Geochemical systematics of south Patagonian Volcanic rocks.

GÜNTHER, M; NTAFLOS, TH; LABUDIA, C; BJERG, E A; KURAT, G

Strasbourg

Congreso; European Union of Geosciences 10 Meeting; 1999

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;} --> Volcanic rocks from Patagonia, 41 oS , along an E-W profil (300 km), consist of trachybasalts and tephriteslbasanites of Pliocene to Quaternary age. Older tholeiitic basalts and basaltic andesites of Oligocene to Miocene age are outcropping in the western part of tbe profile (Comallo and Jacobacci). Trachybasalts and tephriteslbasanites carry mantle and deep crustal derived xenoliths, whereas the older lavas (W) are free of xenoliths. Deep crustal xenoliths (granulites and pyroxene-amphibolites) are more common to tbe east (Queupuniyeu) and, arguably, indicate different genetic conditions.