Petrogenesis of Pliocene limestones in southern Hawke’s Bay, New Zealand: a contribution to unravelling the sequence stratigraphy and diagenetic pathways of cool-water shelf carbonate facies
type: CreativeWork
description: Among carbonate sedimentologists, it is now appreciated that shallow-marine carbonates are not restricted to warm-water tropical settings, but can also be produced on modern cool-water shelves outside tropical latitudes. In the last two decades, many publications have not only advanced our knowledge about modern non-tropical carbonates, but have documented ancient skeletal limestones that are fossil analogues of these modern deposits. While the broad environmental and sedimentary characteristics of non-tropical deposits are becoming well established, the nature, timing, and relative importance of the various diagenetic processes affecting their evolution into limestones are yet to be fully appreciated, a topic addressed in the present study. In New Zealand, the Plio-Pleistocene (5-1.5 Ma) Te Aute limestones in southern Hawke’s Bay (eastern North Island) are non-tropical in origin, and formed in shoal areas about the margins of a forearc basin seaway adjacent to the convergent Pacific-Australian Plate boundary. Because of the dynamic tectonic setting, which led to narrowing and shallowing of the host basin over time, the studied carbonates exhibit a variety of sedimentary facies (i.e., from pure coquina to mixed carbonate-siliciclastic) and mineralogical signatures (i.e., calcite- to, more rarely, aragonite-dominated), and have undergone varying degrees of burial before being uplifted to their present position. As such, the Te Aute deposits provide a unique opportunity to: (1) decipher the suite of processes that have altered their texture and composition through time; (2) address the questions of what likely regional and more global parameters, namely tectonics and eustasy, may have driven diagenetic pathways, and how this occurred; and (3) more generally advance fundamental knowledge about models of porosity evolution in non-tropical carbonates. The present study integrates the combined results of detailed field investigations with a variety of analytical technique…
abstract: Among carbonate sedimentologists, it is now appreciated that shallow-marine carbonates are not restricted to warm-water tropical settings, but can also be produced on modern cool-water shelves outside tropical latitudes. In the last two decades, many publications have not only advanced our knowledge about modern non-tropical carbonates, but have documented ancient skeletal limestones that are fossil analogues of these modern deposits. While the broad environmental and sedimentary characteristics of non-tropical deposits are becoming well established, the nature, timing, and relative importance of the various diagenetic processes affecting their evolution into limestones are yet to be fully appreciated, a topic addressed in the present study. In New Zealand, the Plio-Pleistocene (5-1.5 Ma) Te Aute limestones in southern Hawke’s Bay (eastern North Island) are non-tropical in origin, and formed in shoal areas about the margins of a forearc basin seaway adjacent to the convergent Pacific-Australian Plate boundary. Because of the dynamic tectonic setting, which led to narrowing and shallowing of the host basin over time, the studied carbonates exhibit a variety of sedimentary facies (i.e., from pure coquina to mixed carbonate-siliciclastic) and mineralogical signatures (i.e., calcite- to, more rarely, aragonite-dominated), and have undergone varying degrees of burial before being uplifted to their present position. As such, the Te Aute deposits provide a unique opportunity to: (1) decipher the suite of processes that have altered their texture and composition through time; (2) address the questions of what likely regional and more global parameters, namely tectonics and eustasy, may have driven diagenetic pathways, and how this occurred; and (3) more generally advance fundamental knowledge about models of porosity evolution in non-tropical carbonates. The present study integrates the combined results of detailed field investigations with a variety of analytical technique…
author: Caron, Vincent
license: https://researchcommons.waikato.ac.nz/bitstreams/725792ca-7d14-444e-b548-dd7c139672f2/download
date published: 2002
date modified: 2026-07-24T05:57:27Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato