The mafic-ultramafic rocks and surrounding basement of the La Huerta and Valle Fértil Ranges, San Juan, Argentina

CASTRO DE MACHUCA, B; MOGESSIE, A; PREVILEY, L; BJERG, E A; KOSTADINOFF, J; FERRACUTTI, G; SCHNEIDER, I

Schladming

Congreso; Minpet 2005; 2005

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;} --> The La Huerta and Valle Fertil ranges (30 00' -31 27' S, 66 18'-68 09 ' W), Western Sierras Pampeanas, province of San Juan, Argentina, mainly consist of metamorphic and igneous rocks. The Proterozoic-Lower Paleozoic (Pampean) metamorphic basement is made up of Grt-Bt ± Sil ± Crd ± Kfs paragneisses. This grades into migmatites, amphibolites and Fo ± Dio ± Per marbles to the north. The igneous rocks intruded the metamorphic basement in the Early-Middle Ordovician (Famatinian orogeny), when the Cuyania (Precordillera) and Pampia terranes collided.