GSA Guide - Gardens Cafe and Retaining Walls Claimed

History: 

During the 1860s, ships in ballast from South America to Brisbane were ballasted with augen gneiss. When they arrived in Brisbane to collect cargoes the rocks were dumped in the Botanic Gardens where they were used as garden edging.

The rocks which are now used as retaining walls are mixed with coral from St Helena Island or dredged from a small reef in Moreton Bay. The coral was burnt to produce lime for construction of stone and brick buildings.

The former ballast is now used to create retaining walls along some pathways near the caretaker's cottage (now the City Gardens Cafe). The caretaker's cottage was built in Art Nouveau style as a curators residence in 1908 and was the third structure to be built here, as previous structures succumbed to the weather and floods.
 

Building Materials: 

Two major rock types were used in the retaining walls in the vicinity of the cottage: Well-foliated, biotite gneiss with feldspar augen is thought to have come from Brazil. The other rocks are coral from Moreton Bay, in particular from St Helena Island.

Retaining walls near the caretakers cottage added during restoration in the late 1980s comprise porphyry