The Seaview subregion of McLaren Vale generally has shallow soils which are red and brown earths with limestone and ironstone. This contrasts with deeper clays, sand and black biscay soils in other parts of McLaren Vale. Because the soils are shallow, controlled irrigation is critical for good flavour and colour by avoiding extreme stress. The soils at Coriole are about 80% terra rosa, that is red brown earths over limestone. Often this limestone has a capped shiny surface. Another area contails red earth with ironstone, and the oldest vineyard planted in 1920 is on deep clays. Two thirds or more of Cuvee Mary Kathleen is Cabernet Sauvignon, the balance in Merlot.