Geophysical signature of a buried maar diatreme in the Krkonoše-Jizera Granite Massif (Czech Republic)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F21%3A00000077" target="_blank" >RIV/00025798:_____/21:00000077 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Geophysical signature of a buried maar diatreme in the Krkonoše-Jizera Granite Massif (Czech Republic)

Original language description

We present results and a method to geophysically image the subsurface structure of Pytlácká jáma Pit within the Lusatian Volcanic Field of the Eger Rift. The Pytlácká jáma Pit (Rybí loučky nature reserve) is located in the Jizerské hory Mts. in the northern Czech Republic near the state border with Poland. This dominant geomorphologic depression has been previously described as the only example of a glacial cirque in the Jizerské hory Mts. Our high-resolution geophysical data demonstrate its volcanic origin. It is the first maar diatreme ever identified within the Upper Carboniferous Krkonoše-Jizera Granite Massif. The size, shape, depth and geometry of the Pytlácká jáma maar-diatreme interior is described by a combination of ground magnetic and gravity survey with electrical resistivity tomography (ERT). Its funnel-shaped structure is deeply eroded and buried under alluvial, colluvial and glacial sediments, which form mainly from the local Jizera Granite bedrock. The phreatic eruption and maar-diatreme basaltic formation could be an indirect consequence of similar effusive activity near the Bukovec Volcano. Identification of the Pytlácká jáma Pit as a maar diatreme can explain the origin and evolution of the cirque-shaped hollow, and moreover the presence of the gemstones – sapphires and zircons - in nearby Jizerka rivulet alluvial sediments. Such volcanic structures are the attributed provenance of sapphire and ruby deposits in Australia and Southeast Asia (Sutherland et al. 2015).

Czech name

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Czech description

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Type

V_souhrn - Summary research report

CEP classification

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OECD FORD branch

20701 - Environmental and geological engineering, geotechnics

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Number of pages

21

Place of publication

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Publisher/client name

ČGS

Version

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