Jingemia Cave is a distinctive natural feature in a band of low rocky hills between Moora and Carnamah. The hills are an outcropping of Noondine Chert (also known as Coomberdale Chert) and other very old rock types that formed between 2.5 billion and 542 million years ago (mid Proterozoic era). Chert is a variety of quartz consisting largely of the mineral silica. Although it contains other minerals, it is the silica in chert that makes this rock valued for mining. The silicon produced from chert has hundreds of applications in our daily life. Paint, abrasives and concrete are just a few of the products that require silica. Whilst chert is not rare, there are no other known chert resources in Western Australia that posses the chemical and physical characteristics necessary for producing high quality silicon.
The formation also influences an aquifer that supplies groundwater to local towns, and is a source of mineral silica, a vital component in many things used in our everyday lives. In 1912, Western Australian Government geologist Harry Woodward explored the Noondine Hills as part of a Statewide geological survey. In his report of the expedition he described ‘the striking spectacle’ of a sheer rock face 70 feet high, forming an amphitheatre pierced at its base by a large cavern called Jingemia (an Aboriginal word signifying ‘devils abode’). He also described another cave about four and a half miles south-east of Jingemia on land belonging to the Benedictines of New Norcia. This cave had been called Devil’s or Bishop’s Hole by the Bishop Salvado. R. Adams of Electrolytic Zinc Co. of Australia, found a small chalcopyrite vein in the cliff wall near the cave. This vein had been altered by guano to crusts of atacamite with weddellite and minor sampleite. Numerous visits by the authors of the reference also located birnessite, halite, dolomite, taranakite, todorokite, apatite and malachite
Devil’s Hole, Jingemia Cave and the Noodine Hills are a ‘karst’ landform that contains an underground system of fractures and voids. Six to 15 metres below the ground, fractures and voids in the Noondine Chert contain groundwater. This is a regionally significant water source and is likely to also be an important habitat for a unique community of specialised animals. These creatures have survived millions of years of environmental change by taking refuge underground. They are extremely sensitive to any activities that may affect their underground environment and so it is vital that we protect this important part of the State’s biodiversity!They are an aquatic amphipod called Neoniphargidae sp. and are adapted to life underground where light is absent and they lack eyes and pigment.
In order to claim this earthcache please answer the following questions:
1. How did the underground fractures and voids of Jingemia Cave form?
2. What was mined at Jingemia Cave and what was it used for?
3. Go to WP2 at S 30° 15.765' E 116° 0.091' where you will see some rocks containing a different colour than the rest of the cave rocks which are predominantly brown and grey. What colour can you see and what do you think it is?
4. At WP 2 where you see the different colour rocks describe the texture and feel of the rocks
Optional: Photo of you or your GPS enjoying Jingemia Cave
You can log the earthcache straight away but you must send us your answers within 7 days of your log. Logs without answers must be deleted per geocaching guidelines.
Source: Moore Catchment Council