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, reco gnized in three geographic areas spread over 1600 km, have identical strati graphic positions and geochemical characteristics. The lavas have an evolve d, Fe-rich tholeiitic composition with lithospheric trace element ratios an d enriched Sr-87/Sr-86 and Nd-143/Nd-144 isotope ratios. Except for the hig hly mobile elements, the major, trace and isotopic compositions of lavas fr om all these localities lie within, or near, analytical precision of each o ther, and are distinct from other Ferrar rocks. Moreover, the ages of the B ows at all localities are indistinguishable. The unique characteristics of these capping lavas suggest that they were derived from a single batch of m agma. Magma dispersal from a single reservoir through dike swarms at middle to upper crustal levels is considered the most probable mechanism for larg e-scale transport that extended for more than 3000 km. (C) 1999 Published b y Elsevier Science B.V. All rights reserved.