Abstract

AbstractTwo of the most important factors that control the accumulation rate of material in carbonate platform environments on geological time scales are climate and eustasy. Accurately assessing the importance of these inter‐related factors through the study of both modern and ancient carbonate facies, however, is problematic. These difficulties arise from both the complexities inherent in carbonate depositional systems and the demonstrable incompleteness of the stratigraphic record. Here, a new compilation of more than 19 000 global Phanerozoic shallow marine carbonate accumulation rates derived from nearly 300 individual stratigraphic sections is presented. These data provide the first global holistic view of changes in shallow marine carbonate production in response to climate and eustasy on geological time scales. Notably, a clear latitudinal dependence on carbonate accumulation rates is recognized in the data. Moreover, it can also be demonstrated that rates calculated across the last glacial maximum and Holocene track changes in sea‐level. In detail, the data show that globally averaged changes in carbonate accumulation rates lagged changes in sea‐level by ca 3 kyr, reflecting the commonly observed delay in the response of individual carbonate successions to sea‐level rise. Differences between the rates of carbonate accumulation and sea‐level change over the past 25 kyr ostensibly reflect changing accumulation mode, with platform drowning (give‐up mode) pervasive during peak Early Holocene sea‐level rise, followed by a switch to catch‐up mode accumulation from ca 9 ka to the present. Carbonate accumulation rates older than the Quaternary are typically calculated over time spans much greater than 100 kyr, and at these time spans, rates primarily reflect long‐term tectonically mediated accommodation space changes rather than shorter term changes in climate/eustasy. This finding, coupled with issues of stratigraphic incompleteness and data abundance, tempers the utility of this and other compilations for assessing accurately the role of climate and eustasy in mediating carbonate accumulation rates through geological time.

Highlights

  • Tropical biogenic carbonate facies that accumulate at or very near sea-level have long been used as sensitive gauges of past sea-level change

  • The consequential differences between the rates of carbonate accumulation and sea-level change over the past 25 kyr ostensibly reflect changing accumulation mode, from restricted growth and drowning operating prior to ca 9 ka, to growth that outstripped sea-level rise and catch-up style accumulation operating from ca 9 ka to the present day

  • Carbonate accumulation rates during sustained sea-level rise may be the best measures of growth potential, data biases and limitations hinder a fuller understanding of the true responses of pre-Holocene carbonates to climate and eustasy

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Summary

Introduction

Tropical biogenic carbonate facies that accumulate at or very near sea-level have long been used as sensitive gauges of past sea-level change. The first order control on sedimentation rates of shallow water carbonates is neither climate nor eustasy, but the time span over which the rates are calculated (Sadler, 1981; Schlager, 1991, 2005; Wilkinson et al, 1991; Bosscher & Schlager, 1993; Opdyke & Wilkinson, 1993). The critical time span range through which rates are likely to be most influenced by climatic and eustatic processes is 102 to 106 years (Sadler, 1994); i.e. shorter than the scales analysed by Bosscher & Schlager (1993).

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