El Soplao outcrop, an Early Cretaceous amber deposit recently discovered in northern Spain （Cantabria）, has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far. R...El Soplao outcrop, an Early Cretaceous amber deposit recently discovered in northern Spain （Cantabria）, has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far. Relevant data provided herein for biogeochemistry of the amber, palynology, taphonomy and arthropod bioinclusions complement those previously published. This set of data suggests at least two botanical sources for the amber of El Soplao deposit. The first （type A amber） strongly supports a source related to Cheirolepidiaceae, and the second （type B amber） shows non-specific conifer biomarkers. Comparison of molecular composition of type A amber with Frenelopsis leaves （Cheirolepidiaceae） strongly suggests a biochemical affinity and a common botanical origin. A preliminary palynological study indicates a regional high taxonomical diversity, mainly of pteridophyte spores and gymnosperm pollen grains. According to the preliminary palynological data, the region was inhabited by conifer forests adapted to a dry season under a subtropical climate. The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter, and subsequent great accumulation of amber plus plant cuticles. In addition, for the first time in the fossil record, charcoalified plant fibers as bioinclnsions in amber are reported. Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish-water and a mixed assemblage of amber. Lastly, new findings of insect bioiuclusions, some of them uncommon in the fossil record or showing remarkable adaptations, are reported. In conclusion, a documented scenario for the origin of the El Soplao amber outcrop is provided.展开更多
基于黄土高原南部白水河流域下河、南山头、西山、马坡等4处遗址共计2270块木炭记录,结合高精度的AMSC测年,恢复了研究区5.53~4.12 cal.ka B. P.时期木本植被特征和古气候变迁。共存生态因子分析结果和植被组合特征表明该时期的气候整...基于黄土高原南部白水河流域下河、南山头、西山、马坡等4处遗址共计2270块木炭记录,结合高精度的AMSC测年,恢复了研究区5.53~4.12 cal.ka B. P.时期木本植被特征和古气候变迁。共存生态因子分析结果和植被组合特征表明该时期的气候整体较今更加暖湿,但在百年尺度上仍存在气候变迁:5.05 cal.ka B. P.以后植被组合中亚热带种属数量及占比的增加表明气候较前一阶段更加暖湿;4.35~4.12 cal.ka B. P.时期的植被组合中耐旱种属比例增多,表明研究区的气候至少在4.35 cal.ka B. P.之前已经转干。研究区气候的变化对文化的发展产生了重要影响,适宜的气候可以促进文化的繁荣与发展;当气候恶化时,农业的发展可在一定程度上延缓文化的衰落,但持续上百年的气候恶化最终会导致文化的衰退甚至消亡。展开更多
This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to ...This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to establish the chronology of sedimentation and to propose palaeobotanical as well as geochemical evidence for the occurrence of wildfires in these sediments. The palynological investigation suggests a Scheuringipollenites barakarensis palynoassemblage from the lower Barakar Formation, dated as Artinskian(Early Permian) in age. This assemblage reveals the dominance of Glossopteridales and sub-dominance of taxa belonging to Cordaitales and Coniferales.Fossil charcoal in sediments is usually recognized as a direct indicator for the occurrence of palaeo-wildfires. More data involving the anatomical features of fossil charcoal analyzed by Field Emission Scanning Electronic Microscope broaden our knowledge on Early Permian wildfires from the peninsula of India. The studied macroscopic charcoal fragments exhibit anatomical details such as homogenized cell walls, uniseriate simple and biseriate alternate pitting on tracheid walls and rays of varying heights pointing to a gymnospermous wood affinitity. The excellent preservation of charcoal fragments, shown by their large sizes and almost unabraded edges, suggests a parautochthonous origin. The embedded biomarker study performed for charcoal sediments and its characterization demonstrate the presence of n-alkanes, isoprenoids, terpenoids and aromatic compounds. A bimodal distribution pattern of n-alkanes with a Cmaxat n-C25 is identified. Diterpenoids and pentacyclic terpenoids are identified, indicating the input of an early conifer vegetation and bacterial activity, respectively. The identified polyaromatic hydrocarbon(PAH) compounds, together with the charcoal fragments, clearly suggest that repeated wildfire events occurred during the deposition of these Artinskian sediments in the Rajmahal Basin.展开更多
基金supported by a scholarship from the Instituto Geologico y Minero de Espana(IGME),an APIF grant of the University of Barcelona,and a FPI grant from the Spanish Ministry of Science and Technology,respectivelya contribution of the IGME Project 491-CANOA 35015"Investigacion cientifica y tecnica de la Cueva de E1 Soplao y su entorno geologico"+1 种基金the projects CGL2008-/01237BTE from the MICINN,CGL2008- 00550/BTE:"Amber of the Cretaceous of Spain:A multidisciplinary study"the ANR Project AMBRACE BLAN07-1-184190
文摘El Soplao outcrop, an Early Cretaceous amber deposit recently discovered in northern Spain （Cantabria）, has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far. Relevant data provided herein for biogeochemistry of the amber, palynology, taphonomy and arthropod bioinclusions complement those previously published. This set of data suggests at least two botanical sources for the amber of El Soplao deposit. The first （type A amber） strongly supports a source related to Cheirolepidiaceae, and the second （type B amber） shows non-specific conifer biomarkers. Comparison of molecular composition of type A amber with Frenelopsis leaves （Cheirolepidiaceae） strongly suggests a biochemical affinity and a common botanical origin. A preliminary palynological study indicates a regional high taxonomical diversity, mainly of pteridophyte spores and gymnosperm pollen grains. According to the preliminary palynological data, the region was inhabited by conifer forests adapted to a dry season under a subtropical climate. The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter, and subsequent great accumulation of amber plus plant cuticles. In addition, for the first time in the fossil record, charcoalified plant fibers as bioinclnsions in amber are reported. Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish-water and a mixed assemblage of amber. Lastly, new findings of insect bioiuclusions, some of them uncommon in the fossil record or showing remarkable adaptations, are reported. In conclusion, a documented scenario for the origin of the El Soplao amber outcrop is provided.
文摘基于黄土高原南部白水河流域下河、南山头、西山、马坡等4处遗址共计2270块木炭记录,结合高精度的AMSC测年,恢复了研究区5.53~4.12 cal.ka B. P.时期木本植被特征和古气候变迁。共存生态因子分析结果和植被组合特征表明该时期的气候整体较今更加暖湿,但在百年尺度上仍存在气候变迁:5.05 cal.ka B. P.以后植被组合中亚热带种属数量及占比的增加表明气候较前一阶段更加暖湿;4.35~4.12 cal.ka B. P.时期的植被组合中耐旱种属比例增多,表明研究区的气候至少在4.35 cal.ka B. P.之前已经转干。研究区气候的变化对文化的发展产生了重要影响,适宜的气候可以促进文化的繁荣与发展;当气候恶化时,农业的发展可在一定程度上延缓文化的衰落,但持续上百年的气候恶化最终会导致文化的衰退甚至消亡。
基金This study was funded by the Birbal Sahni Institute of Palaeosciences,Department of Science and Technology,Lucknow,India Research Development and Coordination Committee(RDCC,Permission Number 10/2020–2021)。
文摘This study provides a combined analysis on the palynology, fossil charcoal and biomarkers of the subsurface coal deposits from a borehole RMB #2 drilled at the Dhulia Coal Block, Rajmahal Basin, India, in attempts to establish the chronology of sedimentation and to propose palaeobotanical as well as geochemical evidence for the occurrence of wildfires in these sediments. The palynological investigation suggests a Scheuringipollenites barakarensis palynoassemblage from the lower Barakar Formation, dated as Artinskian(Early Permian) in age. This assemblage reveals the dominance of Glossopteridales and sub-dominance of taxa belonging to Cordaitales and Coniferales.Fossil charcoal in sediments is usually recognized as a direct indicator for the occurrence of palaeo-wildfires. More data involving the anatomical features of fossil charcoal analyzed by Field Emission Scanning Electronic Microscope broaden our knowledge on Early Permian wildfires from the peninsula of India. The studied macroscopic charcoal fragments exhibit anatomical details such as homogenized cell walls, uniseriate simple and biseriate alternate pitting on tracheid walls and rays of varying heights pointing to a gymnospermous wood affinitity. The excellent preservation of charcoal fragments, shown by their large sizes and almost unabraded edges, suggests a parautochthonous origin. The embedded biomarker study performed for charcoal sediments and its characterization demonstrate the presence of n-alkanes, isoprenoids, terpenoids and aromatic compounds. A bimodal distribution pattern of n-alkanes with a Cmaxat n-C25 is identified. Diterpenoids and pentacyclic terpenoids are identified, indicating the input of an early conifer vegetation and bacterial activity, respectively. The identified polyaromatic hydrocarbon(PAH) compounds, together with the charcoal fragments, clearly suggest that repeated wildfire events occurred during the deposition of these Artinskian sediments in the Rajmahal Basin.
