3D SEISMIC REFLECTION INTERPRETATION OF IGNEOUS FEATURES IN PARIHAKA-3D, TARANAKI BASIN, NEW ZEALAND

3D seismic data provides insights into the structure and stratigraphy of buried geological formations, and is primarily used in the study of sedimentary sequences. This study aims to characterize the building blocks of a volcanic system; ie. the elements formed during eruptions, magma emplacement, deformation, and co-, syn-, and post-sedimentation. The study site, Parihaka, is within Taranaki Basin, off the west coast of the North Island of New Zealand. Parihaka is a highly faulted region which contains a buried, submarine, startovolcanic complex. The study site was constrained to the Parihaka Volcanic Complex (PVC), which is bound by post-volcanic faults to the north, east and south. Architectural elements of the PVC were separated into syn- and post- eruptive sequences through horizon mapping. They were then analyzed using 2D seismic slices and 3D seismic cubes in Kingdom Software. The syn-eruptive sequence includes the architectural elements of channels, parasitic vents, and sills. The post-eruptive sequence has channels (of differing morphologies) and seamounts. Pre-eruptive channels and units were difficult to identify due to the masking effect of volcanic layers within seismic imaging. Extensive faulting formed a basin to the north of the volcanic complex, causing a channel running north-south along the western edge of the volcanic complex to incise more deeply than the others. Channel morphologies differ based on proximity to the volcanic complex, with those proximal to a volcanic edifice being narrow, straight, deeply incised channels. Those distal from the PVC follow meandering wide paths while remaining shallow, indicating less influence from the elevation of the volcanic complex. The Parihaka Volcanic Complex highlights the ways in which volcanism not only affects the pre-existing strata through which it intrudes and erupts, but also affects the long-term geomorphologies and erosive and depositional processes.