The backbone of the wines is particularly characterized by the rhyolith – also known as quartz porphyry. This is an acidic, magmatic type of igneous rock from the Perm age, and was formed around 290 million years ago by tectonic fault lines in the Nahe-Saar Basin. Siefersheim itself is located on the extreme south-easterly border of this fault line, and is basically surrounded and framed by the hills of this magmatic mass.
What the region of Rheinhessen, which formerly was dominated by a dry, hot climate and characterized by a reddish landscape of desert and grasslands, experienced at that time was not true volcanic activity. Rather, liquid magma made its way to the surface from the core of the earth, emerging at only a few individual sites. In fact, it did not quite reach the surface of the earth, but got stuck close to the surface. The slow process of cooling off and the following process of erosion and decomposition shaped the rhyolithic formations visible today.
In the Tertiary period, when Rheinhessen was covered by an ocean, the hills of quartz porphyry surrounding Siefershein stuck up out of the water as islands, and one can find traces of the former coastal landscape at many locations of the communal area. Limestone deposits, sharks’ teeth and oysters can still be found today in many of the vineyard parcels. It is a surprising unique feature that one can retrace the geological history of this region for more than 250 million years in the volcanic hills surrounding Siefersheim.
