/* DATA DESCRIPTION:
Citation:	Safaierad, Reza; Israde-Alcántara, Isabel; Rantala, Marttiina V; Domínguez-Vázquez, Gabriela; Schefuß, Enno; Tylmann, Wojciech; Francus, Pierre; Mattielli, Nadine; Metcalfe, Sarah; Fagel, Nathalie (2026): δ18O and δ13C from sediment core of Lake Alchichica in Mexico [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.982934
Abstract:	The proxy data are measured from a 57-cm long sediment core collected from Lake Alchichica (19° 24' 38 N, 97° 24' 14 W, 2322 masl) at a water depth of ~ 60 m using a Uwitec® coring device equipped with a 9-cm coring tube. The core was split lengthwise, analyzed using XRF core scanning, and subsampled. A Bayesian chronology was created using 210Pb data and three 14C dates. 
	For stable isotope geochemistry (δ¹⁸O and δ¹³C) of bulk sediments, samples collected at 1 cm intervals were analyzed at MARUM, University of Bremen, using a Finnigan MAT252 mass spectrometer with a Kiel III carbonate preparation device. Results are reported in delta notation (δ) relative to VPDB. Calibration involved a house standard (Solnhofen limestone) referenced to NBS 19 calcite, with standard deviations of 0.06‰ for both δ¹³C and δ¹⁸O.
Keyword(s):	carbon isotope; Deuterium Isotopes; leaf waxes; Mexico; oxygen isotope; Pollen; Sediment core; XRD; XRF core scanner data
Supplement to:	Safaierad, Reza; Israde-Alcántara, Isabel; Rantala, Marttiina V; Domínguez-Vázquez, Gabriela; Mohtadi, Mahyar; Schefuß, Enno; Tylmann, Wojciech; Francus, Pierre; Mattielli, Nadine; Metcalfe, Sarah; Fagel, Nathalie (2025): Late Holocene hydroclimate variability and human–environment interactions in the Cuenca Oriental, Mexico: multiproxy evidence from Lake Alchichica. Quaternary Science Reviews, 369, 109618, https://doi.org/10.1016/j.quascirev.2025.109618
Funding:	Fonds de la Recherche Scientifique (FNRS), grant/award no. PDR T.0079.21: Holocene Mexican Crater Lakes and Climate (HolMeCl)
Coverage:	LATITUDE: 19.505600 * LONGITUDE: -97.438900
	MINIMUM DEPTH, sediment/rock: 0.005 m * MAXIMUM DEPTH, sediment/rock: 0.570 m
Event(s):	Lake_Alchichica * LATITUDE: 19.505600 * LONGITUDE: -97.438900 * ELEVATION: 2322.0 m * LAKE WATER DEPTH: 60 m * PENETRATION: 0.57 m * METHOD/DEVICE: Sediment corer, UWITEC * COMMENT: Uwitec® coring device equipped with a 9-cm coring tube.
Parameter(s):	DEPTH, sediment/rock [m] (Depth sed) * GEOCODE * PI: Safaierad, Reza (https://orcid.org/0000-0002-8295-2560, safaierad.reza@gmail.com)
	AGE [ka BP] (Age) * GEOCODE * PI: Safaierad, Reza (https://orcid.org/0000-0002-8295-2560, safaierad.reza@gmail.com) * METHOD/DEVICE: Age, Bayesian based model Plum on Pb-210 and C-14 data (URI: https://doi.org/10.1007/s13253-018-0328-7)
	δ18O [‰] (δ18O) * PI: Safaierad, Reza (https://orcid.org/0000-0002-8295-2560, safaierad.reza@gmail.com) * METHOD/DEVICE: Mass spectrometer, Finnigan, MAT 252 * COMMENT: Relative to VPDB
	δ18O, standard deviation [±] (δ18O std dev) * PI: Safaierad, Reza (https://orcid.org/0000-0002-8295-2560, safaierad.reza@gmail.com) * METHOD/DEVICE: Mass spectrometer, Finnigan, MAT 252 * COMMENT: Relative to VPDB
	δ13C [‰ PDB] (δ13C) * PI: Safaierad, Reza (https://orcid.org/0000-0002-8295-2560, safaierad.reza@gmail.com) * METHOD/DEVICE: Mass spectrometer, Finnigan, MAT 252 * COMMENT: Relative to VPDB
	δ13C, standard deviation [±] (δ13C std dev) * PI: Safaierad, Reza (https://orcid.org/0000-0002-8295-2560, safaierad.reza@gmail.com) * METHOD/DEVICE: Mass spectrometer, Finnigan, MAT 252 * COMMENT: Relative to VPDB
License:	Creative Commons Attribution 4.0 International (CC-BY-4.0) (URI: https://creativecommons.org/licenses/by/4.0/)
Status:	Curation Level: Enhanced curation (URI: https://wiki.pangaea.de/wiki/Curation_levels)
Size:	228 data points
*/
Depth sed [m]	Age [ka BP]	δ18O [‰]	δ18O std dev [±]	δ13C [‰ PDB]	δ13C std dev [±]
0.005	-0.0670	3.190	0.06	4.690	0.06
0.015	-0.0560	2.897	0.06	4.617	0.06
0.025	-0.0450	2.336	0.06	4.507	0.06
0.035	-0.0360	2.357	0.06	4.895	0.06
0.045	-0.0270	2.039	0.06	4.715	0.06
0.055	-0.0180	1.432	0.06	4.497	0.06
0.065	-0.0060	1.687	0.06	4.712	0.06
0.075	0.0050	1.429	0.06	4.627	0.06
0.085	0.0170	1.593	0.06	4.673	0.06
0.095	0.0350	1.445	0.06	4.708	0.06
0.105	0.0600	1.019	0.06	4.449	0.06
0.115	0.0910	1.553	0.06	4.821	0.06
0.125	0.1260	1.268	0.06	4.594	0.06
0.135	0.1640	1.562	0.06	4.636	0.06
0.150	0.2230	1.717	0.06	4.573	0.06
0.155	0.2430	1.992	0.06	4.487	0.06
0.170	0.3007	2.132	0.06	4.565	0.06
0.180	0.3387	2.023	0.06	4.590	0.06
0.190	0.3773	1.482	0.06	4.140	0.06
0.200	0.4165	1.189	0.06	4.113	0.06
0.210	0.4576	1.362	0.06	4.161	0.06
0.220	0.5016	0.820	0.06	3.743	0.06
0.230	0.5510	0.660	0.06	3.724	0.06
0.240	0.6122	1.287	0.06	4.094	0.06
0.250	0.7063	1.703	0.06	4.345	0.06
0.260	0.8288	2.039	0.06	4.349	0.06
0.270	0.9768	2.129	0.06	4.387	0.06
0.280	1.1364	2.214	0.06	4.349	0.06
0.290	1.3018	2.225	0.06	4.503	0.06
0.300	1.4678	2.340	0.06	4.572	0.06
0.310	1.6331	1.532	0.06	4.353	0.06
0.320	1.7919	1.230	0.06	4.328	0.06
0.330	1.9512	1.262	0.06	4.225	0.06
0.340	2.0954	1.472	0.06	4.503	0.06
0.350	2.2365	1.275	0.06	4.207	0.06
0.360	2.3738	1.104	0.06	4.074	0.06
0.370	2.5089	1.403	0.06	4.393	0.06
0.380	2.6415	1.455	0.06	4.430	0.06
0.390	2.7730	1.490	0.06	4.264	0.06
0.400	2.9040	1.685	0.06	4.417	0.06
0.410	3.0403	1.173	0.06	4.361	0.06
0.420	3.1772	1.182	0.06	4.216	0.06
0.430	3.3112	0.954	0.06	3.884	0.06
0.440	3.4451	1.037	0.06	4.115	0.06
0.450	3.5797	1.503	0.06	4.131	0.06
0.460	3.7111	1.320	0.06	4.261	0.06
0.470	3.8415	1.712	0.06	4.282	0.06
0.480	3.9724	1.453	0.06	4.269	0.06
0.490	4.1015	1.071	0.06	4.084	0.06
0.500	4.2287	1.381	0.06	4.263	0.06
0.510	4.3515	0.786	0.06	4.121	0.06
0.520	4.4590	1.232	0.06	4.129	0.06
0.530	4.5626	1.168	0.06	4.164	0.06
0.540	4.6645	1.092	0.06	4.093	0.06
0.550	4.7673	1.207	0.06	4.076	0.06
0.560	4.8680	1.105	0.06	4.104	0.06
0.570	4.9690	1.214	0.06	4.241	0.06