Major and trace element analyses of ODP Leg 120 volcanic rocks (Table 1)

• Main Authors: Storey, Michael, Kent, R W, Saunders, Andrew D, Salters, Vincent J M, Hergt, Janet M, Whitechurch, Hubert, Sevigny, James H, Thirlwall, Matthew F, Leat, Philip, Ghose, N C, Gifford, M
• Format: Dataset
• Language: English
• Published: PANGAEA 1992
• Subjects: 120-747C; 120-748C; 120-749C; 120-750B; Albite; Aluminium oxide; Anorthite; Apatite; Barium; Calcium oxide; Cerium; Chromium; CIPW Norm; Corundum; Diopside; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Elements; total; Europium; Event label; Gallium; Hafnium; Hypersthene; Ilmenite; Instrumental neutron activation analysis (INAA) (Reimann et al.; 1998); Iron oxide; Fe2O3; Joides Resolution; Lanthanum; Leg120; Loss on ignition; Lutetium; Magnesium oxide; Manganese oxide; Montmorillonite; Neodymium; Nepheline; Nickel; Niobium; Ocean Drilling Program; ODP; Olivine; Orthoclase; Phosphorus oxide; Potassium oxide; Quartz; Rubidium; Antarctic; Indian; Kerguelen; Kerguelen Island; Prince Charles Mountains; The Antarctic; Antarc*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.759908; https://doi.org/10.1594/PANGAEA.759908

Widespread Lower Cretaceous magmatism occurred along the Indian-Australian/Antarctic margins, and in the juvenile Indian Ocean, during the rifting of eastern Gondwana. The formation of this magmatic province probably began around 120-130 Ma with the eruption of basalts on the Naturaliste Plateau and at Bunbury, western Australia. On the northeast margin of India, activity began around 117 Ma with the Rajmahal continental basalts and associated lamprophyre intrusions. The formation of the Kerguelen Plateau in the Indian Ocean began no later than 114 Ma. Ultramafic lamprophyres (alnoites) were emplaced in the Prince Charles Mountains near the Antarctic continental margin at ~ 110 Ma. These events are considered to be related to a major mantle plume, the remnant of which is situated beneath the region of Kerguelen and Heard islands at the present day. Geochemical data are presented for each of these volcanic suites and are indicative of complex interactions between asthenosphere-derived magmas and the continental lithosphere. Kerguelen Plateau basalts have Sr and Nd isotopic compositions lying outside the field for Indian Ocean mid-ocean ridge basalts (MORB) but, with the exception of Site 738 at the southern end of the plateau, within the range of more recent hotspot basalts from Kerguelen and Heard Islands. However, a number of the plateau tholeiites are characterized by lower 206Pb/204Pb ratios than are basalts from Kerguelen Island, and many also have anomalously high La/Nb ratios. These features suggest that the source of the Kerguelen Plateau basalts suffered contamination by components derived from the Gondwana continental lithosphere. An extreme expression of this lithospheric signature is shown by a tholeiite from Site 738, suggesting that the southernmost part of the Kerguelen Plateau may be underlain by continental crust. The Rajmahal tholeiites mostly fall into two distinct geochemical groups. Some Group I tholeiites have Sr and Nd isotopic compositions and incompatible element abundances, similar to ...