The Cretaceous Merín aborted-rift basin of eastern Uruguay is composed of sub-alkaline Paraná-Etendeka province basaltic flows and shallow intrusives (~133 to 131 Ma), rhyolitic ignimbrites (~130 to 128 Ma) and associated mildly alkaline to alkaline intrusions and volcanic rocks (~128 to 127 Ma). Four intrusive complexes from 20 to >30...