Listvenite and related rocks: perspectives on terminology and mineralogy with reference to an occurrence at Cregganbaun, Co. Mayo, Republic of Ireland

Abstract

Abstract. The rock 'listvenite' is named and defined by reference to historical observations and recommendations are made so that listvenite (s.s.) can be distinguished from related carbonate-rich alteration products of ultramafic rocks. The mineralogy and tectonic setting of listvenite are reviewed, taking into account the descriptions and classifications used in the literature. The petrography of listvenite and related rocks at Cregganbaun serves as a reference to illustrate the characteristics of true listvenite and closely related products of listvenitic alteration.During the 150 years since the term 'listwiinite' was first introduced by Rose (1837Rose ( , 1842, much has been written on the topic by Russian field geologists and researchers (Krotov 1915;Lodochnikov 1936;Borodayevskiy and Borodayevskiy 1947;Korzhinskii 1953;Bok 1956;Ploshko 1963; Allakhverdiev 1965, 1971;Shcherban 1967;Shcherban and Borovikova 1969;Goncharenko 1970, Sazonov 1975Abovian 1978; Kuleshevich 1984;Spiridonov 1991). Listvenites and the criteria by which they are defined have more recently become a concern of geologists elsewhere Buisson and Leblanc 1985a, 1985b, 1987Aydal 1989;Ash and Arksey 1990a, 1990b, 1990cMadu et al. 1990;Nixon 1990;Ashley and Brownlow 1993;Auclair et al. 1993) due to their spatial and temporal association with gold deposits of mesothermal type in eugeoclinal terranes worldwide. There are problems concerning the strict definition of 'listw;nite' and also regarding the correct spelling of the word. This is evident in the idiosyncratic transliterations from Russian into other languages. Various spellings can be found e.g. listwaenite, listwanite, listvanite and listvenite. This confusion has arisen because of the free phonetic interpretation of the original transliteration from Russian to German given by Rose (1842). The geological section through the Urals given by Murchison et al. (1845) shows the type locality for listvenite, Listvenya Gora (Larch Hill). The root of the name listvenite is found in the Russian name for the larch tree. In a direct transcription from Cyrillic to English, the correct spelling is therefore 'listvenite'.In order to understand the processes governing the gold mineralization found in association with listvenite, it is also necessary to understand the process of listvenitization. However, a review of the literature shows that the term 'listvenite' is used to describe a diversity of carbonate-rich rocks produced by alteration of mafic-ultramafic bodies. The aim of the present contribution is to re-establish the identity of listvenite in the sense of the original description given by Rose (1837Rose ( , 1842 and to review the current classifications of listvenite and related rocks, using examples from Cregganbaun, Ireland to illustrate the characteristics of true listvenite and associated types of alteration. Characteristics of listvenite The historical problemSince the term 'listvenite' was first introduced to the literature of mineralogy by Rose (1837Rose ( , 1842, the usage of the wor...

The genesis of the carbonatized and silicified ultramafics known as listvenites: a case study from the Mihalıççık region (Eskişehir), NW Turkey

“…1996, 2000). Because, Cr-mica (fuchsite) is absent in the metasomatites of the study area, the alteration assemblages of Mihalıççık region are not proper listvenites but members of the listvenitic series with respect to the description of Halls and Zhao (1995).The temporal phase relations indicate a primary stage of carbonatization that took place before the subsequent silicification. The spatial distribution of the alteration products are not apparent in all of the outcrops; however, in Türkmen Oturaǧı district (Figure 2), thin section studies showed that the carbonate assemblages change into silicacarbonate rocks in the altered body northeastwards.…”

“…J. 41: 557-580 (2006) Copyright # 2006 John Wiley & Sons, Ltd. 1947Bok 1956;Ploshko 1963; Allakhverdiev 1965, 1971;Shcherban 1967;Shcherban and Borovikova 1969;Abovian 1978;Kuleshevich 1984;Ivan et al 1985;Buisson and Leblanc 1985, 1986Aydal 1989;Nixon 1990; Ash and Arksey 1990a,b;Madu et al 1990;Spiridonov 1991;Auclair et al 1993;Halls and Zhao 1995;Uçurum 1996Uçurum , 2000. Listvenites (quartz-carbonate-chromium mica association), quartz-carbonate rocks (silica-carbonate association), carbonate-rich rocks, serpentinetalc-(chlorite)-carbonate rocks, talc-carbonate rocks and talc-silica-carbonate rocks are the examples of the metasomatites.…”

“…Detailed history of these studies and the nomenclature was recently compiled by Halls and Zhao (1995). In summary, the listvenites bear Cr-mica and represent the beresitic facies, whereas the listvenite-like metasomatites include Crclay minerals and represent the argillic facies of metasomatites in ultramafic terranes (Spiridonov 1991;Halls and Zhao 1995).Numerous listvenites and listvenite-like metasomatites have been studied along the Alpine belts (e.g. Rose 1842; Spiridonov 1991; Auclair et al 1993;Halls and Zhao 1995).…”

“…He indicates that the fresh hand specimens of the rock present a granular green and white flecked appearance due to the mixture of white coloured carbonates and green coloured fuchsite, although sometimes gaining a brown appearance caused by weathering of ankerite/magnesite to limonite. Listvenites form by intermediate-low temperature hydrothermal/metasomatic alteration of mafic-ultramafic rocks (especially serpentinites) and are commonly located within or near major fault and shear zones (Halls and Zhao 1995). With the influx of K-bearing hydrothermal fluids in the tectonic fractures, primary ferromagnesian silicates of host rocks are replaced by the Mg-Fe (-Ca) carbonates.…”

“…In summary, the listvenites bear Cr-mica and represent the beresitic facies, whereas the listvenite-like metasomatites include Crclay minerals and represent the argillic facies of metasomatites in ultramafic terranes (Spiridonov 1991;Halls and Zhao 1995).…”