Cultural History: Granite Island is part of the local Ramindjeri Aboriginal landscape, and is identified as Kaiki rather than Granite Island. The island has always been of great importance to this indigenous group, as the male Supreme Creator Ngurunderi is believed to have created the island by throwing a spear into the sea. The Ngurunderi Dreaming extends from the upper reaches of the River Murray, to Kangaroo Island. Geology: Extreme pressure in the earth's crust folded layers of sediment. At the same time, extreme heat melted the base rock. The molten rock was forced upwards into weak points in the earth's crust - Granite Island was located at one of these weak points. The molten rock cooled and hardened into granite. This happened about 480 million years ago. Over millions of years, the thick layers of sediment that covered the granite were gradually eroded away by water, exposing the granite beneath. Granite Island was once connected to the mainland. It has survived the force of the ocean while the land that once surrounded it eroded away. The granite that makes up the Island was formed about 10 km below the surface of the earth. The exposed igneous intrusive rocks of Granite Island have developed into a variety of fascinating shapes. Their shapes are the results of jointing and weathering processes. The granite itself is interesting as it exhibits large mineral inclusions, giving clues to its Geological origins. Granite is made of up to 3 different minerals : Mica, quartz and feldspar. The color on the rocks is cause by lichen. Lichen is the only visible organism that live on those rocks. Lichen can survive without water for many months. When it rains, lichen springs to life in vivid color of orange and green.
In order to log this cache, you must answer those questions:
Q1 : At the GZ, estimate the height of the serpent Head Rock
Q2 : Complete the formula : Lichen = ______ + Fungi
Q3 : Examine the granite close to the Umbrella Rock and give me the color of the mica, the quartz and the feldspar
and post a picture of yourself with your GPS or your GPS/phone alone clearly showing the Umbrella Rock in background.