E.H. McKee A. Roisenberg R.V. Fodor 1989 <p><span>We evaluated 193 K-Ar ages (10 newly determined) of basaltic and differentiated rocks of the Serra Geral (Paran&aacute;) flood-basalt province for indications of magmatism occurring systematically with progressive rifting and complete separation ( &asymp;130-105 Ma) of South America from Africa. The K-Ar ages represent basalt emplacement between 35&deg; and 19&deg;S covering about 1,200,000 km</span>²<span>. We note that volcanism appears ubiquitous across the province between about 140 and 115 Ma, and that there are no significant age differences within that relate directly to progressive south-to-north tectonism. On the other hand, the oldest samples, about 140&ndash;160 Ma, are among those nearest the Brazil coastline (rift margin), perhaps suggesting migration of activity away from the rift with time. Studies of other flood-basalt provinces now indicate short (&lt;3 m.y.) eruption periods, thereby pointing to the need for re-examination of Serra Geral ages by<span class="Apple-converted-space">&nbsp;</span></span>⁴⁰<span>Ar-</span>³⁹<span>Ar incremental heating techniques.</span></p> application/pdf 10.1016/0895-9811(89)90012-6 en Elsevier Age distribution of Serra Geral (Paraná) flood basalts, southern Brazil article