scholarly journals New data towards the development of a comprehensive taphonomic framework for the Cleveland-Lloyd Dinosaur Quarry

2016 ◽  
Author(s):  
Joseph E Peterson ◽  
Jonathan P Warnock ◽  
Shawn L Eberhart ◽  
Steven R Clawson ◽  
Christopher R Noto
Keyword(s):  
Data Sets ◽  
Morrison Formation ◽  
Depositional History ◽  
Theropod Dinosaurs ◽  
The Matrix ◽  
Significant Step ◽  
Primary Driver ◽  
History Of ◽  
Bone Fragments ◽  
Small Bone

The Cleveland-Lloyd Dinosaur Quarry (CLDQ) is the densest deposit of Jurassic theropod dinosaurs discovered to date. Unlike typical Jurassic bone deposits, it is dominated by the presence of Allosaurus fragilis. Since excavation began in the 1920’s numerous hypotheses have been put forward to explain the taphonomy of CLDQ, including a predator trap, a drought assemblage, and a poison spring. In an effort to reconcile the various interpretations of the quarry and reach a consensus on the depositional history of CLDQ, new data is required to develop a robust taphonomic framework congruent with all available data. Here we present two new data sets which aid in the development of such a robust taphonomic framework for CLDQ. First, x-ray fluorescence of CLDQ sediments indicate elevated barite and sulfide minerals relative to other sediments from the Morrison Formation, suggesting an ephemeral environment dominated by periods of hypereutrophic conditions during bone accumulation. Second, the degree of weathering and hydraulic equivalency of small bone fragments dispersed throughout the matrix were analyzed from CLDQ. Results of these analyses suggest that bone fragments are autochthonous or parautochthonous and are derived from bones deposited in the assemblage. The variability in abrasion exhibited by the fragments is most parsimoniously explained by periodic reworking and redeposition during seasonal fluctuations throughout the duration of the quarry assemblage. Collectively, these data support some previous interpretations that the CLDQ represents an attritional assemblage in a poorly-drained overbank deposit where vertebrate remains were introduced post-mortem to an ephemeral pond during flood conditions. Furthermore, elevated heavy metals and rare earth elements detected at the quarry are likely a diagenetic signal, potentially produced in part from an abundance of vertebrate remains, and not the primary driver for the accumulation of carcasses. These new data help to explain the specific depositional environment of the quarry, and represent a significant step in understanding the taphonomy of the bone bed and late Jurassic paleoecology.

scholarly journals New data towards the development of a comprehensive taphonomic framework for the Cleveland-Lloyd Dinosaur Quarry

2016 ◽  
Author(s):  
Joseph E Peterson ◽  
Jonathan P Warnock ◽  
Shawn L Eberhart ◽  
Steven R Clawson ◽  
Christopher R Noto
Keyword(s):  
Data Sets ◽  
Morrison Formation ◽  
Depositional History ◽  
Theropod Dinosaurs ◽  
The Matrix ◽  
Significant Step ◽  
Primary Driver ◽  
History Of ◽  
Bone Fragments ◽  
Small Bone

The Cleveland-Lloyd Dinosaur Quarry (CLDQ) is the densest deposit of Jurassic theropod dinosaurs discovered to date. Unlike typical Jurassic bone deposits, it is dominated by the presence of Allosaurus fragilis. Since excavation began in the 1920’s numerous hypotheses have been put forward to explain the taphonomy of CLDQ, including a predator trap, a drought assemblage, and a poison spring. In an effort to reconcile the various interpretations of the quarry and reach a consensus on the depositional history of CLDQ, new data is required to develop a robust taphonomic framework congruent with all available data. Here we present two new data sets which aid in the development of such a robust taphonomic framework for CLDQ. First, x-ray fluorescence of CLDQ sediments indicate elevated barite and sulfide minerals relative to other sediments from the Morrison Formation, suggesting an ephemeral environment dominated by periods of hypereutrophic conditions during bone accumulation. Second, the degree of weathering and hydraulic equivalency of small bone fragments dispersed throughout the matrix were analyzed from CLDQ. Results of these analyses suggest that bone fragments are autochthonous or parautochthonous and are derived from bones deposited in the assemblage. The variability in abrasion exhibited by the fragments is most parsimoniously explained by periodic reworking and redeposition during seasonal fluctuations throughout the duration of the quarry assemblage. Collectively, these data support some previous interpretations that the CLDQ represents an attritional assemblage in a poorly-drained overbank deposit where vertebrate remains were introduced post-mortem to an ephemeral pond during flood conditions. Furthermore, elevated heavy metals and rare earth elements detected at the quarry are likely a diagenetic signal, potentially produced in part from an abundance of vertebrate remains, and not the primary driver for the accumulation of carcasses. These new data help to explain the specific depositional environment of the quarry, and represent a significant step in understanding the taphonomy of the bone bed and late Jurassic paleoecology.

scholarly journals New data towards the development of a comprehensive taphonomic framework for the Late Jurassic Cleveland-Lloyd Dinosaur Quarry, Central Utah

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3368 ◽  
Author(s):  
Joseph E. Peterson ◽  
Jonathan P. Warnock ◽  
Shawn L. Eberhart ◽  
Steven R. Clawson ◽  
Christopher R. Noto
Keyword(s):  
Late Jurassic ◽  
Data Sets ◽  
Morrison Formation ◽  
Multiple Sources ◽  
Theropod Dinosaurs ◽  
The Matrix ◽  
Significant Step ◽  
Primary Driver ◽  
History Of ◽  
Bone Fragments

The Cleveland-Lloyd Dinosaur Quarry (CLDQ) is the densest deposit of Jurassic theropod dinosaurs discovered to date. Unlike typical Jurassic bone deposits, it is dominated by the presence ofAllosaurus fragilis. Since excavation began in the 1920s, numerous hypotheses have been put forward to explain the taphonomy of CLDQ, including a predator trap, a drought assemblage, and a poison spring. In an effort to reconcile the various interpretations of the quarry and reach a consensus on the depositional history of CLDQ, new data is required to develop a robust taphonomic framework congruent with all available data. Here we present two new data sets that aid in the development of such a robust taphonomic framework for CLDQ. First, x-ray fluorescence of CLDQ sediments indicate elevated barite and sulfide minerals relative to other sediments from the Morrison Formation in the region, suggesting an ephemeral environment dominated by periods of hypereutrophic conditions during bone accumulation. Second, the degree of abrasion and hydraulic equivalency of small bone fragments dispersed throughout the matrix were analyzed from CLDQ. Results of these analyses suggest that bone fragments are autochthonous or parautochthonous and are derived from bones deposited in the assemblage rather than transported. The variability in abrasion exhibited by the fragments is most parsimoniously explained by local periodic re-working and re-deposition during seasonal fluctuations throughout the duration of the quarry assemblage. Collectively, these data support previous interpretations that the CLDQ represents an attritional assemblage in a poorly-drained overbank deposit where vertebrate remains were introduced post-mortem to an ephemeral pond during flood conditions. Furthermore, while the elevated heavy metals detected at the Cleveland-Lloyd Dinosaur Quarry are not likely the primary driver for the accumulation of carcasses, they are likely the result of multiple sources; some metals may be derived from post-depositional and diagenetic processes, and others are potentially produced from an abundance of decomposing vertebrate carcasses. These new data help to support the inferred depositional environment of the quarry as an ephemeral pond, and represent a significant step in understanding the taphonomy of the bonebed and Late Jurassic paleoecology in this region.

New conodont records of the Los Sombreros Formation (Cambrian–Ordovician) from the Western Precordillera, Argentina: biostratigraphic and palaeoenvironmental implications

2019 ◽  
Vol 157 (4) ◽  
pp. 539-550
Author(s):  
Gabriela Torre ◽  
Guillermo L. Albanesi
Keyword(s):  
Continental Margin ◽  
Carbonate Platform ◽  
South American ◽  
The South ◽  
Depositional History ◽  
The Matrix ◽  
Minimum Age ◽  
History Of ◽  
Lower Palaeozoic ◽  
Early Palaeozoic

AbstractThe presence of a carbonate platform that interfingers towards the west with slope facies allows for the identification of an ancient lower Palaeozoic continental margin in the Western Precordillera of Argentina. The Los Sombreros Formation is essential for the interpretation of the continental slope of the Precordillera, which accreted to Gondwana as part of the Cuyania Terrane in the early Palaeozoic. The age of these slope deposits is controversial; therefore, a precise biostratigraphic scheme is critical to reveal the evolution of the South American continental margin of Gondwana. The study of lithic deposits of two sections of the Los Sombreros Formation, the El Salto and Los Túneles sections, provides important information for further understanding the depositional history of the slope. At El Salto section, the conodonts recovered from an allochthonous block refer to the Cordylodus proavus Zone (upper Furongian). The conodonts recovered from the matrix of a calclithite bed of the Los Sombreros Formation in the Los Túneles section are assigned to the Lenodus variabilis Zone (early Darriwilian), providing a minimum age for this stratigraphic unit. In addition, clasts from this sample yielded conodonts from the Paltodus deltifer − Macerodus dianae zones (upper Tremadocian). The contrasting conodont colour alterations and preservation states from the elements of two latter records, coming from the same sample, argue the reworked clasts originated in the carbonate platform and later transported to the slope during the accretion process of the Precordilleran Terrane to the South American Gondwanan margin during the Middle–Late Ordovician.

CLIMATIC AND DEPOSITIONAL HISTORY OF THE LOWER PALEOCENE UPPER NACIMIENTO FORMATION, SAN JUAN BASIN, NEW MEXICO

2016 ◽  
Author(s):  
Caitlin E. Leslie ◽  
◽  
Ross Secord ◽  
Daniel J. Peppe ◽  
Stacy Atchley ◽  
...  
Keyword(s):  
New Mexico ◽  
San Juan ◽  
Depositional History ◽  
San Juan Basin ◽  
History Of

PROVENANCE AND SYNTECTONIC DEPOSITIONAL HISTORY OF THE MIOCENE CAMERINO DEEPWATER BASIN, CENTRAL ITALY

2020 ◽  
Author(s):  
Alan Pitts ◽  
◽  
Achim D. Herrmann ◽  
John T. Haynes ◽  
Gabriele Giuli ◽  
...  
Keyword(s):  
Central Italy ◽  
Depositional History ◽  
History Of ◽  
Deepwater Basin

scholarly journals Possible Pitfalls in the Analysis of Minerals and Loose Materials by Portable XRF, and How to Overcome Them

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 33
Author(s):  
Valérie Laperche ◽  
Bruno Lemière
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laboratory Data ◽  
Data Sets ◽  
Light Elements ◽  
Portable Xrf ◽  
X Ray ◽  
Protective Films ◽  
The Matrix ◽  
Valuable Complement ◽  
Physical Effects

Portable X-ray fluorescence spectroscopy is now widely used in almost any field of geoscience. Handheld XRF analysers are easy to use, and results are available in almost real time anywhere. However, the results do not always match laboratory analyses, and this may deter users. Rather than analytical issues, the bias often results from sample preparation differences. Instrument setup and analysis conditions need to be fully understood to avoid reporting erroneous results. The technique’s limitations must be kept in mind. We describe a number of issues and potential pitfalls observed from our experience and described in the literature. This includes the analytical mode and parameters; protective films; sample geometry and density, especially for light elements; analytical interferences between elements; physical effects of the matrix and sample condition, and more. Nevertheless, portable X-ray fluorescence spectroscopy (pXRF) results gathered with sufficient care by experienced users are both precise and reliable, if not fully accurate, and they can constitute robust data sets. Rather than being a substitute for laboratory analyses, pXRF measurements are a valuable complement to those. pXRF improves the quality and relevance of laboratory data sets.

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