01-P-13 - Mineralogy, chemistry and ion-exchange properties of the zeolitized tuffs from the Sheinovets caldera, E Rhodopes (South Bulgaria)

Ivanova, Rositsa; Yanev, Yotzo; Iliev, Tz.; Koleva, E.; Popova, T. I.; Popov, Nikita Y.

doi:10.1016/s0167-2991(01)81506-8

Cited by 5 publications

(9 citation statements)

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“…LIL elements behave as compatible in the studied rocks. In our previous studies (Ivanova et al, 2018(Ivanova et al, , 2020 we have concluded that Ba and Sr are mainly incorporated in magmatic miner-als (Bt, Fsp) and their contents in tuffs are highest in the crystal-and lithics-rich varieties. For the samples reported here this conclusion is not so evident.…”

Section: Resultsmentioning

confidence: 91%

“…The zeolitized tuffs are not included in the list of critical raw materials and are neither considered as a source of critical elements, however, the interest in them has also increased. Respectively, in the last years we have started to collect data to fill the existing gap in our knowledge of these materials with respect to their trace element geochemistry (Ivanova et al, 2018;. This paper reports recent data from LA-ICP-MS analyses of 10 samples of mainly zeolitized tuffs from different localities with a different position in the pyroclastic section in the Eastern Rhodopes and related to different volcanic phases.…”

Section: Introductionmentioning

confidence: 99%

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Trace element geochemistry of altered pyroclastic deposits from the Eastern Rhodopes (SE Bulgaria)

Ivanova,

Dimitrova,

Sergeeva

et al. 2023

Rev. Bulg. Geol. Soc.

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The contents of major and rare elements in 10 samples of altered (mainly zeolitized) pyroclastic rocks from the Eastern Rhodopes are investigated. The samples are selected to represent different secondary mineral associations specific to the area. The obtained results indicate that the diversity in secondary mineral associations has relatively little influence on the trace element geochemistry of zeolitized pyroclastic rocks in the Eastern Rhodopes. Regarding their trace and rare earth element composition, these rocks show the main characteristics seen in the acid lavas in the area.

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Section: Resultsmentioning

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Trace element geochemistry of altered pyroclastic deposits from the Eastern Rhodopes (SE Bulgaria)

Ivanova,

Dimitrova,

Sergeeva

et al. 2023

Rev. Bulg. Geol. Soc.

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“…Central and Eastern Slovakia. (Own unpublished and published chemical analyses and data after Aleksiev & Djourova, 1982;Djourova & Milakovska, 1987;Ivanova et al, 2001;Yanev et al, 2006). (Cpt À clinoptilolite; Mor À mordenite; Ana À analcime; KFs À potassium feldspar; Cri À cristobalite; Q À quartz; Ad À adularia).…”

Section: Fig 3 Diagram Of the Chemical Composition Of Acidic Volcanmentioning

confidence: 99%

“…Raynov and coworkers correctly point out that the geoautoclave mechanism does not explain the zeolitization of both the fall-out tuffs and the matrix of epiclastic deposits, since they had been deposited as a cold material. Ivanova et al (2001) and Yanev et al (2006) supposed that the heat of the pyroclastic flows, together with abnormally high geothermal gradient in the active volcanic areas, generate hydrothermal systems circulating in the ash layers. According to our field investigations, evidence or indications of hydrothermal solution circulation in the tuff layer have not been observed.…”

Section: Fig 3 Diagram Of the Chemical Composition Of Acidic Volcanmentioning

confidence: 99%

“…The mordenite rocks at Mezek (ER) are within the region of the Sheinovets caldera (Aleksiev et al, 2000;Ivanova et al, 2001) and are also influenced by later rhyolite bodies. At one site in this region erionite has been found together with mordenite (Ivanova et al, 2001). In Central Slovakia near to Jastraba Skala a tuff layer is crosscut by a rhyolite body, causing mordenitization close to the contact (Š amajova et al, 1992).…”

Section: Mordenite Rocksmentioning

confidence: 99%

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Alteration processes and products of acid pyroclastic rocks in Bulgaria and Slovakia

Kirov¹,

Šamajova²,

Nedialkov³

et al. 2011

Clay miner.

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The genesis of the products of the alteration of acid pyroclastic material is discussed and interpreted on the basis of the distribution, sedimentation conditions, post-sedimentation activity, mineral and chemical compositions of pyroclastic deposits in Bulgaria and Slovakia.It is found that the disordered nonequilibrium nature of the volcanic glass induces a diagenetic devitrification of the tuffs and formation of clinoptilolitic, adularia-cristobalite and bentonite rocks. With increasing temperature, the volcanic glass tends forward a stable state through a series of zeolite mineral associations: clinoptilolite-mordenite-analcime-feldspar. The change in mineral composition of this series of rocks occurs without a change in the chemical composition of the rocks, which could be explained by the closed nature of zeolite systems. The formation of bentonites is associated with the removal of alkaline ions under diagenetic conditions, while the formation of halloysite rocks is caused by hydrothermal activity.

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Zeolites and zeolitization of acid pyroclastic rocks from paroxysmal Paleogene volcanism, Eastern Rhodopes, Bulgaria

Yanev¹,

Cochemé²,

Ivanova³

et al. 2006

njma

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An extensive bimodal volcanic suite developed in the Late Paleogene in the Eastern Rhodopes Mountains, Southern Bulgaria. Most of the widespread and thick rhyolitic tuffs and ignimbrites. erupted during two major Early Oligocene acid pha ses, were emplaced in a shallow marine environment and subsequently altered. K-rich Ca-clinoptilolite (in some places K-clinop tilolite. mordenite or analcime). clay minerals (celadonite or/and smectite). adularia (or albite) and opal-CT replace the volcanic glass. The zeolitized pyroclastic rocks are strongly depleted in MnO. Na20. K20, and enriched in CaO. Fe201. Ti02 and MgO. Regional zoning in distribution of the major glass-replacing minerals has been established: quartz+ adularia (or albite)± zeolites in the proximal to the vent area: zeolites in the medial and clay minerals in the distal area. Vertical zoning has been also recog nized because on ly the basal pyroclastic layer is transformed into adularia+ quartz whereas clinoptilolite. accompanied by opal CT and clay mineral s. prevails in the rest of the section. The zeolitized glass shards are characteristically zoned: (I) a thin rim (< 5 �m thick) of celadonite coats the shard surface retaining their original shape: (2) a 30-50 , um-thick zone. made of contiguous platy zeolite crystals. oriented perpendicular to the rim and (3) a central zone of large euhedral crystals. surrounding a central hollow area. Phenocrysts are not affected by the zeolitization and some relict glass is found in the top of the pyroclastic section. According to the semiquantitative X-ray analysis and heat of immersion test of CcLFAZ et a!. (1973) the clinoptilolite content in the zeolitized pyroclastic rocks varies from 38 to 72 wt. 'lc. The cation exchange capacity values range between 40 and 153 meq/ 100 g and show a significant positive correlation with clinoptilolite content obtained by the heat of immersion test (r = 0.71). The lateral zoning and presence of typical hydrothermal minerals such as celadotite indicate that zeolitization of the thick Eastern Rhodopes pyroclastic series results from the operation of a large low temperature hydrothermal system. The hydrothermal solu tions consist of marine water heated by the anomalous geothermal gradient of the active volcanic areas or/and by the hot pyro clastic deposits.

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01-P-13 - Mineralogy, chemistry and ion-exchange properties of the zeolitized tuffs from the Sheinovets caldera, E Rhodopes (South Bulgaria)

Cited by 5 publications

References 0 publications

Trace element geochemistry of altered pyroclastic deposits from the Eastern Rhodopes (SE Bulgaria)

Trace element geochemistry of altered pyroclastic deposits from the Eastern Rhodopes (SE Bulgaria)

Alteration processes and products of acid pyroclastic rocks in Bulgaria and Slovakia

Zeolites and zeolitization of acid pyroclastic rocks from paroxysmal Paleogene volcanism, Eastern Rhodopes, Bulgaria

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