Lots of limestone down in the Central Coast. Much of WestSide Paso…TablasCreek, in particular.
SantaCruzMrns…Ridge MonteBello, in particular.
The most well-known sandy soils would be in ContraCosta around Antioch. Those soils are very sandy and
phylloxera could not survive…many are still on their own-rooted vines.
Tom
I think California’s best example of a limestone soil is found west of Paso Robles (Saxum, Epoch, Tablas Creek etc). Here the limestone (technically Calcareous mudstone) has weathered to create a clay topsoil that looks a lot like Burgundy.
Some other parts of California have limestone but it’s often mixed with sand and granite and lacks the weathered limestone based clay that is possibly the most relevant feature of that soil type.
If you take the 46W from Paso Robles to the Coast, around Vineyard Road you start to hit limestone soils. Lots of the above mentioned vineyards reside there.