@article{KrmičekTimmermanZiemannetal.2020,
  author    = {Krm{\´i}ček, Luk{\´a}š and Timmerman, Martin Jan and Ziemann, Martin Andreas and Sudo, Masafumi and Ulrych, Jaromir},
  title     = {40Ar/39Ar step-heating dating of phlogopite and kaersutite megacrysts from the Železn{\´a} hůrka (Eisenb{\"u}hl) Pleistocene scoria cone, Czech Republic},
  series = {Geologica Carpathica},
  volume    = {71},
  journal   = {Geologica Carpathica},
  number    = {4},
  publisher = {Veda},
  address   = {Bratislava},
  issn      = {1335-0552},
  doi       = {10.31577/GeolCarp.71.4.6},
  pages     = {382 -- 387},
  year      = {2020},
  abstract  = {(40)A/Ar-39 step-heating of mica and amphibole megacrysts from hauyne-bearing olivine melilitite scoria/tephra from the Zelezna hurka yielded a 435 +/- 108 ka isotope correlation age for phlogopite and a more imprecise 1.55 Ma total gas age of the kaersutite megacryst. The amphibole megacrysts may constitute the first, and the younger phlogopite megacrysts the later phase of mafic, hydrous melilitic magma crystallization. It cannot be ruled out that the amphibole megacrysts are petrogenetically unrelated to tephra and phlogopite megacrysts and were derived from mantle xenoliths or disaggregated older, deep crustal pegmatites. This is in line both with the rarity of amphibole at Zelezna hurka and with the observed signs of magmatic resorption at the edges of amphibole crystals.},
  language  = {en}
}
@article{MotuzaSliaupaTimmerman2015,
  author    = {Motuza, Gediminas and Sliaupa, Saulius and Timmerman, Martin Jan},
  title     = {Geochemistry and Ar-40/Ar-39 age of Early Carboniferous dolerite sills in the southern Baltic Sea},
  series = {Estonian journal of earth sciences},
  volume    = {64},
  journal   = {Estonian journal of earth sciences},
  number    = {3},
  publisher = {Estonian Academy Publ.},
  address   = {Tallinn},
  issn      = {1736-4728},
  doi       = {10.3176/earth.2015.30},
  pages     = {233 -- 248},
  year      = {2015},
  abstract  = {The Early Carboniferous magmatic event in the southern Baltic Sea is manifested by dolerite intrusions. The presumable area in which the dolerite intrusions occur ranges from 30 to 60 km in east-west direction, and is about 100 km in north-south direction. The dolerites were sampled in well D1-1 and investigated by applying chemical analysis and Ar-40/Ar-39 step-heating dating. Dolerites are classified as alkali and sodic, characterized by high TiO2 (3.92, 3.99 wt\%) and P2O5 (1.67, 1.77 wt\%) and low MgO (4.89, 4.91 wt\%) concentrations, enriched in light rare earth elements, originated from an enriched mantle magma source and emplaced in a continental rift tectonic setting. The 351 +/- 11 Ma Ar-40/Ar-39 plateau age for groundmass plagioclase indicates a considerable age gap with the 310-250 Ma magmatism in southern Scandinavia and northern Germany. The magmatic rocks in the Baltic Sedimentary Basin are coeval with alkaline intrusions of NE Poland. Both magmatic provinces lie in the northwestward prolongation of the Pripyat-Dnieper-Donetsk Rift (370-359 Ma) and may constitute a later phase of magmatic activity of this propagating rift system.},
  language  = {en}
}