Long-distance transport of magmas in the Jurassic Ferrar Large Igneous Province, Antarctica

The youngest preserved lava flows of the Jurassic Kirkpatrick Basalt of the Ferrar Large Igneous Province are unusually distinctive. These flows, recognized in three geographic areas spread over 1600 km, have identical stratigraphic positions and geochemical characteristics. The lavas have an evolved, Fe-rich tholeiitic composition with lithospheric trace element ratios and enriched 87Sr/86Sr and 143Nd/144Nd isotope ratios. Except for the highly mobile elements, the major, trace and isotopic compositions of lavas from all these localities lie within, or near, analytical precision of each other, and are distinct from other Ferrar rocks. Moreover, the ages of the flows at all localities are indistinguishable. The unique characteristics of these capping lavas suggest that they were derived from a single batch of magma. Magma dispersal from a single reservoir through dike swarms at middle to upper crustal levels is considered the most probable mechanism for large-scale transport that extended for more than 3000 km.