Palynological evidence indicates the paleoclimate evolution in southeast China since late marine isotope stage 5

Depositional control on the sulfur content and isotope of sedimentary pyrite from the southeast coast of China since MIS5

“…However, on the ECS coast, especially the coast area of Zhejiang and Fujian, only one or two transgressive strata were developed, and the period and magnitude of marine transgression are still a controversial topic (Geng, 1982;Zhao et al, 2008;Lin and Dai, 2012). In recent studies of cores collected from Sansha Bay and Xiapu Bay, three transgressive events since MIS5 were identified using geochemical indicators, palynology, and micropalaeontology, which established a well stratigraphic and sedimentologic framework for our study (Dai et al, 2021;Yu et al, 2021;Sun et al, 2022;Wang et al, 2022).…”

“…The Sr/Ba ratio in this interval increases significantly (Figure 2B), which represents a depositional environment with increased salinity (Sun et al, 2022). In addition, the marine dinocyst record of NDGK2, located in Sansha Bay (Figure 1B), also suggests that the study area has experienced a marine incursion during MIS5 (Dai et al, 2021). We suggest that Xiapu Bay is influenced by seawater sulfate during MIS5, but the magnitude of transgression is weak so that the sedimentary environment is not conducive to the growth or later preservation of foraminifera.…”

“…The chronology of core QK11 is referred to a well-established stratigraphic framework of core NDGK2 (Figure 2A), including ages from AMS 14 C and optically stimulated luminescence (OSL), and relative stratigraphic correlation between them (Dai et al, 2021;Sun et al, 2022). According to previous work on core QK11 (Sun et al, 2022), the relative pyrite content in heavy minerals in core QK11 increases significantly during the interglacial stages, which corresponds to the intervals with high salinity reflected by increased Sr/Ba ratios (Figure 2B).…”

“…Pyrite aggregates, main framboids with a large diameter (> 50 mm), consist of octahedral and irregular pyrite microcrystals (Figure 2C). According to the relative pyrite contents and previous research results (Dai et al, 2021;Sun et al, 2022), core QK11 is divided into five sedimentary intervals (Figure 2). Three interglacial intervals at depths of 70.6~70.2, 37.5~22.8, and 15.8~2.2 mbsf correspond to MIS5, MIS3, and MIS1, respectively, whereas glacial intervals at depth of 70.2~37.5 mbsf and 22.8~15.8 mbsf correspond to MIS4 and MIS2, respectively.…”

Vegetation Dynamics vs. Sediment Supply During the Late Quaternary: Paradigm of Sea Level Change and Two Distinct Time-Bound Stages of the Niger Delta Coastal Evolution

“…Significant records of hinterland pollen taxa in several other sediment cores in west equatorial Africa, such as T89-16, MD03-2708, and GeoB-4905 (Kim et al , 2010;Marret et al , 2001;Skonieczny et al, 2015) indicate dry conditions. In addition, the observed fluvial sediment supply could be linked to the seasonal latitudinal migration of the Intertropical Convergent Zone (ITCZ) with a mean annual position assumed to be around 13 o N positioned further south (10 o S) (Leroux, 1993;Marret et al , 2001;Shannahan et al, 2015;Adojoh et al, 2017;Hopker et al, 2019;Dai et al, 2021;Boyden et al, 2021).…”