Floodplains are important organic carbon (OC) storage sites, and the evolution of watercourses modulates the transport, burial, and reworking of organics with cascading effects on watershed CO 2 budgets. Meandering rivers have broadly predictable patterns of channel-planform evolution, providing an opportunity to assess floodplain OC budgets in relation to characteristic migration paces and floodplain ages. However, due to geomorphic complexities in individual meandering rivers, assessments of relationships between channel and OC dynamics have thus far remained limited. We illustrate evolving OC budgets in relation to channel migration in the Vermilion River (Ontario) located in the boreal forest of eastern North America. We combine photogrammetric analyses and dynamic time warping of channel centrelines with analysis of top-soil bulk density and OC. We found that variations of OC stock per unit surface area and soil development are modulated by meander migration through the development of typical boreal-forest vegetation successions. Our results support the hypothesis that meander migration controls soil development, forest age, and floodplain OC budgets. We anticipate our study to inform wider applications to rivers in different bioclimates - an approach that may in turn help carbon assessment in the context of changing climate or land use.
{"title":"Floodplain organic-carbon dynamics modulated by meandering-channel migration: Vermilion River, Ontario, Canada","authors":"Melissa Barrera, A. Ielpi","doi":"10.1144/sp540-2023-94","DOIUrl":"https://doi.org/10.1144/sp540-2023-94","url":null,"abstract":"\u0000 \u0000 Floodplains are important organic carbon (OC) storage sites, and the evolution of watercourses modulates the transport, burial, and reworking of organics with cascading effects on watershed CO\u0000 2\u0000 budgets. Meandering rivers have broadly predictable patterns of channel-planform evolution, providing an opportunity to assess floodplain OC budgets in relation to characteristic migration paces and floodplain ages. However, due to geomorphic complexities in individual meandering rivers, assessments of relationships between channel and OC dynamics have thus far remained limited. We illustrate evolving OC budgets in relation to channel migration in the Vermilion River (Ontario) located in the boreal forest of eastern North America. We combine photogrammetric analyses and dynamic time warping of channel centrelines with analysis of top-soil bulk density and OC. We found that variations of OC stock per unit surface area and soil development are modulated by meander migration through the development of typical boreal-forest vegetation successions. Our results support the hypothesis that meander migration controls soil development, forest age, and floodplain OC budgets. We anticipate our study to inform wider applications to rivers in different bioclimates - an approach that may in turn help carbon assessment in the context of changing climate or land use.\u0000","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":" 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140687014","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}
Bethany J. Allen, T. Vaughan, Louis du Plessis, Thomas L. A. Schouten, Zili Yuan, Sean D. Willett, Tanja Stadler
The current status of the Sino-Himalayan region as a biodiversity hotspot, particularly for flora, has often been linked to the uplift of the Sino-Tibetan Plateau and Himalayan and Hengduan Mountains. However, the relationship between the topological development of the region and the onset of diversification is yet to be confirmed. Here, we apply Bayesian phylodynamic methods to a large phylogeny of angiosperm species from the Sino-Himalayas, to infer changes in their evolutionary rates through time. We find strong evidence for high diversification rates in the Paleocene, late Miocene and Pliocene, and for negative diversification rates in the Quaternary, driven by an increase in extinction rates. Our analyses suggest that changes in global palaeotemperatures are unlikely to be a driving force for these rate shifts. Instead, the collision of the Indian continent with Eurasia and coeval topographic change in the Sino-Himalayas, the Miocene Grassland Expansion, and the impact of Pleistocene glaciations on this altitudinally-variable region may have driven these rates. We also demonstrate the strong influence of change time choice on the shape of inferred piecewise-constant trajectories in Bayesian phylodynamics, and advocate for the use of prior information when making this decision. Supplementary material at https://doi.org/10.6084/m9.figshare.c.7179254
{"title":"Inferring the evolutionary history of the Sino-Himalayan biodiversity hotspot using a Bayesian birth-death skyline model","authors":"Bethany J. Allen, T. Vaughan, Louis du Plessis, Thomas L. A. Schouten, Zili Yuan, Sean D. Willett, Tanja Stadler","doi":"10.1144/sp549-2023-174","DOIUrl":"https://doi.org/10.1144/sp549-2023-174","url":null,"abstract":"\u0000 The current status of the Sino-Himalayan region as a biodiversity hotspot, particularly for flora, has often been linked to the uplift of the Sino-Tibetan Plateau and Himalayan and Hengduan Mountains. However, the relationship between the topological development of the region and the onset of diversification is yet to be confirmed. Here, we apply Bayesian phylodynamic methods to a large phylogeny of angiosperm species from the Sino-Himalayas, to infer changes in their evolutionary rates through time. We find strong evidence for high diversification rates in the Paleocene, late Miocene and Pliocene, and for negative diversification rates in the Quaternary, driven by an increase in extinction rates. Our analyses suggest that changes in global palaeotemperatures are unlikely to be a driving force for these rate shifts. Instead, the collision of the Indian continent with Eurasia and coeval topographic change in the Sino-Himalayas, the Miocene Grassland Expansion, and the impact of Pleistocene glaciations on this altitudinally-variable region may have driven these rates. We also demonstrate the strong influence of change time choice on the shape of inferred piecewise-constant trajectories in Bayesian phylodynamics, and advocate for the use of prior information when making this decision.\u0000 \u0000 Supplementary material at\u0000 https://doi.org/10.6084/m9.figshare.c.7179254\u0000","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"25 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140694261","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}
Scientific drilling provides extended records of continental environmental conditions during the Neogene in Asia and northern Australia. Spectral data allows reconstruction of the environment using abundances of hematite and goethite. Hematite formation is favoured by dry or seasonal conditions. Hemipelagic sites show the most regular records. Monsoon strengthening started in the Early Miocene and peaked at 17–20 Ma in the Bay of Bengal and at 10–15 Ma in southern China before weakening after ∼12 Ma and ∼10 Ma respectively. The Indus dried after ∼8 Ma and again after 3 Ma, while eolian sediment sources to the Sea of Japan show increased aridity after 5 Ma and 3 Ma. The Mekong indicates increasing aridity after 6 Ma, similar to Eastern Australia. In contrast, NW Australia shows a trend towards wetter conditions after 8 Ma, a humid period at 4–6 Ma, followed by drying. There is a link between drying and vegetation in the Mekong and Pearl River basins, as well as Eastern Australia. Monsoon strengthening is linked to topographic uplift in the Himalaya, together with Tethyan gateway closure. Long term drying is likely driven by global cooling since the Middle Miocene.
科学钻探提供了亚洲和澳大利亚北部新近纪大陆环境条件的详细记录。光谱数据可以利用赤铁矿和高铁铁矿的丰度重建环境。干燥或季节性条件有利于赤铁矿的形成。半下潜地点的记录最有规律。季风从早中新世开始加强，分别在孟加拉湾的 17-20 Ma 和中国南部的 10-15 Ma 达到高峰，然后分别在 ∼12 Ma 和 ∼10 Ma 之后减弱。印度河在 ∼8 Ma 后干涸，在 3 Ma 后再次干涸，而日本海的沉积物源则显示在 5 Ma 和 3 Ma 后干旱加剧。湄公河的干旱程度在 6 Ma 之后加剧，与澳大利亚东部相似。与此相反，澳大利亚西北部显示出一种趋势，即在距今 8 马年之后变得更加潮湿，在距今 4-6 马年出现一个潮湿期，随后变得干燥。湄公河流域和珠江流域以及澳大利亚东部的干燥与植被之间存在联系。季风的加强与喜马拉雅山的地形抬升以及泰西门户的关闭有关。中新世中期以来的全球变冷可能是造成长期干旱的原因。
{"title":"Variations in Aridity across the Asia-Australia Region during the Neogene and their Impact on Vegetation","authors":"P. Clift","doi":"10.1144/sp549-2023-58","DOIUrl":"https://doi.org/10.1144/sp549-2023-58","url":null,"abstract":"\u0000 Scientific drilling provides extended records of continental environmental conditions during the Neogene in Asia and northern Australia. Spectral data allows reconstruction of the environment using abundances of hematite and goethite. Hematite formation is favoured by dry or seasonal conditions. Hemipelagic sites show the most regular records. Monsoon strengthening started in the Early Miocene and peaked at 17–20 Ma in the Bay of Bengal and at 10–15 Ma in southern China before weakening after ∼12 Ma and ∼10 Ma respectively. The Indus dried after ∼8 Ma and again after 3 Ma, while eolian sediment sources to the Sea of Japan show increased aridity after 5 Ma and 3 Ma. The Mekong indicates increasing aridity after 6 Ma, similar to Eastern Australia. In contrast, NW Australia shows a trend towards wetter conditions after 8 Ma, a humid period at 4–6 Ma, followed by drying. There is a link between drying and vegetation in the Mekong and Pearl River basins, as well as Eastern Australia. Monsoon strengthening is linked to topographic uplift in the Himalaya, together with Tethyan gateway closure. Long term drying is likely driven by global cooling since the Middle Miocene.","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"309 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140719498","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}
Geoheritage is recognized globally as a critical concept that celebrates unique geological sites, their history and scientific value, educational potential, and geotourism opportunities. Importantly, geoheritage encompasses a wide range of geodiversity, which exists in a variety of scales—from local outcrops to internationally recognized UNESCO sites—and within a continuum of scientific value, historical merit, indigenous meaning, educational potential, and geotourism possibilities. We celebrate a selected example of geoheritage sites across the world that have been noticed, recognized, and utilized. Some of these sites' breadth and geodiversity indicate we should broaden our geoheritage definition, and include historical collections and largely inaccessible sites. Notably, all geoscientists and educators must remain diligent to ensure the sustainability of these sites so that future generations can celebrate and enjoy our geological and cultural heritage.
{"title":"Encompassing Geoheritage's Multiple Voices, Multiple Venues, and Multi-disciplinarity","authors":"Renee M. Clary, Eric J. Pyle, William Andrews","doi":"10.1144/sp543-2024-34","DOIUrl":"https://doi.org/10.1144/sp543-2024-34","url":null,"abstract":"\u0000 Geoheritage is recognized globally as a critical concept that celebrates unique geological sites, their history and scientific value, educational potential, and geotourism opportunities. Importantly, geoheritage encompasses a wide range of geodiversity, which exists in a variety of scales—from local outcrops to internationally recognized UNESCO sites—and within a continuum of scientific value, historical merit, indigenous meaning, educational potential, and geotourism possibilities. We celebrate a selected example of geoheritage sites across the world that have been noticed, recognized, and utilized. Some of these sites' breadth and geodiversity indicate we should broaden our geoheritage definition, and include historical collections and largely inaccessible sites. Notably, all geoscientists and educators must remain diligent to ensure the sustainability of these sites so that future generations can celebrate and enjoy our geological and cultural heritage.","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"58 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140727895","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}
Wolfgang Kuhnt, A. Holbourn, M. Aquit, S. Beil, E. H. Chellai
The Cretaceous marine sediments of Morocco and adjacent coastal basins provide an outstanding archive of environmental diversity from extended shelf seas and marginal basins along the Atlantic and Tethyan margins to deep oceanic basins of the western Tethys and eastern Atlantic Ocean. The geological highlights of Morocco's fascinating landscape include records of Lower Cretaceous Tethyan marginal and deep water clastic sequences in the Rif mountain chain (submarine fan systems of the Massylian and Mauretanian flysch units), as well as siliciclastic sedimentary sequences in subsiding coastal basins (TanTan Delta), which extend offshore along the Northwest African Atlantic margin. Vestiges of the Aptian to Turonian greenhouse climate, sea-level highstands and oceanic anoxic events are exceptionally well-preserved in Tethyan marginal and deep water sedimentary successions of the Rif, in Atlantic coastal basins and as transgressive pulses on the Moroccan Meseta, Sahara platform and High Atlas rift system. Furthermore, sedimentary expressions of the tectonic movements between the African and European plates associated with the end Cretaceous climate and sea-level changes are documented in the Rif mountain chain, in coastal basins, and in the massive marginal marine phosphorite sedimentation in the Middle and High Atlas, on the Moroccan Meseta and Sahara platform. In this review we provide a brief history of geological investigations and an overview of Cretaceous sedimentary archives, as well as a selection of research highlights and outstanding questions concerning the Cretaceous system in Morocco. The Cretaceous sedimentary archives from Morocco and adjacent coastal basins still retain untapped potential to further contribute to our understanding of global eustatic sea-level changes and the response of the oceans and marine biota in upwelling driven oxygen minimum zones under greenhouse climate conditions.
{"title":"Cretaceous geology and stratigraphy of Morocco and adjacent coastal basins","authors":"Wolfgang Kuhnt, A. Holbourn, M. Aquit, S. Beil, E. H. Chellai","doi":"10.1144/sp545-2023-141","DOIUrl":"https://doi.org/10.1144/sp545-2023-141","url":null,"abstract":"\u0000 The Cretaceous marine sediments of Morocco and adjacent coastal basins provide an outstanding archive of environmental diversity from extended shelf seas and marginal basins along the Atlantic and Tethyan margins to deep oceanic basins of the western Tethys and eastern Atlantic Ocean. The geological highlights of Morocco's fascinating landscape include records of Lower Cretaceous Tethyan marginal and deep water clastic sequences in the Rif mountain chain (submarine fan systems of the Massylian and Mauretanian flysch units), as well as siliciclastic sedimentary sequences in subsiding coastal basins (TanTan Delta), which extend offshore along the Northwest African Atlantic margin. Vestiges of the Aptian to Turonian greenhouse climate, sea-level highstands and oceanic anoxic events are exceptionally well-preserved in Tethyan marginal and deep water sedimentary successions of the Rif, in Atlantic coastal basins and as transgressive pulses on the Moroccan Meseta, Sahara platform and High Atlas rift system. Furthermore, sedimentary expressions of the tectonic movements between the African and European plates associated with the end Cretaceous climate and sea-level changes are documented in the Rif mountain chain, in coastal basins, and in the massive marginal marine phosphorite sedimentation in the Middle and High Atlas, on the Moroccan Meseta and Sahara platform. In this review we provide a brief history of geological investigations and an overview of Cretaceous sedimentary archives, as well as a selection of research highlights and outstanding questions concerning the Cretaceous system in Morocco. The Cretaceous sedimentary archives from Morocco and adjacent coastal basins still retain untapped potential to further contribute to our understanding of global eustatic sea-level changes and the response of the oceans and marine biota in upwelling driven oxygen minimum zones under greenhouse climate conditions.","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140750280","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}
Geomechanics has a marked impact on the safe and sustainable use of the subsurface. This Special Publication contains contributions detailing the latest efforts in present-day in-situ stress characterization, prediction and modelling from the borehole to plate-tectonic scale. A particular emphasis is on the uncertainties that are often associated with geomechanics.
{"title":"The quest for high fidelity, accurate geomechanical models and the research leading to it","authors":"M. Ziegler, T. Finkbeiner, C. Massiot, R. Goteti","doi":"10.1144/sp546-2024-38","DOIUrl":"https://doi.org/10.1144/sp546-2024-38","url":null,"abstract":"\u0000 \u0000 Geomechanics has a marked impact on the safe and sustainable use of the subsurface. This Special Publication contains contributions detailing the latest efforts in present-day\u0000 in-situ\u0000 stress characterization, prediction and modelling from the borehole to plate-tectonic scale. A particular emphasis is on the uncertainties that are often associated with geomechanics.\u0000","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"128 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140750701","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 stress field controls patterns of crustal deformation, including which faults are likeliest to cause earthquakes or transmit fluids. Since the 1950s, maps of maximum horizontal stress ( S Hmax ) orientations have advanced dramatically, and the style of faulting (relative principal stress magnitudes) has recently been mapped in some regions as well. This perspectives paper summarizes developments in characterizing stress orientations and (relative) magnitudes, including new seismic and borehole methods, as well as progress in identifying the causes of stress variations. Despite these advances, adding far more spatiotemporal detail would allow geoscientists to address many of today's key challenges regarding natural hazards, energy development, and geodynamics. In particular, it is critically important to characterize stress heterogeneity at multiple scales while also recognizing the coherent variability of the stress field. The second part of the paper considers how more detailed stress datasets could prove essential to addressing some of the grand questions in geoscience, including deciphering the poorly understood feedbacks between crustal dynamics and surface processes, improving earthquake and eruption forecasts, and determining the origins and shared properties of plate boundaries.
{"title":"Recent advances in characterizing the crustal stress field and future applications of stress data: Perspectives from North America","authors":"Jens-Erik Lundstern","doi":"10.1144/sp546-2023-195","DOIUrl":"https://doi.org/10.1144/sp546-2023-195","url":null,"abstract":"\u0000 \u0000 The stress field controls patterns of crustal deformation, including which faults are likeliest to cause earthquakes or transmit fluids. Since the 1950s, maps of maximum horizontal stress (\u0000 S\u0000 Hmax\u0000 ) orientations have advanced dramatically, and the style of faulting (relative principal stress magnitudes) has recently been mapped in some regions as well. This perspectives paper summarizes developments in characterizing stress orientations and (relative) magnitudes, including new seismic and borehole methods, as well as progress in identifying the causes of stress variations. Despite these advances, adding far more spatiotemporal detail would allow geoscientists to address many of today's key challenges regarding natural hazards, energy development, and geodynamics. In particular, it is critically important to characterize stress heterogeneity at multiple scales while also recognizing the coherent variability of the stress field. The second part of the paper considers how more detailed stress datasets could prove essential to addressing some of the grand questions in geoscience, including deciphering the poorly understood feedbacks between crustal dynamics and surface processes, improving earthquake and eruption forecasts, and determining the origins and shared properties of plate boundaries.\u0000","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"163 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140755020","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}
Old-world rainforests of the Palaeotropical kingdom became established at different times in different regions with changing opportunities for plant dispersals in relation to Late Cretaceous and Cenozoic plate movements and climate change. The Palaeotropical and Neotropical kingdoms differentiated in the Late Cretaceous. Maastrichtian records of fossil Dipterocarpus pollen from Sudan show that canopy-forming dipterocarp genera evolved in Africa and Dipterocarpoideae and other taxa dispersed to India with the Africa-India floristic interchange. As the Indian Plate drifted towards Asia in the Eocene multiple lineages dispersed to Southeast Asia from about 48 Myr onward, replacing a depauperate flora of East Asian affinity. Tectonic models for Southeast Asia are in conflict, and the different models impact strongly on how to interpret the subsequent evolution of Southeast Asian rainforests. The lowland floras of the islands of Eastern Indonesia and Oceania originated due to dispersals mainly from Southeast Asia and became established after those areas rose above sea level during the Neogene. Palaeotropical rainforests formed in equatorial Africa during the Campanian, India in the late Maastrichtian to Paleocene, Southeast Asia in the middle Eocene and Oceania in the Miocene. The current megadiverse Southeast Asian rainforests are essentially sourced from immigrants.
{"title":"The establishment of Palaeotropical rainforests from Africa to Oceania in relation to plate tectonics and zonal tropical climates","authors":"Robert J. Morley","doi":"10.1144/sp549-2023-73","DOIUrl":"https://doi.org/10.1144/sp549-2023-73","url":null,"abstract":"\u0000 \u0000 Old-world rainforests of the Palaeotropical kingdom became established at different times in different regions with changing opportunities for plant dispersals in relation to Late Cretaceous and Cenozoic plate movements and climate change. The Palaeotropical and Neotropical kingdoms differentiated in the Late Cretaceous. Maastrichtian records of fossil\u0000 Dipterocarpus\u0000 pollen from Sudan show that canopy-forming dipterocarp genera evolved in Africa and Dipterocarpoideae and other taxa dispersed to India with the Africa-India floristic interchange. As the Indian Plate drifted towards Asia in the Eocene multiple lineages dispersed to Southeast Asia from about 48 Myr onward, replacing a depauperate flora of East Asian affinity. Tectonic models for Southeast Asia are in conflict, and the different models impact strongly on how to interpret the subsequent evolution of Southeast Asian rainforests. The lowland floras of the islands of Eastern Indonesia and Oceania originated due to dispersals mainly from Southeast Asia and became established after those areas rose above sea level during the Neogene. Palaeotropical rainforests formed in equatorial Africa during the Campanian, India in the late Maastrichtian to Paleocene, Southeast Asia in the middle Eocene and Oceania in the Miocene. The current megadiverse Southeast Asian rainforests are essentially sourced from immigrants.\u0000","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":"57 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140378452","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}
G. Dupont-Nivet, T.N. Jonell, R. Dommain, P.D. Clift
How do tectonics and climate force surface processes and the evolution of biodiversity in Asia? This book examines some of the most biogeographically distinct and tectonically active areas on Earth today that straddle the highest mountains and spread across equatorial islands, offering insights into the complex processes driving their evolution.
{"title":"About this title - Asian Geodynamics, Climate and Biodiversity","authors":"G. Dupont-Nivet, T.N. Jonell, R. Dommain, P.D. Clift","doi":"10.1144/sp549-000","DOIUrl":"https://doi.org/10.1144/sp549-000","url":null,"abstract":"How do tectonics and climate force surface processes and the evolution of biodiversity in Asia? This book examines some of the most biogeographically distinct and tectonically active areas on Earth today that straddle the highest mountains and spread across equatorial islands, offering insights into the complex processes driving their evolution.","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":" 43","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140385294","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 Nordland area in northern Norway is the seismically most active area on mainland Fennoscandia. It exhibits patterns of coastal extension, which contrasts with the first-order regional stress pattern that reflects compression aligned with the North Atlantic ridge-push. The regional stress field has been considered to emanate from the interaction of ridge push and glacial isostatic adjustment; while the local stress pattern can be additionally influenced by gravitational, topographic stresses, as well as the flexural effects of erosion and sediment deposition. We employ finite element numerical models at a crustal scale to study the 3D stress field, using existing geometric constraints from previous geophysical studies. Internal body forces, induced by variations in density, topography or Moho depth, already yield significant deviatoric stresses. In the models tested, these can strongly influence the near-surface stress regime, in particular for the continental margin setting we are investigating. In addition, redistribution of rock mass, which occurred mainly under Pleistocene glaciation, can modify the stress field significantly on a semi-regional scale. We consider this process to be the main driver for the coastal extension, in particular in areas where erosion has been high. The northern Atlantic coast of Norway is an area of neotectonic activity and anomalous patterns in seismicity and land uplift. This study aims to improve our understanding of the present-day stress regime in this area. In addition, our study sheds light on the importance of stresses due to redistribution of sediments, a stress driver that is often neglected in stress studies. An earlier version of this manuscript was included in a non-peer reviewed project report (Gradmann et al., 2018).
{"title":"The 3D stress field of Nordland, northern Norway - insights from numerical modelling","authors":"S. Gradmann, O. Olesen, M. Keiding, Y. Maystrenko","doi":"10.1144/sp546-2023-163","DOIUrl":"https://doi.org/10.1144/sp546-2023-163","url":null,"abstract":"\u0000 The Nordland area in northern Norway is the seismically most active area on mainland Fennoscandia. It exhibits patterns of coastal extension, which contrasts with the first-order regional stress pattern that reflects compression aligned with the North Atlantic ridge-push. The regional stress field has been considered to emanate from the interaction of ridge push and glacial isostatic adjustment; while the local stress pattern can be additionally influenced by gravitational, topographic stresses, as well as the flexural effects of erosion and sediment deposition.\u0000 We employ finite element numerical models at a crustal scale to study the 3D stress field, using existing geometric constraints from previous geophysical studies. Internal body forces, induced by variations in density, topography or Moho depth, already yield significant deviatoric stresses. In the models tested, these can strongly influence the near-surface stress regime, in particular for the continental margin setting we are investigating.\u0000 In addition, redistribution of rock mass, which occurred mainly under Pleistocene glaciation, can modify the stress field significantly on a semi-regional scale. We consider this process to be the main driver for the coastal extension, in particular in areas where erosion has been high.\u0000 The northern Atlantic coast of Norway is an area of neotectonic activity and anomalous patterns in seismicity and land uplift. This study aims to improve our understanding of the present-day stress regime in this area. In addition, our study sheds light on the importance of stresses due to redistribution of sediments, a stress driver that is often neglected in stress studies. An earlier version of this manuscript was included in a non-peer reviewed project report (Gradmann et al., 2018).","PeriodicalId":281618,"journal":{"name":"Geological Society, London, Special Publications","volume":" 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381852","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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