Differentiation of sedimentary environment and its carbon sequestration rate since the Late Pleistocene in the Luanhe River Delta, northern Bohai Bay

This paper is the result of marine and environmental geological survey engineering.

Objective Carry out the differentiation of the sedimentary environments since the Late Pleistocene in the Luanhe River Delta, northern Bohai Bay, calculate and analyze the magnitude and controlling factors of the carbon sequestration rate (CSR), and further evaluate the regional carbon storage capacity.

Methods In this paper, the reconstruction of the paleo-sedimentary environment since the Late Pleistocene was carried out on the core of hole BXZK03, and the parameters including particle size, age (AMS¹⁴C and OSL), water content, organic carbon, total carbon and other nutrients contents were sampled and analyzed.

Results Since the Late Pleistocene, the strata were divided from bottom to top into five sedimentary environmental units, including flood plain, sand ridge, shallow sea, barrier sand bar (delta front), and lagoon. The CSRs were in the order of barrier sand bar 51.47 g/(m² · a)> beach sand ridge 32.59 g / (m² · a)> shallow sea 7.82 g/(m² · a)> lagoon 4.66g / (m² · a). Correlation analysis showed that there was a significant (P < 0.01) linear correlation between total carbon, organic carbon and each nutrient element. Variance analysis suggested that CSRs were likely controlled by the deposition rate and carbon concentration, respectively.

Conclusions Although the organic carbon concentrations of sediments in Luanhe River Delta were relatively low, there were relatively high organic CSRs due to an elevated deposition rate during Holocene. Therefore the Holocene sediment has a remarkable carbon storage capacity.