It is now the inactive part of an eastward-migrating, 100 million year old Lau-Tonga-Havre-Kermadec arc/back-arc system or complex[4] and is important in understanding submarine arc volcanism because of these relationships.

The Lau Basin to its east currently contains 6 million year old active spreading centers between the Australian and Niuafo'ou or Tonga microplates.

The southern Colville Ridge (also known as Khrebet Kolvil-Lau from Russian Хребет Колвил-Лау[1])forms the western boundary of the Havre Trough.

[12] The composition range is from mafic picro-basalt to dacite with arc-type element patterns intermediate between Pacific mid ocean ridge basalt and subducted lithosphere.

[20] To the south it is now thought seafloor spreading at the Havre Trough started about 5.5–5.0 million years ago in response to the rollback of the subducting Pacific Plate and terminated abruptly about 3.0–2.5 million years ago, perhaps explaining the long noted lack of a mid oceanic ridge structure but rather rift like subsidance.