The nontropical Oligocene carbonate-rich Tikorangi Formation is an important oil producer in the Taranaki Basin New Zealand. Hydrocarbons are hosted and produced from mineralized natural fracture systems. Petrographic, trace-element, stable-isotope (delta(18)O and delta(13)C) and fluid-inclusion data have enabled a complex sequence of eight paragenetic events to be determined. The Tikorangi Formation host rock was cemented by low-Mg calcite (event 1) corresponding during burial diagenesis from temperatures of 27degreesC to 0.5 km burial and continued until 37degreesC 1-km burial depth producing tight, pressure-dissolved fabrics with essentially no porosity and permeability. The host rock was partially dolomitized 9 (5-50%) (event 2) by Ca- and Fe-rich dolomite rhombohedra at burial depths and temperatures of 1.0-1.5 km and 35-50degreesC without secondary porosity development. Subsequent brittle fracturing formed by Neogene compression (event 3) is constrained to a period following lithification and dolomitization, but before precipitation of first-generation vein calcite (event 4). This initial ferroan low-Mg vein calcite formed after a period of burial from Fe-rich meteorically modified fluids at temperatures of about 50-60degreesC and 1.4-1.9 km burial depth. Baroque dolomite formed (event 5), following a period of Mg-enriched basinal fluid input precursory to hydrocarbon emplacement per se. The dolomite formed mainly as a primary cement but also as a calcite replacement at temperatures following further burial to 2-2.5 km and temperatures of 65-80degreesC. Formation of celestite and quartzine phases (event 6) coincided with or marginally postdated dolomite at similar depths and temperatures to event 6 and formed as both replacements and cements. in Second-generation ferroan vein calcite formed (event 7) at cooler temperatures (53-65degreesC), perhaps resulting from the introduction of cooler meteoric fluids from upsection. The presence of petroleum-fluid inclusions in the second-generation calcite suggests precursory hydrocarbon-bearing fluids have migrated, along with aqueous fluids from about 10 Ma, with hydrocarbon emplacement (event 8) occurring in the last 6 m.y. following a period of rapid late Miocene burial. An improved understanding of the paragenesis of the Tikorangi Formation may, assist in hydrocarbon production from its reservoirs.