in the landscape where rainfall is lower. Light loose surface soils may be susceptible to wind, sheet and rill erosion in drier areas (including drier aspects) when ground coverage is poor. Soil acidification is also probable in wetter areas. Land use is mainly grazing with viticulture well established on northern aspects of the ranges. Vegetation is dominated by Grassy Dry Forest. Other vegetation communities present include Herb-rich Foothill Forest, Hills Herb-rich Woodland, Grassy Woodland and Alluvial Terraces Herb-rich Woodland/Plains Grassy Woodland Complex.
What is Granite?
Granite is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers.
Granite is typical of a larger family of granitic rocks, or granitoids, that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals.
What is Mica?
As magma intrusions such as dikes, sills, and batholiths, slowly cool beneath the ground, they create an astounding variety of different crystalline minerals. This process depends on the rate of cooling and the concentration of various elements in the magma; the process is described by Bowen’s Reaction Series. Heavier minerals with higher concentrations of iron and magnesium (mafic rocks) tend to crystallize first, leaving lighter (felsic rocks) to crystallize subsequently, as the intrusion continues to cool. These lighter minerals include micas, feldspars, and quartz, the three components of granite. Slower cooling allows larger crystals of these minerals to form. If cooling is very slow (over many thousands of years), large-grained granites, called pegmatites, can form. Perhaps the most striking minerals found in such granite pegmatites are sheets of mica.
Mica consists of sheets of silicon-oxygen tetrahedra held together by ionic forces of contained potassium, magnesium or iron. In the ancient world, sheet micas were used for decorative purposes. In the industrial world, their high temperature tolerance and electrical insulating properties made them valuable in a wide variety of applications such as insulators and capacitors. Newer materials have now replaced mica in high temperature electronics, but mica is still important as an additive to paint and makeup (to provide sheen), and to drywall compounds (so it can be more easily sanded). It’s also used as window "glass" in stoves and furnaces.
The EarthCache
1. From the lesson above, consider the properties and appearance of Mica. Can you see a prominent presence of mica in the large rock? Describe its location in the rock and its appearance and form.
2. Near the Aboriginal rock art, there is an intrusion of Mica. Describe how it formed and why it was able to form the large crystals you see here. Where is it in relation to the Aboriginal artwork?
3. Please attach a photo of your team, team name or your GPSr taken in the area, to your online log. (Optional)
Upon completion the EarthCache requirements you can log your find without delay, as per the EarthCache guidelines.
You will also need to verify your find by sending me a message or an email and provide your answers to the questions within 7 days.
Thank you for visiting this EarthCache.
I hope you enjoyed your visit to Lar-ne-jeering/Langi Ghiran.
Please remember to attach your team photo to your log.
Bibliography: Agriculture Victoria, wikipedia, USRA