The North African desert margin is considered one of the areas most sensitive to future climate changes. Improved knowledge about Holocene climatic variability and environmental responses on millennial to centennial scale will help to refine scenarios related to future climate changes. This data set presents calibrated XRF core scanning data (Ca, Sr, Fe, Mn, S, K, Ti) of a ~20 m long Holocene lake sediment sequence from Lake Sidi Ali located in the Middle Atlas, Morocco. The ITRAX core scanner measurements were obtained every 1 mm and calibrated with depth equal quantitative Spectro Xepos XRF data (see. Schmidt et al. 2023, doi:10.1594/PANGAEA.960365) using the multivariate log-ratio calibration model of Weltje et al. 2015 (doi:10.1007/978-94-017-9849-5_21). According to the 210Pb and pollen-based 14C chronology, the calibrated XRF scanning data have a c. annual temporal resolution.

Palynological and X-Ray fluorescence (XRF) data from Tenaghi Philippon (Greece) were generated to reconstruct climate and environmental changes in the Mediterranean region during the past 500 kyrs. The analyses were carried out on peat drillcores from two locations, i.e., TP-2005 – 40° 58' 24.0” N, 24° 13' 25.2” E; TP-2009 – 40° 57' 39.5” N, 24° 16' 03.1” E. A total of 2347 palynological samples, taken every 2-5 cm from the 4–91 m composite depth, were prepared using standard palynological techniques. Pollen percentages were calculated on the number of pollen grains from terrestrial plants excluding Cyperaceae and Poaceae because of their natural over-representation at Tenaghi Philippon. The palynological results present relative abundances of tree pollen, tree pollen without Pinus, temperate taxa, Mediterranean taxa, montane taxa, pioneer taxa, shrubs, steppic taxa, herbs, helophytes, sum of Poaceae and Cyperaceae, aquatic taxa, spores and algae. The XRF core scanning was performed with an AVAATECH (GEN-4) scanner at 5 mm resolution using a 10 kV energy level without filter, a current of 200 mA, and a counting time of 10 s. The geochemical results include the Si normalised counts and the log(Ca/Fe) ratio.

The North African desert margin is considered one of the areas most sensitive to future climate changes. Improved knowledge about Holocene climatic variability and environmental responses on millennial to centennial scale will help to refine scenarios related to future climate changes. This data set presents 198 bulk sample-based Spectro Xepos XRF measurements. Bulk samples from the recovered cores were analysed using a Spectro Xepos X-ray fluorescence instrument. For the XRF sample preparation, air-dried bulk material (4 g) was sieved (2 mm). The sample was then homogenised using a Retsch vibrating mill MM 200. Pressed pellets were produced with a Vaneox press at 20 t for 2 min. The measurements were carried out in a He atmosphere.

Palynological and X-Ray fluorescence (XRF) data from Tenaghi Philippon (Greece) were generated to reconstruct climate and environmental changes in the Mediterranean region during the past 500 kyrs. The analyses were carried out on peat drillcores from two locations, i.e., TP-2005 – 40° 58' 24.0” N, 24° 13' 25.2” E; TP-2009 – 40° 57' 39.5” N, 24° 16' 03.1” E. A total of 2347 palynological samples, taken every 2-5 cm from the 4–91 m composite depth, were prepared using standard palynological techniques. Pollen percentages were calculated on the number of pollen grains from terrestrial plants excluding Cyperaceae and Poaceae because of their natural over-representation at Tenaghi Philippon. The palynological results present relative abundances of tree pollen, tree pollen without Pinus, temperate taxa, Mediterranean taxa, montane taxa, pioneer taxa, shrubs, steppic taxa, herbs, helophytes, sum of Poaceae and Cyperaceae, aquatic taxa, spores and algae. The XRF core scanning was performed with an AVAATECH (GEN-4) scanner at 5 mm resolution using a 10 kV energy level without filter, a current of 200 mA, and a counting time of 10 s. The geochemical results include the Si normalised counts and the log(Ca/Fe) ratio.

Raw data for the Beliche-Guadiana pollen dataset submitted to the Neotoma Paleoecology Database. Data is available through the landing page in JSON format. The landing page referenced by the DOI also contains links to publications and a map-based viewer for the dataset. The Neotoma Paleoecology Database maintains a homepage at https://www.neotomadb.org.

AbstractData provided here includes a Holocene diatom and pollen record from Moss Lake, Washington, USA (N 47o 41' 35.7" W 121o 50' 48.6"). Cores from Moss Lake were collected in 2014 and contain tephra deposits from Mount Mazama and Glacier Peak. Investigations have been carried out on the impact of tephra deposition, but this publication analyses the whole Holocene record. Included in this data set are the raw diatom and pollen counts, sedimentary analyses including Loss on Ignition (raw and interpolated values) and magnetic susceptibility (using a loop scanner), and Radiocarbon dates including the output from an age/depth model created using OxCal. Abstract A diatom record spanning the last 14,500 cal yr BP from Moss Lake, Washington, USA is used to assess Holocene climate change in the Pacific Northwest including evidence for periodicities related to atmospheric-ocean interactions and/or variations in solar output and is directly compared to the pollen record from the same site. Three main climate phases were identified: (i) the Late Pleistocene (until 11,800 Cal yr BP, GI-1, GS-1), with a cold climate evidenced by the low abundance of diatoms; (ii) Greenlandian/early Northgrippian (11,800 - 7500 Cal yr BP), with a shift to a warmer climate,; and (iii) late Northgrippian and Meghalayan from 7500 Cal yr BP onwards, with a cooler and moist climate. These climate shifts are in good agreement with the pollen record of Moss Lake and other records from the region. Fluctuations in Discostella pseudostelligera and Aulacoseira taxa suggest climatic cycles of varying amplitude throughout the assemblage and are conceptually linked to ENSO/PDO like cycles. Spectral analyses revealed periodicities of approximately 2100 yrs, 1400 yrs, and 450 yrs. The ~2100 yr cycle is attributed to solar variation, particularly the Hallstatt Oscillation. Both the ~1400 yr and ~450 yr cycles are attributed to ENSO and PDO like cycles. The ~1400 periodicity is evident throughout the Late Pleistocene and late Northgrippian/Meghalayan reflecting high amplitude shifts from El Niño/positive PDO (weak wind intensity) to La Niña/Negative PDO (high wind intensity). The cycle amplitudes are reduced during the Greenlandian and occur on a 450-year cycle. ENSO suppression is recorded throughout the Pacific Northwest, but most state it occurred during the Northgrippian, suggesting the diatom record from Moss Lake is modulated by endogenic processes during this time. Diatom data from Moss Lake has helped to refine our understanding of Holocene climate change and ENSP/PDO in the Pacific Northwest.

AbstractData provided here includes a Holocene diatom and pollen record from Moss Lake, Washington, USA (N 47o 41' 35.7" W 121o 50' 48.6"). Cores from Moss Lake were collected in 2014 and contain tephra deposits from Mount Mazama and Glacier Peak. Investigations have been carried out on the impact of tephra deposition, but this publication analyses the whole Holocene record. Included in this data set are the raw diatom and pollen counts, sedimentary analyses including Loss on Ignition (raw and interpolated values) and magnetic susceptibility (using a loop scanner), and Radiocarbon dates including the output from an age/depth model created using OxCal. Abstract A diatom record spanning the last 14,500 cal yr BP from Moss Lake, Washington, USA is used to assess Holocene climate change in the Pacific Northwest including evidence for periodicities related to atmospheric-ocean interactions and/or variations in solar output and is directly compared to the pollen record from the same site. Three main climate phases were identified: (i) the Late Pleistocene (until 11,800 Cal yr BP, GI-1, GS-1), with a cold climate evidenced by the low abundance of diatoms; (ii) Greenlandian/early Northgrippian (11,800 - 7500 Cal yr BP), with a shift to a warmer climate,; and (iii) late Northgrippian and Meghalayan from 7500 Cal yr BP onwards, with a cooler and moist climate. These climate shifts are in good agreement with the pollen record of Moss Lake and other records from the region. Fluctuations in Discostella pseudostelligera and Aulacoseira taxa suggest climatic cycles of varying amplitude throughout the assemblage and are conceptually linked to ENSO/PDO like cycles. Spectral analyses revealed periodicities of approximately 2100 yrs, 1400 yrs, and 450 yrs. The ~2100 yr cycle is attributed to solar variation, particularly the Hallstatt Oscillation. Both the ~1400 yr and ~450 yr cycles are attributed to ENSO and PDO like cycles. The ~1400 periodicity is evident throughout the Late Pleistocene and late Northgrippian/Meghalayan reflecting high amplitude shifts from El Niño/positive PDO (weak wind intensity) to La Niña/Negative PDO (high wind intensity). The cycle amplitudes are reduced during the Greenlandian and occur on a 450-year cycle. ENSO suppression is recorded throughout the Pacific Northwest, but most state it occurred during the Northgrippian, suggesting the diatom record from Moss Lake is modulated by endogenic processes during this time. Diatom data from Moss Lake has helped to refine our understanding of Holocene climate change and ENSP/PDO in the Pacific Northwest.

Diatom preparation followed a standard procedure (Battarbee, 1986), and followed Renberg's (1990) recommendation of bulk preparation using a water-bath. Microspheres were added to each sample to determine diatom concentration (Battarbee and Kneen, 1982). The concentration of microspheres added was 2 ml of 5.01x10^6 per 0.01 g dry weight of sediment. The samples were then diluted, placed on a cover slip and mounted to the microscope slide using Naphrax®. Diatoms were identified and counted at 1000x magnification. Identification was aided by the website “Diatoms of the United States” (Spaulding, 2014) and identification keys (Krammer and Lange-Bertalot, 1991, 1999a,b). At least 300 diatom frustules were counted per slide.

Samples were prepared for pollen analysis as follows. A volume of 0.6 ml of each sample was prepared in seven steps following Moore et al. (1991): i) adding HCl, ii) sieving at 180 µm to ensure larger conifer pollen was included, iii) KOH digestion, iv) HF to remove silicates (Heusser and Stock, 1984), v) acetolysis, vi) alcohol dehydration, vii) and mounted in silicone oil. At least 300 terrestrial pollen grains were counted for each sample.

Accelerator mass spectrometry (AMS) radiocarbon dates were obtained for eight bulk sediment samples (pre-treated with HCl) at the NERC Radiocarbon Facility in East Kilbride. An age-depth model was constructed through Bayesian modelling using a P_sequence deposition model in OxCal v.4.2.4, which included an “event free depth scale” (Staff et al., 2011) to account for the instantaneous deposition of a 4 cm thick tephra layer and interpolated ages every 1 cm.