Testing the ‘Vineyard Geologic Identity’ concept in Marquette-producing vineyards in the Champlain Valley, Vermont, USA

ABSTRACT The recently formalized concept of ‘Vineyard Geological Identity’ (VGI) was applied to two vineyards in the Champlain Valley of Vermont, USA. The vineyards studied, LP and SV, both produce the hybrid grape known as ‘Marquette’, are at equivalent elevations, have a similar macroclimate, and were inundated by proglacial Lake Vermont during the last deglaciation. In contrast, the bedrock differs beneath the two sites, and SV was under shallow marine water immediately after Lake Vermont drained. The hypothesis tested was that despite their similar physical settings, the VGI of the two vineyards would vary as a result of differences in their late-Quaternary histories. Samples of soil and sediment were evaluated for grain size distribution, thermogravimetric analysis, mineralogy, major element chemistry, and standard soil fertility assessments, and a map of soil conductivity was made for each site. Results reveal that base cations and silt are significantly more abundant at LP. Conversely, at SV, Na is significantly more abundant, samples are coarser and soil conductivity is higher. These results illuminate the utility of VGI for defining the fingerprint of individual vineyards, and establish a physical foundation for future work evaluating the role of physical setting in controlling aspects of Marquette wines.