Pub Date : 2024-10-22DOI: 10.1016/j.palaeo.2024.112572
Licheng Wang , Eduardo Garzanti , Heng Peng , Yalin Li , Lijian Shen , Songlin He , Yahui Yue , Waseem Khan , Lin Ding
Oceanic anoxic events (OAE) are global carbon-cycle perturbations and major paleoenvironmental changes documented by deposition of black shales rich in organic matter. Jurassic black shales exposed in the Biluo Co Section of the Qiangtang Basin (central Tibet) display a ∼ 3 % negative carbon isotope excursion (CIE) previously regarded as documenting the Toarcian T-OAE based on poorly preserved ammonites and one detrital zircon age. New biostratigraphic data on diagnostic calcareous nannofossils and ammonite assemblages have suggested a younger, Middle Jurassic age, thus raising doubts about the presence of the T-OAE in the Qiangtang Basin. We here present the first accurate in situ LA-ICPMS calcite UPb ages for carbonate layers intercalated in the Biluo Co section. Ages of 165.6 ± 3.7 Ma, 166 ± 16 Ma, and 164.0 ± 7.2 Ma obtained from two samples analyzed in two different laboratories indicate the Late Bathonian to mid-Callovian age, which is consistent with recent age assignments based on calcareous nannofossils and ammonites. Petrographic, geochemical, and C–O isotope analyses testify to only minor diagenetic effects, indicating that geochronological data do reflect the original timing of carbonate deposition. Therefore, the new age assignment does not document the T-OAE in the Qiangtang Basin, but possibly a younger, Callovian global-warming event.
{"title":"Discovery of the Callovian Oceanic Anoxic Event in the Qiangtang Basin, eastern Tethys: Insights from in situ calcite UPb dating","authors":"Licheng Wang , Eduardo Garzanti , Heng Peng , Yalin Li , Lijian Shen , Songlin He , Yahui Yue , Waseem Khan , Lin Ding","doi":"10.1016/j.palaeo.2024.112572","DOIUrl":"10.1016/j.palaeo.2024.112572","url":null,"abstract":"<div><div>Oceanic anoxic events (OAE) are global carbon-cycle perturbations and major paleoenvironmental changes documented by deposition of black shales rich in organic matter. Jurassic black shales exposed in the Biluo Co Section of the Qiangtang Basin (central Tibet) display a ∼ 3 % negative carbon isotope excursion (CIE) previously regarded as documenting the Toarcian T-OAE based on poorly preserved ammonites and one detrital zircon age. New biostratigraphic data on diagnostic calcareous nannofossils and ammonite assemblages have suggested a younger, Middle Jurassic age, thus raising doubts about the presence of the T-OAE in the Qiangtang Basin. We here present the first accurate in situ LA-ICPMS calcite U<img>Pb ages for carbonate layers intercalated in the Biluo Co section. Ages of 165.6 ± 3.7 Ma, 166 ± 16 Ma, and 164.0 ± 7.2 Ma obtained from two samples analyzed in two different laboratories indicate the Late Bathonian to mid-Callovian age, which is consistent with recent age assignments based on calcareous nannofossils and ammonites. Petrographic, geochemical, and C–O isotope analyses testify to only minor diagenetic effects, indicating that geochronological data do reflect the original timing of carbonate deposition. Therefore, the new age assignment does not document the T-OAE in the Qiangtang Basin, but possibly a younger, Callovian global-warming event.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"656 ","pages":"Article 112572"},"PeriodicalIF":2.6,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-19DOI: 10.1016/j.palaeo.2024.112565
Antigone Uzunidis , Jean-Philip Brugal , Roman Croitor , Joan Daura , Pierre Magniez , Joaquín Panera , Susana Rubio-Jara , Montserrat Sanz , Jose Yravedra , Florent Rivals
Haploidoceros mediterraneus is one of the recently described cervid taxa endemic to the Iberian Peninsula (three sites) and southern France (two sites). Compared to the other endemic cervids from Iberia that have emerged, as well, during the mid-Middle Pleistocene, its chronological and geographical range are more expanded, indicative of a relative adaptative success. However, very little is known about H. mediterraneus ecology. From site contexts and faunal associations, its habitat during the Middle and Late Pleistocene corresponded to open forest under a mildly-humid temperate Mediterranean or semi-continental climate. First, its diet was reconstructed using dental meso- and microwear and second, its relationships with other cervids over time was analysed using Multiple Component Analysis (MCA). Diet reconstruction indicates that it was mostly a browse-dominated mixed-feeder during the Middle Pleistocene. Such a relatively flexible diet has allowed it to coexist, often with some cervid taxa (Cervus and Capreolus) and exceptionally with others (Praedama/Megaloceros and Dama sp.) by resource partitioning. During the Late Pleistocene, H. mediterraneus shifted toward a more browse-specialized diet. At this period, co-occurrence analyses show that the presence of H. mediterraneus seems to exclude that of C. capreolus and D. dama. The evolution of H. mediterraneus dietary habits from the Middle to the Late Pleistocene may have led to direct competition with other browsing-specialist cervids, which may be one of the causes of its extinction.
{"title":"Paleoecology of an extinct Cervidae (Haploidoceros mediterraneus) of the Middle-late Pleistocene in Southern Europe","authors":"Antigone Uzunidis , Jean-Philip Brugal , Roman Croitor , Joan Daura , Pierre Magniez , Joaquín Panera , Susana Rubio-Jara , Montserrat Sanz , Jose Yravedra , Florent Rivals","doi":"10.1016/j.palaeo.2024.112565","DOIUrl":"10.1016/j.palaeo.2024.112565","url":null,"abstract":"<div><div><em>Haploidoceros mediterraneus</em> is one of the recently described cervid taxa endemic to the Iberian Peninsula (three sites) and southern France (two sites). Compared to the other endemic cervids from Iberia that have emerged, as well, during the mid-Middle Pleistocene, its chronological and geographical range are more expanded, indicative of a relative adaptative success. However, very little is known about <em>H. mediterraneus</em> ecology. From site contexts and faunal associations, its habitat during the Middle and Late Pleistocene corresponded to open forest under a mildly-humid temperate Mediterranean or semi-continental climate. First, its diet was reconstructed using dental meso- and microwear and second, its relationships with other cervids over time was analysed using Multiple Component Analysis (MCA). Diet reconstruction indicates that it was mostly a browse-dominated mixed-feeder during the Middle Pleistocene. Such a relatively flexible diet has allowed it to coexist, often with some cervid taxa (<em>Cervus</em> and <em>Capreolus</em>) and exceptionally with others (<em>Praedama</em>/<em>Megaloceros</em> and <em>Dama</em> sp.) by resource partitioning. During the Late Pleistocene, <em>H. mediterraneus</em> shifted toward a more browse-specialized diet. At this period, co-occurrence analyses show that the presence of <em>H. mediterraneus</em> seems to exclude that of <em>C. capreolus</em> and <em>D. dama</em>. The evolution of <em>H. mediterraneus</em> dietary habits from the Middle to the Late Pleistocene may have led to direct competition with other browsing-specialist cervids, which may be one of the causes of its extinction.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"656 ","pages":"Article 112565"},"PeriodicalIF":2.6,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.palaeo.2024.112564
N. Toledo , N.A. Muñoz , M.S. Bargo , V. Krapovickas , M.L. Taglioretti , L.M. Pérez , M.A. Zárate , S.F. Vizcaíno , M. Arregui , A. Boscaini , F.I. Isla , A.I. Vassallo , F. Scaglia
Pliocene and Pleistocene sedimentary successions in the Pampean region of Argentina contain abundant and diverse fossil mammalian burrows. In this paper, we report fossil burrows from eight localities from near Miramar to the northern area of Mar del Plata, spanning the Early Pliocene to the Late Pleistocene, and analyze burrow size patterns. The minimum width of each fossil burrow was measured as an indicator of its diameter. Available allometric equations for extant burrowing vertebrates were used to estimate the body size of potential producers based on burrow diameter. Size distribution patterns indicate that, in the Early Pliocene to Early Pleistocene levels, small burrows (attributed to rodents, typotheres, and small armadillos) were abundant, while medium- to large-sized burrows (attributed to large cingulates) were less common. In the Middle to Late Pleistocene levels, small burrows are very scarce, and medium-sized burrows are most abundant, together with giant burrows (attributed to ground sloths). Our findings indicate a significant size diversity for Pliocene–Pleistocene burrowing mammals in the studied area, from small rodents to giant ground sloths. Although present in Pliocene to Early Pleistocene times, the largest ground sloths began to build subterranean galleries only later in the Middle to Late Pleistocene. Small burrowers were comparatively less active during that time. These patterns are discussed in the light of paleoclimate and paleoecology of the putative guild of extinct burrowers, to develop working hypotheses for future studies. A paleoclimatic shift from Pliocene Climate Optimum to more arid and colder conditions from the Late Pliocene to Late Pleistocene, and the incursion of large predators to the region, are proposed as major factors promoting large ground sloths to adopt a fossorial lifestyle.
{"title":"Paleoecology and diversity of Pliocene to Pleistocene fossorial mammals in the Pampean region of Argentina based on a quantitative analysis of fossil burrows","authors":"N. Toledo , N.A. Muñoz , M.S. Bargo , V. Krapovickas , M.L. Taglioretti , L.M. Pérez , M.A. Zárate , S.F. Vizcaíno , M. Arregui , A. Boscaini , F.I. Isla , A.I. Vassallo , F. Scaglia","doi":"10.1016/j.palaeo.2024.112564","DOIUrl":"10.1016/j.palaeo.2024.112564","url":null,"abstract":"<div><div>Pliocene and Pleistocene sedimentary successions in the Pampean region of Argentina contain abundant and diverse fossil mammalian burrows. In this paper, we report fossil burrows from eight localities from near Miramar to the northern area of Mar del Plata, spanning the Early Pliocene to the Late Pleistocene, and analyze burrow size patterns. The minimum width of each fossil burrow was measured as an indicator of its diameter. Available allometric equations for extant burrowing vertebrates were used to estimate the body size of potential producers based on burrow diameter. Size distribution patterns indicate that, in the Early Pliocene to Early Pleistocene levels, small burrows (attributed to rodents, typotheres, and small armadillos) were abundant, while medium- to large-sized burrows (attributed to large cingulates) were less common. In the Middle to Late Pleistocene levels, small burrows are very scarce, and medium-sized burrows are most abundant, together with giant burrows (attributed to ground sloths). Our findings indicate a significant size diversity for Pliocene–Pleistocene burrowing mammals in the studied area, from small rodents to giant ground sloths. Although present in Pliocene to Early Pleistocene times, the largest ground sloths began to build subterranean galleries only later in the Middle to Late Pleistocene. Small burrowers were comparatively less active during that time. These patterns are discussed in the light of paleoclimate and paleoecology of the putative guild of extinct burrowers, to develop working hypotheses for future studies. A paleoclimatic shift from Pliocene Climate Optimum to more arid and colder conditions from the Late Pliocene to Late Pleistocene, and the incursion of large predators to the region, are proposed as major factors promoting large ground sloths to adopt a fossorial lifestyle.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112564"},"PeriodicalIF":2.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-18DOI: 10.1016/j.palaeo.2024.112563
Xiao-Mei Li , Jia-Yi Chen , Zhen-Dong Cao , Li-Ming Liu , Si-Hang Zhang , Yun-Zhe Zhang , Li-Jie Wei , San-Ping Xie
The uplift of the Tibetan Plateau (TP) during the Cenozoic has played a pivotal role in shaping global climate and vegetation evolution, however, understanding the uplift history of its various tectonic blocks remains complex. In this paper, we analyze palynological samples from the Miocene Xiayoushashan and Shangyoushashan formations in the Wulan Basin to explore the relationship between climate change and TP uplift. The analysis identified four distinct pollen zones: Zone I (18–15.3 Ma) characterized by Artemisia-Lycopodium-Aster-Polygonaceae; Zone II (15.3–12.7 Ma) dominated by Pinus-Picea-Aster-Artemisia; Zone III (12.7–11.7 Ma) featuring Lycopodium-Picea-Pinus-Polygonaceae; Zone IV (11.7–8.7 Ma) characterized by Picea-Chenopodiaceae-Lycopodium-Artemisia. Results indicate that the whole study interval was dominated by shrubs and grasses, interspersed with conifers and broad-leaved trees, exhibiting an altitudinally zonal pattern. Using the Coexistence Likelihood Estimation (CRACLE) method, we estimate a mean annual temperature (MAT) ranging from 6.0 to 14.7 °C and a mean annual precipitation (MAP) between 919.1 and 1612.4 mm during Miocene period. While minor climatic fluctuations occurred, the region experienced a cool-temperate and sub-humid climate significantly warmer and more humid conditions compared to the present. Based on MAT differences, the paleoelevation of the Wulan Basin during the Miocene was estimated to be c. 1655–2025 m, suggesting an uplift of c. 1275–1645 m since that time. These findings corroborate previous suggestions that the northeastern TP had not reached its current elevation prior to the Late Miocene.
{"title":"Miocene evolution of vegetation, climate, and elevation in the Wulan Basin of northeast Tibetan Plateau based on a CRACLE analysis of palynological assemblages","authors":"Xiao-Mei Li , Jia-Yi Chen , Zhen-Dong Cao , Li-Ming Liu , Si-Hang Zhang , Yun-Zhe Zhang , Li-Jie Wei , San-Ping Xie","doi":"10.1016/j.palaeo.2024.112563","DOIUrl":"10.1016/j.palaeo.2024.112563","url":null,"abstract":"<div><div>The uplift of the Tibetan Plateau (TP) during the Cenozoic has played a pivotal role in shaping global climate and vegetation evolution, however, understanding the uplift history of its various tectonic blocks remains complex. In this paper, we analyze palynological samples from the Miocene Xiayoushashan and Shangyoushashan formations in the Wulan Basin to explore the relationship between climate change and TP uplift. The analysis identified four distinct pollen zones: Zone I (18–15.3 Ma) characterized by <em>Artemisia</em>-<em>Lycopodium</em>-<em>Aster</em>-Polygonaceae; Zone II (15.3–12.7 Ma) dominated by <em>Pinus</em>-<em>Picea</em>-<em>Aster</em>-<em>Artemisia</em>; Zone III (12.7–11.7 Ma) featuring <em>Lycopodium</em>-<em>Picea</em>-<em>Pinus</em>-Polygonaceae; Zone IV (11.7–8.7 Ma) characterized by <em>Picea</em>-Chenopodiaceae-<em>Lycopodium</em>-<em>Artemisia</em>. Results indicate that the whole study interval was dominated by shrubs and grasses, interspersed with conifers and broad-leaved trees, exhibiting an altitudinally zonal pattern. Using the Coexistence Likelihood Estimation (CRACLE) method, we estimate a mean annual temperature (MAT) ranging from 6.0 to 14.7 °C and a mean annual precipitation (MAP) between 919.1 and 1612.4 mm during Miocene period. While minor climatic fluctuations occurred, the region experienced a cool-temperate and sub-humid climate significantly warmer and more humid conditions compared to the present. Based on MAT differences, the paleoelevation of the Wulan Basin during the Miocene was estimated to be c. 1655–2025 m, suggesting an uplift of c. 1275–1645 m since that time. These findings corroborate previous suggestions that the northeastern TP had not reached its current elevation prior to the Late Miocene.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"656 ","pages":"Article 112563"},"PeriodicalIF":2.6,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-17DOI: 10.1016/j.palaeo.2024.112560
Page C. Quinton, Michael C. Rygel, Anah Bogdan, Lauryn Higgins, Ty Paddock, Caroline Winstead, Chelsea Wright
The Guadalupian Permian Reef Complex of the Delaware Basin is one of the most studied carbonate reef systems of the Paleozoic. Despite extensive work on the carbonate sedimentology, sequence stratigraphy, and diagenetic history of the Delaware Basin, a high-resolution carbonate carbon isotope record along a platform to basin transect for the Capitanian (264.3–259.5 Ma, the youngest age of the Guadalupian Epoch) does not yet exist. The carbon isotopic record of the Delaware Basin is important because 1) it allows us to test hypotheses about controls on the carbon isotope proxy, 2) it provides constraints on how well modern carbonate platforms like the Great Bahama Banks serve as analogues for ancient carbonate settings, and 3) these types of restricted basins likely played an important role in Permian carbon cycling and the Capitanian extinctions.
In this study we present 493 new Capitanian carbonate carbon isotopic values paired with a detailed sedimentological and sequence stratigraphic framework from the platform, slope, toe of slope, and deep basin of the Delaware Basin. The bulk of the new δ13C values fall within the range of previously reported unaltered carbonates from the basin, suggesting that these results record primary environmental processes and were not significantly altered by diagenetic overprinting. With this dataset, we test hypotheses about sources of carbon isotopic variability in shallow carbonate platforms. Our results indicate that in the Delaware Basin there are no systematic and resolvable depth or lateral gradients in carbon isotopic values, that δ13C values do not vary as a function of grain type, and that there is no resolvable relationship between carbon isotopic composition and sea level change. However, we do document statistically significant differences in δ13C distributions among facies associations which we attribute to the isotopic evolution of an upwelling water mass due to direct precipitation of mud along the slope. Our results support the idea that increasing carbon isotopic values through the Capitanian were driven by increased organic carbon burial in restricted basins.
{"title":"Carbon isotopic record of a platform-to-basin transect through the Permian Reef Complex (Guadalupian) in the Delaware Basin of Texas and New Mexico","authors":"Page C. Quinton, Michael C. Rygel, Anah Bogdan, Lauryn Higgins, Ty Paddock, Caroline Winstead, Chelsea Wright","doi":"10.1016/j.palaeo.2024.112560","DOIUrl":"10.1016/j.palaeo.2024.112560","url":null,"abstract":"<div><div>The Guadalupian Permian Reef Complex of the Delaware Basin is one of the most studied carbonate reef systems of the Paleozoic. Despite extensive work on the carbonate sedimentology, sequence stratigraphy, and diagenetic history of the Delaware Basin, a high-resolution carbonate carbon isotope record along a platform to basin transect for the Capitanian (264.3–259.5 Ma, the youngest age of the Guadalupian Epoch) does not yet exist. The carbon isotopic record of the Delaware Basin is important because 1) it allows us to test hypotheses about controls on the carbon isotope proxy, 2) it provides constraints on how well modern carbonate platforms like the Great Bahama Banks serve as analogues for ancient carbonate settings, and 3) these types of restricted basins likely played an important role in Permian carbon cycling and the Capitanian extinctions.</div><div>In this study we present 493 new Capitanian carbonate carbon isotopic values paired with a detailed sedimentological and sequence stratigraphic framework from the platform, slope, toe of slope, and deep basin of the Delaware Basin. The bulk of the new δ<sup>13</sup>C values fall within the range of previously reported unaltered carbonates from the basin, suggesting that these results record primary environmental processes and were not significantly altered by diagenetic overprinting. With this dataset, we test hypotheses about sources of carbon isotopic variability in shallow carbonate platforms. Our results indicate that in the Delaware Basin there are no systematic and resolvable depth or lateral gradients in carbon isotopic values, that δ<sup>13</sup>C values do not vary as a function of grain type, and that there is no resolvable relationship between carbon isotopic composition and sea level change. However, we do document statistically significant differences in δ<sup>13</sup>C distributions among facies associations which we attribute to the isotopic evolution of an upwelling water mass due to direct precipitation of mud along the slope. Our results support the idea that increasing carbon isotopic values through the Capitanian were driven by increased organic carbon burial in restricted basins.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112560"},"PeriodicalIF":2.6,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.palaeo.2024.112561
Zixuan Wang , Shuang Dai , Tianqi Ji , Xiaojun Ma , Zhongzhao Ding , Zhaobin Zhang , Chunyan Li , Jiayi Xing
Knowledge of the climate of the Late Eocene is important for understanding the global climatic shift from a global Warmhouse to a Coolhouse. We obtained a climatic record for the interval of 38.10–36.33 Ma based on sedimentary facies analysis combined with measurements of color indices (CI) and magnetic susceptibility (MS) of the lower Huoshaogou Formation in the westernmost Hexi Corridor, Northeastern Tibetan Plateau. Our results reveal the following temporal sequence of sedimentary environments: delta plain, shore–shallow lake, deep lake, and braided river. The records of MS and CI co-vary with changes in sedimentary facies and color, respectively. The various proxy indicators indicate an overall warm and dry climate interrupted by a cold and wet interval in the middle part of the section during ∼37.67–36.44 Ma, corresponding to a thick, greenish-colored lacustrine sedimentary layer with high values of lightness and low valuer of MS, frequency-dependent MS and redness. We suggest that this event was driven by the diversion of westerly winds due to the uplift of the southern Tibetan Plateau, together with the Tethys Sea retreat and the short-lived emergence or enhancement of the Asian monsoon.
了解晚始新世的气候对于理解全球气候从 "暖温带 "向 "冷温带 "的转变非常重要。我们通过对青藏高原东北部河西走廊最西端的老虎沟地层下部进行沉积面分析，并结合色度指数（CI）和磁感应强度（MS）的测量，获得了38.10-36.33 Ma期间的气候记录。我们的研究结果揭示了以下沉积环境的时间序列：三角洲平原、滨浅湖、深湖和辫状河。MS和CI的记录分别与沉积面和颜色的变化共同变化。各种代用指标表明，在 37.67-36.44 Ma 期间，该剖面的中段出现了一个寒冷和潮湿的间歇期，与之相对应的是厚厚的绿色湖相沉积层，其亮度值较高，而 MS、频率相关的 MS 和红度值较低。我们认为，这一事件是由青藏高原南部隆升导致的西风转向、特提斯海退缩以及亚洲季风的短暂出现或增强所驱动的。
{"title":"Middle - Late Eocene cold and wet climatic interval in East Asia: Evidence from lacustrine sediments of the lower Huoshaogou Formation in the Hexi Corridor, NE Tibetan Plateau","authors":"Zixuan Wang , Shuang Dai , Tianqi Ji , Xiaojun Ma , Zhongzhao Ding , Zhaobin Zhang , Chunyan Li , Jiayi Xing","doi":"10.1016/j.palaeo.2024.112561","DOIUrl":"10.1016/j.palaeo.2024.112561","url":null,"abstract":"<div><div>Knowledge of the climate of the Late Eocene is important for understanding the global climatic shift from a global Warmhouse to a Coolhouse. We obtained a climatic record for the interval of 38.10–36.33 Ma based on sedimentary facies analysis combined with measurements of color indices (CI) and magnetic susceptibility (MS) of the lower Huoshaogou Formation in the westernmost Hexi Corridor, Northeastern Tibetan Plateau. Our results reveal the following temporal sequence of sedimentary environments: delta plain, shore–shallow lake, deep lake, and braided river. The records of MS and CI co-vary with changes in sedimentary facies and color, respectively. The various proxy indicators indicate an overall warm and dry climate interrupted by a cold and wet interval in the middle part of the section during ∼37.67–36.44 Ma, corresponding to a thick, greenish-colored lacustrine sedimentary layer with high values of lightness and low valuer of MS, frequency-dependent MS and redness. We suggest that this event was driven by the diversion of westerly winds due to the uplift of the southern Tibetan Plateau, together with the Tethys Sea retreat and the short-lived emergence or enhancement of the Asian monsoon.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112561"},"PeriodicalIF":2.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.palaeo.2024.112562
Zhong Han , Santanu Banerjee , Jacopo Dal Corso , Xiumian Hu , David B. Kemp
The Mesozoic–Paleogene hyperthermals represent critical intervals of rapid global warming associated with abrupt carbon cycle perturbations. These events can provide valuable deep-time insights into how climate might respond to the current rise in temperatures driven by anthropogenic greenhouse gas emissions. This special issue comprises 17 publications that cover a broad spectrum of the research on hyperthermals, and these can be grouped into four main themes: (1) carbon-cycle perturbations, (2) environmental changes and biogeochemical extremes, (3) biotic responses to warming, and (4) long-term climatic and environmental changes in greenhouse climates. By integrating sedimentological, geochemical, and paleontological methods, the studies in this issue explore carbon sources and release mechanisms, provide insights into the initiation, development, and termination of hyperthermal events, and elucidate their longer-term impacts. The studies provide new insights into the interactions between short-term extreme events and long-term climate trends, offering valuable perspectives on the future trajectory of Earth's climate in response to ongoing anthropogenic warming.
{"title":"Editorial preface to special issue: Response of marine and terrestrial environments to Triassic–Paleogene hyperthermals","authors":"Zhong Han , Santanu Banerjee , Jacopo Dal Corso , Xiumian Hu , David B. Kemp","doi":"10.1016/j.palaeo.2024.112562","DOIUrl":"10.1016/j.palaeo.2024.112562","url":null,"abstract":"<div><div>The Mesozoic–Paleogene hyperthermals represent critical intervals of rapid global warming associated with abrupt carbon cycle perturbations. These events can provide valuable deep-time insights into how climate might respond to the current rise in temperatures driven by anthropogenic greenhouse gas emissions. This special issue comprises 17 publications that cover a broad spectrum of the research on hyperthermals, and these can be grouped into four main themes: (1) carbon-cycle perturbations, (2) environmental changes and biogeochemical extremes, (3) biotic responses to warming, and (4) long-term climatic and environmental changes in greenhouse climates. By integrating sedimentological, geochemical, and paleontological methods, the studies in this issue explore carbon sources and release mechanisms, provide insights into the initiation, development, and termination of hyperthermal events, and elucidate their longer-term impacts. The studies provide new insights into the interactions between short-term extreme events and long-term climate trends, offering valuable perspectives on the future trajectory of Earth's climate in response to ongoing anthropogenic warming.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112562"},"PeriodicalIF":2.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-15DOI: 10.1016/j.palaeo.2024.112558
Igor Hamid , Mariana Silvestre Martins , Antônio Álamo Feitosa Saraiva , Ana Paula Aquino Benigno , Flaviana Jorge de Lima , Renan Alfredo Machado Bantim , Alcides Nobrega Sial , José Edvar Aguiar , Minh Thao Nguyen Duong , Duc Huy Dang , Luiz Drude de Lacerda
Geochemical records from the Cretaceous (Aptian) Crato paleolake in Brazil reveal the influence of volcanism and wet-dry paleoclimatic variations on the lake system and improve understanding of the mass mortalities represented by Konservat-Laggerstätte assemblages in the deposits. Specifically, we used paleoredox (PbEF, MnEF, UEF, VEF, MoEF, FeEF, V/Cr and U/Th ratios) and paleoproductivity (PEF, CuEF, ZnEF, NiEF, BaEF, and δ13CVPDB) indexes to elucidate changes in detrital input (Al and Fe), paleoclimate (Sr/Cu, C- values, Sr/Al and Mg/Al), paleosalinity (Sr/Ba and Rb/K), and lake level (Fe/Mn and δ18OVPDB), and their linkage to episodes of volcanism (Hg/Al and Hg/Fe). The mass mortalities of lacustrine organisms are found to be closely related to paleoclimatic variations. During dry episodes, the lake became more saline and alkaline, which impeded the larval development and the maturation of mayflies (Ephemeroptera), and triggered mass mortality events of these organisms. During wet periods, metal enrichment indicates that a rise in paleoproductivity may have caused hypoxia, thereby inducing the mass mortality events among Dastilbe fish. Mercury anomalies suggest that extrusion of Rajmahal-Kerguelen Plateau basalts in the late Aptian times influenced regional paleoclimatic and depositional processes, and may have been ultimately responsible for generating the Konservat-Lagerstätte of the Crato paleolake.
{"title":"Geochemical analysis of mass mortality events in the Cretaceous (Aptian) Konservatt-Lagerstätte of Crato paleolake, Brazil","authors":"Igor Hamid , Mariana Silvestre Martins , Antônio Álamo Feitosa Saraiva , Ana Paula Aquino Benigno , Flaviana Jorge de Lima , Renan Alfredo Machado Bantim , Alcides Nobrega Sial , José Edvar Aguiar , Minh Thao Nguyen Duong , Duc Huy Dang , Luiz Drude de Lacerda","doi":"10.1016/j.palaeo.2024.112558","DOIUrl":"10.1016/j.palaeo.2024.112558","url":null,"abstract":"<div><div>Geochemical records from the Cretaceous (Aptian) Crato paleolake in Brazil reveal the influence of volcanism and wet-dry paleoclimatic variations on the lake system and improve understanding of the mass mortalities represented by Konservat-Laggerstätte assemblages in the deposits. Specifically, we used paleoredox (Pb<sup>EF</sup>, Mn<sup>EF</sup>, U<sup>EF</sup>, V<sup>EF</sup>, Mo<sup>EF</sup>, Fe<sup>EF</sup>, V/Cr and U/Th ratios) and paleoproductivity (P<sup>EF</sup>, Cu<sup>EF</sup>, Zn<sup>EF</sup>, Ni<sup>EF</sup>, Ba<sup>EF</sup>, and δ<sup>13</sup>C<sub>VPDB</sub>) indexes to elucidate changes in detrital input (Al and Fe), paleoclimate (Sr/Cu, C- values, Sr/Al and Mg/Al), paleosalinity (Sr/Ba and Rb/K), and lake level (Fe/Mn and δ<sup>18</sup>O<sub>VPDB</sub>), and their linkage to episodes of volcanism (Hg/Al and Hg/Fe). The mass mortalities of lacustrine organisms are found to be closely related to paleoclimatic variations. During dry episodes, the lake became more saline and alkaline, which impeded the larval development and the maturation of mayflies (Ephemeroptera), and triggered mass mortality events of these organisms. During wet periods, metal enrichment indicates that a rise in paleoproductivity may have caused hypoxia, thereby inducing the mass mortality events among <em>Dastilbe</em> fish. Mercury anomalies suggest that extrusion of Rajmahal-Kerguelen Plateau basalts in the late Aptian times influenced regional paleoclimatic and depositional processes, and may have been ultimately responsible for generating the Konservat-Lagerstätte of the Crato paleolake.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112558"},"PeriodicalIF":2.6,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-12DOI: 10.1016/j.palaeo.2024.112559
Li-Jun Zhang , Luis A. Buatois , M. Gabriela Mángano , Ruoying Fan , Qiqi Yang , Fan Wei , Zhen Wang , Xiaoya Ma
Microbial mats sealed the sea bottom, becoming the food supply of many early metazoans, which exploited this resource in multiple ways during the late Ediacaran and earliest Cambrian. The onset of highly penetrative bioturbation in shallow-marine environments later in the early Cambrian removed this seal, resulting in the protracted restriction of microbial mats to marginal- and deep-marine environments. In this study, we demonstrate that the undermat-miner trace fossil Oldhamia followed the pattern of matground restriction to deep-marine environments. This is shown by a dataset compilation of Cambrian Oldhamia based on a comprehensive review of the literature with addition of recently discovered Oldhamia in the Cambrian strata of North and South China. Oldhamia is one of the most distinctive and widely distributed ichnogenera in early to middle Cambrian siliciclastic successions. It consists of semi-permanent, very shallow-tier, undermat-miner structures produced by stationary vermiform organisms. Despite its importance, details of Oldhamia ichnodiversity trajectories at ichnospecies level, environmental trends, and potential palaeogeographic patterns have not been explored. Our results demonstrate that Oldhamia displays high diversification in Fortunian shallow- and deep-marine settings, representing a signal of the Cambrian Information Revolution. Oldhamia alata and O. geniculata only occurred in shallow-marine settings, O. curvata and O. flabellata were restricted to the deep sea, and O. antiqua and O. radiata ranged from shallow- to deep-marine settings. The producers of Oldhamia retreated into deep sea since the end of the Fortunian mirroring the restriction of matgrounds as a response of intense bioturbation in shallow-marine deposits during the Agronomic Revolution. The producers of Oldhamia originated from the Iapetus Ocean and then migrated into other oceans, most likely through dispersal assisted by ocean currents.
{"title":"Evolution and palaeoenvironmental migration of a Cambrian undermat miner","authors":"Li-Jun Zhang , Luis A. Buatois , M. Gabriela Mángano , Ruoying Fan , Qiqi Yang , Fan Wei , Zhen Wang , Xiaoya Ma","doi":"10.1016/j.palaeo.2024.112559","DOIUrl":"10.1016/j.palaeo.2024.112559","url":null,"abstract":"<div><div>Microbial mats sealed the sea bottom, becoming the food supply of many early metazoans, which exploited this resource in multiple ways during the late Ediacaran and earliest Cambrian. The onset of highly penetrative bioturbation in shallow-marine environments later in the early Cambrian removed this seal, resulting in the protracted restriction of microbial mats to marginal- and deep-marine environments. In this study, we demonstrate that the undermat-miner trace fossil <em>Oldhamia</em> followed the pattern of matground restriction to deep-marine environments. This is shown by a dataset compilation of Cambrian <em>Oldhamia</em> based on a comprehensive review of the literature with addition of recently discovered <em>Oldhamia</em> in the Cambrian strata of North and South China. <em>Oldhamia</em> is one of the most distinctive and widely distributed ichnogenera in early to middle Cambrian siliciclastic successions. It consists of semi-permanent, very shallow-tier, undermat-miner structures produced by stationary vermiform organisms. Despite its importance, details of <em>Oldhamia</em> ichnodiversity trajectories at ichnospecies level, environmental trends, and potential palaeogeographic patterns have not been explored. Our results demonstrate that <em>Oldhamia</em> displays high diversification in Fortunian shallow- and deep-marine settings, representing a signal of the Cambrian Information Revolution. <em>Oldhamia alata</em> and <em>O. geniculata</em> only occurred in shallow-marine settings, <em>O. curvata</em> and <em>O. flabellata</em> were restricted to the deep sea, and <em>O. antiqua</em> and <em>O. radiata</em> ranged from shallow- to deep-marine settings. The producers of <em>Oldhamia</em> retreated into deep sea since the end of the Fortunian mirroring the restriction of matgrounds as a response of intense bioturbation in shallow-marine deposits during the Agronomic Revolution. The producers of <em>Oldhamia</em> originated from the Iapetus Ocean and then migrated into other oceans, most likely through dispersal assisted by ocean currents.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112559"},"PeriodicalIF":2.6,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-11DOI: 10.1016/j.palaeo.2024.112557
Qiangqiang Kou , Liping Zhu , Junbo Wang , Qingfeng Ma , Jianting Ju
Understanding the past climatic conditions and their possible driving mechanism can contribute to better constrain future climate projection, and to provide potential insights into the disputed Holocene temperature variations. In this study, we quantitatively reconstruct the mean annual air temperature (MAAT) of Serling Co since 17.3 cal kyr BP using a novel terrestrial thermometer (ring index of OH-GDGTs, RI-OH), and reconstructed the hydroclimatic evolutionary history in combination with n-alkanes and their associated proxies. Our temperature records indicate that Serling Co experienced a period of reduced temperatures during the Younger Dryas event, approximately 6 °C cooler than the present conditions. Subsequently, there was a rapid warming phase, leading to peak temperatures in the early Holocene, roughly 5.5 °C warmer than the modern MAAT, followed by a protracted cooling trend during the subsequent middle and late Holocene. The temperature and hydroclimate trends at Serling Co exhibit a synchronized evolutionary pattern since the last deglaciation, featuring an optimal hydrothermal combination in the early Holocene. This period witnessed the peak productivity of terrestrial and aquatic ecosystems, followed by a gradual decline. Summer insolation emerges as a primary controlling factor for temperature variations, with Indian Summer Monsoon intensity and internal climate system variability exerting dominance over atmospheric moisture and precipitation variations in the region.
了解过去的气候条件及其可能的驱动机制有助于更好地制约未来的气候预测，并提供对有争议的全新世温度变化的潜在见解。在这项研究中，我们利用一种新型陆地温度计（OH-GDGTs环指数，RI-OH）定量重建了自17.3 cal kyr BP以来塞林格年平均气温（MAAT），并结合正构烷烃及其相关代用指标重建了水文气候演化史。我们的气温记录表明，塞林格公司在少干世经历了一段气温降低期，比现在的气温低约 6 °C。随后，出现了一个快速变暖阶段，导致全新世早期温度达到峰值，比现代 MAAT 温度高出约 5.5 °C，随后在全新世中期和晚期出现了长期的降温趋势。塞林公司的温度和水文气候趋势显示了自上一次冰期以来的同步演化模式，其特点是全新世早期的最佳热液组合。在这一时期，陆地和水生生态系统的生产力达到顶峰，随后逐渐衰退。夏季日照成为气温变化的主要控制因素，印度夏季季风强度和内部气候系统变异对该地区的大气湿度和降水变化起着主导作用。
{"title":"Reconstruction of temperature and hydroclimate in Serling Co (Central Tibet) since the last deglaciation","authors":"Qiangqiang Kou , Liping Zhu , Junbo Wang , Qingfeng Ma , Jianting Ju","doi":"10.1016/j.palaeo.2024.112557","DOIUrl":"10.1016/j.palaeo.2024.112557","url":null,"abstract":"<div><div>Understanding the past climatic conditions and their possible driving mechanism can contribute to better constrain future climate projection, and to provide potential insights into the disputed Holocene temperature variations. In this study, we quantitatively reconstruct the mean annual air temperature (MAAT) of Serling Co since 17.3 cal kyr BP using a novel terrestrial thermometer (ring index of OH-GDGTs, RI-OH), and reconstructed the hydroclimatic evolutionary history in combination with <em>n</em>-alkanes and their associated proxies. Our temperature records indicate that Serling Co experienced a period of reduced temperatures during the Younger Dryas event, approximately 6 °C cooler than the present conditions. Subsequently, there was a rapid warming phase, leading to peak temperatures in the early Holocene, roughly 5.5 °C warmer than the modern MAAT, followed by a protracted cooling trend during the subsequent middle and late Holocene. The temperature and hydroclimate trends at Serling Co exhibit a synchronized evolutionary pattern since the last deglaciation, featuring an optimal hydrothermal combination in the early Holocene. This period witnessed the peak productivity of terrestrial and aquatic ecosystems, followed by a gradual decline. Summer insolation emerges as a primary controlling factor for temperature variations, with Indian Summer Monsoon intensity and internal climate system variability exerting dominance over atmospheric moisture and precipitation variations in the region.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112557"},"PeriodicalIF":2.6,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号