Lomilik has a 40-by-15-kilometre-wide (24.9 mi × 9.3 mi) summit terrace with the proper summit at circa 1,500 metres (4,900 ft) depth; a
scarp separates the two and small hills reach depths of 1,350 metres (4,430 ft). The summit terrace is covered by rocks with
ooze in between. A notch in the southern flank of Lomilik was likely created by a
landslide.[2][4] It is part of the
Magellan Seamounts[5] and consists of a
Cretaceousvolcano with a thin layer of
carbonate rocks and
ferromanganese.[6] Lami seamount lies northwest of Lomilik.[7]
The rocks found on Lomilik consist of
basalt and
limestone.[8]Fluorapatite,
hyaloclastite,[9]mudstone,
phosphorite and
siltstone have been identified in rocks from the seamount.[10]Manganese nodules have been found on Lomilik[1] and the manganese crusts on the seamount reach thicknesses of over 10 centimetres (3.9 in);[11] the thickest crust recovered from an ocean is a 18 centimetres (7.1 in) thick ferromanganese crust from Lomilik recovered in 1989.[2] The deposits on Lomilik could potentially be
mined.[12]
^Hyeong, Kiseong; Kim, Jonguk; Yoo, Chan Min; Moon, Jai-Woon; Seo, Inah (December 2013). "Cenozoic history of phosphogenesis recorded in the ferromanganese crusts of central and western Pacific seamounts: Implications for deepwater circulation and phosphorus budgets". Palaeogeography, Palaeoclimatology, Palaeoecology. 392: 294.
Bibcode:
2013PPP...392..293H.
doi:
10.1016/j.palaeo.2013.09.012.
ISSN0031-0182.