separated as a text (ACE file) to be converted to an independent ontology (DL
species is AL(D)). Thus, the DB will be converted to 1,174 ontologies. Columns values mainly form attribute values, but also class names (rhyolite, harzburgite)
and individual names (Iceland). Let's consider the ontology obtained for an article with a DB number of 5633. The obtained classes, properties and individuals are listed below.

Classes: place, publication, rhyolite, sample, substance, weight **percent.**
Object properties: component, describes, gathering **place, includes, mixture, part.** Data properties: authorial number, chemical formula, first page, journal **reference,**
last **page, latitude, longitude, reference, title, value, year.**
Individuails: Atlantic **Ocean, Iceland etc.**
All the terms used except rhyolite refer to contexts outside of petrology and even geology. These are the contexts of geography (place, etc), scientific publications (publication etc), solid state physics (sample, substance, weight **percent**
etc), chemistry (chemical **formula). The rest of the report focuses on obtaining** rock type definitions, including that for rhyolite.

## 3 Formalizing Terminology: From Natural Language To Owl

The ontology of the facts specifies that the part of names used for classes, relations, individuals belongs to a different ontology (vocabulary). This dictionary ontology is supposed to provide term definitions, and the author of **the article has exactly this understanding in mind. Such scientific terms are normally**
already collected in a dictionary, for example, Petrographic Dictionary [12], Dictionary of Geological Terms [4], Dictionary of Igneous Rocks Terms [7], Glossary of Geology [1]. The dictionary represents a very important and specific type of knowledge. It is based on subject domain terms and informal definitions of these terms. Example: harzburgite rock type article from [10], p.88:
HARZBURGITE. An ultramafic plutonic rock composed essentially of olivine and orthopyroxene. Now defined modally in the ultramafic rock classification (Fig. 2.9, p.28). (Rosenbusch, 1887, p.269; Harzburg, Harz Mts, Lower Saxony, Germany; Troeger 732; Johannsen v.4, p.438; Tomkeieff p.247)
We have converted a specific dictionary ([7]) initially presented by authors as an html page to an OWL ontology. We begin the formalization of relations between terms (for example, synonymy) and term properties (for example, become outdated).

Converting the dictionary text to ontology. **We took the Dictionary of**
Terms of Igneous Rock Types compiled by the Interdepartmental **Petrographic** Committee in the Department of Earth Sciences of the Russian Academy of Sciences [7]. The dictionary contains 1,567 articles, the overwhelming majority 4