Response Characteristics of Marine Sediments in Luhai Village, Southern Liaodong Peninsula to Environmental Changes

Luhai Village in the southern part of Liaodong Peninsula is located at the confluence of rivers and oceans, and is an area of frequent material and energy exchange. Studying the response characteristics of marine sediments to environmental changes is of great importance. This research analyzes the grain size and geo-chemical characteristics of marine sediments in Luhai Village and investigates their response to environmental changes to provide a scientific basis for regional environmental evolution and coastal management. Field observations, columnar sample collection, and marine hydro-logical data analysis are used in the study. Experimental analyses were carried out in combination with X-ray fluorescence spectrometry, 210Pb dating, laser diffraction particle size analyzer, elemental geochemistry, organic carbon and nitrogen indicators. The results indicated that the sediment mainly contained silty sand and sandy silt, with a particle size range of $4.25\sim 5.54\Phi $ and poor sorting. High magnesium content might be related to geology or human activities. The carbon to nitrogen ratio ranged from 8.8 to 15.84, indicating significant input and preservation of organic matter. The sedimentation rate was 1.06 cm/a, and a dating framework was constructed using 210Pb dating. Particle size analysis showed a negative correlation between sand and silt, with low and stable clay content. Total organic carbon (TOC) was positively correlated with total nitrogen (TN). Moreover, carbon nitrogen ratio and $\delta 13$ C analysis showed that organic matter mainly come from marine plankton with some terrestrial inputs. The study provides quantitative data for understanding the evolution of regional sedimentary environments, which has important practical value for the sustainable development of coastal resources and ecological environment protection.