(c.1859)
Gorge of the Lerderderg looking towards Mount Blackwood, Vic. The Lerderderg Gorge is cut by the Lerderderg River into the blocks of the Rowsley, Greendale and Coimadai Faults. Side slopes are commonly of with some vertical rocky cliffs up to high. The
topography of the area is dominated by long, narrow ridges and steep secondary spurs, with a high degree of rock outcrop on ridge crests, slopes, and stream channels.
Lower Ordovician sandstones and mudstones intruded by numerous small
quartz veins form the dominant geology. The river descends steeply through boulders along a convoluted course with several steep-sided gooseneck
meanders. In a 1994 assessment of soil erosion in the shire of Bacchus Marsh, Spinoso and Rollings used the
Universal Soil Loss Equation to confirm identification in 1973 and 1985 by the Land Conservation Council of Victoria of "an appreciable erosion hazard on steep slopes increas[ing] in intensity in the low rainfall areas in the south east. Particularly high hazards exist in the Lerderderg Gorge...associated with steep slopes and erodible soils." Gold is reputed to have been found in the Lerderderg River early in 1851 and was mined in November and December that year near Blackwood. In his 1869 report Smythe noted the Blackwood goldfields "on the upper tributaries of the River Lerderderg which have cut deeply into the schists, exposing in some places high cliffs," and quoted from contemporary Mining Surveyors' Reports that; "The formation of the Blackwood goldfield is peculiarly favorable for allnvial miners with limited capital, inasmuch as there is no deep sinking required, nor machinery for lifting water, as there is ample fall for drainage in every part; that, in fact, the only outlay necessary is for sluicing-boxes and mining tools. Thus equipped, a party with small capital, and a fair share of skill, patience, and perseverance, may realize a competency in a few years." In 1855 the Geelong Rush began when 300 diggers arrived, soon joined by 2000 to work the alluvial deposits of the Lerderderg River known as Adelaide Flat, Nuggetty Gully, Ballan Flat, Frenchman's Gully, Long Gully and Yankee Gully. By September around 13,000 diggers and associated trades were on the goldfield. Gold mining continued, conducted by individuals and small companies who panned the creek, dug shafts and diverted the waters to wash gold took place in the Lerderderg Gorge. Their most notable engineering was the
diversion of the Lerderderg River at Tunnel Bend, cut 25 m through solid rock, in order to extract alluvial gold in the large meander of the original river bed. Chinese miners reworked ground others had left and cleaned the river to bedrock. Remains of water races, stone walls and mining spoils can also still be seen. == Vegetation ==