Inclusiones fluidas en piroxenos alojados en lavas alcalinas, Sierra de Queupuniyeu.

LABUDIA, C; NTAFLOS, TH; BJERG, E A

Rio Cuarto

Congreso; VII Congreso de Mineralogia y Metalogenia; 2004

The hills of La Huerta and Valle Fertil, wich belong to the Western Pampean Ranges in the Province of San Juan, NW Argentina, mainly consist of metagabboic to metadioritic rocks that intruded the Proterozoic basement in the Early Middle Ordovician (Famat <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:21.0cm 842.0pt; margin:70.9pt 3.0cm 70.9pt 3.0cm; mso-header-margin:35.45pt; mso-footer-margin:35.45pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Melt and fluid inclusions reflect interaction between basaltic magma volatiles and early-formed minerals. Queupuniyeu Hills, located NWof Somoncura basaltic plateau, is one of the main areas where alkaline basalts crops out in Rio Negro Province, Argentina. The olivine, clinopyroxene and orthopyroxene phenocryst display a wide variety of melt and fluid inclusions, composed by different solid, liquid and gas phases. At the moment CO2 is the sole immiscible fluid phase coexisting with magma in Queupuniyeu Hills. The relative density differences of CO2 in secondary fluid inclusions may be attributed to selective phenocryst deformation during ascent of the alkaline basaltic magma.