Which two soils are distinguished in the Yarra Valley?

The Yarra Valley, located in Victoria, Australia, is renowned for its diverse terroir, which significantly influences the wines produced in the region. The correct answer identifies grey-brown sandy clay and basalt-derived soils as the two distinguished soil types.

Grey-brown sandy clay is significant for its ability to retain moisture while providing good drainage, which is essential for growing high-quality grapes. This type of soil also tends to have nutrients that benefit the vine's health and fruit development. Basalt-derived soils, formed from ancient volcanic activity, offer a rich mineral profile that enhances the expression of the grape varieties grown in the Yarra Valley. These soils are particularly conducive to the cultivation of Pinot Noir and Chardonnay, which thrive in the region's cool climate.

Together, these soil types contribute to the complexities and characteristics found in the Yarra Valley wines, highlighting the importance of understanding local geology in viticulture and enology. The other options, while they may describe soil types found in various regions, do not accurately reflect the specific soils recognized as distinctive features of the Yarra Valley.