Carbon isotope composition as indicator for climatic changes during the middle and late Holocene in a peat bog from Maramureş Mountains (Romania)

Abstract

The main goal of this study was to use stable carbon isotopic composition of bulk peat sampled in Tăul Mare-Bardău peat bog, Maramureş Mountains, as a tool to provide paleoclimatic information over the middle and late Holocene in this region. A peat core of 3.60 m was sampled for δ13C analysis, and bulk peat samples were analyzed by isotope ratio mass spectrometry (IRMS) method. δ13C values reveal a maximum variation of 4.69‰ along a 3.6-m-long peat core. We examined the vertical variation of δ13C bulk peat and concluded that several factors could contribute to up core trends of δ13C. Four intervals of climatic variability could be related with variations of δ13C values between ~6800 cal. yr BP and present: two wet periods (around 2800 and 545 cal. yr BP) and two dry periods (6760 and 1430 cal. yr BP). We concluded that variability in the δ13C of bulk peat profile could be influenced most heavily by the water availability, which in turn is related to the amount of precipitation at the time. Four intervals of δ13C variations of the peat sequence between 225 and 25 cm can be related with generally accepted intervals of climatic variability that have occurred within the last 2000–2500 years (‘Roman Warm Period’ (RWP), ‘Dark Age Cold Period’ (DACP), ‘Medieval Warm Period’ (MWP) and ‘Little Ice Age’ (LIA)). The climate was probably of warm–cold alternations, as revealed in our peat core by δ13C variations between 2800 cal. yr BP and present. The δ13C values of the peat profile showed two positive signals at 40 and 225 cm depth and two negative signals at 105 and 350 cm depth. We suggest that these could also represent a change in vegetation at the time.

Periodic input of dust over the Eastern Carpathians during the Holocene linked with Saharan desertification and human impact

“…The climate is temperate continental, with average annual temperatures of 15 • C and precipitation of 800 mm (Kristó, 1995). Surrounding vegetation is typical of this altitude in the Carpathians (Cristea, 1993), the bog being located at the upper limit of the beech forest, with spruce also found on surrounding slopes. Vegetation on the bog itself is diverse, with common occurrences of Pinus sylvestris, Alnus glutinosa, and Betula pubescens, alongside various Salix species (Pop, 1960;Tanţau et al, 2003).…”

Reconstructing climate change and ombrotrophic bog development during the last 4000years in northern Poland using biotic proxies, stable isotopes and trait-based approach

“…The principal applicability of bulk peat as a comparably easy and less time consuming approach for stable carbon isotope analyses in palaeoenvironmental peat studies was demonstrated by Pancost et al (2003) and Cristea et al (2014). Even if both authors also express the need for caution in interpreting this variable, further justification for such an approach arises from a comparison study between bulk peat and cellulose d13C which demonstrated common patterns between the two datasets (Jędrysek and Skrzypek, 2005).…”

Stratigraphic architecture and coal character of Late Permian Fort Cooper Coal Measures, Bowen Basin, Queensland

“…The use of carbon isotope composition of organic matter or coal as an indicator of climatic and palaeoenvironmental conditions is well established in the literature (Cristea et al, 2013;Faure et al, 1995;Gröcke and Wortmann, 2008;Rimmer et al, 2006). During the process of photosynthesis and respiration, both modern and ancient plants preferentially absorb 12 C fraction of CO 2 from the atmosphere and become depleted in 13 Cisotopes.…”

“…Compositional variation between formations, if due to climatic and environmental variables (temperature, water availability, pH) can be identified through carbon isotope analysis (Cristea et al, 2013;Rimmer et al, 2006). (2013), even though the coals tested in this study approach anthracite in rank.…”

“…Lithotypes in conjunction with stable carbon isotope analysis can assist in identifying the controls on coal formation, especially climatic controls (Cristea et al, 2013;Lücke et al, 1999;Rimmer et al, 2006;Widodo et al, 2009 . On the other hand, increasing decomposition of plant material enriches the residual organic matter/inertinite macerals in 13 C (Whiticar, 1996).…”