Permian volcanics in the Northern Gemericum and Bôrka Nappe system: U-Pb zircon dating and the implications for geodynamic evolution (Western Carpathians, Slovakia)

Permian volcanics in the Northern Gemericum and Bôrka Nappe system: U-Pb zircon dating and the implications for geodynamic evolution (Western Carpathians, Slovakia)U-Pb dating (SHRIMP) of magmatic zircon ages from the Northern Gemericum Permian volcanics (Petrová Hora Formation) yielded the Concordia age of 272.4 ± 7.3 Ma for basaltic andesite, as well as the Concordia age of 275.2 ± 4 Ma for rhyodacites. Both zircon ages correspond to the Cisuralian Epoch in the time span of the Kungurian Stage. Acquired206Pb/238U zircon age data support the nearly contemporaneous origin of the acid and basic volcanogenic members in the Northern Gemericum Permian strata. The bimodal volcanic suite proves the transtension/extension tectonic regime in the North Gemeric sedimentary basin during the Late Cisuralian. The magmatic zircon ages of rhyodacites, occurring in the lower thrust sheet of the Bôrka Nappe (Jasov Formation), gave a younger Concordia age of 266 ± 1.8 Ma proving the Guadalupian Epoch, in the time span of the Wordian/Capitanian. In comparison to the Northern Gemericum realm, this age refers to the relatively younger stage of rift-related extensional movements. In the wide Alpine-Dinarides realm the Middle Permian (Guadalupian) movements are related to the beginning of the Alpine sedimentary cycle. Thus, the Middle Permian rifting expresses the beginning of the formation of the future Meliata oceanic trough.

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Permian single crystal U-Pb zircon age of the Rožňava Formation volcanites (Southern Gemeric Unit, Western Carpathians, Slovakia)

Geologica Carpathica ◽

10.2478/v10096-009-0032-1 ◽

2009 ◽

Vol 60 (6) ◽

pp. 439-448 ◽

Cited By ~ 11

Author(s):

Anna Vozárová ◽

Miloš Šmelko ◽

Ilya Paderin

Keyword(s):

Single Crystal ◽

Volcanic Activity ◽

Late Ordovician ◽

Western Carpathians ◽

Magmatic Zircon ◽

Zircon Age ◽

Zircon Population ◽

Growth Zoning ◽

Gemeric Unit ◽

Rock Complex

Permian single crystal U-Pb zircon age of the Rožňava Formation volcanites (Southern Gemeric Unit, Western Carpathians, Slovakia)Zircon populations from the Rožňava Formation volcanic rock complex have been analysed. Euhedral zircons from the 1stvolcanogenic horizon with fine oscillatory growth zoning, typical of magmatic origin, gave the average concordia age of 273.3 ± 2.8 Ma, with Th/U ratios in the range of 0.44-0.73. The Permian ages ranging from 266 to 284 Ma were identified in the wider, zoned or unzoned, central zircon parts, as well as in their fine-zoned oscillatory rims. The average concordia age of 275.3 ± 2.9 was obtained from the euhedral zircon population of the 2ndvolcanogenic horizon of the Rožňava Formation. The analyses were performed on zoned magmatic zircons in the age interval from 267 to 287 Ma, with Th/U ratios in the range of 0.39-0.75. In the later zircon population two inherited zircon grains were dated giving the age of 842 ± 12 Ma (Neoproterozoic) and 456 ± 7 Ma (Late Ordovician). The magmatic zircon ages document the Kungurian age of Permian volcanic activity and contemporaneous establishment of the south-Gemeric basin. The time span of volcanic activity corresponds to the collapse of the Western Carpathian Variscan foreland which expanded southward.

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Preliminary detrital zircon U-Pb Geochronology of the Wasatch Formation, Powder River Basin, Wyoming

The Mountain Geologist ◽

10.31582/rmag.mg.56.3.247 ◽

2019 ◽

Vol 56 (3) ◽

pp. 247-266

Author(s):

Ian Anderson ◽

David H. Malone ◽

John Craddock

Keyword(s):

River Basin ◽

Detrital Zircon ◽

Middle Part ◽

Detrital Zircons ◽

Powder River Basin ◽

Zircon Age ◽

Lower Eocene ◽

The North ◽

Mountain Front ◽

Fluvial Sandstone

The lower Eocene Wasatch Formation is more than 1500 m thick in the Powder River Basin of Wyoming. The Wasatch is a Laramide synorgenic deposit that consists of paludal and lacustrine mudstone, fluvial sandstone, and coal. U-Pb geochronologic data on detrital zircons were gathered for a sandstone unit in the middle part of the succession. The Wasatch was collected along Interstate 90 just west of the Powder River, which is about 50 km east of the Bighorn Mountain front. The sandstone is lenticular in geometry and consists of arkosic arenite and wacke. The detrital zircon age spectrum ranged (n=99) from 1433-2957 Ma in age, and consisted of more than 95% Archean age grains, with an age peak of about 2900 Ma. Three populations of Archean ages are evident: 2886.6±10 Ma (24%), 2906.6±8.4 Ma (56%) and 2934.1±6.6 Ma (20%; all results 2 sigma). These ages are consistent with the age of Archean rocks exposed in the northern part of the range. The sparse Proterozoic grains were likely derived from the recycling of Cambrian and Carboniferous strata. These sands were transported to the Powder River Basin through the alluvial fans adjacent to the Piney Creek thrust. Drainage continued to the north through the basin and eventually into the Ancestral Missouri River and Gulf of Mexico. The provenance of the Wasatch is distinct from coeval Tatman and Willwood strata in the Bighorn and Absaroka basins, which were derived from distal source (>500 km) areas in the Sevier Highlands of Idaho and the Laramide Beartooth and Tobacco Root uplifts. Why the Bighorn Mountains shed abundant Eocene strata only to the east and not to the west remains enigmatic, and merits further study.

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Measuring the ‘Great Unconformity’ on the North China Craton using new detrital zircon age data

Geological Society London Special Publications ◽

10.1144/sp448.14 ◽

2016 ◽

Vol 448 (1) ◽

pp. 145-159 ◽

Cited By ~ 14

Author(s):

Tianchen He ◽

Ying Zhou ◽

Pieter Vermeesch ◽

Martin Rittner ◽

Lanyun Miao ◽

...

Keyword(s):

Detrital Zircon ◽

North China Craton ◽

North China ◽

Zircon Age ◽

The North

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Caledonian terrane amalgamation of Svalbard: detrital zircon provenance of Mesoproterozoic to Carboniferous strata from Oscar II Land, western Spitsbergen

Geological Magazine ◽

10.1017/s0016756813000174 ◽

2013 ◽

Vol 150 (6) ◽

pp. 1103-1126 ◽

Cited By ~ 33

Author(s):

DETA GASSER ◽

ARILD ANDRESEN

Keyword(s):

Detrital Zircon ◽

Large Scale ◽

Strike Slip ◽

Western Coast ◽

Zircon Age ◽

The North ◽

Tectonic History ◽

Icp Ms ◽

Depositional Age ◽

Sveconorwegian Orogen

AbstractThe tectonic origin of pre-Devonian rocks of Svalbard has long been a matter of debate. In particular, the origin and assemblage of pre-Devonian rocks of western Spitsbergen, including a blueschist-eclogite complex in Oscar II Land, are enigmatic. We present detrital zircon U–Pb LA-ICP-MS data from six Mesoproterozoic to Carboniferous samples and one U–Pb TIMS zircon age from an orthogneiss from Oscar II Land in order to discuss tectonic models for this region. Variable proportions of Palaeo- to Neoproterozoic detritus dominate the metasedimentary samples. The orthogneiss has an intrusion age of 927 ± 3 Ma. Comparison with detrital zircon age spectra from other units of similar depositional age within the North Atlantic region indicates that Oscar II Land experienced the following tectonic history: (1) the latest Mesoproterozoic sequence was part of a successor basin which originated close to the Grenvillian–Sveconorwegian orogen, and which was intruded byc. 980–920 Ma plutons; (2) the Neoproterozoic sediments were deposited in a large-scale basin which stretched along the Baltoscandian margin; (3) the eclogite-blueschist complex and the overlying Ordovician–Silurian sediments probably formed to the north of the Grampian/Taconian arc; (4) strike-slip movements assembled the western coast of Spitsbergen outside of, and prior to, the main Scandian collision; and (5) the remaining parts of Svalbard were assembled by strike-slip movements during the Devonian. Our study confirms previous models of complex Caledonian terrane amalgamation with contrasting tectonic histories for the different pre-Devonian terranes of Svalbard and particularly highlights the non-Laurentian origin of Oscar II Land.

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The Influence of Geodynamic Evolution on the Formation of the Cenozoic Sedimentary Cover of the North-Eastern Part of the Sakhalin Shelf

10.3997/2214-4609.202050035 ◽

2020 ◽

Author(s):

A.Y. Makarova

Keyword(s):

Sedimentary Cover ◽

Geodynamic Evolution ◽

The North ◽

Sakhalin Shelf ◽

North Eastern ◽

North Eastern Part

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A mid-Palaeozoic ocean–continent transition in the Mazongshan subduction–accretion complex, Beishan, NW China: new structural, chemical and age data constrain the petrogenesis and tectonic evolution

Geological Magazine ◽

10.1017/s0016756820000114 ◽

2020 ◽

Vol 157 (11) ◽

pp. 1877-1897 ◽

Cited By ~ 1

Author(s):

J.-X. Wang ◽

K.-X. Zhang ◽

Brian F. Windley ◽

B.-W. Song ◽

X.-H. Kou ◽

...

Keyword(s):

Continental Crust ◽

Early Carboniferous ◽

Orogenic Belt ◽

Central Asian Orogenic Belt ◽

Published Data ◽

Zircon Age ◽

The North ◽

Tectonic History ◽

Central Asian ◽

Tectonic Mélange

AbstractAccretionary orogens contain key evidence for the conversion of oceanic to continental crust. The late tectonic history and closure time of the Palaeo-Asian Ocean are recorded in the Mazongshan subduction–accretion complex in the southern Beishan margin of the Central Asian Orogenic Belt. We present new data on the structure, petrology, geochemistry and zircon U–Pb isotope ages of the Mazongshan subduction–accretion complex, which is a tectonic mélange with a block-in-matrix structure. The blocks are of serpentinized peridotite, basalt, gabbro, basaltic andesite, chert and seamount sediments within a matrix that is mainly composed of fore-arc-trench turbidites. U–Pb zircon ages of two gabbros are 454.6 ± 2.5 Ma and 434.1 ± 3.6 Ma, an andesite has a U–Pb zircon age of 451.3 ± 3.5 Ma and a tuffaceous slate has the youngest U–Pb zircon age of 353.6 ± 5.1 Ma. These new isotopic ages, combined with published data on ophiolitic mélanges from central Beishan, indicate that the subduction–accretion of Beishan in the southernmost Central Asian Orogenic Belt lasted until Late Ordovician – Early Carboniferous time. Structure and age data demonstrate that the younging direction of accretion was southwards and that the subduction zone dipped continuously to the north. Accordingly, these results record the conversion of oceanic to continental crust in the southern Beishan accretionary collage.

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