J 2020

Long-Lasting (65 Ma) Regionally Contrasting Late- to Post-Orogenic Variscan Mantle-derived Potassic Magmatism in the Bohemian Massif

KRMÍČEK, Lukáš, Rolf L. ROMER, Martin J. TIMMERMAN, Jaromír ULRYCH, Johannes GLODNY et. al.

Základní údaje

Originální název

Long-Lasting (65 Ma) Regionally Contrasting Late- to Post-Orogenic Variscan Mantle-derived Potassic Magmatism in the Bohemian Massif

Autoři

KRMÍČEK, Lukáš (203 Česká republika), Rolf L. ROMER (756 Švýcarsko), Martin J. TIMMERMAN (528 Nizozemské království), Jaromír ULRYCH (203 Česká republika), Johannes GLODNY (276 Německo), Antonín PŘICHYSTAL (203 Česká republika, garant, domácí) a Masafumi SUDO

Vydání

Journal of Petrology, Oxford, Oxford University Press, 2020, 0022-3530

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10505 Geology

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

URL

Impakt faktor

Impact factor: 4.515

Kód RIV

RIV/00216224:14310/20:00117734

Organizační jednotka

Přírodovědecká fakulta

DOI

http://dx.doi.org/10.1093/petrology/egaa072

UT WoS

000599223300007

Klíčová slova anglicky

Ar-40/Ar-39 age determination; mantle melts; mantle metasomatism; lamprophyres; lampyrites; lamproites; Sr-Nd-Pb-Li isotopes

Štítky

rivok

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 11. 3. 2021 09:54, Mgr. Marie Šípková, DiS.

Anotace

V originále

The orogenic development after the continental collision between Laurussia and Gondwana, led to two contrasting associations of mantle-derived magmatic rocks on the territory of the Bohemian Massif: (i) a 340-310Ma lamprophyre-lamproite orogenic association; and (ii) a 300-275Ma lamprophyre association of anorogenic affinity. Major types of potassic mantle-derived magmatic rocks recognized in the orogenic and anorogenic associations include: (i) calc-alkaline to alkaline lamprophyres; (ii) alkaline 'orthopyroxene minettes' and geochemically related rocks grouped here under the new term lampyrite; and (iii) peralkaline lamproites. These three types significantly differ with respect to mineral, whole-rock and Sr-Nd-Pb-Li isotope composition and spatial distribution. The calc-alkaline lamprophyres occur throughout the entire Saxo-Thuringian and Moldanubian zones, whereas the different types of malte-derived potassic rocks are spatially restricted to particular zones. Rocks of the Carboniferous lamprophyre-lamproite orogenic association are characterized by variable negative epsilon Nd-(i) and variably radiogenic Sr-(i), whereas the rocks of the Permian lamprophyre association of anorogenic affinity are characterized by positive epsilon Nd-(i) and relatively young depleted-mantle Nd-model ages reflecting increasing input from upwelling asthenospheric mantle. The small variation in the Pb isotopic composition of post-collisional potassic mantle-derived magmatic rocks (of both the orogenic and anorogenic series) implies that the Pb budget of the mantle beneath the Bohemian Massif is dominated by the same crust-derived material, which itself may include material derived from several sources. The source rocks of 'orthopyroxene minettes' are characterized by isotopically light ('eclogitic') Li and strongly radiogenic (crustal) Sr and may have been metasomatized by high-pressure fluids along the edge of a subduction zone. In contrast, the strongly Al2O3 and CaO depleted mantle source of the lamproites is characterized by isotopically heavy Li and high SiO2 and extreme K2O contents. This mantle source may have been metasomatized predominantly by melts. The mantle source of the lamprophyres may have undergone metasomatism by both fluids and melts.
Zobrazeno: 10. 11. 2024 21:51