scholarly journals Geochronology and petrogenesis of granitoid rocks from the Goryczkowa Unit, Tatra Mountains (Central Western Carpathians)

2013 ◽  
Vol 64 (6) ◽  
pp. 419-435 ◽  
Author(s):  
Jolanta Burda ◽  
Aleksandra Gawęda ◽  
Urs Klötzli
Keyword(s):  
Tectonic Setting ◽  
Regional Metamorphism ◽  
Source Material ◽  
Tatra Mountains ◽  
Volcanic Arc ◽  
Zircon Age ◽  
Icp Ms ◽  
Crystalline Core ◽  
Granitoid Rocks ◽  
Central Western Carpathians

Abstract The geochemical characteristics as well as the LA-MC-ICP-MS U-Pb zircon age relationship between two granitoid suites found in the Goryczkowa crystalline core in the Western Tatra Mountains were studied. The petrological investigations indicate that both granitoid suites were emplaced at medium crustal level, in a VAG (volcanic arc granites) tectonic setting. However, these suites differ in source material melted and represent two different magmatic stages: suite 1 represents a high temperature, oxidized, pre-plate collision intrusion, emplaced at ca. 371 Ma while suite 2 is late orogenic/anatectic magma, which intruded at ca. 350 Ma. These data are consistent with a period of intensive magmatic activity in the Tatra Mountain crystalline basement. The emplacement of granitoids postdates the LP-HT regional metamorphism/ partial melting at ca. 387 Ma and at 433-410 Ma, imprinted in the inherited zircon cores.

scholarly journals U-Pb zircon age of the youngest magmatic activity in the High Tatra granites (Central Western Carpathians)

2013 ◽  
Vol 40 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Jolanta Burda ◽  
Aleksandra Gawęda ◽  
Urs Klötzli
Keyword(s):  
Inductively Coupled Plasma ◽  
Age Groups ◽  
Hydrothermal Activity ◽  
Magmatic Activity ◽  
Zircon Age ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Central Western Carpathians ◽  
High Tatra Mountains

Abstract Detailed cathodoluminescence (CL) imaging of zircon crystals, coupled with Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICP-MS) U-Pb zircon dating was used to develop new insights into the evolution of granitoids from the High Tatra Mountains. The zircon U-Pb results show two distinct age groups (350±5 Ma and 337±6 Ma) recorded from cores and rims domains, respectively. Obtained results point that the last magmatic activity in the Tatra granitoid intrusion occurred at ca. 330 Ma. The previously suggested age of 314 Ma reflects rather the hydrothermal activity and Pb-loss, coupled with post-magmatic shearing.

Petrology, age, and tectonic setting of the Seal Island Pluton, offshore southwestern Nova Scotia

2007 ◽  
Vol 44 (10) ◽  
pp. 1467-1478 ◽  
Author(s):  
Patrick C Moran ◽  
Sandra M Barr ◽  
Chris E White ◽  
Michael A Hamilton
Keyword(s):  
Nova Scotia ◽  
Tectonic Setting ◽  
Heavy Rare Earth ◽  
Zircon Age ◽  
Relative Age ◽  
Form Part ◽  
Heavy Rare Earth Elements ◽  
Granitoid Rocks ◽  
Meguma Terrane ◽  
Granite Samples

The Seal Island Pluton outcrops only on small islands located on the continental shelf 45 km south of Nova Scotia, although geophysical data indicate that the pluton is part of large granitoid units that cover thousands of square kilometres farther offshore. Based on the island outcrops, the Seal Island Pluton consists of biotite monzogranite and muscovite–biotite monzogranite of uncertain relative age. Metasedimentary xenoliths combined with characteristic magnetic patterns indicate that the pluton intruded the Cambrian–Ordovician Meguma Group. Compared with the biotite monzogranite, the muscovite–biotite monzogranite is higher in SiO2, more peraluminous, and more depleted in heavy rare-earth elements, and also has lower εNd (–1.39 versus +0.82), possibly the result of more contamination by Meguma Group sedimentary rocks. The biotite monzogranite yielded a Late Devonian U–Pb (zircon) age of 362.8 ± 0.7 Ma. Although the relatively minor petrological differences between the two units do not preclude a co-magmatic relationship, the muscovite–biotite monzogranite could be 10–15 Ma older than the biotite monzogranite, based on its petrological similarities to parts of the onshore ca. 376–372 Ma Shelburne and Port Mouton plutons. Comparison with granite samples in offshore drill core indicates that granitoid rocks similar to those exposed on Seal and surrounding islands form part of large plutons farther offshore in the Meguma terrane. The age and petrochemical data from both onshore and offshore plutons indicate that peraluminous granitoid rocks in the Meguma terrane were derived from similar sources over a span of at least 20 million years. Magma genesis may have been related to mantle upwelling and stepping back of the subduction zone to the southeast subsequent to docking of Meguma terrane with adjacent Avalonia.

scholarly journals U-Pb (zircon) age, petrology, and tectonic setting of the Canaan River pluton, southeastern New Brunswick, Canada

2018 ◽  
pp. 389-408
Author(s):  
Susan Johnson ◽  
Sandra M. Barr ◽  
Deanne Van Rooyen ◽  
Chris E. White
Keyword(s):  
New Brunswick ◽  
Tectonic Setting ◽  
Leading Edge ◽  
Borehole Data ◽  
Zircon Age ◽  
Early Devonian ◽  
Icp Ms ◽  
Laurentian Margin ◽  
Radiometric Data

 The Canaan River pluton comprises megacrystic monzogranite and quartz diorite to monzodiorite that is exposed in several small inliers on the Carboniferous New Brunswick Platform west of Moncton in southeastern New Brunswick. Its distinct geophysical signature and borehole data suggest that the Canaan River pluton is part of a large buried felsic to mafic intrusive body that lies at relatively shallow depths beneath flat-lying Pennsylvanian sandstone on the platform. New laser ablation ICP-MS in situ analysis of the megacrystic monzogranite yielded a U-Pb zircon concordia age of 412.6 ± 2.1 Ma, indicating that the intrusion is of Early Devonian (upper Lochkovian) age.The new radiometric data along with lithological, geochemical, and isotopic data suggest that the Canaan River pluton is most like the megacrystic Hawkshaw Granite of upper Lochkovian age in the Pokiok Batholith in southwestern New Brunswick. The similarities shown by these granites suggests that they may have been generated in the same complex tectonomagmatic setting related to the successive arrival of the leading edge of Ganderia and Avalonia at the composite Laurentian margin during the Salinic and Acadian orogenies. 

Geology, geochemistry and geochronology of a taconic batholith, southwestern Newfoundland

1989 ◽  
Vol 80 (2) ◽  
pp. 159-168 ◽  
Author(s):  
G. R. Dunning ◽  
D. H. C. Wilton ◽  
R. K. Herd
Keyword(s):  
North America ◽  
Partial Melting ◽  
Tectonic Setting ◽  
Eastern North America ◽  
Volcanic Arc ◽  
Zircon Age ◽  
Metasedimentary Rocks ◽  
Collision Zone ◽  
Taconic Orogeny ◽  
Platform Carbonates

ABSTRACTFoliated to massive hornblende and biotite-bearing tonalite, trondhjemite and granodiorite comprise a terrane of batholithic dimensions in southwestern to central Newfoundland. These rocks intrude and include Ordovician ophiolite fragments and metasedimentary rocks of Fleur de Lys type, and are cut by a suite of Silurian gabbro-diorite and norite and Siluro-Devonian (?) granite intrusions.A U/Pb (zircon, sphene) age of 456 ± 3 Ma (2σ) and a K/Ar (hornblende) age of 455 ± 14 Ma (previously reported) for a representative least-deformed tonalite of the Southwest Brook Complex indicate that it crystallised and cooled in Caradoc time. A less precise U/Pb (zircon) age of 428 ± 41 Ma (2σ) is measured for tonalitic Cape Ray Granite in southern Newfoundland. On discrimination diagrams which use Rb, Nb and Y contents to infer tectonic setting, these rocks fall in the field of volcanic arc granites. The occurrence of zircon cores with average ages of 1430 + 18/–17 and 1541 ± 173 Ma (2σ) also indicate that the magmas formed in part by partial melting of Proterozoic crust, or sediments derived from such crust. It is suggested that the tonalitic magmas were generated during the Taconic Orogeny in an arc: continent collision zone at the ancient margin of eastern North America.Tonalitic rocks in western Newfoundland broadly correlative in age and chemistry with the batholith include the Burlington Granodiorite and Hungry Mountain Complex, as well as allochthonous slices of foliated tonalite emplaced over Ordovician platform carbonates W of Grand Lake.

scholarly journals The Litchfield Pluton in South-Central Maine: Carboniferous Alkalic Magmatism in northern New England, USA

2016 ◽  
Vol 52 ◽  
pp. 169
Author(s):  
David P West ◽  
Dwight Bradley ◽  
Raymond Coish
Keyword(s):  
New England ◽  
Nepheline Syenite ◽  
Tectonic Setting ◽  
Coarse Grained ◽  
Zircon Age ◽  
South Central ◽  
Appalachian Orogen ◽  
Granitoid Rocks ◽  
Northern New England ◽  
Geochemical Analyses

The Litchfield pluton is a poorly exposed 7 km2 composite alkalic intrusive complex that cuts previously deformed and metamorphosed Silurian turbidites in south-central Maine.  The pluton includes a variety of alkaline syenites, including the type locality of “litchfieldite”, a coarse-grained cancrinite, sodalite, and lepidomelane bearing nepheline syenite first recognized over 150 years ago and common in many petrologic collections.  A new U-Pb zircon age of 321 ± 2 Ma from the nepheline syenite is interpreted to represent the crystallization age of the plutonic complex.  A new biotite 40Ar/39Ar age of 239 ± 1 Ma from the syenite is similar to previously published mica ages from the surrounding country rocks and dates the time of regional cooling in the area below ~ 300°C.  Whole rock geochemical analyses from rocks of the Litchfield pluton are compatible with strongly alkaline A-type granitoid rocks that formed in a within plate or continental rift tectonic setting.  The age and geochemical characteristics of the alkalic igneous rocks near Litchfield are consistent with a model that invokes the generation of a small volume of alkalic magma beneath south-central Maine during a period of Carboniferous transcurrent tectonism in the northern Appalachian orogen.       

The petrological and geochemical study of granitoid rocks from Mashhad area, Iran: Evidence for the Late Triassic Collisional Belt Northeast of Iran

2021 ◽  
Author(s):  
Banafsheh Vahdati ◽  
Seyed Ahmad Mazaheri
Keyword(s):  
Subduction Zones ◽  
Tectonic Setting ◽  
Crustal Contamination ◽  
Oceanic Lithosphere ◽  
Late Triassic ◽  
Common Belief ◽  
Thrust Tectonics ◽  
Wide Range ◽  
Lree Enrichment ◽  
Granitoid Rocks

<p>Mashhad granitoid complex is part of the northern slope of the Binalood Structural Zone (BSZ), Northeast of Iran, which is composed of granitoids and metamorphic rocks. This research presents new petrological and geochemical whole-rock major and trace elements analyses in order to determine the origin of granitoid rocks from Mashhad area. Field and petrographic observations indicate that these granitoid rocks have a wide range of lithological compositions and they are categorized into intermediate to felsic intrusive rocks (SiO<sub>2</sub>: 57.62-74.39 Wt.%). Qartzdiorite, tonalite, granodiorite and monzogranite are common granitoids with intrusive pegmatite and aplitic dikes and veins intruding them. Based on geochemical analyses, the granitoid rocks are calc-alkaline in nature and they are mostly peraluminous. On geochemical variation diagrams (major and minor oxides versus silica) Na<sub>2</sub>O and K<sub>2</sub>O show a positive correlation with silica while Al<sub>2</sub>O<sub>3</sub>, TiO<sub>2</sub>, CaO, Fe<sub>2</sub>O<sub>3</sub>, and MgO show a negative trend. Therefore fractional crystallization played a considerable role in the evolution of Mashhad granitoids. Based on the spider diagrams, there are enrichments in LILE and depletion in HFSE. Low degrees of melting or crustal contamination may be responsible for LILE enrichment. Elements such as Pb, Sm, Dy and Rb are enriched, while Ba, Sr, Nd, Zr, P, Ti and Yb (in monzogranites) are all depleted. LREE enrichment and HREE depletion are observed in all samples on the Chondrite-normalized REE diagram. Similar trends may be evidence for the granitoids to have the same origin. Besides, LREE enrichment relative to HREE in some samples can indicate the presence of garnet in their source rock. Negative anomalies of Eu and Yb are observed in monzogranites. Our results show that Mashhad granitoid rocks are orogenic related and tectonic discrimination diagrams mostly indicate its syn-to-post collisional tectonic setting. No negative Nb anomaly compared with MORB seems to be an indication of non-subduction zone related magma formation. According to the theory of thrust tectonics of the Binalood region, the oceanic lithosphere of the Palo-Tethys has subducted under the Turan microplate. Since the Mashhad granitoid outcrops are settled on the Iranian plate, this is far from common belief that these granitoid rocks are related to the subduction zones and the continental arcs. The western Mashhad granitoids show more mafic characteristics and are possibly crystallized from a magma with sedimentary and igneous origin. Thus, Western granitoid outcrops in Mashhad are probably hybrid type and other granitoid rocks, S and SE Mashhad are S-type. Evidences suggest that these continental collision granitoid rocks are associated with the late stages of the collision between the Iranian and the Turan microplates during the Paleo-Tethys Ocean closure which occurred in the Late Triassic.</p>

scholarly journals Lower Permian basaltic agglomerate from the Tsengel River valley, Mongolian Altai

2020 ◽  
Vol 51 ◽  
pp. 1-11
Author(s):  
Kristýna Hrdličková ◽  
Altanbaatar Battushig ◽  
Pavel Hanžl ◽  
Alice Zavřelová ◽  
Jitka Míková
Keyword(s):  
River Valley ◽  
Lower Permian ◽  
Basalt Lava ◽  
Volcanic Arc ◽  
Lower Carboniferous ◽  
Upper Carboniferous ◽  
Mongolian Altai ◽  
Icp Ms ◽  
Volcaniclastic Rocks ◽  
Data Yield

A new occurrence of Permian volcanic and volcaniclastic rocks in the Mongolian Altai south of the Main Mongolian Lineament was described between soums of Tugrug and Tseel in Gobi-Altai aimag. Studied vitrophyric pyroxene basalt lies in a layer of agglomerate and amygdaloidal lavas, which is a part of NE–SW trending subvertical sequence of varicolored siltstones and volcaniclastic rocks in the Tsengel River valley. This high-Mg basalt is enriched in large ion lithophile elements, Pb and Sr and depleted in Nb and Ta. LA-ICP-MS dating on 44 spots reveals several concordia clusters. The whole rock geochemistry of sample fits volcanic arc characteristic in the geotectonic discrimination diagrams. Dominant zircon data yield Upper Carboniferous and Permian magmatic ages 304.4 ± 2.3 and 288.6 ± 1.9 Ma. Two smaller clusters of Upper Devonian (376 ± 4.7 Ma) to Lower Carboniferous ages (351.9 ± 3.5 Ma) indicate probably contamination of ascending magmatic material. Youngest Triassic age found in three morphologically differing grains reflects probably lead loss. Described high-Mg basalt lava represents sub-aerial volcanism in volcanic arc environment developed over the N dipping subduction zone in the southwestern Mongolia in the time span from Uppermost Carboniferous to Permian during terminal stage of its activity.

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

2013 ◽  
Vol 150 (6) ◽  
pp. 1103-1126 ◽  
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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