TY - JOUR T1 - Petrography and Geochemistry of the Javaherdasht basalts (east of Guilan Province): The investigation of the role of crystal fractionation and crustal contamination in the magmatic evolution TT - سنگ‌شناختی و ژئوشیمی بازالت‌های جواهردشت (شرق گیلان): بررسی نقش فرایندهای تفریق بلورین و آلایش پوسته‌ای در سیر تکامل ماگمایی JF - ijcmir JO - ijcmir VL - 17 IS - 2 UR - http://ijcm.ir/article-1-585-en.html Y1 - 2009 SP - 253 EP - 266 KW - basalts KW - Geochemistry KW - Crustal contamination KW - Nd-Sr isotopes KW - Javaherdasht KW - Guilan. N2 - The Javaherdasht Basalts show compositional range from olivine basalts to quartz basaltic andesites. Petrographic studies indicate that the differentiation of clinopyroxene and olivine minerals has main role for lithologic variety of the basalts.The corosion golf, crenated margins and lack of the same colour in the clinopyroxene phenochrysts margins with matrix Pyroxene grains express a nonequilibrium and are petrographic features for crustal contamination of the basalts.The positive correlation CaO,CaO/Al2O3 and Cr with Mg# and CaO/Al2O3 with Sc and the negative correlation Al2O3 with Mg# are geochemical characters for the differentiation of clinopyroxene and olivine in the magmatic evolution of the area.The high ratios of Ba/Zr and Pb/Nd and low ratio of Ce/Pb and positive correlation of SiO2 and Rb with 87Sr/86Sr and negative correlation of Nd-Sr isotopes display the contamination of these basalts with continental crust. M3 ER -