It’s fifteen kilometers from the Gulf St Vincent. The farm stretches north from the ridge route of Schuller Road, which separates it from the south-facing Blewett Springs gullies, to the historic stock marshalling area called Eyer’s Flat. While it has a straightforward north-easterly aspect, at between 150 and 210 metres altitude, Yangarra has three distinctive geologies.
The basement is Maslin Sand. This is red riverine sand washed down from the South Mount Lofty Ranges by freshwater in the Eocene epoch, about 50 Million years ago. While it’s loose beneath, its cap has oxidized and turned to ironstone. Atop this lies a layer of clay, and the sandwich is finished by a gentle dune of Semaphore Sand, blown there by the wind in the last 10,000 years. Vines planted here: High Sands Grenache, Old Vine Grenache, young Bush Vine Carignan, Cinsault and Mourvèdre.
This section of Yangarra is the same as the Western side, but without the wind-blown Semaphore sand on top. So the ironstone is exposed, capped here and there by thin layers of loam or clay. Vines planted here: Ironheart Shiraz, Old Vine Grenache, new graftings of Counoise, Muscardin, Vaccarèse, Piquepoul noir, Terret noir, Grenache blanc, Clairette, Bourboulenc, and Piquepoul blanc.
The geology on the Eastern side is heavily influenced by Peter’s Creek, which runs through the garden of the farmhouse. Over the last couple of million years, this creek has deposited a conglomerate layer of riverine and glacial stone on top of the Maslin Sands ironstone. This alluvial Kurrajong Formation, from the Pleistocene, is composed of many types of rock from different preceding epochs, going back 1.6 billion years. It also contains chunks of petrified wood. In places this rubble is exposed, but it’s mainly covered by a thin layer of sandy clay. Vines planted here: Roussanne and Shiraz, and young Bush Vine Grenache and Mourvèdre.