Potassic, ultrapotassic lava domes, flows, and volcano-sedimentary deposits including leucite-bearing and leucite-free grains crop out to the north of Senirkent (Isparta), at the apex of the Isparta Angle (southwestern Turkey).… Click to show full abstract
Potassic, ultrapotassic lava domes, flows, and volcano-sedimentary deposits including leucite-bearing and leucite-free grains crop out to the north of Senirkent (Isparta), at the apex of the Isparta Angle (southwestern Turkey). Ultrapotassic rocks are nepheline-foidolite, italite, leucitite, melilite leucitite, melilite-gehlenite leucitite, diopside leucitite, and leucitophyre with lowest SiO2 content (38.71–44.72 wt%, but the leucitophyre has 51.4 wt%), higher K2O (4.36–10.19 wt%), MgO (3.25–6.98 wt%), and K2O/Na2O ratio (2.65–32.8). Potassic rocks are phonolitic leucitites, sanidine-phyric phonolite, and trachytes with SiO2 (49.35–64.46 wt%), K2O (8.28–11.38 wt%), MgO (0.17–1.39 wt%), and K2O/Na2O ratio (2.25–11.8). Some leucitites, diopside leucitites, and phonolitic leucitites enclose partly carbonatite occurences or associated with carbonate-rich part including carbonatite globules, phlogopite, clinopyroxene, and/or leucite, melanite crystals embedded in glassy volcanic matrix and/or carbonate matrix. Primitive mantle-normalized incompatible element patterns display strong enrichments in LILEs (Cs, Rb, Ba, U, Th, Sr) relative to HFSEs (Nb, Ti) with distinct negative Nb–Ti anomalies, suggesting subduction-related lavas. Chondrite-normalized REE patterns are characterized by light REE enrichment (251–493 times chondrite for La) and flat heavy REE patterns (10–27 times chondrite for Yb). All the leucite-bearing and leucite-free rocks display similar, subparallel chondrite-normalized and primitive mantle-normalized trace element patterns, suggesting cogenetic origin. Mineralogical, petrological, and geochemical data suggest magma–carbonate wall-rock interaction and tapping of different parts of the melts within the magma chamber along the fault lines formed during neotectonic period and extension-related block faulting.
               
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