The analysis of the ostracods from three boreholes (1AS-7D-AM, 1AS-8-AM, and 1AS-31-AM) drilled in Atalaia do Norte town, Amazonas State, Brazil, allowed to recognize 30 species and nine genera. Cyprideis is the most abundant and diverse genus and is represented by 19 species already identified for the Solimões Formation, besides two new species described herein: Cyprideis atalaiensis sp. nov. and Cyprideis dictyon sp. nov. Intraspecific morphological variability, as well as the presence of nodes and tubercles, are observed in some species of Cyprideis and interpreted as a response to the paleoenvironmental changes during the Neogene in western Amazon region. Keywords: Cyprideis, morphological variability, paleoenvironmental changes, western Amazonia.
{"title":"Neogene ostracods from the Solimões Formation (Atalaia do Norte, Amazonas State, Brazil), with the description of two new species","authors":"A. P. Linhares, M. I. Ramos","doi":"10.4072/rbp.2022.1.05","DOIUrl":"https://doi.org/10.4072/rbp.2022.1.05","url":null,"abstract":"The analysis of the ostracods from three boreholes (1AS-7D-AM, 1AS-8-AM, and 1AS-31-AM) drilled in Atalaia do Norte town, Amazonas State, Brazil, allowed to recognize 30 species and nine genera. Cyprideis is the most abundant and diverse genus and is represented by 19 species already identified for the Solimões Formation, besides two new species described herein: Cyprideis atalaiensis sp. nov. and Cyprideis dictyon sp. nov. Intraspecific morphological variability, as well as the presence of nodes and tubercles, are observed in some species of Cyprideis and interpreted as a response to the paleoenvironmental changes during the Neogene in western Amazon region. Keywords: Cyprideis, morphological variability, paleoenvironmental changes, western Amazonia.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42528193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mechanisms of fertilization inferred from the coccolithophorid record during the Late Quaternary in the southern Brazilian Continental Margin. This study aimed to understand which fertilization mechanisms are preponderant over oceanic primary productivity and its relationship with remarkable climatic events of the Late Quaternary in the south of the Brazilian Continental Margin. The investigation was carried out through geochemical and coccolithophorid analyzes in the SIS188 marine core, recovered from the Pelotas Basin slope at 1,514 m water depth. The record shows that productivity was related to insolation (with a predominance of the precession cycle) and atmospheric processes that influence ocean dynamics. During the glacial period (MIS 3 and 2), the highest productivity intervals were associated with the expansion of the upwelling system in the Santa Marta Cape region, driven by the northeast winds. However, the interval of greatest productivity recorded in the core is the initial Holocene, when the upwelling was attenuated. This substantial increase in productivity is attributed to lagging processes resulting from the decrease in sea level that occurred during the Last Glacial Maximum. Keywords: productivity, Pelotas Basin, upwelling, Quaternary, coccolithophorids.
{"title":"Mecanismos de fertilização inferidos através do registro de cocolitoforídeos durante o Quaternário Tardio na Margem Continental Sul-Brasileira","authors":"J. F. Gonçalves, Adriana Leonhardt","doi":"10.4072/rbp.2022.1.06","DOIUrl":"https://doi.org/10.4072/rbp.2022.1.06","url":null,"abstract":"Mechanisms of fertilization inferred from the coccolithophorid record during the Late Quaternary in the southern Brazilian Continental Margin. This study aimed to understand which fertilization mechanisms are preponderant over oceanic primary productivity and its relationship with remarkable climatic events of the Late Quaternary in the south of the Brazilian Continental Margin. The investigation was carried out through geochemical and coccolithophorid analyzes in the SIS188 marine core, recovered from the Pelotas Basin slope at 1,514 m water depth. The record shows that productivity was related to insolation (with a predominance of the precession cycle) and atmospheric processes that influence ocean dynamics. During the glacial period (MIS 3 and 2), the highest productivity intervals were associated with the expansion of the upwelling system in the Santa Marta Cape region, driven by the northeast winds. However, the interval of greatest productivity recorded in the core is the initial Holocene, when the upwelling was attenuated. This substantial increase in productivity is attributed to lagging processes resulting from the decrease in sea level that occurred during the Last Glacial Maximum. Keywords: productivity, Pelotas Basin, upwelling, Quaternary, coccolithophorids.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42957196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new material of a Quaternary waterfowl is described here. The implications of this finding, in the context of the dispersal of Anatidae in the past, are discussed. The specimen consists in a partial humerus coming from the Upper Pleistocene of austral Chaco from Santiago del Estero Province, Argentina. The specimen here described belongs to the tribe Cygnini, being larger than most members of the clade. The humerus shows different size than with other members of the tribe Cygnini, being larger than the humeri referred to the Andean goose (Oressochen melanopterus), the Sheldgeese of the genus Chloephaga, the Comb Duck (Sarkidiornis sylvicola), and larger than the Ruddy Shelduck (Tadorna ferruginea). However, the humerus have several anatomical characters indicating that it belongs to a basal anserine duck. These combinations of features allow us to assign this fossil to a species of waterfowl: Coscoroba coscoroba. This finding, it context with the history of the South American Cygnini, provides new environmental interpretations associated with wetlands, which will be tested in the austral Chaco and Northern Pampa through future multi-proxy studies. Keywords: Anseriformes bird, goose, Coscoroba coscoroba, Quaternary, South America, Santiago del Estero.
本文介绍了一种第四纪水禽的新材料。讨论了这一发现在过去安纳科传播的背景下的意义。该标本包含一个部分肱骨，来自阿根廷圣地亚哥-德尔埃斯特罗省南部查科的上更新世。这里描述的标本属于赛格尼尼部落，比该分支的大多数成员都要大。肱骨的大小与Cygnini部落的其他成员不同，比安第斯鹅（Oresochen melanopterus）、Chloephaga属Sheldgeese、梳鸭（Sarkidiornis sylvicola）所称的肱骨大，比Ruddy Shelduck（Tadorna ferroginea）大。然而，肱骨有几个解剖特征，表明它属于基底anserine鸭。这些特征的组合使我们能够将这一化石归属于水禽的一个物种：水禽。这一发现结合了南美洲赛格尼尼的历史，提供了与湿地相关的新的环境解释，将通过未来的多代理研究在查科南部和潘帕北部进行测试。关键词：Anseriformes鸟，鹅，Coscoroba Coscoroba，第四纪，南美洲，Santiago del Estero。
{"title":"A Patagonian swan (Anatidae: Anserinae) from the Upper Pleistocene of Austral Chaco (Argentina)","authors":"R. Vezzosi, W. Jones, P. Gaudioso, R. Barquez","doi":"10.4072/rbp.2021.4.07","DOIUrl":"https://doi.org/10.4072/rbp.2021.4.07","url":null,"abstract":"A new material of a Quaternary waterfowl is described here. The implications of this finding, in the context of the dispersal of Anatidae in the past, are discussed. The specimen consists in a partial humerus coming from the Upper Pleistocene of austral Chaco from Santiago del Estero Province, Argentina. The specimen here described belongs to the tribe Cygnini, being larger than most members of the clade. The humerus shows different size than with other members of the tribe Cygnini, being larger than the humeri referred to the Andean goose (Oressochen melanopterus), the Sheldgeese of the genus Chloephaga, the Comb Duck (Sarkidiornis sylvicola), and larger than the Ruddy Shelduck (Tadorna ferruginea). However, the humerus have several anatomical characters indicating that it belongs to a basal anserine duck. These combinations of features allow us to assign this fossil to a species of waterfowl: Coscoroba coscoroba. This finding, it context with the history of the South American Cygnini, provides new environmental interpretations associated with wetlands, which will be tested in the austral Chaco and Northern Pampa through future multi-proxy studies. Keywords: Anseriformes bird, goose, Coscoroba coscoroba, Quaternary, South America, Santiago del Estero.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48940817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Benkhedda, N. Defaflia, Amine Cherif, M. Naimi, E. Mazouz, Arturo Palma-Ramírez
The northeastern part of Algeria is characterized by Meso–Cenozoic fossiliferous deposits. All the previous studies have been focused on invertebrate and vertebrate body fossils from this region. In the present paper we provide the first ichnological study from the region of Ouenza, Tebessa Wilaya (northeastern Algeria). An ichnoassemblage composed of eight ichnotaxa, namely cf. Archaeonassa isp., Arenicolites isp., Diplocraterion isp., Helminthopsis isp., Palaeophycus tubularis, Skolithoscf. linearis, cf. Taenidium isp., and Thalassinoides isp., reported from the lower Langhian (Middle Miocene) of Aïn Sidi Salah locality (Tebessa Basin) is discussed. These trace-fossils belong to the Skolithos and proximal Cruziana ichnofacies indicating deposition within a shallow marine (littoral). The large size of Thalassinoides suggests well-oxygenated setting, under moderate- to high-energy conditions, with occasional storm events. Keywords: trace-fossils, paleoenvironments, shallow marine, Middle Miocene, Tebessa.
{"title":"Shallow marine trace-fossils from the Middle Miocene of the Tebessa Basin (NE Algeria) and their paleoenvironmental implications","authors":"A. Benkhedda, N. Defaflia, Amine Cherif, M. Naimi, E. Mazouz, Arturo Palma-Ramírez","doi":"10.4072/rbp.2021.4.03","DOIUrl":"https://doi.org/10.4072/rbp.2021.4.03","url":null,"abstract":"The northeastern part of Algeria is characterized by Meso–Cenozoic fossiliferous deposits. All the previous studies have been focused on invertebrate and vertebrate body fossils from this region. In the present paper we provide the first ichnological study from the region of Ouenza, Tebessa Wilaya (northeastern Algeria). An ichnoassemblage composed of eight ichnotaxa, namely cf. Archaeonassa isp., Arenicolites isp., Diplocraterion isp., Helminthopsis isp., Palaeophycus tubularis, Skolithoscf. linearis, cf. Taenidium isp., and Thalassinoides isp., reported from the lower Langhian (Middle Miocene) of Aïn Sidi Salah locality (Tebessa Basin) is discussed. These trace-fossils belong to the Skolithos and proximal Cruziana ichnofacies indicating deposition within a shallow marine (littoral). The large size of Thalassinoides suggests well-oxygenated setting, under moderate- to high-energy conditions, with occasional storm events. Keywords: trace-fossils, paleoenvironments, shallow marine, Middle Miocene, Tebessa.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48979482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Herrera, G. Esteban, D. Garcia-Lopez, Virginia Deraco, Judith Babot, C. D. del Papa, S. Bertelli, N. Giannini
We describe isolated remains of a Paleogene cingulate from El Simbolar locality, Upper Lumbrera Formation (Bartonian), southern Salta Province, northwestern Argentina. The material consists of numerous fixed, movable, and caudal sheath osteoderms. The specimen has large-sized osteoderms, with a lageniform main figure, as in Utaetus buccatus, U. laxus, U. argos, ?U. deustus, Punatherium catamarcensis, and the basal euphractin Archaeutatus. The combination of morphological characters, in addition to its large size, allows us to recognize a new species of “Utaetini” for the Paleogene of northwestern Argentina. This new species of ?Utaetus represents the oldest record of Euphractinae in this region, and strengthens the endemic condition of its Paleogene faunas. Keywords: Cingulata, osteoderms, El Simbolar, Paleogene, Salta, Argentina.
我们描述了阿根廷西北部萨尔塔省南部上Lumbrera组(Bartonian) El Simbolar地区古近系扣带带的孤立遗骸。材料由许多固定的、可活动的和尾鞘骨皮组成。标本具有大尺寸的骨皮，有一个长尾状的主象，如Utaetus buccatus, U. laxus, U. argos, U. ?双峰蕨、双峰蕨和基生胡杨。结合形态特征，加上它的大尺寸，使我们能够识别出阿根廷西北部古近系的“Utaetini”新种。该新种代表了该地区最古老的Euphractinae记录，加强了该地区古近系动物群的特有条件。关键词:辛古拉，骨皮动物，El Simbolar，古近系，萨尔塔，阿根廷
{"title":"New Cingulata (Mammalia, Xenarthra) from the Upper Lumbrera Formation (Bartonian, middle Eocene), Salta Province, Argentina","authors":"C. Herrera, G. Esteban, D. Garcia-Lopez, Virginia Deraco, Judith Babot, C. D. del Papa, S. Bertelli, N. Giannini","doi":"10.4072/rbp.2021.3.05","DOIUrl":"https://doi.org/10.4072/rbp.2021.3.05","url":null,"abstract":"We describe isolated remains of a Paleogene cingulate from El Simbolar locality, Upper Lumbrera Formation (Bartonian), southern Salta Province, northwestern Argentina. The material consists of numerous fixed, movable, and caudal sheath osteoderms. The specimen has large-sized osteoderms, with a lageniform main figure, as in Utaetus buccatus, U. laxus, U. argos, ?U. deustus, Punatherium catamarcensis, and the basal euphractin Archaeutatus. The combination of morphological characters, in addition to its large size, allows us to recognize a new species of “Utaetini” for the Paleogene of northwestern Argentina. This new species of ?Utaetus represents the oldest record of Euphractinae in this region, and strengthens the endemic condition of its Paleogene faunas. Keywords: Cingulata, osteoderms, El Simbolar, Paleogene, Salta, Argentina.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44016186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Edenir Bagio Perin, Gisele Leite de Lima Primam, M. A. T. D. Oliveira
Palynology of peaty sediments from the high course of Cará Brook Creek, Coxilha Rica, Santa Catarina, Brazil. This paper presents the results of the palynological study of a sedimentary core collected in a bog in the upper part valley of Cará Brook Creek, in the cultural territory of Coxilha Rica, located in the Campos Gerais Plateau in Santa Catarina, Southern Brazil. The base of the core was dated in 6.900 14C years BP (7,845–7,690 cal years BP). The identification of the palynomorphs and the cluster analysis made possible to define two distinct palynological phases, despite the predominance of grassland vegetation throughout the whole core. From 34 cm, the frequency of bryophytes decreases, accompanied by the increase of the diversity of all vegetal taxa. Throughout the core, the most frequent families are Poaceae, Cyperaceae Apiaceae. The results indicate that the landscape of the upper course of the Brook Creek was characterized by grasslands from 6,900 14C years BP under a regional and humid climate, with a temperature increase in the historical period. Keywords: Middle Holocene, palynomorphs, grasslands, Araucaria forest, Highland.
{"title":"Palinologia de turfas do alto curso do Arroio Cará, Coxilha Rica, Santa Catarina, Brasil","authors":"Edenir Bagio Perin, Gisele Leite de Lima Primam, M. A. T. D. Oliveira","doi":"10.4072/rbp.2021.3.07","DOIUrl":"https://doi.org/10.4072/rbp.2021.3.07","url":null,"abstract":"Palynology of peaty sediments from the high course of Cará Brook Creek, Coxilha Rica, Santa Catarina, Brazil. This paper presents the results of the palynological study of a sedimentary core collected in a bog in the upper part valley of Cará Brook Creek, in the cultural territory of Coxilha Rica, located in the Campos Gerais Plateau in Santa Catarina, Southern Brazil. The base of the core was dated in 6.900 14C years BP (7,845–7,690 cal years BP). The identification of the palynomorphs and the cluster analysis made possible to define two distinct palynological phases, despite the predominance of grassland vegetation throughout the whole core. From 34 cm, the frequency of bryophytes decreases, accompanied by the increase of the diversity of all vegetal taxa. Throughout the core, the most frequent families are Poaceae, Cyperaceae Apiaceae. The results indicate that the landscape of the upper course of the Brook Creek was characterized by grasslands from 6,900 14C years BP under a regional and humid climate, with a temperature increase in the historical period. Keywords: Middle Holocene, palynomorphs, grasslands, Araucaria forest, Highland.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42011923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Piñeiro, Jorge Ferigolo, A. Mones, Pablo A. Núñez Demarco
Mesosaurs are basal amniotes that lived at the beginning of the Permian or close to the Permo–Carboniferous boundary. Despite the several hundred specimens that have been found, including complete skeletons of adult and juvenile individuals, mesosaur taxonomy has been subjected to a high controversy over time. Currently, three monotypic genera, Mesosaurus tenuidens Gervais, Stereosternum tumidum Cope, and Brazilosaurus sanpauloensis Shikama & Ozaki are recognized, but identification of new specimens using the available diagnostic characters are arbitrary and influenced by high subjectivity. We performed anatomical and morphometric analyses to look for statistical support to these previously suggested basic diagnostic characters through an exhaustive anatomical revision of these characters and also of some new attributes discovered during the course of our study. We found a notable influence of taphonomic features in most of the diagnostic characters used to differentiate the three monotypic genera, including strong bias derived from the preservation of individuals in different ontogenetic stages, whose size and degree of ossification could have been controlled by particular environmental conditions that resulted in subtle polymorphisms of these and other few characters. Other features may even represent sexual dimorphism. After the detailed revision of the type specimens of the three currently accepted mesosaur taxa, for which we include here good-quality photographs, and considering the lack of statistical support for the most applied putative diagnostic features such as the different ratio found when comparing skull and cervical region lengths and the low or higher intensity of pachyosteosclerosis observed in dorsal ribs, which can be controlled by taphonomic and ecological conditions, we recognize Mesosaurus as the only mesosaurid taxon in the Paraná and Karoo basins, probably including dwarf individuals. Therefore, S.tumidum and B. sanpauloensis are suggested here as nomina dubia taking into account that the autapomorphies that supported these taxa cannot be confirmed to be absent in Mesosaurus. Keywords: Mesosaurus, morphometrics, taxonomy, ?Early Permian, Gondwana.
{"title":"Mesosaur taxonomy reappraisal: are Stereosternum and Brazilosaurus valid taxa?","authors":"G. Piñeiro, Jorge Ferigolo, A. Mones, Pablo A. Núñez Demarco","doi":"10.4072/rbp.2021.3.04","DOIUrl":"https://doi.org/10.4072/rbp.2021.3.04","url":null,"abstract":"Mesosaurs are basal amniotes that lived at the beginning of the Permian or close to the Permo–Carboniferous boundary. Despite the several hundred specimens that have been found, including complete skeletons of adult and juvenile individuals, mesosaur taxonomy has been subjected to a high controversy over time. Currently, three monotypic genera, Mesosaurus tenuidens Gervais, Stereosternum tumidum Cope, and Brazilosaurus sanpauloensis Shikama & Ozaki are recognized, but identification of new specimens using the available diagnostic characters are arbitrary and influenced by high subjectivity. We performed anatomical and morphometric analyses to look for statistical support to these previously suggested basic diagnostic characters through an exhaustive anatomical revision of these characters and also of some new attributes discovered during the course of our study. We found a notable influence of taphonomic features in most of the diagnostic characters used to differentiate the three monotypic genera, including strong bias derived from the preservation of individuals in different ontogenetic stages, whose size and degree of ossification could have been controlled by particular environmental conditions that resulted in subtle polymorphisms of these and other few characters. Other features may even represent sexual dimorphism. After the detailed revision of the type specimens of the three currently accepted mesosaur taxa, for which we include here good-quality photographs, and considering the lack of statistical support for the most applied putative diagnostic features such as the different ratio found when comparing skull and cervical region lengths and the low or higher intensity of pachyosteosclerosis observed in dorsal ribs, which can be controlled by taphonomic and ecological conditions, we recognize Mesosaurus as the only mesosaurid taxon in the Paraná and Karoo basins, probably including dwarf individuals. Therefore, S.tumidum and B. sanpauloensis are suggested here as nomina dubia taking into account that the autapomorphies that supported these taxa cannot be confirmed to be absent in Mesosaurus. Keywords: Mesosaurus, morphometrics, taxonomy, ?Early Permian, Gondwana.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46093446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Azadeh Bordbar, F. Hadavi, A. Ghaderi, Marziyeh Notghi Moghaddam
The Tabas Block is part of the Central Iran microcontinent, located between the Lut Block in the East and the Yazd Block in the West. The Baghamshah Formation is the second lithostratigraphic unit from the sedimentary cycle of the Magu Group and the Baghamshah Subgroup in the Jurassic of Tabas Block. This formation is conformably underlaid with the grey pisoidal limestones of the Parvadeh Formation and overlaid with the Pectinid limestones of the Kamar-e-Mehdi Formation (Esfandiar Subgroup). In this research, the biostratigraphy of the Baghamshah Formation in the Rizu and Kamar-e-Mehdi sections, based on calcareous nannofossils, is examined. The thickness of the Baghamshah Formation in the Rizu section is 270 m (mostly including marl and green shales with intercalation of limestones and calcareous sandstones), and in the Kamar-e- Mehdi section is 236 m (composed of gypsiferous marly shales, marl, marly shales and alternation of marl-shale with limestones and calcareous sandstones). According to the taxonomic studies in the Rizu section, 52 species belong to 24 genera, and in the Kamar-e-Mehdi section, 45 species belong to 23 genera of calcareous nannofossils. Based on index calcareous nannofossils, the CC1, CC2, CC3, and CC4 biozones established by Sissinghh in both sections were determined. It is mentioned that CC5 biozone only occur in Kamar-e-Mehdi section. According to the identified biozones, the suggested age of the Baghamshah Formation is early Berriasian–early Hauterivian in the Rizu section, and early Berriasian–late Hauterivian in the Kamar-e-Mehdi section. Keywords: biostratigraphy, Baghamshah, calcareous nannofossils,Tabas, Iran.
{"title":"Biostratigraphy of Baghamshah Formation based on calcareous nannofossils in the Southwest Tabas, Iran","authors":"Azadeh Bordbar, F. Hadavi, A. Ghaderi, Marziyeh Notghi Moghaddam","doi":"10.4072/rbp.2021.3.01","DOIUrl":"https://doi.org/10.4072/rbp.2021.3.01","url":null,"abstract":"The Tabas Block is part of the Central Iran microcontinent, located between the Lut Block in the East and the Yazd Block in the West. The Baghamshah Formation is the second lithostratigraphic unit from the sedimentary cycle of the Magu Group and the Baghamshah Subgroup in the Jurassic of Tabas Block. This formation is conformably underlaid with the grey pisoidal limestones of the Parvadeh Formation and overlaid with the Pectinid limestones of the Kamar-e-Mehdi Formation (Esfandiar Subgroup). In this research, the biostratigraphy of the Baghamshah Formation in the Rizu and Kamar-e-Mehdi sections, based on calcareous nannofossils, is examined. The thickness of the Baghamshah Formation in the Rizu section is 270 m (mostly including marl and green shales with intercalation of limestones and calcareous sandstones), and in the Kamar-e- Mehdi section is 236 m (composed of gypsiferous marly shales, marl, marly shales and alternation of marl-shale with limestones and calcareous sandstones). According to the taxonomic studies in the Rizu section, 52 species belong to 24 genera, and in the Kamar-e-Mehdi section, 45 species belong to 23 genera of calcareous nannofossils. Based on index calcareous nannofossils, the CC1, CC2, CC3, and CC4 biozones established by Sissinghh in both sections were determined. It is mentioned that CC5 biozone only occur in Kamar-e-Mehdi section. According to the identified biozones, the suggested age of the Baghamshah Formation is early Berriasian–early Hauterivian in the Rizu section, and early Berriasian–late Hauterivian in the Kamar-e-Mehdi section. Keywords: biostratigraphy, Baghamshah, calcareous nannofossils,Tabas, Iran.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43901746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Agathe Arrissa Noucoucouk, R. M. Melo, George Satander Sá Freire, E. A. Menor
This research addresses paleoclimatic variations using sedimentological, geochemical, and planktic foraminifera. The study was carried out in a survey core (ANP 1011) collected on the continental slope of the Icaraí Sub-basin (Ceará Basin), on the coast of the Municipality of Itapipoca, CE, Brazil. Particle size analysis, CaCO3 content, Ti/Ca and Fe/Ca ratios, and the analysis of foraminifera associations for biostratigraphic purposes were performed. Based on the relative abundance of planktic foraminifera, with indicators of warm and cold water throughout the studied cores, two biozones (Y: Upper Pleistocene and Z: Holocene), and two subzones (Z2 and Z1) were recognized. The data of sedimentological markers obtained confirmed the occurrence of more wet phases in northeastern Brazil during the early stages of the Holocene. The Ti/Ca and Fe/Ca ratios, as well as the geochemical and micropaleontological proxies, indicated a farther north displacement of the Intertropical Convergence Zone (ITCZ) in the Pleistocene–Holocene transition. This may have caused greater precipitation in the Northeastern region of Brazil, effectuating the entry of a high volume of terrestrial sediments directly into the ocean basin. Keywords: Quaternary biostratigraphy, marine sedimentation, ITCZ mobility, paleoclimate.
{"title":"Upper Pleistocene–Holocene in the continental slope of the Cará Basin: an integrated analysis based on planktic foraminifera, sedimentological and geochemical aspects","authors":"Agathe Arrissa Noucoucouk, R. M. Melo, George Satander Sá Freire, E. A. Menor","doi":"10.4072/rbp.2021.3.02","DOIUrl":"https://doi.org/10.4072/rbp.2021.3.02","url":null,"abstract":"This research addresses paleoclimatic variations using sedimentological, geochemical, and planktic foraminifera. The study was carried out in a survey core (ANP 1011) collected on the continental slope of the Icaraí Sub-basin (Ceará Basin), on the coast of the Municipality of Itapipoca, CE, Brazil. Particle size analysis, CaCO3 content, Ti/Ca and Fe/Ca ratios, and the analysis of foraminifera associations for biostratigraphic purposes were performed. Based on the relative abundance of planktic foraminifera, with indicators of warm and cold water throughout the studied cores, two biozones (Y: Upper Pleistocene and Z: Holocene), and two subzones (Z2 and Z1) were recognized. The data of sedimentological markers obtained confirmed the occurrence of more wet phases in northeastern Brazil during the early stages of the Holocene. The Ti/Ca and Fe/Ca ratios, as well as the geochemical and micropaleontological proxies, indicated a farther north displacement of the Intertropical Convergence Zone (ITCZ) in the Pleistocene–Holocene transition. This may have caused greater precipitation in the Northeastern region of Brazil, effectuating the entry of a high volume of terrestrial sediments directly into the ocean basin. Keywords: Quaternary biostratigraphy, marine sedimentation, ITCZ mobility, paleoclimate.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45187023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Felipe Nascimento Sousa, R. C. Marques, Victor Rodrigues Ribeiro, G. Gaia, E. Guilherme, Andréa Maciente, J. P. Souza-Filho, A. S. Hsiou, R. P. Ghilardi
A taxonomic review of Miocene gastropods from the Solimões Formation, Acre Basin, Brazil, from specimens collected at Cachoeira do Bandeira, Oriente, and an outcrop named Spot 04, is here presented. Three ampullariid species (Pomacea maculata, P.planorbula, Pomacea sp.), one thiarid species (Aylacostoma sp.), and one cochliopid species (Sioliella sp.) are identified for these deposits. These gastropod are known to occur in freshwaters environments, thus consolidating the hypothesis of a non-influence of brackish water on the upper Miocene deposits of the Acre Basin. The previous identification of P. maculata and Aylacostoma sp. is changed here considering biometrical analyses and shell morphological descriptions. The first report of Sioliella in this basin increases the gastropod fauna known for these strata and expands the range of this genus. Keywords: Pomacea, Aylacostoma, Sioliella, Ampullariidae, Thiaridae, Cochliopidae.
本文介绍了巴西阿克里盆地Solimões组中新世腹足类的分类学综述，这些腹足类来自于在Oriente的Cachoeira do Bandeira采集的标本和一个名为Spot 04的露头。为这些矿床确定了三种安瓿菌（Pomacea maculata、P.planorbula、Pomacea sp.）、一种噻虫属（Aylacostoma sp.）和一种胭脂虫属（Sioliella sp。已知这些腹足纲动物出现在淡水环境中，从而巩固了半咸水对阿克里盆地上中新世沉积物没有影响的假设。考虑到生物特征分析和外壳形态描述，先前对斑点假单胞菌和Aylacostoma sp.的鉴定在这里发生了变化。Sioliella在该盆地的首次报告增加了以这些地层闻名的腹足类动物群，并扩大了该属的范围。关键词：Pomacea，Aylacostoma，Sioliella，Ampullariidae，Thiaridae，Cochliopidae。
{"title":"Gastropods from the Solimões Formation (upper Miocene), Acre Basin, Brazil","authors":"Felipe Nascimento Sousa, R. C. Marques, Victor Rodrigues Ribeiro, G. Gaia, E. Guilherme, Andréa Maciente, J. P. Souza-Filho, A. S. Hsiou, R. P. Ghilardi","doi":"10.4072/rbp.2021.3.03","DOIUrl":"https://doi.org/10.4072/rbp.2021.3.03","url":null,"abstract":"A taxonomic review of Miocene gastropods from the Solimões Formation, Acre Basin, Brazil, from specimens collected at Cachoeira do Bandeira, Oriente, and an outcrop named Spot 04, is here presented. Three ampullariid species (Pomacea maculata, P.planorbula, Pomacea sp.), one thiarid species (Aylacostoma sp.), and one cochliopid species (Sioliella sp.) are identified for these deposits. These gastropod are known to occur in freshwaters environments, thus consolidating the hypothesis of a non-influence of brackish water on the upper Miocene deposits of the Acre Basin. The previous identification of P. maculata and Aylacostoma sp. is changed here considering biometrical analyses and shell morphological descriptions. The first report of Sioliella in this basin increases the gastropod fauna known for these strata and expands the range of this genus. Keywords: Pomacea, Aylacostoma, Sioliella, Ampullariidae, Thiaridae, Cochliopidae.","PeriodicalId":49616,"journal":{"name":"Revista Brasileira De Paleontologia","volume":" ","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49404737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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