You can see it along roadside gulleys and in cavernous gorges where it sometimes peels off like layers of earth's skin. Barges stacked with sheets of this shale traveled the new Erie Canal in the mid-1800s to pave Brooklyn sidewalks. Laced with fissures and easily split, the shale underlying Finger Lakes vineyards fulfills two important requirements of grapevines. It lets their roots probe deep into mineral resources that infuse wine with nuance. And it keeps the soil well drained.
Grapevines suffocate in soggy soil.
As the sea receded, evaporating water left salt beds and deposits of marine animal shells and decayed organic matter. Today the salt is mined from shafts burrowing underneath the lakes. Not all grapevines do well in high-lime soil. But European vinifera varieties prefer high-lime soil. Gold Seal winemaker Charles Fournier knew this well from his early years in France's Champagne district, where the soil is white with lime.