Strategies towards statistically robust interpretations of in situ U–Pb zircon geochronology

Spencer, Christopher J.; Kirkland, Christopher L.; Taylor, Richard

doi:10.1016/j.gsf.2015.11.006

Cited by 562 publications

(302 citation statements)

References 35 publications

Supporting

Mentioning

268

Contrasting

Unclassified

Order By: Relevance

“…(1991) and Spencer et al (2016), the resulting MSWD value of 2.2 is slightly too high (as it should not exceed 2). In addition, this age was calculated after excluding the two youngest (perfectly concordant) zircon analyses, interpreted by the authors as resulting from a slight Pb loss; and the eight analyses used for the age calculation were either poorly concordant or slightly discordant, thus needing a re-evaluation.…”

Section: Revision Of Available Radiometric Agesmentioning

confidence: 95%

See 1 more Smart Citation

Cadomian volcanosedimentary complexes across the Ediacaran–Cambrian transition of the Eastern Pyrenees, southwestern Europe

Padel

Álvaro

Casas

et al. 2017

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

International audienceThe volcanism hosted by the Ediacaran–Terreneuvian Canaveilles Group of the Eastern Pyrenees displays two distinct geochemical affinities: (1) metabasites of the Nyer and Olette formations reflect the emplacement of a tholeiitic magmatism linked to extensional conditions, whereas (2) subsequent felsic and calc-alkaline magmatic rocks marking the top of the Olette Formation and forming the overlying Fabert and Finestrelles members represent Cadomian magmatic events. Based on U–Pb zircon dating constraints, palaeotopographic relationships linked to onlap geometries and distance from vent sources, three volcanosedimentary edifices can be distinguished, the so-called Tregurà (ca. 565–552 Ma), Cap de Creus (ca. 558 Ma) and Coll d’Ares (ca. 542–532 Ma) edifices. The top of their palaeoreliefs recorded locally the nucleation of centres of microbial carbonate productivity (Puig Sec Member) linked to synsedimentary tilting and karstification. Throughout West Gondwana, the presence of carbonate production across the Ediacaran–Cambrian transition is exclusively located in back-arc settings (Central-Iberian Zone) and areas far from the Cadomian subduction trench and devoid of significant terrigenous input, such as those reported in the Eastern Pyrenees and the neighbouring Montagne Noire

show abstract

Section: Revision Of Available Radiometric Agesmentioning

confidence: 95%

“…If MSWD > 1 + 2(2/f) 1/2 at 2σ, where f is the degree of freedom (Wendt and Carl 1991), the calculated date has to be consider as meaningless. In the case of U-Pb dating, f = n − 1, where n corresponds to the number of analyses used to calculate a date (Spencer et al 2016).…”

mentioning

confidence: 99%

Cadomian volcanosedimentary complexes across the Ediacaran–Cambrian transition of the Eastern Pyrenees, southwestern Europe

Padel

Álvaro

Casas

et al. 2017

Int J Earth Sci (Geol Rundsch)

View full text Add to dashboard Cite

show abstract

“…1 of Spencer et al, 2016). However, the ease by which large detrital zircon datasets can be acquired by the geoscience community has led to diverse data handling approaches and interpretations of geochronological data (see discussion by Spencer et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Maximising data and precision from detrital zircon U-Pb analysis by LA-ICPMS: The use of core-rim ages and the single-analysis concordia age

Zimmermann

Mark

Chew

et al. 2018

Sedimentary Geology

View full text Add to dashboard Cite

Available online xxxx U-Pb detrital zircon geochronology is a powerful and well-established tool in provenance studies. Modern analytical techniques (particularly LA-ICPMS) increasingly facilitate the rapid acquisition of large datasets. While improvements in data handling approaches have been explored in detail (e.g., more robust propagation of analytical uncertainties and inter-laboratory age reproducibility studies), there currently are no commonly established protocols for target spot location on polyphase detrital zircon grains: should the analyst ablate the zircon core, rim, or both? Here, we present two regional U-Pb detrital zircon datasets, one from the Banda Arc in Eastern Indonesia and one from the European Alps pro-foreland basin. We demonstrate that preferential ablation solely of cores or rim overgrowths results in a failure to detect age peaks, and also that generation of single-grain core-rim age pairs can permit additional characterisation of the source rock. Thus, both cores and rims should be analysed where possible, to maximise the data obtained from detrital zircon. In addition, we advocate the use of the single-analysis concordia age in visualizing and presenting U-Pb data, which is currently under-utilised in detrital provenance studies. We utilise a large (ca. 49,500 analyses) detrital zircon dataset to demonstrate that the single-analysis concordia age maximises precision throughout geological time (which removes the need to present ages derived from different isotopic ratios across an arbitrary age threshold), and obviates the necessity to separately assess discordance.

show abstract

“…206 U/ 238 Pb ages were used for analyses younger than 1,000 Ma, while 207 Pb/ 206 Pb ages were used for analyses older than 1,000 Ma. A complete discussion of the discordance cutoffs for provenance studies and strategies defining the maximum depositional age can be found in Spencer et al (2016). The errors in the tables and figures were at the 1-sigma level.…”

Section: Methodsmentioning

confidence: 99%

Tectonics and sedimentation of the central sector of the Santo Onofre rift, north Minas Gerais, Brazil

Costa

Filho

2017

Braz. J. Geol.

View full text Add to dashboard Cite

ABSTRACT:The Santo Onofre Group registers the filling of a Tonian, intracontinental paleo-rift that developed along the northern and central Espinhaço regions. This paper examines this unit in the central Espinhaço region with stratigraphic analysis and U-Pb geochronology, reviewing and dividing into the Canatiba and Rio Peixe Bravo Formations, which include the Barrinha Member. The Canatiba Formation mainly comprises carbon-rich mudstones that were deposited through low-density turbidity flows that alternated with sediment settling under anoxic conditions. The Rio Peixe Bravo Formation consists of a succession of sandstones and minor mudstones, which were deposited through low-to high-density turbidity flows. The Barrinha Member mainly consists of conglomerates and is related to channelized debris flows. Detrital zircon grains show maximum depositional ages of 930 ± 33 Ma and around 865 Ma for the Canatiba and Rio Peixe Bravo Formations, respectively. We interpret the Santo Onofre rifting to be relative younger than that for the Sítio Novo Group and to be a precursor stage of the glacial and post-glacial rift-to-passive margin-related sequences of the Macaúbas Group. The lithostratigraphic term "Macaúbas Supergroup" would be of better use to accommodate the unconformity-bounded Tonian sequences that were related to the Rodinia breakup in the Congo-São Francisco paleocontinent. (Hoffman 1991, Meert 2001. Several phases that involved the breaking of Rodinia occurred, either through passive or active rifting, which were induced by remotely applied tensions (in-plane stress) and mantle plumes, respectively . These processes operated diachronically through a continental mass, and the full disintegration of the continent was complete at the end of the Tonian Period (Hoffman 1991, Cawood et al. 2016. Many rifts were formed before reaching this stage, some of which were aborted, and mafic dyke swarms intruded, which became dispersed in the scattered continents (Chew et al. 2010, Volkert et al. 2015. Investigations of these features have provided a better understanding of the space-temporal evolution of the Rodinia, for reconstructions (Hoffman 1991, Meert 2001. KEYWORDS:The Congo-São Francisco paleocontinent is characterized as one of several fragments of the Rodinia (Hoffman 1991. This paleocontinent encompasses the cover and basement rocks of São Francisco and Congo cratons and their marginal orogenic belts ( Fig. 1; Almeida 1977, Alkmim et al. 1993, Trompette 1994. The Espinhaço mountain range is a remarkable feature that extends with a sub-meridian direction across the entire extent of the Congo-São Francisco paleocontinent. The southern and central Espinhaço range regions integrate the Araçuaí fold and thrust belt as one of the external domains of the Neoproterozoic Araçuaí-West Congo orogen (Almeida 1977, Pedrosa-Soares et al. 1992, while the northern extension occurs along the eastern border of the Paramirim aulacogen, which was partially inverted, and involves the basement in the cover deformation (Schobbenhau...

show abstract

Strategies towards statistically robust interpretations of in situ U–Pb zircon geochronology

Cited by 562 publications

References 35 publications

Cadomian volcanosedimentary complexes across the Ediacaran–Cambrian transition of the Eastern Pyrenees, southwestern Europe

Cadomian volcanosedimentary complexes across the Ediacaran–Cambrian transition of the Eastern Pyrenees, southwestern Europe

Maximising data and precision from detrital zircon U-Pb analysis by LA-ICPMS: The use of core-rim ages and the single-analysis concordia age

Tectonics and sedimentation of the central sector of the Santo Onofre rift, north Minas Gerais, Brazil

Contact Info

Product

Resources

About