Structure and evolution of the Kapuni Anticline, Taranaki Basin, New Zealand: Evidence from the Kapuni 3D seismic survey

Abstract

Styles of deformation and timing of tectonic events documented by the Kapuni 3D seismic survey provide important constraints on models for the structural evolution of the Taranaki Basin. Two-way travel time and seismic attribute maps of this survey reveal a large degree of structural complexity and a pronounced vertical change in structural style. Taranaki Basin stratigraphy has, to a large extent, been controlled by distinct tectonic events resulting in discrete seismostratigraphic units being recognised in the Kapuni area.Seismic units 3 and 2 represent coals, shales, siltstones, and sandstones of the Eocene Kapuni Group and bathyal mudstones and turbidite sandstones of the Oligocene-middle Miocene Ngatoro and Wai-iti Groups, respectively. Their bulk strain can be described as triaxial oblate flattening in response to east-west-oriented compression during the late Eocene-late Miocene.The overlying seismic unit 1 represents sandstones, siltstones, and mudstones of the late Miocene-Pleistocene Rotokare Group. Its structure is dominated by a dense array of left-stepping oblique-slip normal faults that originated from Pliocene-Pleistocene oblique extension/dextral transtension and are possibly detached from seismic units 2 and 3 by an inclined detachment surface that cuts stratigraphically deeper from northeast to southwest.

Regional structure and kinematic history of a large subduction back thrust: Taranaki Fault, New Zealand

“… Childs et al , 1995]. Growth strata across the Manaia Anticline (and within the relay ramp) indicate displacement on the Manaia Fault from the middle‐late Eocene (circa 43–35 Ma) [ Voggenreiter , 1993; Holstege and Bishop , 1998]. Therefore we infer that the Taranaki Fault was also active during the middle‐late Eocene.…”

“…Growth strata on the limbs of the Manaia and Herangi High anticlines indicate that these structures continued to develop during the Oligocene [ Voggenreiter , 1993; Palmer and Andrews , 1993; Nelson et al , 1994]. In the region of the Herangi High, for example, calcareous sandstone and siltstone, and limestone units of Oligocene age indicate gentle eastward tectonic tilting of 1–1.5°/Ma from 32–28 Ma to the start of the Miocene [ Nelson et al , 1994].…”

Geomorphologic Controls on the Evolution of Submarine Channels in the Clifdenian-Tongaporutuan Interval of the Southern Taranaki Basin, offshore New Zealand

“…The final but varied phase of basin evolution, which began with incipient shortening from ca. 43 to 40 Ma (Palmer and Andrews, 1993;Voggenreiter, 1993;Stagpoole and Nicol, 2008). Furthermore, contraction in the middle Eocene was characterized by reverse faulting and foreland basin development resulting in uplift and erosion of Late Cretaceous to Paleocene strata along the eastern margins of the basin (Stagpoole and Nicol, 2008).…”

Tectonic controls on Miocene sedimentation in the Southern Taranaki Basin and implications for New Zealand plate boundary deformation

“…Previously normal faults of Cretaceous and Paleocene age were inverted along with the creation of new thrust faults (Fohrmann et al, ; Holt & Stern, ; King & Thrasher, ; Pilaar & Wakefield, ; Reilly et al, ). Contraction is linked to the onset of Pacific Plate subduction along the proto‐Hikurangi Margin to the east and north of New Zealand (Bache et al, ; Palmer & Andrews, ; Reilly et al, ; Stagpoole & Nicol, ; Voggenreiter, ). Miocene faulting in the STB was initially focused on the eastern basin margin, formed by the Taranaki Fault System (TFS), which is defined (Stagpoole & Nicol, ) as being composed of the Taranaki, Manaia and Waimea–Flaxmore faults (Figure ).…”