Insolation-paced sea level and sediment flux during the early Pleistocene in Southeast Asia

Romain Vaucher,Shahin E Dashtgard,Wen-Rong Chi,Chorng-Shern Horng,Antoine Dillinger,Romy A Setiaji,Yu-Yen Pan,Christian Zeeden,Ludvig Löwemark

doi:10.1038/s41598-021-96372-x

Abstract

Global marine archives from the early Pleistocene indicate that glacial-interglacial cycles, and their corresponding sea-level cycles, have predominantly a periodicity of ~ 41 kyrs driven by Earth’s obliquity. Here, we present a clastic shallow-marine record from the early Pleistocene in Southeast Asia (Cholan Formation, Taiwan). The studied strata comprise stacked cyclic successions deposited in offshore to nearshore environments in the paleo-Taiwan Strait. The stratigraphy was compared to both a δ18O isotope record of benthic foraminifera and orbital parameters driving insolation at the time of deposition. Analyses indicate a strong correlation between depositional cycles and Northern Hemisphere summer insolation, which is precession-dominated with an obliquity component. Our results represent geological evidence of precession-dominated sea-level fluctuations during the early Pleistocene, independent of a global ice-volume proxy. Preservation of this signal is possible due to the high-accommodation creation and high-sedimentation rate in the basin enhancing the completeness of the stratigraphic record.

Highlights

Climate oscillations are controlled by variations in Earth’s orbital and astronomical motions, which modulate changes in insolation received by the atmosphere
High temporal completeness of the stratigraphic record is required to accurately determine the controls on cyclicity in the sedimentary record, including shallow-marine strata. Such critical conditions likely occur in sedimentary basins with young sedimentary strata that accumulated under high rates of both sediment accumulation and accommodation creation as these settings promote the completeness of their record
This study provides the first stratigraphic evidence of insolation-paced sea-level changes in Southeast Asia that is dominated by precession; this is in contrast to the obliquity-dominated records preserved in marine archives during the early Pleistocene globally

Summary

Introduction

Climate oscillations are controlled by variations in Earth’s orbital and astronomical motions (i.e., precession, obliquity, eccentricity), which modulate changes in insolation received by the atmosphere. Shallow-marine settings are directly affected by long- and short-term climatic variations (e.g., sea level changes, extreme weather events) and their preserved stratigraphic architecture is controlled primarily by variations in sea level, sediment supply and subsidence[12] These latter factors control the preservation and scale of depositional cycles in sedimentary b asins[13,14]. Plio-Pleistocene shallow-marine sedimentary strata in the Western Foreland Basin (WFB) of Taiwan accumulated under high rates of sedimentation and accommodation creation, suggesting that the record should have relatively high temporal completeness[19,20,21,22,23,24,25]. The overall shallowing-upward trend preserved in the Chinshui-Cholan-Toukoshan succession reflects the westward migration of the Taiwan Orogeny[20,35]

Methods

Results

Discussion

Conclusion