Table 1

Chemical composition of the microdiorite intrusion in Borehole E (Fig. 2). XRF analysis conducted at the GAU-Radioanalytical Laboratories, National Oceanography Centre, University of Southampton, UK. A Philips® MAGIX-PRO automatic sequential wavelength dispersive X-ray Fluorescence spectrometer was used to determine element concentrations. The instrument is calibrated using a wide range of international geochemical reference samples and accuracy is typically within 5% of the consensus value when an international reference sample is run as an unknown. The 2σ precision is typically 1–5%

Major elements (wt. %)Trace elements (ppm)
SiO256.08Ba911
TiO20.66Ce34
Al2O316.91Co20
Fe2O35.86Cr114
MnO0.09Ga18
MgO3.12La22
CaO5.66Nb6
K2O2.97Ni34
Na2O2.53Rb90
P2O50.23Sr280
Tot100.93Th3
LOI6.81V135
Y15
Zr150
(Zr/TiO2)226
Nb/Y)0.39