Contents
EVOLUTION OF THE NEOGENE GURGHIU MOUNTAINS VOLCANIC RANGE (EASTERN CARPATHIANS, ROMANIA), BASED ON K-Ar GEOCHRONOLOGY
Published: Aug 2004
Pages: 325 - 332
Authors: IOAN SEGHEDI, ALEXANDRU SZAKACS, NORMAN J. SNELLING,ZOLTAN PECSKAY
Abstract: K-Ar ages of rocks from the Gurghiu Mountains, the middle part of the longest volcanic chain in the Eastern Carpathians (Călimani–Gurghiu–Harghita), indicate an interval of volcanic activity between 9.4–5.4 Ma. Magmatic activity migrated from North to South and built the following volcanic centres: Jirca (J), Fâncel-Lăpusna (FL), Bacta (B), Seaca-Tătarca (ST), Borzont (BZ), Sumuleu (S) and Ciumani-Fierăstraie (CF). The timing of volcanic activity in each volcanic centre reflects the previously recognized overlapping age progression from North to South along the arc: J=9.2–7.0 Ma; FL=9.4–6.0 Ma; B=7.5–7.0 Ma; ST=7.3–5.4 Ma; BZ=6.8 Ma; S=6.8–6.2 Ma; CF=7.1–6.3 Ma. Two peripheral small intrusive bodies have also been dated (Ditrău — 7.9 Ma and Corund — 7.4 Ma). The duration of volcanic activity of each centre is ca. 1 Ma, with a larger interval of 2.5 Ma for the Fâncel-Lăpusna volcano. Volcanic activity in the southernmost volcanic centres (ST; BZ; S; CF) between 7–6 Ma was contemporaneous. Certain volcanological problems are pointed out: (i) the voluminous debris-avalanche deposit assumed to belong to the Călimani Mountains includes blocks of ca. 8 Ma up to the Gurghiu Valley and between 7.5–7.8 Ma south of the Gurghiu Valley (ii) the Fâncel-Lăpusna caldera was generated around 6.9 Ma and involved a post-caldera uplift and/or erosion of the caldera floor and younger domes; and (iii) the model based on volcanic facies distribution is consistent with the new age-data.
Keywords: Eastern Carpathians, Gurghiu Mountains, K-Ar data, volcanology, debris-avalanche
Download PDF documentVolume 55 no. 4 / August 2004
WILFRIED GRUBER, REINHARD F. SACHSENHOFER, NICOLA KOFLER, KURT DECKER
THE ARCHITECTURE OF THE TROFAIACH PULL-APART BASIN (EASTERN ALPS): AN INTEGRATED GEOPHYSICAL AND STRUCTURAL STUDYLISA GIOCONDA GIGLIUTO, CONSTANTIN GRASU, FRANCESCO LOIACONO, CRINA MICLAUS, ELVIO MORETTI, DIEGO PUGLISI, GIULIANA RAFFAELLI
PROVENANCE CHANGES AND SEDIMENTOLOGY OF THE EOCENE–OLIGOCENE ”MOLDOVIŢA LITHOFACIES” OF THE TARCĂU NAPPE (EASTERN CARPATHIANS, ROMANIA)HANS-MARTIN SCHULZ, ACHIM BECHTEL, THOMAS RAINER, REINHARD F. SACHSENHOFER, ULRICH STRUCK
PALEOCEANOGRAPHY OF THE WESTERN CENTRAL PARATETHYS DURING EARLY OLIGOCENE NANNOPLANKTON ZONE NP23 IN THE AUSTRIAN MOLASSE BASINIOAN SEGHEDI, ALEXANDRU SZAKACS, NORMAN J. SNELLING, ZOLTAN PECSKAY
EVOLUTION OF THE NEOGENE GURGHIU MOUNTAINS VOLCANIC RANGE (EASTERN CARPATHIANS, ROMANIA), BASED ON K-Ar GEOCHRONOLOGYCRISTIAN G. PANAIOTU, ZOLTAN PECSKAY, ULRICH HAMBACH, IOAN SEGHEDI, CRISTINA E. PANAIOTU, ITAYA TETSUMARU, MIHAI ORLEANU, ALEXANDRU SZAKACS
SHORT-LIVED QUATERNARY VOLCANISM IN THE PERSANI MOUNTAINS (ROMANIA) REVEALED BY COMBINED K-Ar AND PALEOMAGNETIC DATAGIUSEPPE CARERI, FRANCESCO GUERRERA, AGUSTIN MARTIN-ALGARRA, MANUEL MARTIN-MARTIN, ANTONIA MESSINA, VINCENZO PERRONE
DISCUSSION OF ”PETROGRAPHY AND GEOCHEMISTRY OF GRANITOID PEBBLES FROM THE OLIGOCENE-MIOCENE DEPOSITS OF THE INTERNAL RIFIAN CHAIN (MOROCCO): A POSSIBLE NEW HYPOTHESIS OF PROVENANCE AND PALEOGEOGRAPHICAL IMPLICATIONS” BY L.G. GIGLIUTO et al.LISA GIOCONDA GIGLIUTO, DIEGO PUGLISI, GIUSEPPA PUGLISI
REPLY TO THE DISCUSSION OF ”PETROGRAPHY AND GEOCHEMISTRY OF GRANITOID PEBBLES FROM THE OLIGOCENE-MIOCENE DEPOSITS OF THE INTERNAL RIFIAN CHAIN (MOROCCO): A POSSIBLE NEW HYPOTHESIS OF PROVENANCE AND PALEOGEOGRAPHICAL IMPLICATIONS” BY G. CARERI et al.