Results 71 to 80 of about 3,413 (232)

Destabilization of Long‐Lived Hadean Protocrust and the Onset of Pervasive Hydrous Melting at 3.8 Ga

open access: yesAGU Advances, 2022
The nature of Earth's earliest crust and crustal processes remain unresolved questions in Precambrian geology. While some hypotheses suggest that plate tectonics began in the Hadean, others suggest that the Hadean was characterized by long‐lived ...
Nadja Drabon   +8 more
doaj   +1 more source

Detrital Avalonian zircons in the Laurentian Southern Uplands terrane, Scotland [PDF]

open access: yesGeology, 2003
The Silurian–Ordovician Southern Uplands terrane occupies a key position in the Caledonian orogen, yet its genesis is controversial. Marginal-basin, backarc, and forearc tectonic regimes have all been invoked as operative at the Laurentian margin of the Iapetus Ocean.
Phillips, E.R.   +7 more
openaire   +2 more sources

The Ames impact structure, Oklahoma: New radioisotopic constraints and implications for North American impact chronology

open access: yesMeteoritics &Planetary Science, EarlyView.
Abstract The Ames impact structure (Oklahoma) is thought to have formed during the Ordovician Meteor Event, based on conodont biostratigraphy of its crater fill. Here, U–Pb zircon dates from its impact‐melt portion, conducted using secondary ion mass spectrometry and laser ablation–inductively coupled plasma–mass spectrometry (n = 37 spots), yield a ...
Elizabeth J. Catlos   +9 more
wiley   +1 more source

Climate conditions on the South‐Iberian Palaeomargin during the latest Pliensbachian to early Toarcian: A mineralogical and geochemical study from hemipelagic deposits

open access: yesSedimentology, EarlyView.
ABSTRACT The integrated analysis of lithofacies, mineralogy and geochemistry of the hemipelagic marine succession exposed in La Cerradura section (South‐Iberian Palaeomargin) provides new information to characterise the palaeoenvironmental conditions during the latest Pliensbachian to early Toarcian, including the Jenkyns Event.
Chaima Ayadi   +4 more
wiley   +1 more source

A database of detrital zircon U–Pb ages in the North China Craton from the Paleoproterozoic to the early Palaeozoic

open access: yesGeoscience Data Journal
U–Pb dating of detrital zircon is widely used in geology to identify the source of sediments and constrain palaeogeography and tectonic history. We collected the detrital zircon from the Paleoproterozoic to early Palaeozoic strata to understand the North
Yiming Dong   +6 more
doaj   +1 more source

Sedimentology of silica granules and haematite in the 3.47 Ga Antarctic Creek Member, Mount Ada Basalt, Western Australia

open access: yesSedimentology, EarlyView.
ABSTRACT The Paleoarchean Antarctic Creek Member of the Mount Ada Basalt, Eastern Pilbara Terrane, Western Australia, includes beds of jasper and white chert composed of sand‐sized silica granules that often contain or are mixed with silt‐sized particles of haematite.
Donald R. Lowe, Gary R. Byerly
wiley   +1 more source

U-Pb and Hf isotopic study of detrital zircons from the meta-sedimentary rocks in central Jiangxi Province, South China: Implications for the Neoproterozoic tectonic evolution of South China Block

open access: yes, 2011
The Zhoutan Group, made of meta-sedimentary rocks and mafic volcanic, outcrops at the western margin of the Cathaysia Block. These rocks have been previously considered to represent a Mesoproterozoic sequence.
Yuejun Wang   +21 more
core   +1 more source

Spatial and temporal evolution of a coastal erg margin: the Middle Jurassic Page Sandstone, southern Utah, USA

open access: yesSedimentology, EarlyView.
ABSTRACT Aeolian deflationary events are erosive to static stages where sediment supply is insufficient to support bedform migration and preservation in the rock record. In the vicinity of shallow‐marine environments, inland rises of relative water table and associated generation of deflationary super surfaces may be driven by the onset of ...
Victor J. P. Hême de Lacotte   +4 more
wiley   +1 more source

Detrital zircons from Neoproterozoic sedimentary rocks in the Yili Block: Constraints on the affinity of microcontinents in the southern Central Asian Orogenic Belt

open access: yes, 2016
The Yili Block is one of the Precambrian microcontinents dispersed in the Central Asian Orogenic Belt (CAOB). Detrital zircon U-Pb ages and Hf isotopic data of Neoproterozoic meta-sedimentary rocks (the Wenquan Group) are presented to constrain the ...
Wang, Y   +13 more
core   +1 more source

LA-ICP-MS U–Pb ages of detrital zircons from Middle Jurassic sedimentary rocks in southwestern Fujian: Sedimentary provenance and its geological significance

open access: yesOpen Geosciences, 2020
In order to determine the tectonic regime change of the early Mesozoic in the South China Block, this study analyzed sedimentary rocks in the Middle Jurassic of southwestern Fujian by modal analysis of sandstones, elemental geochemical analysis of ...
Zhongjie Xu   +4 more
doaj   +1 more source

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