Late Miocene surface heat flow and thermal modelling of Murchison and southern Taranaki basins, New Zealand

Abstract

Numerical thermal modelling of the successions interescted in Fresne-1, North Tasman-1 and Surville-1, southern Taranaki Basin, establishes a Late Miocene surface heat flow value of 77 ± 6 mWm-2 compared with a present-day value of 70 ± 12 mWm-2. This analysis relies upon 2700 m of Late Miocene – Pliocene erosion at Fresne-1, established by seismic reflection mapping. The use of this Late Miocene surface heat flow value in thermal modelling of the succession in Bounty-1 together with apatite fission track data, establishes a 10 Ma timing for the start of uplift and an c. 8 Ma timing for the start of erosion of the 2700 m of the sedimentary section that formerly overlay the top of the Bounty-1 succession. Murchison and southern Taranaki basins had similar timing (Late Miocene) and duration of hydrocarbon maturation prior to the start of Basin inversion.