The Gray Fossil Site (GFS) includes multiple karst sub-basins that are filled with lacustrine sediments. Early paleontologic work on one of the sub-basins (GFS-2) indicates a late Miocene/early Pliocene age based on an assemblage of well-preserved vertebrate fossils. However, detailed palynological analysis of the 38.7. m deep GFS-1 core recovered from another sub-basin indicates an older age. The presence of Caryapollenites imparalis, C. inelegans and C. prodromus association suggests a Paleocene to Eocene age for the GFS-1 core section. This age is also supported by the absence of pollen of the Poaceae, the grass family that is not commonly present until the Neogene. Age constraints from palynologic data suggest that the GFS has a more complex basin-fill history than previously suspected, and that multiple depo-centers within the basin may have been periodically active through the Cenozoic. Palynofacies analysis of the GFS-1 core indicates that phytoclasts and opaques are the most abundant organic constituents and have diluted both the palynomorph population and amorphous organic matter. Two possible scenarios can account for this observation: 1) an oxidizing depositional paleoenvironment; and 2) a localized high flux of charcoal following wildfires and subsequent increased runoff.

This study aimed to investigate the influence of historical peat mining on current sedimentation and sediment quality in Håtjärnen, Håsjön and primarily Yttersjön. One sediment sample were collected from Håtjärnen and from Håsjön, along with 23 additional samples from Yttersjön. Sampling sites in Yttersjön were strategically located from upstream to downstream, near an inlet draining the nearest peat mining site, to assess its impact on sediment composition. This study analyzed subaqueous sediments, which consists of three constituents: minerogenic material, organic material (OM), and biogenic silica (Si). The sediment geochemistry was analyzed through loss on ignition, X-ray fluorescence, Near Infrared spectroscopy, Si/Al-ratio and lastly C/N ratio serving as a proxy for the origin of OM. No patterns in variation were observed in OM, Si/Al ratio, chlorophyll content, or C/N ratios between the upstream and downstream samples in Yttersjön, suggesting that the peat drainage inlet has a negligible impact on the sediment composition. In comparison, Håtjärnen and Håsjön displayed similar compositions of the sediment. An earlier study conducted in this area reported high sediment accumulation rates for the lakes investigated, as well as a substantial organic composition that included peat residues. These new findings, which contradict the earlier study, highlights the importance of analyzing all constituents of sediment to obtain a comprehensive understanding of the sediment composition.

Wetlands play a crucial role not only as significant carbon sinks but also as natural archives of environmental and cultural history. However, investigating wetland sediments is challenging due to their complex stratigraphy and sensitive waterlogged conditions, requiring a specialised approach to subsurface exploration. This thesis investigates a unique wetland site using a multi-method approach that combines Electromagnetic Induction (EMI), Electrical Resistivity Tomography (ERT), Direct Push (DP) sensing, and core drilling. The research comprehensively analyses the Holocene depositional history and evaluates the carbon storage capacity of the Verlorener Bach and Loosbach valley in the Bavarian Alpine foothills, with a focus on the Late Neolithic wetland settlement of Pestenacker, a UNESCO World Heritage site. i) Three primary stratigraphic units were identified: Pleistocene gravel deposits (unit I), organic- rich peat layers with freshwater carbonates (unit II), and overbank deposits with associated redeposited carbonates (unit III). EMI and ERT provided high-resolution spatial and vertical insights into the distribution and thickness of these units, leading to the creation of a validated 3D model of sediment stratigraphy. This revealed key transitions, including a significant Mid Holocene hydrological shift that halted peat formation in unit II. ii) Hydrological changes during the Mid Holocene were particularly influential in shaping the valley's stratigraphy. Increased precipitation and groundwater levels led to stream incision into the valley floor, which caused the drainage of peatlands (unit II) and the deposition of overbank deposits in unit III. These changes interrupted the accumulation of peat in unit II, transforming the landscape from a waterlogged, peat-forming environment into one dominated by fluvial processes and overbank deposits. This hydrological shift not only impacted peat development but also contributed to the environmental conditions that allowed for the Neolithic settlement of Pestenacker. iii) Geochemical analysis quantified the Total Carbon (TC) and Total Organic Carbon (TOC) stored in unit II and III. The peat layers in unit II were found to contain an estimated 43 kt of TC and 35 kt of TOC across the 15-hectare study area. These high carbon values highlight the importance of the peatlands as significant carbon sinks, due to their ability to store large amounts of organic material. The carbon content of the peat is closely linked to the waterlogged conditions that prevent the oxidation and decomposition of organic matter. These findings not only emphasize the role of this wetland in carbon storage but also underline its vulnerability to environmental changes that can lead to carbon release.:Acknowledgements Abstract Kurzfassung Table of content List of Figures List of Tables Acronyms and Symbols 1. Introduction 1.1 Investigating Wetlands – Significances, Challenges and Advancements 1.1.1 Importance of Wetlands as Environmental and Cultural Archives 1.1.2 Challenges in Investigating Wetlands 1.1.3 Multi-Method Investigation Approach 1.2 The Study Site 1.2.1 The Neolithic Settlement Site of Pestenacker 1.2.2 Geographical setting 1.3 Thesis Objectives 2. Published Studies 2.1 Compilation of different data sets of the Late Neolithic wetland site of Pestenacker and of the adjacent valley depositions 2.2 A hydrological tipping point and onset of Neolithic wetland occupation in Pestenacker (Lech catchment, S Germany) 2.3 Determining carbon storage of a complex peat stratigraphy using non- and minimal-invasive geophysical prospection techniques (Verlorener Bach and Loosbach valleys, southern Germany) 3. Discussion 3.1 Methodological Advancements: The Strength of a Multi-Method Approach 3.2 Stratigraphic Evolution of the Study Area 3.2.1 First stratigraphic shift: From the Pleistocene to the Early Holocene 3.2.2 Second stratigraphic Shift: The Mid Holocene Hydrological Tipping Point 3.3 Carbon Storage in Wetlands 3.4 Future Research Directions 3.4.1 Enhanced Direct Push Capabilities 3.4.2 Future Directions in Geoarchaeological Methods in Pestenacker 3.4.3 Long-term Monitoring of Hydrological Dynamics 4. Conclusion References Appendix A1 Summary of the Thesis A2 Author's List of Publications A3 Information of the Thesis and Overview of included contributions A4 Declaration of Independent Work A5 Bibliographic Description A6 Curriculum Vitae / Feuchtgebiete spielen eine zentrale Rolle, nicht nur als bedeutende Kohlenstoffsenken, sondern auch als natürliche Archive für Umwelt- und Kulturgeschichte. Die Untersuchung von Feuchtbodensedimenten ist jedoch aufgrund ihrer komplexen Stratigraphie und empfindlichen, wasserreichen Bedingungen eine Herausforderung und erfordert angepasste Erkundungsmethoden. Diese Arbeit untersucht ein besonderes Feuchtgebiet mithilfe eines multimethodischen Ansatzes, der die Ergebnisse der elektromagnetischen Induktion (EMI), der elektrischen Widerstandstomographie (ERT), der Direct-Push-Technologie und klassischer Bohrkernuntersuchungen kombiniert. Die Studie analysiert umfassend die holozäne Talentwicklung und bewertet das Kohlenstoffspeicherpotenzial des Talsystems des Verlorenen Bachs und Loosbachs im bayerischen Alpenvorland. Im Fokus steht dabei die jungneolithische Feuchtbodensiedlung Pestenacker, eine UNESCO-Weltkulturerbestätte. i) Es werden drei primäre stratigraphische Einheiten identifiziert: pleistozäne glazi-fluviale Kiese (unit I), Niedermoortorfe mit Frischwassercarbonaten (unit II) und Überflutungssedimenten (unit III). Mithilfe von EMI und ERT lassen sich hochauflösende räumliche und vertikale Einblicke in die Verteilung und Mächtigkeit dieser Einheiten gewinnen, was zur Erstellung eines validierten 3D- Modells der Sedimentstratigraphie führt. Dabei werden bedeutende Übergänge sichtbar, darunter ein Kipppunkt im Mittleren Holozän, der die Torfbildung in unit II zum Stillstand bringt. ii) Die hydrologischen Veränderungen während des Mittleren Holozäns hatten einen besonders starken Einfluss auf die Entwicklung der Talstratigraphie. Erhöhte Niederschläge und steigende Grundwasserstände führten zur Eintiefung der Bäche in den Talboden, was die Entwässerung der Niedermoortorfe und die Ablagerung der Sedimente in unit III zur Folge hat. Diese Veränderungen beenden die Torfbildung in unit II und verwandelten die Landschaft von einem wasserreichen Niedermoor in ein von Überflutungssedimenten und Flussaktivitäten geprägtes Gebiet. Dieser hydrologische Wandel schuf die Umweltbedingungen, die es den Menschen der Altheimer Kultur ermöglichen, in diesem Gebiet zu siedeln. iii) Geochemische Analysen zeigen, dass die Torfschichten in unit II schätzungsweise 43 kt an Kohlenstoff (TC) und 35 kt an organischen Kohlenstoff (TOC) auf der 15 Hektar großen Untersuchungsfläche speichern. Diese hohen Kohlenstoffgehalte unterstreichen die Bedeutung der Niedermoortorfe als Kohlenstoffsenken, da sie in der Lage sind, große Mengen organischen Materials zu speichern. Der Kohlenstoffgehalt des Torfs ist eng mit den wasserreichen Bedingungen verknüpft, die die Oxidation und den Abbau organischer Substanzen verhindern. Diese Ergebnisse betonen nicht nur die Rolle dieses Feuchtgebietes bei der Kohlenstoffspeicherung, sondern auch seiner Anfälligkeit gegenüber Umweltveränderungen, die zur Freisetzung von gespeichertem Kohlenstoff führen könnten.:Acknowledgements Abstract Kurzfassung Table of content List of Figures List of Tables Acronyms and Symbols 1. Introduction 1.1 Investigating Wetlands – Significances, Challenges and Advancements 1.1.1 Importance of Wetlands as Environmental and Cultural Archives 1.1.2 Challenges in Investigating Wetlands 1.1.3 Multi-Method Investigation Approach 1.2 The Study Site 1.2.1 The Neolithic Settlement Site of Pestenacker 1.2.2 Geographical setting 1.3 Thesis Objectives 2. Published Studies 2.1 Compilation of different data sets of the Late Neolithic wetland site of Pestenacker and of the adjacent valley depositions 2.2 A hydrological tipping point and onset of Neolithic wetland occupation in Pestenacker (Lech catchment, S Germany) 2.3 Determining carbon storage of a complex peat stratigraphy using non- and minimal-invasive geophysical prospection techniques (Verlorener Bach and Loosbach valleys, southern Germany) 3. Discussion 3.1 Methodological Advancements: The Strength of a Multi-Method Approach 3.2 Stratigraphic Evolution of the Study Area 3.2.1 First stratigraphic shift: From the Pleistocene to the Early Holocene 3.2.2 Second stratigraphic Shift: The Mid Holocene Hydrological Tipping Point 3.3 Carbon Storage in Wetlands 3.4 Future Research Directions 3.4.1 Enhanced Direct Push Capabilities 3.4.2 Future Directions in Geoarchaeological Methods in Pestenacker 3.4.3 Long-term Monitoring of Hydrological Dynamics 4. Conclusion References Appendix A1 Summary of the Thesis A2 Author's List of Publications A3 Information of the Thesis and Overview of included contributions A4 Declaration of Independent Work A5 Bibliographic Description A6 Curriculum Vitae