High temperature, low pressure garnet-peridotites from Praguaniyeu: evidence for plume activity in Northern Patagonia.

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

Calafate

Congreso; XV Congreso Geológico Argentino; 2002

<!-- /* 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;} --> Xenoliths from alkali basaltic extrusions provide valuable information on the nature of the lithospheric mantle. Whereas garnet-bearing xenoliths are rare, the most common xenoliths in alkali basaltic extrusions, world wide, are spinel-bearing peridotites, Therefore, garnet-bearing peridotites are an important source of information on the geochemical and thermal evolution of the deepest lithosphere. The Pali Aike volcanic field in southernmost Patagonia was until now the only one well-known locality in the South American subcontinent where garnet-bearing mantle xenoliths occur, We present, geochemical data and PT estimates for garnet-bearing mantle xenoliths from Praguaniyeu, Rio Negro province, a new locality close to the Meseta de Somuncura, in northern Patagonia.