Dr. Kubassek János szerk.: A Kárpát-medence természeti értékei (Érd, 2004)

Dr. Péter Rózsa: Robert Townson (1762-1827): a pioneer scientific explorer of the Carpathian Basin

O He indicated porphyry and volcanic tuff in the mountains on his map, therefore, like Ignaz Born (1742-1791) and Johann Ehrenreich von Fichtel, he recognised the volcanic character of these mountains. This conclusion may be obvious nowadays, however, Townson's age was characterised by furious debates of plutonists and neptunists. For instance, the Norwegian Jens Esmark (1763-1839), who came here some years later, took a stand on the neptunian origin of the mountains.

9 Townson's first stop was only one or two miles from Tokaj town: the classic perlite outcrop near the so-called Lebuj Inn. He identified the rock as Fichtel's "volcanic zeolite",

10 but he corrected Fichtel's characterisation in several respects: Jt is of an ash colour, here and there variegated with red, very fragile, and the texture like congeries of small tunicated ill-shaped beads, of a rather greasy lustre. It greatly intumesces under the blow-pipe, even to thrice its bulk, and forms a white scoria; but it only slightly phosphoresces, and forms nogelly with nitrous acid, which are two of the principal characters of Zeolite. In some parts the little globules, which are formed of different coats, contain a nucleus of Obsidian; the thin coats are easily detached. Of these nuclei I picked up a great many at the foot of the bank, mostly of the size of a pea, but some of the size of a bean: they are more or less angular, but never crystallized as Mr. Fichtel inform us. I have seen his pretended crystals, and can assure my readers, that none but those who are blinded by mineralogical hypotheses, and call in conceding fancy instead of severe judgement to be their counsellors, can think them such. These globules likewise swell under blow-pipe, and form a whitish glass. [...] This is probably the »Verre volcanique en grains noirs, réunis par une Lave compacte grise, « of Mr. Born's Catalogue Raisonné

11 page 449, and loose grains, his »Verre volcanique noir, en grains isolés, « page 450. "

n Townson asked the famous German chemist Martin Heinrich Klaproth (1743-1817) to analyse the pearly matrix, and published the result. Possibly, tins is the first published chemical analysis of the rock.

13 The rock of the Tokaj-Lebuj outcrop is often mentioned as marekanitic perlite. The name perlite (as "Perlstein") was first applied by Esmark,

14 however, Townson was the first who suggested that the rock of Tokaj-Lebuj is eye-strikingly similar to the rock described by Peter Simon Pallas (1741-1811) in 1793 and named as marekanite

15 (RÓZSA P. - SZAKÁLL S., 1999; SZÖORGY. et al., 1999). O o