Mortimer, N.; Palmer, M.C.; Saito, S.; Hackney, R.; Hutton, I.; Chatzaras, V.; Tamura, Y. 2024 Xenoliths from Lord Howe Island are not Zealandia continental crust basement. Lower Hutt, N.Z.: GNS Science. GNS Science report 2024/48. 18 p.; doi: 10.21420/514D-0160
Abstract
Fourteen rock samples comprising eight lavas and six xenoliths were collected from the west coast of Lord Howe Island in March 2019. Three of the xenoliths were examined in Sydney in 2024. Two of the xenoliths, a gabbro and a peridotite, were <1 cm3 in volume and were set aside. The third, a c. 5 x 4 x 3 cm gabbro, was selected for further work in New Zealand. Petrographic and mineral chemistry data on this gabbro indicates that it is a cognate xenolith, genetically related to the Pliocene lavas of Lord Howe Island. Because it is not a crustal xenolith from the continental basement of Zealandia, no further work is planned. (auths)
