Bibliography

http://en.wikipedia.org/wiki/Dights_Falls
http://en.wikipedia.org/wiki/Organ_Pipes_National_Park
http://en.wikipedia.org/wiki/Mill
http://en.wikipedia.org/wiki/Sedimentary_rock
http://en.wikipedia.org/wiki/Yarra_Bend_Park,_Melbourne
http://www.parkweb.vic.gov.au/
http://maps.google.com.au
http://home.vicnet.net.au/~foopnp/opnp.htm

Dight's Mill

In Yarra Bend Park, there's also an attraction called the Dight's Mill. A mill is a type of equipment used for grinding or pulverizing of grain and other raw materials using milestones. The Dight's Mill is one of Melbourne's oldest and most significant industrial sites. In the early 1840's John Dight established Melbourne's first water-powered flour mill on the site. In 1888, 'Yarra Falls Roller Mills' bulit a water-turbine powered mill, which was the largest and most sophisticated of the thirty two water powered mills, bulit in Victoria before 1900. It opened to the public at that time.

The Dights Mill and millrace was normally bulit out of natural rock. Natural rock can be found in rivers and waterfalls across Australia and across Asia and some in South America. It can also be seen in mostly national parks.

Dight's Falls

 Dight's Falls is just downstream of the junction of the Yarra River with Merri Creek. The river is constricted to be 800,000 volcanic, basaltic lava flow and a much older steep, silurian sedimentary spur. The north side also contains abundant graptolite fossils in sedimentary sandstone. It was believed the only fall on the River  although it connects creeks and even lakes throughout the course of this river.

It may took  a time when an Earth's surface breaks a part of the River's crust to form a sedimentary layer. It may took more years than the formation of Digit's falls to make the rock face shown opposite. In Digit's falls the rocks weren't really at the bottom of the sea. They're visibally still so it won't avoid very large waves of the waterfall when at a very fast speed. It also crosses and parallels each other so it creates effect of the sound of the waterfall. Some geological features visible are the size of boundaries, the type of rock and how it forms many years ago and a large rock next to the falls can be classified as a unusual plate tectonic.                                                 

Yarra Bend Park 1 & 2

Yarra Bend Park includes Deep Rock. It is known as a significant place because it's famous for its picnic area and its swimming club. It is a great place for family or work functions with open grassy areas allowing a variety of recreation.

The basalts in the Yarra Bend area originated from two separated volcanic lava flows. The first filled the ancestral Merri Creek Valley approximately 2.2 million years ago; the second flowed down the valley of Darebin Creek and into the Yarra Valley around 800,000 years ago. The Merri and Darebin creeks managed to reestablish their flow across the basult, however the Yarra was blocked, producing a lake and broad floodplain upsteam of Kew. Eventually the Yarra began to cut a new course between the basult and uplifted silurian mudstone/sandstone sediments which dominate the southern part of the park. The current course of the river meanders with very steep outer sides and gentle slopes on the inner sides.

The natural state of the area has been completely clean. It might seen to have a bit of litter on the sides but the creek itself is always an example of Melbourne's environment today.

Scoria Rock

The car park at the Organ Pipes National Park is on a eroded scoria cone - a small volcano that ejected molten volcanic rock called scoria. Scoria is a reddish-brown and light in weight; it has many airholes because it was full of steam when ejected. The word comes from the greek word meaning "rust". An old name for scoria is cinder. It can be used for sculptures, statues for volcanoes but not in this national park.
As rising magma encounters lower pressures, dissolved gases are able to exsolve and form vesicles. Some of the vesicles are trapped when the magma chills and solidifies. Vesicles are usually small, spheroidal and do not impinge upon one another, instead they open into one another with little distortion. Volcanic cones of scoria can be left behind after eruptions, usually forming monsters with a crater at the summit. Reticulite differs from scoria in being considerably less dense. It is formed from a thin layer of froth occuring on some basaltic lava flows due to the bursting of vesicle walls. The thin glass threads are the intersections of burst vessicles. This is the lightest rock on Earth, with its specific gravity less than 0.3. The delicate framework of thread-lace scoria is so open that the average porosity is 98-99%.

Tessellated Pavement

The Tessellated Pavement is where the rock surface has been split into regular "tiles". It has a tiled or mosaic-like appearance. It is another area of columnar basult, but instead of the vertical faces being visible as at the Organ Pipes, the horizontal faces are visible - you can walk and climb over them. The coloums tend to be hexagonal, but many have sides of unequal length and there may be from four to eight sides on each column.

Organ Pipes National Park 3 & 4

Downstream along Jackson's Creek, we can see sedimentary rocks on the other side of the creek. These rocks are not blowing everywhere all over the place, they're all bunched together. There's normally little holes all around each rock so it creates effect on the texture and appearance. The rocks quite older are the ones that they started to get a little darker or maybe it won't allow us to hold it because of the size. Its recently shaped like a person's face with the boomerang as hair and the bunch of rocks as a person's face.

                                                     

Organ Pipes National Park 1 & 2

Jacksons Creek

The carved valley in Jacksons Creek was formed in volanic geological formations but millions of them buliding up together.It leads the way to the Organ Pipes which is larger in size. The river is normally flat with lots of trees at both sides. If people walk along Jacksons Creek, it can offer a cool relief even on the hottest days.

Organ Pipes.

The Organ Pipes is a set of basult columns formed by the cooling and cracking of molten lava.
It's beileved that the lava filled a river valley running ar right angles to Jacksons Creek and was perhaps 70 metres thick. Once a surface crust has formed, the lava beneath cooled very slowly. During cooling, the lava constracted and surface cracks developed. As it continued to harden, the cracks lengthened until the basult mass was divided into columns. Over the million years since the lava flow, Jacksons Creek has cut a deep valley through the basult and revealed the Organ Pipes.