Premise: I am staying well clear of the definition of terroir …

Wonderful Eric Asimov in the New York Times http://tinyurl.com/yb7q373 recently compared the set-up in Bordeaux to that of Montalcino:

“Bordeaux .. recognizes .. adjoining territories can have differing characteristics and so distinguishes Pauillac from St-Estèphe, and St-Julien. But as far as Brunello di Montalcino is concerned, it is left to consumers to try to recognize which wines come from the lower elevations and clay soils in the south, and which are from the higher, lighter soils in the central area around the town of Montalcino”

Anyone visiting Montalcino who is sufficiently unconcerned with map-reading to be able to look out of the car window will see enormous differences in soil types visible to the naked eye (even at speed). The red colour of the earth on the Sesta road that links Castelnuovo and S.Angelo in Colle (where the Terra Rossa estate is, funnily enough), the huge dolmen like rocks that many estates prop up around the property and that have been extracted from the vineyards, lumps of clay between the vine-rows, patches of burnt sienna earth and so on. Montalcino exhibits an extraordinary array of types and combinations of types of soil and these, combined with a vineyard’s position (altitude and exposition) and the microclimate of the vineyard, exalt different aspects of Montalcino.

 Though generalisations can certainly be made and it is interesting to know the distribution of “alberese” (marl-rich limestone / half way up the hill, both north and south-east sides) or distinguish Pliocene from plasticine but nothing beats talking to the producers or walking their vineyards.

Ps. Actually producers of Brunello are increasingly are sharing the details of single vineyards, for example:

http://www.casanovadineri.it/en/vino/vigneti.asp 

http://www.lagerlamontalcino.com/ivigneti_eng.html

 http://www.ilpalazzone.mikelee.nyc/the-estate/location-and-terroir/

Alessandro Bindocci is about to embark on a discussion of the 9 subzones of Montalcino (as described by Emanuele Pellucci) on his blog http://www.montalcinoreport.com/ which will be interesting reading.