South Canyon, type locality of the Lower Carnian Trachyceras desatoyense Zone of the North Americ... more South Canyon, type locality of the Lower Carnian Trachyceras desatoyense Zone of the North American Standard Scale, has been extensively sampled utilizing a bed-by-bed approach. The ammonoid rich Middle Member of the Augusta Mountain Formation (Star Peak Group) has been sampled at five sites, and preliminary data are presented. Suture line analysis permits the identification of the genus Daxatina from the lower part of the Middle Member and subsequently, this genus is reported for the first time from South Canyon. Trachyceras, also identified on the basis of its suture line, definitely occurs in the higher part of the studied interval, about 50 m from the base. This discovery of Daxatina, a genus almost identical to Trachyceras except for its ceratitic suture line, brings into question the definite taxonomical position of Trachyceras desatoyense Johnston, 1941, a species whose suture line is not known. Taxonomical analysis of South Canyon Trachyceratidae is also complicated by the v...
Towards the definition of the Carnian/Norian boundary: new data on ammonoids and conodonts from c... more Towards the definition of the Carnian/Norian boundary: new data on ammonoids and conodonts from central Nevada. / M. Balini, MJ Orchard, JA Jenks, NJ Silberling, R. Martin. - In: Albertiana. - ISSN 0169-4324. - 40(2012 Jun), pp. 37-37. ((Intervento presentato al convegno Canadian Paleontology Conference. tenutosi a Vancouver nel 2011. ... There are no files associated with this item. ... Items in AIR are protected by copyright, with all rights reserved, unless otherwise indicated. ... ICT Support, development & maintenance are provided by the AePIC team ...
M. Balini, The GSSP defined in Italy. State of the art for the Triassic. In the last 10 years the... more M. Balini, The GSSP defined in Italy. State of the art for the Triassic. In the last 10 years the Subcommission on Triassic Stratigraphy increased speed in the definition of the GSSP of the Triassic Standard Global Chronostratigraphic Scale. In 2001 the base of the Induan has been defined in China and few years later in 2005 the base of the Ladinian has been defined in Italy. Among the GSSP candidate sections which are at the present under discussion there are two sections in Italy with a great potential. Prati di Stuores/Stuores Wiesen (Dolomites) has been finally selected by the Task Group as the only candidate for the base of the Carnian stage and the final ballot is in progress. Pizzo Mondello (Agrigento) is one of the two candidates for the definition of the base of the Norian stage and a final decision is expected by 2009. The italian successions exposed in Lagonegro and western Sicily might also have some potential for the definition of the base of the Rhaetian, but more work...
Rivista Italiana Di Paleontologia E Stratigrafia, 1994
This paper is focused on the description of an assemblage of ceratitids collected more than 50 y... more This paper is focused on the description of an assemblage of ceratitids collected more than 50 years ago by C. Renz from the Han-Bulog Limestone of Hydra (Greece), up to the present never described. The identified forms are Asseretoceras camunum (Assereto, 1963), Megaceratites aff. fallax Balini, 1992b, Ronconites sp. n. A, " Kellnerites " sp. ind., Nevadites sp. ind. Two ceratitids of uncertain attribution are also described. These species have only paleoecological implications, since a stratigraphic bed-by-bed sampling has not been performed. A. camunum and the genera Megaceratites and Ronconites are reported for the first time from the Han-Bulog Limestone. Megaceratites and Ronconites are also reported for the first time out of the Southern Alps.
Rivista Italiana Di Paleontologia E Stratigrafia, 1992
On the basis of ammonoids collected in the uppermost part of the Prezzo Limestone (Anisian), the ... more On the basis of ammonoids collected in the uppermost part of the Prezzo Limestone (Anisian), the new genus Lardaroceras and two new species L. krystyni (type species) and L. pseudohungaricum are described; a third one is left in open nomenclature. The genus Lardaroceras comprises involute and compressed ceratitids, whose subtrapezoidal whorl section is characterized by an evident periumbilical margin and a rounded ventral keel. The ornamentation is made of umbilical and lateroventral nodes, to which sometimes lateral nodes are added, and of lightly proverse and sinuous, primary, intercalatory and bifurcate ribs. The very distinctive suture line is subammonitic. The two species, L. krystyni and L. pseadohungaricam , differ mainly in the ornamentation and in the adult body chember: the former has umbilical and lareroventral nodes and its ornamentation fades on the adult body chamber, the latter has also lateral nodes and its ornamentation strengthens in the latest stage of growth. Be...
Rivista Italiana Di Paleontologia E Stratigrafia, 2012
Four vertebral centra from the well known fossil-bearing Prezzo Limestone (Upper Anisian, Middle ... more Four vertebral centra from the well known fossil-bearing Prezzo Limestone (Upper Anisian, Middle Triassic) at the newly discovered locality Piazza Brembana (Bergamo) are described. The four bones were found exposed on the bed surface in an articulated position. Despite the incompleteness of three centra due to erosion, their otherwise fairly good preservation facilitated their study and attribution to a shastasaurid ichthyosaur. Even though the classification of isolated vertebral centra at the genus level is controversial, the presence of diapophyses truncated by the cranial margin of the centra is still considered to be diagnostic for Cymbospondylu s . The new discovery comes from an ammonoid-bearing facies, which is not unusual for ichthyosaurs, and the bio-chronostratigraphic position of the Piazza Brembana bones is accurately defined by ammonoids from the lowest part of the Trinodosus Zone (Illyrian, Middle Triassic). Records of Cymbospondylu s in the Southern Alps, Germanic Ba...
Most geological handbooks attribute the birth of stratigraphy to William Smith in the 18 th centu... more Most geological handbooks attribute the birth of stratigraphy to William Smith in the 18 th century, after a brief mention of the pioneering contribution of Niels Stensen (Nicholaus Stenonis) who, almost a century before, had introduced in his Dissertationis prodromus of 1669 the principles of geometric relationships between strata. On the contrary, Leonardo da Vinci is related, among other scientists, to the intuition that fossils are remains of living organisms. Da Vinci was indeed much more than that. All concepts commonly associated with stratigraphy, e.g., fossils as agediagnostic tools, geometric properties and position of strata, correlations of stratigraphic successions, are deeply-rooted in Leonardo's writings and fully expressed in his paintings, integrated in mature observations and reproduction of the landscape. The celebration of the fivehundredth anniversary of Leonardo's death gives us the opportunity to finally link Leonardo da Vinci to the birth of modern stratigraphy.
The structural analysis of large intracontinental wrench faults is fundamental for deciphering th... more The structural analysis of large intracontinental wrench faults is fundamental for deciphering the longterm evolution of continental crust in complex areas in terms of their geodynamic evolution and largescale crustal block displacements. In this contribution, we demonstrate a pre-Miocene dextral activity of the present-day left-lateral Great Kavir-Doruneh Fault System (GKDFS, Central Iran), one of the major intracontinental active strike-slip faults extending from the Afghan border to the Nain region between Central Iran and the Sanandaj-Sirjan Zone. We document important dextral shearing recorded along a segment of the GKDFS, the Arusan Fault System (AFS), located east of Jandaq, close to the present-day active trace of the GKDFS. The AFS include several ENE-WSW striking strands exposed for a length of more than 50 km, which couple pre-Cretaceous ophiolites and metamorphic basement units with the Cretaceous succession of the Khur basin. The fault shows transpressional structures consistent with a dextral shear including thrusts and en échelon folds affecting the Cretaceous carbonate units. Paleostress reconstruction based on mesoscopic fault analysis and related folds geometry allowed to establish vorticity parameters indicating that deformation occurred close to a total simple shear regime with a calculated Wk between 0.9 and 1. The enormous Meso-Cenozoic dextral displacements occurred along the AFS and along the entire GKDFS are attested by the up to several hundreds of kilometers offset of the Paleotethys suture zone, from NE Iran to the western border of Central Iran.
The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the fl... more The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the flourishing Ceratitida and the appearance of the first heteromorphs. Following the end-Permian mass extinction, ammonoids were among the first groups to rediversify by producing many new taxa. Already in the late nineteenth century, the still currently recognized Triassic stages and substages were introduced. The historical development of Triassic ammonoid biostratigraphy is a good example of worldwide cooperation between many geographically-diverse research groups, which initially began in Germany and the European Alps. This cooperation was then extended to North America, Transcaucasia, North Indian Margin, South China, and Russia. A renewed interest in Triassic ammonoid biozonation has occurred during the last few decades, leading to the recognition of tens of ammonoid zones spanning about 50.9 Myr (leading to an average duration for ammonoid biochronozones of about 0.74 Myr), whose correlation and definition are herein synthesized.
The biostratigraphic study of the Pizzo Lupo section was conducted as part of the doctoral thesis... more The biostratigraphic study of the Pizzo Lupo section was conducted as part of the doctoral thesis “ La collezione di ammonoidi triassici G.G. Gemmellaro. Revisione sistematica ed importanza Paleobiogeografica” (Tripodo, 2010) and further developed in the project PRIN2008 “Stratigrafia integrata del Triassico Superiore: GSSP e sezioni ausiliarie in Italia”. This study was aimed to identify an auxiliary section of Pizzo Mondello for the definition of the Carnian/Norian boundary (Upper Triassic). The section of Pizzo Lupo is located in a quarry in the eastern Sicani mountains (Castronovo di Sicilia) and belongs to a tectonic unit resulting from deformation of the Sicanian Basin. The Scillato Formation (Schmidt di Friedberg et al., 1960), informally known as "calcari con selce" or "calcari ad Halobia", is very well exposed in the quarry. Pizzo Lupo is located in the area from which Gemmellaro collected most of his Upper Triassic ammonoids, described in his monograph ...
The Norian Stage is one of the two stages of the Upper Triassic Series that remains undefined. Co... more The Norian Stage is one of the two stages of the Upper Triassic Series that remains undefined. Considerable research has been undertaken in the last 10 years in order to identify the best candidate sections and more recently this research has focused on the Black Bear Ridge section on Williston Lake (British Columbia, Canada) and the Pizzo Mondello section in Sicily (Italy). Both sections are characterized by good exposure, rather uniform facies, and good paleontologic records and are thus suitable as GSSP sections for the Carnian-Norian Boundary (CNB). In recent years the two sections have been studied in great detail in regards to conodont, pelagic bivalve, ammonoid, and radiolarian biostratigraphies as well as by facies analysis, magnetostratigraphy, and stable isotopic variations. Both sections show a rich conodont and pelagic bivalve record that is calibrated by less commonly occurring ammonoids. Pizzo Mondello has also yielded radiolarians and a very good magnetostratigraphic record. Black Bear Ridge is exceptional in preserving an unrivalled record of conodont evolution through the boundary interval, with demonstrable faunal turnover and appearance of key conodont indices that coincide with the FAD of the bivalve Halobia austriaca, which has been proposed as a primary marker for the GSSP. The conodont record of Black Bear Ridge is also calibrated with ammonoid and radiolarian faunas from nearby sections. The correlatability of the CNB datum is under evaluation
South Canyon, type locality of the Lower Carnian Trachyceras desatoyense Zone of the North Americ... more South Canyon, type locality of the Lower Carnian Trachyceras desatoyense Zone of the North American Standard Scale, has been extensively sampled utilizing a bed-by-bed approach. The ammonoid rich Middle Member of the Augusta Mountain Formation (Star Peak Group) has been sampled at five sites, and preliminary data are presented. Suture line analysis permits the identification of the genus Daxatina from the lower part of the Middle Member and subsequently, this genus is reported for the first time from South Canyon. Trachyceras, also identified on the basis of its suture line, definitely occurs in the higher part of the studied interval, about 50 m from the base. This discovery of Daxatina, a genus almost identical to Trachyceras except for its ceratitic suture line, brings into question the definite taxonomical position of Trachyceras desatoyense Johnston, 1941, a species whose suture line is not known. Taxonomical analysis of South Canyon Trachyceratidae is also complicated by the v...
Towards the definition of the Carnian/Norian boundary: new data on ammonoids and conodonts from c... more Towards the definition of the Carnian/Norian boundary: new data on ammonoids and conodonts from central Nevada. / M. Balini, MJ Orchard, JA Jenks, NJ Silberling, R. Martin. - In: Albertiana. - ISSN 0169-4324. - 40(2012 Jun), pp. 37-37. ((Intervento presentato al convegno Canadian Paleontology Conference. tenutosi a Vancouver nel 2011. ... There are no files associated with this item. ... Items in AIR are protected by copyright, with all rights reserved, unless otherwise indicated. ... ICT Support, development & maintenance are provided by the AePIC team ...
M. Balini, The GSSP defined in Italy. State of the art for the Triassic. In the last 10 years the... more M. Balini, The GSSP defined in Italy. State of the art for the Triassic. In the last 10 years the Subcommission on Triassic Stratigraphy increased speed in the definition of the GSSP of the Triassic Standard Global Chronostratigraphic Scale. In 2001 the base of the Induan has been defined in China and few years later in 2005 the base of the Ladinian has been defined in Italy. Among the GSSP candidate sections which are at the present under discussion there are two sections in Italy with a great potential. Prati di Stuores/Stuores Wiesen (Dolomites) has been finally selected by the Task Group as the only candidate for the base of the Carnian stage and the final ballot is in progress. Pizzo Mondello (Agrigento) is one of the two candidates for the definition of the base of the Norian stage and a final decision is expected by 2009. The italian successions exposed in Lagonegro and western Sicily might also have some potential for the definition of the base of the Rhaetian, but more work...
Rivista Italiana Di Paleontologia E Stratigrafia, 1994
This paper is focused on the description of an assemblage of ceratitids collected more than 50 y... more This paper is focused on the description of an assemblage of ceratitids collected more than 50 years ago by C. Renz from the Han-Bulog Limestone of Hydra (Greece), up to the present never described. The identified forms are Asseretoceras camunum (Assereto, 1963), Megaceratites aff. fallax Balini, 1992b, Ronconites sp. n. A, " Kellnerites " sp. ind., Nevadites sp. ind. Two ceratitids of uncertain attribution are also described. These species have only paleoecological implications, since a stratigraphic bed-by-bed sampling has not been performed. A. camunum and the genera Megaceratites and Ronconites are reported for the first time from the Han-Bulog Limestone. Megaceratites and Ronconites are also reported for the first time out of the Southern Alps.
Rivista Italiana Di Paleontologia E Stratigrafia, 1992
On the basis of ammonoids collected in the uppermost part of the Prezzo Limestone (Anisian), the ... more On the basis of ammonoids collected in the uppermost part of the Prezzo Limestone (Anisian), the new genus Lardaroceras and two new species L. krystyni (type species) and L. pseudohungaricum are described; a third one is left in open nomenclature. The genus Lardaroceras comprises involute and compressed ceratitids, whose subtrapezoidal whorl section is characterized by an evident periumbilical margin and a rounded ventral keel. The ornamentation is made of umbilical and lateroventral nodes, to which sometimes lateral nodes are added, and of lightly proverse and sinuous, primary, intercalatory and bifurcate ribs. The very distinctive suture line is subammonitic. The two species, L. krystyni and L. pseadohungaricam , differ mainly in the ornamentation and in the adult body chember: the former has umbilical and lareroventral nodes and its ornamentation fades on the adult body chamber, the latter has also lateral nodes and its ornamentation strengthens in the latest stage of growth. Be...
Rivista Italiana Di Paleontologia E Stratigrafia, 2012
Four vertebral centra from the well known fossil-bearing Prezzo Limestone (Upper Anisian, Middle ... more Four vertebral centra from the well known fossil-bearing Prezzo Limestone (Upper Anisian, Middle Triassic) at the newly discovered locality Piazza Brembana (Bergamo) are described. The four bones were found exposed on the bed surface in an articulated position. Despite the incompleteness of three centra due to erosion, their otherwise fairly good preservation facilitated their study and attribution to a shastasaurid ichthyosaur. Even though the classification of isolated vertebral centra at the genus level is controversial, the presence of diapophyses truncated by the cranial margin of the centra is still considered to be diagnostic for Cymbospondylu s . The new discovery comes from an ammonoid-bearing facies, which is not unusual for ichthyosaurs, and the bio-chronostratigraphic position of the Piazza Brembana bones is accurately defined by ammonoids from the lowest part of the Trinodosus Zone (Illyrian, Middle Triassic). Records of Cymbospondylu s in the Southern Alps, Germanic Ba...
Most geological handbooks attribute the birth of stratigraphy to William Smith in the 18 th centu... more Most geological handbooks attribute the birth of stratigraphy to William Smith in the 18 th century, after a brief mention of the pioneering contribution of Niels Stensen (Nicholaus Stenonis) who, almost a century before, had introduced in his Dissertationis prodromus of 1669 the principles of geometric relationships between strata. On the contrary, Leonardo da Vinci is related, among other scientists, to the intuition that fossils are remains of living organisms. Da Vinci was indeed much more than that. All concepts commonly associated with stratigraphy, e.g., fossils as agediagnostic tools, geometric properties and position of strata, correlations of stratigraphic successions, are deeply-rooted in Leonardo's writings and fully expressed in his paintings, integrated in mature observations and reproduction of the landscape. The celebration of the fivehundredth anniversary of Leonardo's death gives us the opportunity to finally link Leonardo da Vinci to the birth of modern stratigraphy.
The structural analysis of large intracontinental wrench faults is fundamental for deciphering th... more The structural analysis of large intracontinental wrench faults is fundamental for deciphering the longterm evolution of continental crust in complex areas in terms of their geodynamic evolution and largescale crustal block displacements. In this contribution, we demonstrate a pre-Miocene dextral activity of the present-day left-lateral Great Kavir-Doruneh Fault System (GKDFS, Central Iran), one of the major intracontinental active strike-slip faults extending from the Afghan border to the Nain region between Central Iran and the Sanandaj-Sirjan Zone. We document important dextral shearing recorded along a segment of the GKDFS, the Arusan Fault System (AFS), located east of Jandaq, close to the present-day active trace of the GKDFS. The AFS include several ENE-WSW striking strands exposed for a length of more than 50 km, which couple pre-Cretaceous ophiolites and metamorphic basement units with the Cretaceous succession of the Khur basin. The fault shows transpressional structures consistent with a dextral shear including thrusts and en échelon folds affecting the Cretaceous carbonate units. Paleostress reconstruction based on mesoscopic fault analysis and related folds geometry allowed to establish vorticity parameters indicating that deformation occurred close to a total simple shear regime with a calculated Wk between 0.9 and 1. The enormous Meso-Cenozoic dextral displacements occurred along the AFS and along the entire GKDFS are attested by the up to several hundreds of kilometers offset of the Paleotethys suture zone, from NE Iran to the western border of Central Iran.
The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the fl... more The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the flourishing Ceratitida and the appearance of the first heteromorphs. Following the end-Permian mass extinction, ammonoids were among the first groups to rediversify by producing many new taxa. Already in the late nineteenth century, the still currently recognized Triassic stages and substages were introduced. The historical development of Triassic ammonoid biostratigraphy is a good example of worldwide cooperation between many geographically-diverse research groups, which initially began in Germany and the European Alps. This cooperation was then extended to North America, Transcaucasia, North Indian Margin, South China, and Russia. A renewed interest in Triassic ammonoid biozonation has occurred during the last few decades, leading to the recognition of tens of ammonoid zones spanning about 50.9 Myr (leading to an average duration for ammonoid biochronozones of about 0.74 Myr), whose correlation and definition are herein synthesized.
The biostratigraphic study of the Pizzo Lupo section was conducted as part of the doctoral thesis... more The biostratigraphic study of the Pizzo Lupo section was conducted as part of the doctoral thesis “ La collezione di ammonoidi triassici G.G. Gemmellaro. Revisione sistematica ed importanza Paleobiogeografica” (Tripodo, 2010) and further developed in the project PRIN2008 “Stratigrafia integrata del Triassico Superiore: GSSP e sezioni ausiliarie in Italia”. This study was aimed to identify an auxiliary section of Pizzo Mondello for the definition of the Carnian/Norian boundary (Upper Triassic). The section of Pizzo Lupo is located in a quarry in the eastern Sicani mountains (Castronovo di Sicilia) and belongs to a tectonic unit resulting from deformation of the Sicanian Basin. The Scillato Formation (Schmidt di Friedberg et al., 1960), informally known as "calcari con selce" or "calcari ad Halobia", is very well exposed in the quarry. Pizzo Lupo is located in the area from which Gemmellaro collected most of his Upper Triassic ammonoids, described in his monograph ...
The Norian Stage is one of the two stages of the Upper Triassic Series that remains undefined. Co... more The Norian Stage is one of the two stages of the Upper Triassic Series that remains undefined. Considerable research has been undertaken in the last 10 years in order to identify the best candidate sections and more recently this research has focused on the Black Bear Ridge section on Williston Lake (British Columbia, Canada) and the Pizzo Mondello section in Sicily (Italy). Both sections are characterized by good exposure, rather uniform facies, and good paleontologic records and are thus suitable as GSSP sections for the Carnian-Norian Boundary (CNB). In recent years the two sections have been studied in great detail in regards to conodont, pelagic bivalve, ammonoid, and radiolarian biostratigraphies as well as by facies analysis, magnetostratigraphy, and stable isotopic variations. Both sections show a rich conodont and pelagic bivalve record that is calibrated by less commonly occurring ammonoids. Pizzo Mondello has also yielded radiolarians and a very good magnetostratigraphic record. Black Bear Ridge is exceptional in preserving an unrivalled record of conodont evolution through the boundary interval, with demonstrable faunal turnover and appearance of key conodont indices that coincide with the FAD of the bivalve Halobia austriaca, which has been proposed as a primary marker for the GSSP. The conodont record of Black Bear Ridge is also calibrated with ammonoid and radiolarian faunas from nearby sections. The correlatability of the CNB datum is under evaluation
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