The rock on Mount Stromlo consists of ignimbrite from the Laidlaw Volcanics. This erupted in the upper Silurian period over the top of the Deakin Volcanicsrhyodacite which is visible on the surface on the lower slopes in the east and southeast sides. The northern lower slopes are covered with a calcareous shale which is included in the Laidlaw Volcanics as it was deposited at the same time. This is cut off on the northwest side by the Winslade Fault, which heads north east to and. A spur fault heads off east from the Winslade Fault to under the Scrivener Dam. On the northwest and north side of these faults are middle Silurian period rhyodacite volcanic deposits from the Walker Volcanics. The northern side was uplifted compared with the southern side. The name Stromlo is taken from the poems of Ossian.
Landform
Stoney Creek and its tributaries drain the north side of the mountain, The east side drains into the Molonglo River. The south side supplies Blugar Creek that runs into the Murrumbidgee River. The summit of the mountain where the telescopes are located is elongated in a north-south direction, with a spur running to the southwest where the water treatment plant is situated.
Observatory history
The first telescope installed at Mount Stromlo was the Oddie telescope which was installed on 8 September 1911. The building housing this telescope was the first construction funded by the Commonwealth Government in Canberra. In January 1913 the first telephone was connected to the Queanbeyan telephone exchange. Mount Stromlo was devastated by the Canberra bushfires of 2003. The fire, fueled by the pine plantation that covered the mountain, destroyed or badly damaged much of the observatory and water treatment plant. Road access is via the Cotter Road on the south side, and Uriarra Road on the east and north. The summit is reached by a road joining Cotter Road just outside.
Mountain biking
Mount Stromlo is home to one of the finest and most well equipped mountain biking facilities in Australia. Prior to the 2003 bushfires, Mount Stromlo hosted some of the best and oldest mountain bike trails in Australia. In May 2006 extensive remedial work and trail reconstruction was commenced by World Trail in partnership with Canberra Off-Road Cyclists mountain bike club and the ACT Government. Stromlo Forest Park now includes more than of cross country single trail, a Four-Cross course, several observed trials areas and a downhill track. Mount Stromlo hosted the 2009 UCI Mountain Bike & Trials World Championships that attracted more than visitors from up to 40 countries. The event involved more than 750 of the world's top riders who competed in the four mountain bike disciplines of Cross Country, Downhill, Four Cross and Observed Trials. Mount Stromlo currently plays host to two large annual Mountain Biking events, the Scott Australian 24-hour MTB Championships in October, and the Mountain Bike Festival Australia in December. In addition to the mountain biking facilities Mount Stromlo also boasts an event pavilion with office space and change rooms, a kids play area, BBQ's, a road cycling criterium circuit, a groomed grass cross country running track and equestrian trails.
