microgabbro
nounEtymology From micro- + gabbro.
1
Geography, Geology, Natural sciences A fine-grained igneous rock with the same composition as gabbro but having an ophitic texture; diabase.
- Among these sequences, the Early Cretaceous parts (Urutawan–Motuan) contain spilites and keratophyres within greywacke-type detritus and conglomerates (Battey 1950; Ash 1970; Hay 1975), whilst the Late Cretaceous lithologies are predominantly basalts, dolerites, and microgabbros, with minor amounts of sediment (Le Couteur 1967; Hay 1975).1982 November 26, R. N. Brothers, M. Delaloye, “Obducted ophiolites of North Island, New Zealand: origin, age, emplacement and tectonic implications for Tertiary and Quaternary volcanicity”, in New Zealand Journal of Geology and Geophysics, volume 25, number 2, →ISSN, page 258: