Pub Date : 2024-09-14DOI: 10.1177/09596836241275010
Amy Hatton, Paul S Breeze, Maria Guagnin, Faisal al-Jibrin, Abdullah M Alsharekh, Michael Petraglia, Huw S Groucutt
Monumental rectangular stone structures called mustatils are an important emerging feature of the Holocene archaeological record of northwestern Arabia. To date, few have been excavated, with available radiocarbon dates suggesting an age range of ca. 5400–4200 BC. Here we present a rigorous spatial analysis to identify the patterning and landscape context of 169 mustatils in the southern and western margins of the Nefud Desert. This included: (1) a systematic survey of satellite imagery to identify mustatils; (2) viewshed analysis to examine location and landscape visibility; (3) a point process model to understand how diverse environmental and landscape variables affect mustatil locations; (4) mark correlation function to assess spatial patterning of mustatils based on their size. Results indicate that mustatil locations are determined most by proximity to water (likely locations of enhanced surface water occurrence under the enhanced humidity of the Mid-Holocene), on east facing slopes, close to rocky areas, at elevations between 880 and 950 masl, and on or near topographic ridges (positive topographic position index). Viewshed analysis showed that mustatils are preferentially located in areas that have good views, but not the best that are available, indicating complex landscape positioning that balances a range of topographic and behavioural factors. Using a rank permutation method with size (length) of mustatils as a proxy for labour mobilization we show that mustatils within clusters are not arranged hierarchically based on size, and were likely built by non-stratified groups of people. Our analyses show that people were choosing multiple factors when deciding where to build mustatils, and that the distribution of mustatils may relate to different groups of people resulting in the construction of complex ritual landscapes. As one of the earliest examples of large-scale monumental stone structure construction in global prehistory, understanding mustatils can enlighten us on human-environment interaction during the Neolithic.
{"title":"Landscape positioning of Neolithic mustatil stone structures along the margins of the Nefud Desert, Saudi Arabia","authors":"Amy Hatton, Paul S Breeze, Maria Guagnin, Faisal al-Jibrin, Abdullah M Alsharekh, Michael Petraglia, Huw S Groucutt","doi":"10.1177/09596836241275010","DOIUrl":"https://doi.org/10.1177/09596836241275010","url":null,"abstract":"Monumental rectangular stone structures called mustatils are an important emerging feature of the Holocene archaeological record of northwestern Arabia. To date, few have been excavated, with available radiocarbon dates suggesting an age range of ca. 5400–4200 BC. Here we present a rigorous spatial analysis to identify the patterning and landscape context of 169 mustatils in the southern and western margins of the Nefud Desert. This included: (1) a systematic survey of satellite imagery to identify mustatils; (2) viewshed analysis to examine location and landscape visibility; (3) a point process model to understand how diverse environmental and landscape variables affect mustatil locations; (4) mark correlation function to assess spatial patterning of mustatils based on their size. Results indicate that mustatil locations are determined most by proximity to water (likely locations of enhanced surface water occurrence under the enhanced humidity of the Mid-Holocene), on east facing slopes, close to rocky areas, at elevations between 880 and 950 masl, and on or near topographic ridges (positive topographic position index). Viewshed analysis showed that mustatils are preferentially located in areas that have good views, but not the best that are available, indicating complex landscape positioning that balances a range of topographic and behavioural factors. Using a rank permutation method with size (length) of mustatils as a proxy for labour mobilization we show that mustatils within clusters are not arranged hierarchically based on size, and were likely built by non-stratified groups of people. Our analyses show that people were choosing multiple factors when deciding where to build mustatils, and that the distribution of mustatils may relate to different groups of people resulting in the construction of complex ritual landscapes. As one of the earliest examples of large-scale monumental stone structure construction in global prehistory, understanding mustatils can enlighten us on human-environment interaction during the Neolithic.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-14DOI: 10.1177/09596836241275021
Michel Michaelovitch de Mahiques, Renata Hanae Nagai, Irys Martins Rodrigues Ventura, Samara Cazzoli y Goya
Today, the South Atlantic Convergence Zone (SACZ), a convective band that extends across central Brazil to the western South Atlantic Ocean, modulates Southern Hemisphere summer rainfall in Southeastern Brazil. During the Holocene, however, the role of the SACZ over the rainfall regime in this part of South America is still under debate. This study aims to provide new insights into the SACZ Late-Holocene variability through analysis of the geochemical (XRF-based bulk sediment Metal/Metal ratios) and sedimentological (grain size and end-member modeling) variations along four cores retrieved in a coastal area (24–49 m water depth) located in the core of modern SACZ. Our records show an increase in Ti/Ca ratios, suggesting increased rainfall and that the terrigenous input to the Brazilian southeastern inner shelf changed in the Late-Holocene (last 4200 years). These changes are also followed by a decrease in the K/Ti ratio, indicative of an increase in chemical weathering in the sediment source, and an increase in the Mn/Ti, suggesting an increase in oxidation. Additionally, decadal-scale variability with periodicities of 25 and 55 years obtained by a time-series (Redfit) analysis highlights a potential role of the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation, respectively, as drivers of the SACZ variability over the last 4200 years.
{"title":"Sedimentological and geochemical proxies reveal changes in the South Atlantic Convergence Zone in Southeast South America during the Late-Holocene","authors":"Michel Michaelovitch de Mahiques, Renata Hanae Nagai, Irys Martins Rodrigues Ventura, Samara Cazzoli y Goya","doi":"10.1177/09596836241275021","DOIUrl":"https://doi.org/10.1177/09596836241275021","url":null,"abstract":"Today, the South Atlantic Convergence Zone (SACZ), a convective band that extends across central Brazil to the western South Atlantic Ocean, modulates Southern Hemisphere summer rainfall in Southeastern Brazil. During the Holocene, however, the role of the SACZ over the rainfall regime in this part of South America is still under debate. This study aims to provide new insights into the SACZ Late-Holocene variability through analysis of the geochemical (XRF-based bulk sediment Metal/Metal ratios) and sedimentological (grain size and end-member modeling) variations along four cores retrieved in a coastal area (24–49 m water depth) located in the core of modern SACZ. Our records show an increase in Ti/Ca ratios, suggesting increased rainfall and that the terrigenous input to the Brazilian southeastern inner shelf changed in the Late-Holocene (last 4200 years). These changes are also followed by a decrease in the K/Ti ratio, indicative of an increase in chemical weathering in the sediment source, and an increase in the Mn/Ti, suggesting an increase in oxidation. Additionally, decadal-scale variability with periodicities of 25 and 55 years obtained by a time-series (Redfit) analysis highlights a potential role of the Pacific Decadal Oscillation and the Atlantic Multidecadal Oscillation, respectively, as drivers of the SACZ variability over the last 4200 years.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The first paleoparasitological analyses in Brazil are related to the Gruta do Gentio ll (GGll) an archeological site related to the beginning of the Una ceramist tradition (13,000–410 cal B.P.), with two subsistence horizons, an ancient one related do hunter-gatherers, and a more recent one related to a horticulturist population. Crucial cultural traces of Una tradition such as pottery, fabric, adornments made from animal teeth and shells, and food remnants were also identified during the GGII excavations. Coprolites, fossilized or mineralized feces are important elements in the studies on taphonomy and sedimentology, and yield valuable information on parasitological, environmental, producer origin, and diet. In the present study, GGll coprolites were submitted to morphological and morphometrical procedures to identify the probable origin of samples within the geographical location of study. The results of the identification of coprolites showed four different morphotypes including complex, flat, spherical, and cylindrical, in 10 distinct colors, distributed heterogeneously in 16 sectors and 11 stratigraphic layers, indicating a great variety of not only human but animal coprolites. With the collected data, along with previous archeological evaluations, we can propose a primary GGII paleoecological scenario, with the presence of animals and humans that used de cave in the Pleistocene and Holocene times of Southeast Brazil.
{"title":"Coprolite diversity from the archeological site Gruta Do Gentio Ll, Unaí, Minas Gerais, Brazil","authors":"Ludmila Gurjão, Ondemar Dias, Jandira Neto, Alena Iñiguez","doi":"10.1177/09596836241275019","DOIUrl":"https://doi.org/10.1177/09596836241275019","url":null,"abstract":"The first paleoparasitological analyses in Brazil are related to the Gruta do Gentio ll (GGll) an archeological site related to the beginning of the Una ceramist tradition (13,000–410 cal B.P.), with two subsistence horizons, an ancient one related do hunter-gatherers, and a more recent one related to a horticulturist population. Crucial cultural traces of Una tradition such as pottery, fabric, adornments made from animal teeth and shells, and food remnants were also identified during the GGII excavations. Coprolites, fossilized or mineralized feces are important elements in the studies on taphonomy and sedimentology, and yield valuable information on parasitological, environmental, producer origin, and diet. In the present study, GGll coprolites were submitted to morphological and morphometrical procedures to identify the probable origin of samples within the geographical location of study. The results of the identification of coprolites showed four different morphotypes including complex, flat, spherical, and cylindrical, in 10 distinct colors, distributed heterogeneously in 16 sectors and 11 stratigraphic layers, indicating a great variety of not only human but animal coprolites. With the collected data, along with previous archeological evaluations, we can propose a primary GGII paleoecological scenario, with the presence of animals and humans that used de cave in the Pleistocene and Holocene times of Southeast Brazil.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1177/09596836241275028
Matthew J Jacobson, Joana Seguin, Martin Finné
The Aegean region has a wealth of archeological data originating from a long and rich human history and is frequently used as a testbed for climate-society interactions at different time scales. Here, we summarize and synthesize 31 proxy records derived from lake and wetland sediments, marine sediments, and speleothems reflecting hydroclimatic conditions over the last 10,000 years in the Aegean. To enable comparison and numerical analyses, we convert each record into z-scores and average values into centurial and decadal bins. The long-term hydroclimatic trajectory is best described by individual trends in three sub-regions that periodically converge and diverge. The results from our analyses highlight the complex long- and short-term spatio-temporal patterns of the hydroclimate with periods of wetter and drier conditions. Statistical analyses of the last 3500 years, the most data-rich period, corroborate the complex climate picture. Three periods that appear dry in the regional averages, at 7250–6650 BP, 3350–2750 BP, and 1200–700 BP, highlight spatio-temporal variability and underpin the importance of local data when comparing hydroclimate data with archeological information. Considering the complexities and uncertainties in hydroclimate records, we advocate for careful consideration when utilizing these in studies of climate-society interactions, including transparency regarding their uncertainties and the relevance of each record to a respective archeological site. We have produced a freely available, simplified dataset that can be used by those interested in studying the region, as well as maps displaying climatic conditions during each century.
{"title":"Holocene hydroclimate synthesis of the Aegean: Diverging patterns, dry periods and implications for climate-society interactions","authors":"Matthew J Jacobson, Joana Seguin, Martin Finné","doi":"10.1177/09596836241275028","DOIUrl":"https://doi.org/10.1177/09596836241275028","url":null,"abstract":"The Aegean region has a wealth of archeological data originating from a long and rich human history and is frequently used as a testbed for climate-society interactions at different time scales. Here, we summarize and synthesize 31 proxy records derived from lake and wetland sediments, marine sediments, and speleothems reflecting hydroclimatic conditions over the last 10,000 years in the Aegean. To enable comparison and numerical analyses, we convert each record into z-scores and average values into centurial and decadal bins. The long-term hydroclimatic trajectory is best described by individual trends in three sub-regions that periodically converge and diverge. The results from our analyses highlight the complex long- and short-term spatio-temporal patterns of the hydroclimate with periods of wetter and drier conditions. Statistical analyses of the last 3500 years, the most data-rich period, corroborate the complex climate picture. Three periods that appear dry in the regional averages, at 7250–6650 BP, 3350–2750 BP, and 1200–700 BP, highlight spatio-temporal variability and underpin the importance of local data when comparing hydroclimate data with archeological information. Considering the complexities and uncertainties in hydroclimate records, we advocate for careful consideration when utilizing these in studies of climate-society interactions, including transparency regarding their uncertainties and the relevance of each record to a respective archeological site. We have produced a freely available, simplified dataset that can be used by those interested in studying the region, as well as maps displaying climatic conditions during each century.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1177/09596836241275007
Mustafa Doğan, Yavuz Özdemir, Yunus Bozkurt, Çetin Şenkul
Throughout the long eruption history of the Santorini volcano, the Cape Riva/Y-2 and Minoan/Z-2 eruptions had a profound impact on the environment. The Minoan eruptions also had a significant impact on society. These two tephras, as well as the Y-2 tephra individually, have been recorded for the first time in a lacustrine area in western Anatolia. This study examines the geochemical properties of Y-2 (23 cm) and Z-2 tephra layers (19 cm; 14 cm pure and 5 cm mixed) from 18 m sediment cores in Lake Yayla (Denizli-Buldan). Additionally, high-resolution µXRF, fossil pollen, charcoal, and dating analyses were conducted on the cores to determine the chronologies and environmental effects of the tephra layers. Fossil pollen findings show consistent forest and steppe/grassland vegetation before and after the Z-2 tephra, with the forest impact lasting for 240 years after the eruption. Increased aquatic vegetation and changes in specific taxa (e.g. Pinus sp. and Amaranthaceae increased, while Quercus deciduous, Olea europaea, and cereals decreased) were observed following the Minoan eruption. Charcoal analysis indicates heightened fire activity post-Minoan eruption, while XRF data reveal no associated climatic change. At the same time, no correlation has been identified between the Cape Riva eruption and ecological changes (climate, vegetation, and fire activity). Contribution to dating the tephra was provided by radiocarbon dating from the lowest part of the tephra layer (17,684 ± 63 years BP). This study sheds light on the extensive impacts of the Y-2 and Z-2 tephra eruptions, focusing on their dating, geochemistry, environmental effects, tephra transport directions, and thicknesses. It demonstrates the presence of a significant geological event for the settlements in the Büyük Menderes Valley.
{"title":"Discovery and environmental implications of Santorini tephras (Cape Riva and Minoan) in sediments of Lake Yayla (West Anatolia)","authors":"Mustafa Doğan, Yavuz Özdemir, Yunus Bozkurt, Çetin Şenkul","doi":"10.1177/09596836241275007","DOIUrl":"https://doi.org/10.1177/09596836241275007","url":null,"abstract":"Throughout the long eruption history of the Santorini volcano, the Cape Riva/Y-2 and Minoan/Z-2 eruptions had a profound impact on the environment. The Minoan eruptions also had a significant impact on society. These two tephras, as well as the Y-2 tephra individually, have been recorded for the first time in a lacustrine area in western Anatolia. This study examines the geochemical properties of Y-2 (23 cm) and Z-2 tephra layers (19 cm; 14 cm pure and 5 cm mixed) from 18 m sediment cores in Lake Yayla (Denizli-Buldan). Additionally, high-resolution µXRF, fossil pollen, charcoal, and dating analyses were conducted on the cores to determine the chronologies and environmental effects of the tephra layers. Fossil pollen findings show consistent forest and steppe/grassland vegetation before and after the Z-2 tephra, with the forest impact lasting for 240 years after the eruption. Increased aquatic vegetation and changes in specific taxa (e.g. Pinus sp. and Amaranthaceae increased, while Quercus deciduous, Olea europaea, and cereals decreased) were observed following the Minoan eruption. Charcoal analysis indicates heightened fire activity post-Minoan eruption, while XRF data reveal no associated climatic change. At the same time, no correlation has been identified between the Cape Riva eruption and ecological changes (climate, vegetation, and fire activity). Contribution to dating the tephra was provided by radiocarbon dating from the lowest part of the tephra layer (17,684 ± 63 years BP). This study sheds light on the extensive impacts of the Y-2 and Z-2 tephra eruptions, focusing on their dating, geochemistry, environmental effects, tephra transport directions, and thicknesses. It demonstrates the presence of a significant geological event for the settlements in the Büyük Menderes Valley.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1177/09596836241275008
María Luján García, Stella Birlo, Petra Zahajská, Giulia Wienhues, Martin Grosjean, Bernd Zolitschka
Features like solar cyclicities and trends as well as grand solar minima are used to attribute natural climate variability to solar forcing on decadal to millennial time scales. Here we focus on ecological responses of a Grand Solar Minimum on annually- laminated lake sediments from Holzmaar (Germany) covering the Homeric Climate Anomaly (HCA). Diatom assemblages and pigments of purple sulphur bacteria (Bphe a) analysed at decadal resolution document well-stratified conditions with relatively low lacustrine productivity prior to the HCA (2950–2750 cal. BP). Colder temperatures, a well-mixed water column and higher primary aquatic productivity established during the HCA (2750–2680 cal. BP) as indicated for Holzmaar by dominance of the planktonic diatom Stephanodiscus minutulus, decreasing Bphe a and peaking total chloropigment concentrations. The termination of the HCA after 2680 cal. BP is marked by additional anthropogenic signals related to deforestation that changed the catchment at the contemporaneous Bronze Age/Iron Age transition. Our high-resolution and well-dated multiproxy study based on varved sediments contributes to a better understanding of decadal-scale responses of aquatic ecosystems to solar forcing and compares well with hypotheses suggested by other investigations indicating colder and more windy climatic conditions as the consequences of a Grand Solar Minimum for mid-latitudes of the Northern Hemisphere.
{"title":"Ecological responses to solar forcing during the Homerian Climate Anomaly recorded by varved sediments from Holzmaar, Germany","authors":"María Luján García, Stella Birlo, Petra Zahajská, Giulia Wienhues, Martin Grosjean, Bernd Zolitschka","doi":"10.1177/09596836241275008","DOIUrl":"https://doi.org/10.1177/09596836241275008","url":null,"abstract":"Features like solar cyclicities and trends as well as grand solar minima are used to attribute natural climate variability to solar forcing on decadal to millennial time scales. Here we focus on ecological responses of a Grand Solar Minimum on annually- laminated lake sediments from Holzmaar (Germany) covering the Homeric Climate Anomaly (HCA). Diatom assemblages and pigments of purple sulphur bacteria (Bphe a) analysed at decadal resolution document well-stratified conditions with relatively low lacustrine productivity prior to the HCA (2950–2750 cal. BP). Colder temperatures, a well-mixed water column and higher primary aquatic productivity established during the HCA (2750–2680 cal. BP) as indicated for Holzmaar by dominance of the planktonic diatom Stephanodiscus minutulus, decreasing Bphe a and peaking total chloropigment concentrations. The termination of the HCA after 2680 cal. BP is marked by additional anthropogenic signals related to deforestation that changed the catchment at the contemporaneous Bronze Age/Iron Age transition. Our high-resolution and well-dated multiproxy study based on varved sediments contributes to a better understanding of decadal-scale responses of aquatic ecosystems to solar forcing and compares well with hypotheses suggested by other investigations indicating colder and more windy climatic conditions as the consequences of a Grand Solar Minimum for mid-latitudes of the Northern Hemisphere.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-07DOI: 10.1177/09596836241274989
Mark Golitko, Mitchell J Power, Jason Kariwiga, Kenneth Miamba
The coastlines of the southwestern Pacific are dynamic environments that have been repeatedly reshaped by tectonic forces as well as changing global climate and sea level. It has been theorized that much of the north coast of New Guinea was sparsely inhabited until stabilization of coastal flats fallowing the Mid-Holocene Thermal Maximum and resulting marine high stand. We report on environmental proxy indicators measured in core samples taken near modern day Aitape, Papua New Guinea. These cores record the formation of a large lagoonal system on the modern coastal flats by 5800 cal BP. This lagoon infilled over the next several 1000 years as sea level dropped, with the modern coastal flats stabilizing by 1400 cal BP. A charcoal record spanning the period between 6200 and 1400 cal BP documents substantial increases in influx between ~6200 and 6000 cal BP and particularly from ~3000 to 2600 cal BP. Comparison to regional charcoal and ENSO records suggests that increasing aridity and ENSO intensity may drive regional patterning in fire records, however, localized charcoal records are also heavily influenced by human activity. Between 3000 and 2600 cal BP, forest management practices in the Aitape area, currently focused on tree crops and horticulture characterized by long fallowing and limited burning, shifted to a regime characterized by large scale forest clearance and shorter fallowing. We hypothesize that increasing population driven by abundant Mid-Holocene lagoonal resources may have been difficult to maintain as lagoons infilled and climate became more variable, leading to horticultural intensification.
{"title":"Waking the “sleeping giant?” Mid- to Late-Holocene environment and fire history in the Aitape area, northern Papua New Guinea","authors":"Mark Golitko, Mitchell J Power, Jason Kariwiga, Kenneth Miamba","doi":"10.1177/09596836241274989","DOIUrl":"https://doi.org/10.1177/09596836241274989","url":null,"abstract":"The coastlines of the southwestern Pacific are dynamic environments that have been repeatedly reshaped by tectonic forces as well as changing global climate and sea level. It has been theorized that much of the north coast of New Guinea was sparsely inhabited until stabilization of coastal flats fallowing the Mid-Holocene Thermal Maximum and resulting marine high stand. We report on environmental proxy indicators measured in core samples taken near modern day Aitape, Papua New Guinea. These cores record the formation of a large lagoonal system on the modern coastal flats by 5800 cal BP. This lagoon infilled over the next several 1000 years as sea level dropped, with the modern coastal flats stabilizing by 1400 cal BP. A charcoal record spanning the period between 6200 and 1400 cal BP documents substantial increases in influx between ~6200 and 6000 cal BP and particularly from ~3000 to 2600 cal BP. Comparison to regional charcoal and ENSO records suggests that increasing aridity and ENSO intensity may drive regional patterning in fire records, however, localized charcoal records are also heavily influenced by human activity. Between 3000 and 2600 cal BP, forest management practices in the Aitape area, currently focused on tree crops and horticulture characterized by long fallowing and limited burning, shifted to a regime characterized by large scale forest clearance and shorter fallowing. We hypothesize that increasing population driven by abundant Mid-Holocene lagoonal resources may have been difficult to maintain as lagoons infilled and climate became more variable, leading to horticultural intensification.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-06DOI: 10.1177/09596836241266408
Maria I Vélez, Jorge Salgado, Miguel Delgado, Luisa F Patiño, Broxton Bird, Jaime H Escobar, Sebastian Fajardo
Tota is an Andean lake located in the Altiplano of the Eastern Andes of Colombia where socio-politically hierarchical societies of the Herrera and Muisca, flourished for millennia. To them, the lake and surrounding forest were places used for diverse of activities including religious rituals. In this study we produced a multi-proxy paleolimnological reconstruction using diatoms, isotopes, and geochemistry, to try to understand the lake’s pathways of change in response to natural climatic variations and anthropogenic activities. The diatom record is dominated by tychoplanktonic Staurosirella dubia and planktonic Aulacoseira species including species A. cf lirata, A. granulata, A. distans, and A. ambigua. Diatoms were grouped into functional groups and used to infer limnological changes that were further complemented with the geochemistry of the sediments to reconstruct the past environment. Results show three main periods in which the lake changed significantly, these are dated from ~800 to 1200, 1200 to 1500, and 1500 to 1900 CE. A correlation with the archeological record of the region, ethnohistoric accounts and climate suggests that these changes occurred simultaneously with changes in archeological stages, the Spanish arrival, and more recently by the industrial revolution, and the Little Ice Age.
托塔是位于哥伦比亚东安第斯山脉阿尔蒂普拉诺地区的一个安第斯湖泊，埃雷拉和穆伊斯卡社会政治等级森严的社会在这里繁衍生息了数千年。对他们来说，湖泊和周围的森林是进行各种活动（包括宗教仪式）的场所。在这项研究中，我们利用硅藻、同位素和地球化学进行了多代理古气候学重建，试图了解该湖在自然气候变化和人类活动影响下的变化路径。硅藻记录主要是浮游生物 Staurosirella dubia 和浮游生物 Aulacoseira，包括 A. cf lirata、A. granulata、A. distans 和 A. ambigua。硅藻被划分为不同的功能组别，用于推断湖沼学的变化，并通过沉积物的地球化学特征来重建过去的环境。结果显示，湖泊在三个主要时期发生了显著变化，时间分别为公元约 800 年至 1200 年、1200 年至 1500 年以及 1500 年至 1900 年。与该地区考古记录、人种史记载和气候的相关性表明，这些变化是与考古阶段的变化、西班牙人的到来以及最近的工业革命和小冰河时期同时发生的。
{"title":"Humans and climate in ritualized landscapes, the case of Lake Tota in the eastern highlands of Colombia","authors":"Maria I Vélez, Jorge Salgado, Miguel Delgado, Luisa F Patiño, Broxton Bird, Jaime H Escobar, Sebastian Fajardo","doi":"10.1177/09596836241266408","DOIUrl":"https://doi.org/10.1177/09596836241266408","url":null,"abstract":"Tota is an Andean lake located in the Altiplano of the Eastern Andes of Colombia where socio-politically hierarchical societies of the Herrera and Muisca, flourished for millennia. To them, the lake and surrounding forest were places used for diverse of activities including religious rituals. In this study we produced a multi-proxy paleolimnological reconstruction using diatoms, isotopes, and geochemistry, to try to understand the lake’s pathways of change in response to natural climatic variations and anthropogenic activities. The diatom record is dominated by tychoplanktonic Staurosirella dubia and planktonic Aulacoseira species including species A. cf lirata, A. granulata, A. distans, and A. ambigua. Diatoms were grouped into functional groups and used to infer limnological changes that were further complemented with the geochemistry of the sediments to reconstruct the past environment. Results show three main periods in which the lake changed significantly, these are dated from ~800 to 1200, 1200 to 1500, and 1500 to 1900 CE. A correlation with the archeological record of the region, ethnohistoric accounts and climate suggests that these changes occurred simultaneously with changes in archeological stages, the Spanish arrival, and more recently by the industrial revolution, and the Little Ice Age.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"2022 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1177/09596836241274975
Richard S Vachula, Thomas M Cullen, Matthew R Galinger, J Conner Welch, Jeremiah Battaglia, Dallyn Smith, Matthew N Waters
Charcoal shape variations provide insight into past fuel types burned, with charcoal length:width (L:W) being the most popular means of distinguishing fuel types. This paper presents morphometric data (L:W) of charcoal produced from plant taxa (n = 21) native to the southeastern United States of America (USA). These taxa included monocots (n = 3), dicots (n = 12), and gymnosperms (n = 6), which represented a range of growth habits including graminoids, trees, shrubs, and subshrubs. We further divided these taxa into tissues (n = 36 total samples) which included leaves, wood, bark, needles, stems, and a seed pod. Our results show that charcoal produced from plants native to southeastern USA exhibits more variable L:W values than those tested in previous research, but that when aggregated, they broadly agree with published L:W value ranges. Within the dicot group, leaves produced charcoal lower L:W values (median = 1.92, interquartile range (IQR) = 1.33) than wood (median = 2.43, IQR = 3.00), whereas the opposite was true for gymnosperms whose needles produced greater L:W values (median = 2.60, IQR = 3.22) than wood (median = 1.93, IQR = 1.44). The monocot graminoid we tested produced greater L:W values (median = 3.47, IQR = 6.02) than dicot or gymnosperm fuels. Further, our results provide conflicting perspectives on the likelihood of evolutionary relationships as the cause of variations in charcoal L:W values. Last, our results underscore the importance of site-specific experimental charcoal approaches to enable robust paleofire applications of charcoal morphometry.
{"title":"Morphometric characteristics of charcoal produced from plants native to the southeastern United States of America (USA)","authors":"Richard S Vachula, Thomas M Cullen, Matthew R Galinger, J Conner Welch, Jeremiah Battaglia, Dallyn Smith, Matthew N Waters","doi":"10.1177/09596836241274975","DOIUrl":"https://doi.org/10.1177/09596836241274975","url":null,"abstract":"Charcoal shape variations provide insight into past fuel types burned, with charcoal length:width (L:W) being the most popular means of distinguishing fuel types. This paper presents morphometric data (L:W) of charcoal produced from plant taxa (n = 21) native to the southeastern United States of America (USA). These taxa included monocots (n = 3), dicots (n = 12), and gymnosperms (n = 6), which represented a range of growth habits including graminoids, trees, shrubs, and subshrubs. We further divided these taxa into tissues (n = 36 total samples) which included leaves, wood, bark, needles, stems, and a seed pod. Our results show that charcoal produced from plants native to southeastern USA exhibits more variable L:W values than those tested in previous research, but that when aggregated, they broadly agree with published L:W value ranges. Within the dicot group, leaves produced charcoal lower L:W values (median = 1.92, interquartile range (IQR) = 1.33) than wood (median = 2.43, IQR = 3.00), whereas the opposite was true for gymnosperms whose needles produced greater L:W values (median = 2.60, IQR = 3.22) than wood (median = 1.93, IQR = 1.44). The monocot graminoid we tested produced greater L:W values (median = 3.47, IQR = 6.02) than dicot or gymnosperm fuels. Further, our results provide conflicting perspectives on the likelihood of evolutionary relationships as the cause of variations in charcoal L:W values. Last, our results underscore the importance of site-specific experimental charcoal approaches to enable robust paleofire applications of charcoal morphometry.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-13DOI: 10.1177/09596836241266398
Upasana S Banerji, Ravi Bhushan, Kumar Batuk Joshi, Ankur Dabhi, AK Sudheer, Chandra Prakash Dubey, Rakesh Kumar Panda, Nayana V Haridas, Mahesh Gaddam
The heat transfer from the low latitudes to high latitudes is responsible for maintaining the earth’s climate dynamics. Thus, deciphering the possible mechanism driving the variability of the Indian summer monsoon (ISM) during the Holocene Epoch has been critical to understand the hydroclimatic changes of the low latitudes. Despite several efforts, the teleconnection of ISM with the global climate dynamics remains under-represented and poorly understood. The present study aims to delineate the ISM variability and its possible forcing mechanism from western India (Gujarat). In this study, a sediment core (~65 cm long) was raised from the Jaffrabad mudflat (MIT) in western Gujarat. The sediment samples were subjected to geochemical analysis to investigate paleomonsoon, paleo-sediment source and paleoweathering changes. The results show that, with the addition of intermediate sources, the sediments were principally derived from the hinterland’s Deccan basalts. Further, the study suggested a warm and wet climate due to strong ISM during 10,650−5500 cal yr BP associated with the solar as well as orbital forcings. The weak monsoon during 5500−2700 cal yr BP has been linked with southward migration of the Intertropical Convergence Zone (ITCZ) along with the increased El Niño-like conditions. Further, the wavelet analysis revealed that a combined influence of solar, orbital and North Atlantic forcings led to monsoon variability along western India, during the Holocene Epoch. By reconciling the geochemical proxies, the present study has implications in the reconstruction of paleomonsoon and establishing the possible teleconnection with the global climate system.
{"title":"Geochemical records of mudflat sediments from southern Saurashtra, Western India: Implications for Holocene climate and global teleconnection","authors":"Upasana S Banerji, Ravi Bhushan, Kumar Batuk Joshi, Ankur Dabhi, AK Sudheer, Chandra Prakash Dubey, Rakesh Kumar Panda, Nayana V Haridas, Mahesh Gaddam","doi":"10.1177/09596836241266398","DOIUrl":"https://doi.org/10.1177/09596836241266398","url":null,"abstract":"The heat transfer from the low latitudes to high latitudes is responsible for maintaining the earth’s climate dynamics. Thus, deciphering the possible mechanism driving the variability of the Indian summer monsoon (ISM) during the Holocene Epoch has been critical to understand the hydroclimatic changes of the low latitudes. Despite several efforts, the teleconnection of ISM with the global climate dynamics remains under-represented and poorly understood. The present study aims to delineate the ISM variability and its possible forcing mechanism from western India (Gujarat). In this study, a sediment core (~65 cm long) was raised from the Jaffrabad mudflat (MIT) in western Gujarat. The sediment samples were subjected to geochemical analysis to investigate paleomonsoon, paleo-sediment source and paleoweathering changes. The results show that, with the addition of intermediate sources, the sediments were principally derived from the hinterland’s Deccan basalts. Further, the study suggested a warm and wet climate due to strong ISM during 10,650−5500 cal yr BP associated with the solar as well as orbital forcings. The weak monsoon during 5500−2700 cal yr BP has been linked with southward migration of the Intertropical Convergence Zone (ITCZ) along with the increased El Niño-like conditions. Further, the wavelet analysis revealed that a combined influence of solar, orbital and North Atlantic forcings led to monsoon variability along western India, during the Holocene Epoch. By reconciling the geochemical proxies, the present study has implications in the reconstruction of paleomonsoon and establishing the possible teleconnection with the global climate system.","PeriodicalId":517388,"journal":{"name":"The Holocene","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142186839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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