Editing Westerwald (section)

== Geology ==
[[File:Hummelsberg Basalt Säulen 3.JPG|thumb|Basalt columns at the Hummelsberg]]
[[Geology|Geologically]], the Westerwald is part of the Rhenish Massif, and likewise represents a heavily [[truncated upland|eroded remnant]] of a great [[Variscan orogeny|Variscan]] mountain system which in the [[Mesozoic]] characterized a great deal of Europe.

The [[Devonian]] [[bedrock]] is covered by volcanic masses from the [[Tertiary]], particularly [[basalt]] and [[tuff]]s. Economically important, besides slate, [[limestone]] and clay [[quarry]]ing, were, and still are, iron and its processing industry between [[Rhine|Rheintal]] (Unkel, Linz) and the lower Wied, [[pumice]] gravel in the [[Neuwied]] Basin, various mineral springs and, once, [[Lignite|brown coal]] mining.

The whole Westerwald region lay under a tropically warm arm of the sea in the [[Palaeozoic]] (600 to 270 million years ago). This sea deposited layers of sediments many kilometres thick into the Variscan [[geosyncline]], which were heavily folded in the [[orogeny]] that followed. The towns of [[Siegen]] and [[Koblenz]] on the Westerwald's north and southwest edges even gave two Lower Devonian layers, with their colourful slates, their names. The upper mountain layers are formed of volcanic strata made of basalt containing tuffs.
[[File:WesterwaldTopf3475.JPG|thumb|Typical everyday Westerwald pottery]]
In a few areas, slate and clay have long been quarried, the latter notably in the so-called [[Kannenbäckerland]], but also in a few other places where the clay is worked into the salt-[[Ceramic glaze|glazed]] grey [[Westerwald Pottery]] with [[cobalt blue]] decoration. The pottery industry is centred on [[Höhr-Grenzhausen]]. Exports, particularly to Italy, are also important (more than one million metric tons each year). In the mid 16th century, potters from [[Raeren]] in Belgium migrated into the Westerwald, bringing with them some of their [[Molding (process)|moulds]]. This type of pottery was taken to the [[New World]] and was found in the early [[Chesapeake (tribe)|Chesapeake]] settlements. Today one finds not only highly crafted moulded vases and mugs but also a range of handcrafted utility ware, with hand-painted swirling floral motifs.

In the eastern Westerwald (the part lying in Hesse) are found interesting limestone deposits from the most varied of geological times. Erdbach limestone from the Lower [[Carboniferous]] gave one small time period the name "Erdbachian".<ref>{{cite web|url=http://www.bernstein.naturkundemuseum-bw.de/odonata/paleodat.htm|title=Synoptic Time Table of Earth History<!-- Bot generated title -->}}</ref>

Near [[Breitscheid, Hesse|Breitscheid]] are found the remnants of an [[atoll]] from the subtropical Devonian sea that was here 380,000,000 years ago. Parts of this limestone formation are worked in [[open-pit mining]]; near [[Enspel]], a "[[fossil]] conservation area" has been instituted, in which institutes from several [[Hochschule|colleges]] conduct research and excursions. A few [[Karst topography|karst]] caves are of interest to [[spelaeology]] and bring about the temporary disappearance and reappearance of the Erdbach.