WANG Y Y，ZHANG Y B，MIAO M，ZHANG G C. The response relationship between crab traces and Physicochemical Stresses in the modern Pearl River Delta plain and its indication to paleogeography [J]. Journal of Henan Polytechnic University( Natural Science), doi: 10.16186/j.cnki.1673-9787.2025040020.

doi: 10.16186/j.cnki.1673-9787.2025040020

Received：2025-04-09

Revised：2025-06-17

Online：2025-09-02

The response relationship between crab traces and Physicochemical Stresses in the modern Pearl River Delta plain and its indication to paleogeography (Online)

WANG Yuanyuan^1，2, ZHANG Yabin¹, MIAO Miao¹, ZHANG Guocheng^1，2

（1. Institute of Resource and Environment, Henan Polytechnic University, Jiaozuo 454000, Henan, China；2. Henan International Joint Laboratory of Biogenic Traces and Sedimentary Minerals, Henan Polytechnic University, Jiaozuo 454000, Henan, China）

Abstract: Objectives Trace fossils provide critical information for paleoenvironmental reconstruction. In-depth study of modern biological traces is crucial for using them as indicators of paleoenvironmental reconstruction. By analyzing the relationship between the characteristics of crab traces in the modern Pearl River Delta Plain and grain size, TOC, salinity, and turbidity, this study aims to provide empirical evidence for paleoenvironmental reconstruction. Methods Field sampling, laboratory testing, CT scanning, and 3D reconstruction were employed. Grain size, TOC content, salinity, turbidity, and crab trace characteristics were investigated at 92 sampling sites across the delta plain. Results Crab traces showed clear spatial distribution patterns: high bioturbation occurred in southern coastal and estuarine zones, while minimal disturbance was observed in northern and western areas. Grain size, TOC, salinity, and turbidity all influenced crab trace density, with factors being interconnected: Crabs preferred muddy or sandy substrates (fine silt and coarse silt) with higher TOC; Salinity variations affected crab species distribution and thus bioturbation density; Moderate turbidity favored crab survival while excessive levels were detrimental. Conclusions The distribution of modern crab traces in the Pearl River Delta plain is co-influenced by multiple physicochemical conditions. This study holds significance for interpreting deltaic paleoenvironmental reconstruction and ichnofacies. Analysis of crab trace characteristics enables inferences about paleosalinity, hydrodynamic energy, and depositional stability, aiding reconstruction of deltaic evolution while enriching ichnological and sedimentological databases.

Key words：The Pearl River Delta Plain; ichnology; crab biological traces; physical and chemical conditions

CLC: Q958.1