New insights from western Latvia into Holocene spatial and temporal patterns of tufa deposition in central European alkaline fens

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ABSTRACT We present a sediment record from the Maitiku Springs alkaline spring‐fed fen in western Latvia, documenting the history of fen development and CaCO 3 precipitation. Our ultimate goal is to determine whether new data from this previously underexplored eastern Baltic region align with spatial and temporal patterns of tufa deposition in Central Europe. Our analysis integrates geochemical proxies, palaeobiological data and radiocarbon‐dated terrestrial plant macrofossils recovered from two sediment cores extracted from the fen dome's top and slope. The Maitiku fen has been active since approximately 9.4 ka BP and shows two main phases of intensive CaCO 3 precipitation: between 6.3 and 5.2 ka BP, and from around 3.6 ka BP to the present. These results support the view that, in the eastern Baltic, CaCO 3 precipitation was largely limited during the Holocene Thermal Maximum (HTM), with current tufa formation initiating only in the late Holocene (after 5000 cal a BP). This pattern contrasts with that of the southern Baltic region, where the HTM coincided with the peak of tufa deposition, commonly followed by a decline in carbonate precipitation later in the Holocene. We attribute this regional difference primarily to contrasting hydroclimatic conditions during the HTM, linked to frequent anticyclonic circulation over northern Europe.

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