/* DATA DESCRIPTION:
Citation:	Rantala, Marttiina V; Israde-Alcántara, Isabel; Safaierad, Reza; Mattielli, Nadine; Tylmann, Wojciech; Smol, John P; Grooms, Christopher; Lepoint, Gilles; Francus, Pierre; Metcalfe, Sarah; Etmański, Paweł; Fagel, Nathalie (2026): Downcore sediment biogeochemical and physical data from Lake Alchichica (Puebla, Mexico) [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.990132
Abstract:	Multiproxy biogeochemical and physical data of sediment core LAc22-1 retrieved from Lake Alchichica in April 2022. Measurements (elemental and isotope biogeochemistry, visible range spectroscopy, loss on ignition) were performed on discrete sediment samples and extend back to the late 1800s. Ages were estimated using Pb-210 dating and Bayesian age-depth modeling.
Keyword(s):	Anthropocene; biogeochemistry; Carbon accumulation; crater lake; Lake sediment; Mexico; Primary production; Tropical
Supplement to:	Rantala, Marttiina V; Israde-Alcántara, Isabel; Safaierad, Reza; Mattielli, Nadine; Tylmann, Wojciech; Smol, John P; Grooms, Christopher; Lepoint, Gilles; Francus, Pierre; Metcalfe, Sarah; Etmański, Paweł; Fagel, Nathalie (2026): Increasing lake primary production and organic carbon sequestration in tropical Mexican lakes during the past century. CATENA, 273, 110448, https://doi.org/10.1016/j.catena.2026.110448
References:	Aquino-Lopez, Marco A; Blaauw, Maarten; Christen, Andrés; Sanderson, Nicole K (2018): Bayesian Analysis of 210Pb Dating. Journal of Agricultural Biological and Environmental Statistics, 23(3), 317-333, https://doi.org/10.1007/s13253-018-0328-7
	Heiri, Oliver; Lotter, André F; Lemcke, G (2001): Loss on ignition as a method for estimating organic and carbonate content in sediments: reproducibility and comparability of results. Journal of Paleolimnology, 25(1), 101-110, https://doi.org/10.1023/A:1008119611481
	Zhang, Fule; Wang, Jinlong; Baskaran, Mark; Zhong, Qiangqiang; Wang, Yali; Paatero, Jussi; Du, Jinzhou (2021): A global dataset of atmospheric 7Be and 210Pb measurements: annual air concentration and depositional flux. Earth System Science Data, 13(6), 2963-2994, https://doi.org/10.5194/essd-13-2963-2021
Funding:	Fonds de la Recherche Scientifique (FNRS), grant/award no. PDR T.0079.21: Holocene Mexican Crater Lakes and Climate (HolMeCl)
Coverage:	LATITUDE: 19.410556 * LONGITUDE: -97.403889
	DATE/TIME START: 2022-04-12T00:00:00 * DATE/TIME END: 2022-04-12T00:00:00
	MINIMUM DEPTH, sediment/rock: 0.0025 m * MAXIMUM DEPTH, sediment/rock: 0.1425 m
Event(s):	LAc22-1 * LATITUDE: 19.410556 * LONGITUDE: -97.403889 * DATE/TIME: 2022-04-12T00:00:00 * ELEVATION: 2322.0 m * LOCATION: Lake Alchichica, Puebla, Mexico * METHOD/DEVICE: Sediment corer, UWITEC
Parameter(s):	DEPTH, sediment/rock [m] (Depth sed) * GEOCODE * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * COMMENT: Middle depth of sediment section.
	Depth, sediment/rock, top/minimum [m] (Depth sed top) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * COMMENT: Top depth of sediment section.
	Depth, sediment/rock, bottom/maximum [m] (Depth sed bot) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * COMMENT: Bottom depth of sediment section.
	Age [a AD/CE] (Age) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Bayesian age model, according to Aquino-López et al. (2018) (URI: https://doi.org/10.1007/s13253-018-0328-7) * COMMENT: Mean age for middle depth of sediment section, Plum version 0.5.1 by Aquino-López et al. (2018 , doi:10.1007/s13253-018-0328-7).
	AGE [ka BP] (Age) * GEOCODE * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com)
	Organic matter [%] (OM) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Determined by loss on ignition at 550 °C, according to Heiri et al. (2010) (URI: https://doi.org/10.1023/A:1008119611481)
	Carbonates [%] (Carb) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Determined by loss on ignition at 950 °C, according to Heiri et al. (2010) (URI: https://doi.org/10.1023/A:1008119611481)
	Density, dry bulk [g/cm**3] (DBD) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Calculated, see Comment * COMMENT: Mass of dry sediment divided by wet sediment volume (1 cm³).
	Sedimentation rate per year [cm/a] (SR) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Calculated, see Comment * COMMENT: Sediment section thickness divided by elapsed time.
	Accumulation rate, mass, per year [g/cm**2/a] (MAR) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Calculated, see Comment * COMMENT: Dry bulk density multiplied by sediment accumulation rate.
	Accumulation rate, mass, carbon, organic, total [g/m**2/a] (MAR TOC) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Calculated, see Comment * COMMENT: Sediment organic carbon content multiplied by mass accumulation rate.
	Accumulation rate, mass, carbon, organic, total [g/m**2/a] (MAR TOC) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Calculated, see Comment * COMMENT: Sediment organic carbon content multiplied by mass accumulation rate. Values corrected for sediment focusing based on measured unsupported 210Pb flux in the sediment core and atmospheric 210Pb flux estimated based on mean annual precipitation and Zhang et al. (2021, doi:10.5194/essd-13-2963-2021) equations for latitudinal bands 10-20°N and 20-30°N.
	Carbon, organic, total [%] (TOC) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Elemental analyzer (EA), Elementar, vario MICRO cube
	Nitrogen, total [%] (TN) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Elemental analyzer (EA), Elementar, vario MICRO cube
	δ13C [‰] (δ13C) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Isotope ratio mass spectrometer (IRMS), Elementar, isoprime precisION * COMMENT: Values from acidified samples.
	δ15N [‰] (δ15N) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Isotope ratio mass spectrometer (IRMS), Elementar, isoprime precisION * COMMENT: Values from nonacidified samples.
	Carbon/Nitrogen ratio [mol/mol] (C/N) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Elemental analyzer (EA), Elementar, vario MICRO cube * COMMENT: Calculated based on values from acidified samples for both elements, mass ratio multiplied by 1.167.
	Chlorophyll a, per dry mass [mg/g] (Chl a/dm) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Visible-near infrared spectroscopy, Foss NIRsystems, Model 6500 Rapid Content Analyzer
	Chlorophyll a, z-score (Chl a z) * PI: Rantala, Marttiina V (https://orcid.org/0000-0002-3231-5926, marttiina.rantala@gmail.com) * METHOD/DEVICE: Visible-near infrared spectroscopy, Foss NIRsystems, Model 6500 Rapid Content Analyzer * COMMENT: Initial values z-score transformed.
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:	423 data points
*/
Depth sed [m] (Middle depth of sediment sect...)	Depth sed top [m] (Top depth of sediment section.)	Depth sed bot [m] (Bottom depth of sediment sect...)	Age [a AD/CE] (Mean age for middle depth of ...)	Age [ka BP]	OM [%] (Determined by loss on ignitio...)	Carb [%] (Determined by loss on ignitio...)	DBD [g/cm**3] (Mass of dry sediment divided ...)	SR [cm/a] (Sediment section thickness di...)	MAR [g/cm**2/a] (Dry bulk density multiplied b...)	MAR TOC [g/m**2/a] (Sediment organic carbon conte...)	MAR TOC [g/m**2/a] (Sediment organic carbon conte...)	TOC [%] (Elemental analyzer (EA), Elem...)	TN [%] (Elemental analyzer (EA), Elem...)	δ13C [‰] (Values from acidified samples...)	δ15N [‰] (Values from nonacidified samp...)	C/N [mol/mol] (Calculated based on values fr...)	Chl a/dm [mg/g] (Visible-near infrared spectro...)	Chl a z (Initial values z-score transf...)
0.0025	0.000	0.005	2019.8	-0.070	21.43	11.23	0.550	0.102	0.058	33.71	12.47	6.01	0.49	-24.99	6.48	9.48	0.117	2.01
0.0075	0.005	0.010	2015.0	-0.065			0.551	0.104	0.059	35.51	13.14	6.19	0.43	-25.03	6.19	9.76		
0.0125	0.010	0.015	2010.1	-0.060	17.35	13.07	0.552	0.100	0.057	28.36	10.49	5.14	0.39	-24.81	5.89	10.00		
0.0175	0.015	0.020	2005.1	-0.055			0.553	0.102	0.058	25.34	9.38	4.49	0.35	-24.54	5.87	10.08		
0.0225	0.020	0.025	2000.3	-0.050	17.12	13.00	0.554	0.102	0.060	23.76	8.79	4.20	0.32	-24.11	5.55	10.21	0.090	0.76
0.0275	0.025	0.030	1995.4	-0.045			0.508	0.104	0.055	21.90	8.10	4.14	0.31	-24.23	5.62	10.28		
0.0325	0.030	0.035	1991.4	-0.041	15.03	13.54	0.461	0.156	0.074	27.31	10.10	3.79	0.29	-24.11	5.60	10.29		
0.0375	0.035	0.040	1988.2	-0.038			0.460	0.156	0.074	26.74	9.89	3.72	0.32	-24.08	5.56	10.10		
0.0425	0.040	0.045	1984.7	-0.035	14.89	13.64	0.459	0.132	0.064	22.88	8.47	3.79	0.29	-24.05	5.52	10.53	0.082	0.36
0.0475	0.045	0.050	1980.9	-0.031			0.472	0.132	0.064	22.73	8.41	3.66	0.29	-23.94	5.40	10.42		
0.0525	0.050	0.055	1977.1	-0.027	14.68	13.21	0.485	0.128	0.067	22.26	8.24	3.58	0.29	-23.97	5.68	10.44		
0.0575	0.055	0.060	1973.2	-0.023			0.451	0.132	0.061	22.14	8.19	3.73	0.30	-23.88	5.57	10.36		
0.0625	0.060	0.065	1969.1	-0.019	13.52	14.90	0.417	0.114	0.051	16.73	6.19	3.53	0.29	-23.92	5.61	10.30	0.069	-0.25
0.0675	0.065	0.070	1964.7	-0.015			0.399	0.114	0.049	17.74	6.56	3.91	0.29	-23.81	5.67	10.61		
0.0725	0.070	0.075	1960.7	-0.011	13.45	14.37	0.382	0.143	0.058	21.96	8.13	4.03	0.28	-23.07	5.54	11.20		
0.0775	0.075	0.080	1957.2	-0.007			0.398	0.139	0.058	20.65	7.64	3.74	0.28	-23.80	6.03	10.39		
0.0825	0.080	0.085	1953.2	-0.003	12.92	12.76	0.413	0.111	0.049	16.72	6.19	3.64	0.26	-23.87	5.91	10.11	0.062	-0.58
0.0875	0.085	0.090	1948.6	0.001			0.450	0.109	0.054	18.23	6.75	3.73	0.27	-23.89	6.12	10.36		
0.0925	0.090	0.095	1943.7	0.006	12.65	14.69	0.486	0.094	0.051	15.91	5.89	3.47	0.26	-23.97	6.12	10.38		
0.0975	0.095	0.100	1938.4	0.012			0.473	0.096	0.048	17.09	6.32	3.76	0.27	-23.95	6.44	10.70		
0.1025	0.100	0.105	1932.7	0.017	13.21	15.15	0.460	0.081	0.041	12.82	4.74	3.46	0.25	-23.86	6.25	10.35	0.059	-0.68
0.1075	0.105	0.110	1926.6	0.023			0.450	0.082	0.040	14.24	5.27	3.86	0.26	-23.69	6.34	10.48		
0.1125	0.110	0.115	1920.4	0.030	13.06	15.19	0.440	0.081	0.039	12.18	4.51	3.43	0.25	-23.54	5.97	10.26		
0.1175	0.115	0.120	1914.2	0.036			0.433	0.079	0.039	13.67	5.06	3.98	0.26	-23.72	5.88	10.56		
0.1225	0.120	0.125	1907.8	0.042	12.61	15.77	0.425	0.078	0.037	11.23	4.15	3.38	0.26	-23.54	5.97	10.38	0.060	-0.64
0.1275	0.125	0.130	1901.3	0.049			0.423	0.077	0.036	11.59	4.29	3.56	0.26	-23.59	5.95	10.13		
0.1325	0.130	0.135	1894.9	0.055	12.54	16.34	0.421	0.077	0.038	10.95	4.05	3.38	0.24	-23.66	5.61	10.11		
0.1375	0.135	0.140	1888.4	0.062			0.416	0.077	0.038	11.37	4.21	3.55	0.24	-23.75	5.94	10.36		
0.1425	0.140	0.145	1881.9	0.068	13.01	16.10	0.411	0.077	0.039	10.72	3.96	3.39	0.23	-23.95	5.70	10.69	0.053	-0.99