TY - JOUR
T1 - Structural and geochronological evidence for Paleogene thrusting in the western Rhodopes, SW Bulgaria: Elements for a new tectonic model of the Rhodope Metamorphic Province
AU - Jahn-Awe, Silke
AU - Froitzheim, Nikolaus
AU - Nagel, Thorsten J.
AU - Frei, Dirk
AU - Georgiev, Neven
AU - Pleuger, Jan
PY - 2010/6
Y1 - 2010/6
N2 - The Rhodope Metamorphic Province in the area around the Mesta Graben (SW Bulgaria) exposes a structurally lower complex, the Pangaion-Pirin Complex of Variscan continental crust and its cover (mostly orthogneiss and marble), and a higher complex, the Rhodope Terrane of mixed oceanic and continental origin with metamorphosed Jurassic arc magmatites. The boundary between the two is the top-to-thesouthwest Nestos Shear Zone. The regional top-tothe-southwest shearing of the two basement complexes is related to the emplacement of the Rhodope Terrane over the Pangaion-Pirin Complex along this shear zone. Syntectonic and posttectonic Alpine intrusions within the basement can provide age limits for the thrusting. Zircons from the posttectonic Teshovo (south Pirin) Granitoid Pluton in the Pangaion-Pirin Complex yielded crystallization ages of 32 ± 0.2 Ma (LA-SFICP-MS U-Pb method). Zircons from two syntectonic granite plutons in the Rhodope Terrane (Dolno Dryanovo and Spanchevo) have circa 143 to 145 Ma old inherited magmatic cores and circa 55 to 56 Ma old magmatic rims. These ages, especially the presence of the Upper Jurassic/Lower Cretaceous cores in the plutons from the Rhodope Terrane, and the structural relations indicate that the southwestward thrusting of the Rhodope Terrane over the Pangaion-Pirin Complex took place in the Paleogene. A model is proposed in which the Pangaion-Pirin Complex represents the margin of Apulia and the structure of the Rhodopes is explained by a switch of subduction polarity from SW dipping in the Jurassic and Early Cretaceous to NE dipping in the Late Cretaceous and Paleogene.
AB - The Rhodope Metamorphic Province in the area around the Mesta Graben (SW Bulgaria) exposes a structurally lower complex, the Pangaion-Pirin Complex of Variscan continental crust and its cover (mostly orthogneiss and marble), and a higher complex, the Rhodope Terrane of mixed oceanic and continental origin with metamorphosed Jurassic arc magmatites. The boundary between the two is the top-to-thesouthwest Nestos Shear Zone. The regional top-tothe-southwest shearing of the two basement complexes is related to the emplacement of the Rhodope Terrane over the Pangaion-Pirin Complex along this shear zone. Syntectonic and posttectonic Alpine intrusions within the basement can provide age limits for the thrusting. Zircons from the posttectonic Teshovo (south Pirin) Granitoid Pluton in the Pangaion-Pirin Complex yielded crystallization ages of 32 ± 0.2 Ma (LA-SFICP-MS U-Pb method). Zircons from two syntectonic granite plutons in the Rhodope Terrane (Dolno Dryanovo and Spanchevo) have circa 143 to 145 Ma old inherited magmatic cores and circa 55 to 56 Ma old magmatic rims. These ages, especially the presence of the Upper Jurassic/Lower Cretaceous cores in the plutons from the Rhodope Terrane, and the structural relations indicate that the southwestward thrusting of the Rhodope Terrane over the Pangaion-Pirin Complex took place in the Paleogene. A model is proposed in which the Pangaion-Pirin Complex represents the margin of Apulia and the structure of the Rhodopes is explained by a switch of subduction polarity from SW dipping in the Jurassic and Early Cretaceous to NE dipping in the Late Cretaceous and Paleogene.
UR - http://www.scopus.com/inward/record.url?scp=77954601601&partnerID=8YFLogxK
U2 - 10.1029/2009TC002558
DO - 10.1029/2009TC002558
M3 - Article
SN - 0278-7407
VL - 29
JO - Tectonics
JF - Tectonics
IS - 3
M1 - TC3008
ER -