近日，德国哥廷根格奥尔格·奥古斯特大学地球科学中心Michael Tatzel团队报道了燧石中的氧同位素记录了古沙斯基隆起（西太平洋）的热流。这一研究成果于2025年9月8日发表在《地质学》杂志上。

沉积燧石由无定形硅质前体形成，在埋藏成岩作用中逐渐结晶成蛋白石和石英。最近的研究表明，石英多晶的转变动力学强烈依赖于前向热历史，表明基底热流在确定燧石（Δ¹⁸_ochert， Δ^'17_Ochert）中¹⁸O/¹⁶O和¹⁷O/¹⁶O、¹⁸O/¹⁶O氧同位素比值中起关键作用。

为了研究古热流与燧石氧同位素之间的关系，研究组使用了在西太平洋沙茨基隆起大型火成岩省形成的白垩纪至新近纪燧石，以及之前研究中海洋燧石氧同位素比值的汇编。利用反应平流扩散模型，他们证明了Δ¹⁸_ochert， Δ^'17_Ochert与下伏地壳年龄之间的关系是由于随着海洋地壳冷却，沉积物中的热流减少造成的。研究组对Shatsky Rise热流的重建与既定的地热背景值一致。他们提出，太古宙燧石记录表明，成岩环境以高热流为主，在十亿年的时间尺度上向类似现代成岩作用的条件过渡。

附：英文原文

Title: Oxygen isotopes in cherts record paleoheat flow on Shatsky Rise (western Pacific Ocean)

Author: Oskar Schramm, Patrick J. Frings, Tommaso di Rocco, Andreas Pack, Michael Tatzel

Issue&Volume: 2025-09-08

Abstract: Sedimentary cherts form from amorphous silica precursors that progressively crystallize into opal-CT and quartz during burial diagenesis. Recent studies have shown that the transformation kinetics of the silica polymorphs strongly depend on the prograde thermal history, suggesting a key role of basal heat flow in setting the 18O/16O and 17O/16O 18O/16O oxygen isotope ratios in chert (δ18Ochert, Δ′17Ochert). To investigate the relationship between paleoheat flow and chert oxygen isotopes, we used Cretaceous to Neogene cherts that formed in the large igneous province Shatsky Rise in the western Pacific Ocean and a compilation of marine chert oxygen isotope ratios from previous studies. Using a reaction-advection-diffusion model, we demonstrate that the relationship between δ18Ochert, Δ′17Ochert, and the age of the underlying crust results from declining heat flow through sediment as the oceanic crust cools. Our reconstruction of heat flow at Shatsky Rise aligns with established geothermal background values. We propose that the Archean chert record indicates a diagenetic environment dominated by high heat flow that transitioned on billion-year time scales toward conditions resembling modern diagenesis.

DOI: 10.1130/G53296.1

Source: https://pubs.geoscienceworld.org/gsa/geology/article/doi/10.1130/G53296.1/661082/Oxygen-isotopes-in-cherts-record-paleo-heat-flow