Paleoclimatic Variations in Ningjinpo Area since Late Pleistocene as Indicated by n-Alkanes

It is of importance to reconstruct the paleoclimatic variations since late Pleistocene in North China. In this paper, it selected Ningjinpo area to characterize the paleoclimatic oscillations with the aid of microbial lipids. Results indicate that the carbon number distributions of most samples ranged from C₁₅ to C₃₃, with the dominance of high carbon (C₂₉ and C₃₁ in particular) in most samples and some lower homologue as secondary peak (C₁₇ for instance), suggesting the mixed origin from higher plants and aquatic organisms. According to the parameters derived from n-alkanes, alternative paleoclimatic conditions of the study area from warm climate with low lake level (83-68 ka), hot-wet period with lake expansion (68-30 ka), cold-dry duration with shrinking lake (30-22 ka), hot and wet climate with increasing lake level (22-10 ka), to moderate climate period (10-0 ka) were reconstructed since late Pleistocene. Regional comparison demonstrated the similar glacial-interglacial paleoclimatic patterns occurred in Ningjinpo area and Yanqing basin, potentially suggesting the principal control of solar radiation.