TY - JOUR
T1 - Petrology, geochemistry and geotectonic environment of the Alvand Intrusive Complex, Hamedan, Iran
AU - Aliani, Farhad
AU - Maanijou, Mohammad
AU - Sabouri, Zahra
AU - Sepahi, Ali Asghar
PY - 2012/12
Y1 - 2012/12
N2 - The Alvand Intrusive Complex is located near Hamedan (Iran) and crops out over an area 400km2 intruding the Sanandaj-Sirjan plutono-metamorphic belt. The emplacement age of the AIC is constrained to Upper to Middle Jurassic, based on U-Pb zircon geochronogic data. This complex consists of granites (monzogranite and syenogranite), leucocratic granitoids (leucocratic tonalite, leucocratic granodiorite, and leucocratic quartz monzodiorite), mesocratic granitoids (tonalite, granodiorite, and quartz diorites), and abundant aplitic and pegmatitic dikes. The sequence of intrusion is as follows gabbro-diorites→mesocratic granitoids→granites and aplites and pegmatites associated with granites →leucocratic granitoids, based on emplacement relationships. Geochemically, this complex is metaluminous (ACNK=0.87) to peraluminous (ACNK=1.15). The mineralogical, lithological, and geochemical studies along with field observations indicate that the Alvand granites have S-type characteristics, leucocratic granitoids are arc-related I-type intrusions, mesocratic granitoids (tonalite and quartz diorites) possess transitional H-type features and granodiorites have S-type attributes. This complex has petrochemical characteristics that span the high K calc-alkaline and calc-alkaline series and displays the geochemical characteristics typical of magmatic arc intrusions related to an active continental margin. Depletion in Ti, Nb, Ta, Zr, Hf, Y, and HREE and enrichment in K, Rb, Cs, Th, and LREE are consistent with an arc setting associated with the subduction of Neo-Tethyan oceanic crust beneath the Sanandaj-Sirjan zone.
AB - The Alvand Intrusive Complex is located near Hamedan (Iran) and crops out over an area 400km2 intruding the Sanandaj-Sirjan plutono-metamorphic belt. The emplacement age of the AIC is constrained to Upper to Middle Jurassic, based on U-Pb zircon geochronogic data. This complex consists of granites (monzogranite and syenogranite), leucocratic granitoids (leucocratic tonalite, leucocratic granodiorite, and leucocratic quartz monzodiorite), mesocratic granitoids (tonalite, granodiorite, and quartz diorites), and abundant aplitic and pegmatitic dikes. The sequence of intrusion is as follows gabbro-diorites→mesocratic granitoids→granites and aplites and pegmatites associated with granites →leucocratic granitoids, based on emplacement relationships. Geochemically, this complex is metaluminous (ACNK=0.87) to peraluminous (ACNK=1.15). The mineralogical, lithological, and geochemical studies along with field observations indicate that the Alvand granites have S-type characteristics, leucocratic granitoids are arc-related I-type intrusions, mesocratic granitoids (tonalite and quartz diorites) possess transitional H-type features and granodiorites have S-type attributes. This complex has petrochemical characteristics that span the high K calc-alkaline and calc-alkaline series and displays the geochemical characteristics typical of magmatic arc intrusions related to an active continental margin. Depletion in Ti, Nb, Ta, Zr, Hf, Y, and HREE and enrichment in K, Rb, Cs, Th, and LREE are consistent with an arc setting associated with the subduction of Neo-Tethyan oceanic crust beneath the Sanandaj-Sirjan zone.
KW - Alvand intrusive complex
KW - Calc-alkaline series
KW - Continental margin
KW - Iran
KW - Sanandaj-Sirjan zone
UR - http://www.scopus.com/inward/record.url?scp=84870522922&partnerID=8YFLogxK
U2 - 10.1016/j.chemer.2012.05.001
DO - 10.1016/j.chemer.2012.05.001
M3 - Article
AN - SCOPUS:84870522922
SN - 0009-2819
VL - 72
SP - 363
EP - 383
JO - Geochemistry
JF - Geochemistry
IS - 4
ER -