Noble gas magmatic signature of the Andean Northern Volcanic Zone from fluid inclusions in minerals

Late Miocene to Pleistocene volcanism within the Vardar zone (N. Macedonia) covers a large area, has a wide range in composition and it is largely connected to the tectonic evolution of the South Balkan extensional system, the northern part of the Aegean extensional regime. A recent study indicated an increasing rate of mantle metasomatism towards the younger centers in the region [1]. During the last stage of activity, ultrapotassic (UK) centers that formed between ca. 3.2 and 1.5 Ma originated from the lithospheric mantle beneath the region [2]. Although there are no reported mantle xenoliths from these centers, the erupted mafic rocks contain abundant olivine as phenocrysts [3]. Noble gas isotopic characteristics of fluid inclusions in olivine can reveal important information about the origin of the fluid and the metasomatic state of the lithospheric mantle. We analyzed for the first time the noble gas composition of fluid inclusions of olivine phenocrysts from the Mlado Nagori&#269;ane volcanic center, the northernmost member of the UK centers with an eruption age of 1.8 &#177; 0.1 Ma [2]. The R/RA ratios give a range of 3.1-4.5 with 4He/20Ne values of 11.7-14.6. These R/RA values are lower than the MORB and the averaged subcontinental lithospheric values, and considering the negligible amount of atmospheric contribution, imply a more metasomatized character for the underlying lithospheric mantle beneath the region. Mantle-derived noble gases were detected in a recent geochemical study on the thermal springs and gas exhalations in the region, with up to 20% of mantle contribution calculated based on their noble gas composition using the MORB R/RA value [4]. These new Mlado Nagori&#269;ane fluid inclusion noble gas values indicate that the mantle contribution in the recent gas emissions in the region could be higher than what was thought.This research was supported by the European Union and the State of Hungary, financed by the European Regional and Development Fund in the project of GINOP-2.3.2-15-2016-00009 &#8216;ICER&#8217; project[1] Moln&#225;r et al. 2020 &#8211; EGU2020-13101.[2] Yanev et al., 2008 &#8211; Mineralogy and Petrology, 94(1-2), 45-60.[3] Yanev et al., 2008 &#8211; Geochemistry, Mineralogy and Petrology, Sofia, 46, 35-67.[4] Temovski et al. 2020 &#8211; EGU2020-2763.

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Fluid inclusions, H-O, S, Pb, and noble gas isotope studies of the Baiyun gold deposit in the Qingchengzi orefield, NE China

Journal of Geochemical Exploration ◽

10.1016/j.gexplo.2019.01.016 ◽

2019 ◽

Vol 200 ◽

pp. 37-53 ◽

Cited By ~ 7

Author(s):

Peng Zhang ◽

Lin-Lin Kou ◽

Yan Zhao ◽

Zhong-Wei Bi ◽

De-Ming Sha ◽

...

Keyword(s):

Gold Deposit ◽

Fluid Inclusions ◽

Noble Gas ◽

Ne China ◽

Noble Gas Isotope ◽

Isotope Studies

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Temporal Evolution of Magmatism in the Northern Volcanic Zone of the Andes: The Geology and Petrology of Cayambe Volcanic Complex (Ecuador)

Journal of Petrology ◽

10.1093/petrology/egi053 ◽

2005 ◽

Vol 46 (11) ◽

pp. 2225-2252 ◽

Cited By ~ 65

Author(s):

PABLO SAMANIEGO ◽

HERVÉ MARTIN ◽

MICHEL MONZIER ◽

CLAUDE ROBIN ◽

MICHEL FORNARI ◽

...

Keyword(s):

Temporal Evolution ◽

Volcanic Complex ◽

Volcanic Zone ◽

The Andes ◽

Northern Volcanic Zone

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Tectonic evolution of the Northern Volcanic Zone, Abitibi belt, Quebec

Canadian Journal of Earth Sciences ◽

10.1139/e92-175 ◽

1992 ◽

Vol 29 (10) ◽

pp. 2211-2225 ◽

Cited By ~ 88

Author(s):

E. H. Chown ◽

Réal Daigneault ◽

Wulf Mueller ◽

J. K. Mortensen

Keyword(s):

Structural Evolution ◽

Sedimentary Basins ◽

Volcanic Zone ◽

Tectonic Model ◽

Sedimentary Evolution ◽

Southern Volcanic Zone ◽

Oblique Convergence ◽

Northern Volcanic Zone ◽

Abitibi Subprovince ◽

Felsic Volcanic

The Archean Abitibi Subprovince has been divided formally into a Northern Volcanic Zone (NVZ), including the entire northern part of the subprovince, and a Southern Volcanic Zone (SVZ) on the basis of distinct volcano-sedimentary successions, related plutonic suites, and precise U–Pb age determinations. The NVZ has been further formally subdivided into (i) a Monocyclic Volcanic Segment (MVS) composed of an extensive subaqueous basalt plain with scattered felsic volcanic complexes (2730–2725 Ma), interstratified with or overlain by linear volcaniclastic sedimentary basins; and (ii) a Polycyclic Volcanic Segment (PVS) comprising a second mafic–felsic volcanic cycle (2722–2711 Ma) and a sedimentary assemblage with local shoshonitic volcanic rocks.A sequence of deformational events (D1–D6) over a period of 25 Ma in the NVZ is consistent with a major compressional event. North–south shortening was first accommodated by near-vertical east-trending folds and, with continued deformation, was concentrated along major east-trending fault zones and contact-strain aureoles around synvolcanic intrusions, both with a downdip movement. Subsequent dextral strike-slip movement occurred on southeast-trending faults and major east-trending faults which controlled the emplacement of syntectonic plutons (2703–2690 Ma).This study suggests that the NVZ, which is a coherent geotectonic unit, initially formed as a diffuse volcanic arc, represented by the MVZ, in which the northern part, represented by the PVS, evolved into a mature arc as documented by a second volcanic and sedimentary cycle associated with major plutonic accretion. Volcano-sedimentary evolution and associated plutonism, as well as structural evolution, are best explained by a plate-tectonic model involving oblique convergence.

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