Bricks and Mortar

Trying to connect the topic of this post to the Barwon River is drawing a rather long bow, however I though it interesting enough to include anyway. So here goes:
A recent geocache hunt took me to Limeburners' Point where the remains of five lime kilns can still be seen so of course I snapped a few photos and did some research.

Remains of lime burning kiln at Limeburners' Point, East
Geelong

One of the earliest and most important industries to develop in the Geelong region was the production of lime which was in high demand by the building trade where it was used in the production of mortar, cement, plaster and stucco amongst other things. Lime production on the site is believed to date back to 1838 and the earliest days of European settlement in the region when limestone was quarried nearby and burnt in kilns on the western side of the point. Seashells were also collected and used in production. This site was no doubt chosen for the availability of limestone which was found in the cliffs, in the limestone gravel of the beach and in the shells which collected there. 
The limestone in the cliff face which is believed to be between 65 and 3 million years old was covered by a layer of clay, deposited in a later period. Other limestone deposits in the region are believed to have formed around 20 - 35 million years ago during the Oligocene-Miocene periods, when changing sea levels lead deposits of shells to form along shorelines which no longer exist. I wasn't able to discover how the deposit at Limeburners' Point relates geologically to these other deposits at places like Waurn Ponds, Fyansford and Batesford.
During the peak of operations at Limeburners' Point, the kilns operated day and night, burning timber which was hauled in on drays. Alternating layers of timber and limestone were fed into a funnel-like chimney at the top of the kilns which were stone and brick structures built into the cliff face. The contents were burnt, then the lime rendered by this process was collected from the chamber at the bottom of the chimney, bagged and carted away.

Remains of a bluestone quarry on the Barwon River

Initially owned by Messrs Taylor and Bourchier, the kilns were purchased in 1852 by George Cakebread from Caleb Joshua Jenner. Sources appear to differ on when the surviving kilns were built, however it would seem that these kilns date only to the 1860s or 70s. There are also the remains of a powder magazine at the site which dates back to 1854.
So important to the early building industry of the region was Cakebread's lime (the only other source of lime at that time was Point Nepean Peninsula) that it was shipped all over the Western District. I would imagine therefore that many of the significant homesteads of the region were built from rock quarried from basalt deposits along the Barwon and held together with mortar made using lime from the shores of Corio Bay.
One such example is Sladen House, Newtown which was built in 1849 with basalt taken from Melville's Quarry on the river at the bottom end of Noble Street. The first to do so.

Sladen House

Quite a number of quarries operated in this area: on West Fyans Street either side of Shannon Avenue, at Windmill Reserve overlooking Queen's Park and also near the end of Camden Road. All tapped into the deposits of basalt along the Barwon Valley, providing stone for local churches such as the Wesleyan Church in Noble Street, houses and even the Geelong-Queenscliff railway line.
Another example perhaps is the privately owned Barwon Bank in Riversdale Road, Newtown which was constructed between 1853 and 1856 from - I assume local - basalt, trimmed with freestone from the Barrabool Hills. Likewise, Barwon Park Mansion at Winchelsea is also built from basalt.
In addition to these buildings, Barwon Grange, Kardinia House and St. Albans Homestead along the banks of the Barwon are all brick, or stone and brick, structures built between 1850 and 1875 which presumably used Cakebread's lime.
Despite this overwhelming need for lime, pressure from tourist interests at nearby Eastern Beach soon saw the lime burning process forced to move to the eastern side of Limeburners' Point where these remaining kilns are situated. Production was not affected by the move and reached a peak in the 1870s, however nothing lasts forever and by 1875, another lime-burning operation located on the opposite side of Corio Bay at Duckponds (near Lara) was producing a superior quality lime. By the 1880s only one of the kilns at Limeburners' Point remained in operation and profits had dropped ten-fold.

Barwon Bank

The new producers had set up their kilns on the shores of the small lagoon into which Hovell's Creek empties. Somewhat confusingly, this is now known as Limeburners' Bay. At that time however, the entrance to the lagoon was known as  Limeburners' Point, with the site which is known by that name today, instead called Galena Point.
It is also worth mentioning that Duckponds and Limeburner's Point weren't the only source of Limestone in the region. The deposit near Waurn Ponds - an extension of which reaches to the Barwon where it forms the Belmont Escarpment - is still being quarried to make cement by Blue Circle Southern Cement Ltd. The stone is also used for monument-making purposes by various stonemasons in the region.
Historically, it seems that quarrying took place at Waurn Ponds as early as the 1840s, however it was probably only used for building purposes at this time. It was not until the 1880s when production at Limeburner's Point was in decline that kilns were built at Waurn Ponds and lime production began.
A little later, in 1890, the cement works at Fyansford commenced operation. The lime to supply these works was quarried about 5.6km away at Batesford from the Miocene era deposit which was found there in 1888. The rock was crushed on site and then transferred to the works at Fyansford first by a ropeworks and then by rail. With the opening of a new quarry in 1931, stone was loaded straight onto trucks and then taken to the works by rail for crushing. This open cut quarry is still in use today, despite the closure of the cement works.
Further research has just shown me that there was almost a very direct link between lime production in Geelong and the Barwon River. In the early 20th century the Fyansford Cement Works needed to get their product to the rail lines which would take it to Melbourne. Before the route from North Geelong to Herne Hill was eventually chosen, two other options were put forward. One was a railway line running from South Geelong through Newtown and Chilwell and then along what would become Deviation Road, whilst the other involved a siding running from South Geelong Station to the Barwon River and a wharf at Yarra Street. A second wharf upstream at Fyansford would be serviced by an aerial ropeway from the cement works. This plan however was overlooked in favour of the branch line from North Geelong.

In the beginning...

It occurred to me recently that I knew very little about the geological origins of the Barwon River, so I set out to redress the issue, but found I was suddenly in some danger of having a great deal of information but very little in the way of understanding. I spent some time sifting through what I could find online and trying to put it in some kind of order. As I understand it, the geological evolution of the Barwon runs very roughly along the following lines:

Cretaceous rock formations at the West Barwon Dam
in the Otway Ranges

Several million years ago, the landscape surrounding the Barwon River looked rather different to what it does today. In fact, the formation of the Barwon dates back as far as the Cretaceous period (70-145 million years ago) when Australia separated from the super-continent Gondwanaland and dinosaurs still roamed Earth. During this period, sedimentary rocks were laid down which can still be seen to the south of the Barwon as rocky outcrops in some places. They also lie off the coast of western Victoria in the Otway Basin.
As recently as 40 million years ago, much of the land through which the Barwon now flows was covered by a wide sea. Early streams flowed from the higher ground of the Otways, northwards to the sea and limestone deposits formed along this ancient coastline.

Limestone outcrop forming the Belmont Escarpment

The Belmont Escarpment overlooking Barwon Valley and the Jerringot Wetlands is one such limestone outcrop, formed between 25 and 30 million years ago, which extends from a large deposit at Waurn Ponds towards Corio Bay.

More recently, during the Miocene period (7-23 million years ago) a series of plate movements and volcanic eruptions saw the coastline extending as far inland as the town of Meredith and the estuary of the Barwon located at Belmont Common. At this time, much of the present course of the Barwon lay under the sea with only a few nearby features such as the ancient granite of the the Dog Rocks at Batesford protruding above the water's surface to form small islands. It was this sea which deposited the limestone which can be found in the Batesford-Fyansford area and which was quarried for use by the Fyansford Cement Works throughout the 20th century. At around the same time, clay and other materials laid down combined with the Batesford Limestone to produce a band of sedimentary rock running down as far as the eastern fringes of Lake Connewarre. This is known as the Fyansford Formation.
Continuing plate movement throughout the Miocene period affected the various fault lines around the Geelong region such as the Bellarine Fault, causing the Bellarine region to lift and then around 20 million years ago, the sea to withdraw, uncovering the land and the current course of the Barwon.

Plioscene basalt rock formation beside the
walking track to Baum's Weir

Subsequent sea movements in the early Pliocene period (3.5-5 million years ago) resulted in the formation of a shallow bay between Torquay and Ocean Grove, covering the lower reaches of the Barwon once again and led to the deposition of shell beds which now lie under this part of the river including Lake Connewarre and surrounds. Sedimentary deposits across the region including the Bellarine Peninsula at this time produced what is called the Moorabool Viaduct Formation. In places it lies over the top of the Fyansford Formation.
It was also around this time that the movement of fault lines pushed the Cretaceous rocks of the Otway Ranges to their current height, giving the Barwon the strength to carve a path to the sea through new lava flows which occured in the later Pliocene era.
It was at this time that volcanic activity around Mount Duneed, Mount Moriac and Mount Pollock led to further changes in the river and the landscape. Until about 2 million years ago, the Barwon followed a course which saw it flow through a gap in the Barrabool Hills south of Lake Modewarre, then down a valley adjacent to the hills before reaching Fyansford. Around 2 million years ago, lava flows north of Inverleigh blocked this course, causing the inundation of the land to the west of Winchelsea before the river once again carved a new path to the sea. The lava flow followed the old riverbed, leaving a deep basalt deposit in this area and contributing to the wide basalt plains which extend across the region, providing extensive farming land today.

Newly-arrived European settlers were quick to see the material value of these basalt deposits, establishing bluestone quarries along the banks of the Barwon. It is this rock which can still be seen in the stonework of many historical homesteads and buildings across the region - the Barwon Paper Mill and its water race being a prominent example. Naturally, this quarrying made a lasting impact on the river surrounds. This is particularly noticeable along the walking track to Baum's Weir where the quarrying exposed the pliocene basalt, leaving high, rocky escarpments which tower over the river below, whilst a number of quarries were located along the river through Newtown which today have been converted to parkland.

Disused bluestone quarry at Baum's Weir showing
pliocene basalt deposits

At the same time, these lava flows extended out into the bay with three branches forming which dammed the lower Barwon in several places and created a number of lagoons - including a lake at Queen's Park, with another blockage below the Belmont Escarpment.

One of these flows produced the basalt ridge line which runs between Tait's Point and Fisherman's Point, separating Reedy Lake and Hospital Swamp from Lake Connewarre and Salt Swamp. As a result, Reedy Lake was fed by fresh water from the now-dammed Barwon whilst Lake Connewarre and the swamplands below the ridge were filled with seawater.

In time however, the barrier at Queen's Park along with that at the Escarpment eroded away, creating alluvial flats downstream. Likewise the lava flow at Tait's Point and another between Sheoak and Pelican Points which had obstructed the river flow were eroded away and water from the upper Barwon and Reedy Lake once more flowed into Lake Connewarre and the lower reaches of the river. This reconnected watercourse now ran alongside the third lava flow which extended to The Bluff and Ocean Grove, establishing the present course of the lower parts of the river and location of the river mouth.

Remains of basalt flow from the late Pliocene era
 forming Tait's Point (right)

It is believed that much of this erosion occurred during times of high flooding - such as 1995 - and as a result of seismic movement. The returning flow of water along with fluctuations in sea levels during the late Pleistocene period (c18,000 years ago) resulted in the build up of sand dunes along the southern basalt flow. In very recent times, with European settlement, this natural rate of sedimentation has been greatly increased by land-reclamation, farming, tree clearing and for a short but intense period, mining in the catchment region of the Moorabool River. All these factors have contributed to sedimentation, causing in-filling which has affected the depth of water in the lakes complex, turning Reedy Lake from an open water system to the swampy complex it has become.

In addition to the various geological and environmental events which shaped the course of the river, across millions of years, continuous erosion and subsequent sedimentation have also influenced the soil of the region, forming the land we see today.