Detrital Zircon Geochronological Data Research Articles

Local Singularity Spectrum: An Innovative Graphical Approach for Analyzing Detrital Zircon Geochronology Data in Provenance Analysis

Detrital zircon geochronology plays a crucial role in provenance analysis, serving as one of the fundamental strategies. The age spectrum of detrital zircons collected from the sedimentary unit of interest is often compared or correlated with that of potential source terranes. However, biases in the age data can arise due to factors related to detrital sampling, analysis techniques, and nonlinear geological mechanisms. The current study reviewed two sets of detrital zircon datasets established in 2011 and 2021 to discuss the origins of the Tibetan Plateau. These datasets collected from different media effectively demonstrate a progressive understanding of provenance affinity among the main terranes on the Tibetan Plateau. This highlights issues regarding weak and unclear temporal connections identified through analyzing the age spectrum for provenance analysis. Within this context, a local singularity analysis approach is currently employed to address issues associated with unclear and weak provenance information by characterizing local variations in nonlinear behaviors and enhancing detection sensitivity towards subtle anomalies. This new graphical approach effectively quantifies temporal variations in detrital zircon age populations and enhances identification of weak provenance information that may not be readily apparent on conventional age spectra.

A database of detrital zircon geochronology ages of Cambrian to Paleogene deposits in South China

AbstractComplications of detrital zircons databases provide a means for statistically analysing a variety of significant geological problems. In this work, we tried to collect a database about the South China Phanerozoic detrital zircon geochronology data. The data statistics of this paper rely on the OneSediment Working Group of The Deep‐time Digital Earth program (DDE). By November 2022, the database contains a total of 699 samples with 55,532 U–Pb ages and 3,770 effective Hf isotope data, from 130 papers. Abundant information including reference title, sample ID, locality, rock type, research institution, GPS coordinates, U–Pb ages, εHf(t) values, etc., have been involved in our database, and all data can be downloaded from DDE Data Publish & Repository website, https://repository.deep‐time.org/. Through the integrated data, we can improve the previous studies and avoid the waste of resources caused by a large number of repeated studies.

A middle Pleistocene to Holocene perspective on sediment sources for the Tengger Desert, China

Dust plays a critical role in global biogeochemical and carbon cycles. The deserts of northern China have been important East Asian dust sources throughout the Quaternary. The Tengger Desert, one such major arid dust-producing region in northern China, is thought to have started resembling its current form during the middle to late Pleistocene. As such, understanding the nature of the Tengger Desert’s formation and the associated import, storage, and export of sediments are consequential for the regional, and potentially global, climate. The U-Pb detrital zircon geochronology data reported here from both present-day and middle to late Pleistocene Tengger Desert sediments support derivation from the Shiyang River system sourced from the Qilian Mountains mixed with sediments eroded from local basement uplifts and Gobi Altay sources. This interpretation is different from the view that sediments of this age were primarily transported to the Tengger Desert from the arid East Asian continental interior upwind. We note that this analysis suggests a common provenance for Quaternary sediments in the Tengger, Badain Jaran, and Mu Us Deserts wherein these deserts received riverine-sourced sediments from the Qilian Mountains and northeastern Tibetan Plateau. This observation highlights the importance of precipitation at elevation along the present-day margin of the East Asian summer monsoon in driving sediment supply during the middle to late Quaternary desertification within the East Asian continental interior.

A Late Palaeozoic disconformity in the Moqinwula area: Insights into the tectonic evolution and basement nature of the Junggar Block, NW China

The recognition of unconformities is important for stratigraphic subdivision and correlation and for determining the timing of tectonic activity and the ocean‐continent transition process. Here, we have identified a Late Palaeozoic disconformity in the Moqinwula area of the northern Junggar Block, NW China. Integrated field relationship observations and sedimentological, biostratigraphical, geochemical and detrital zircon geochronological data, suggest that the underlying Hongliugou Formation is of Devonian age and was deposited in a passive continental margin setting. The overlying Tamugang Formation formed in the Early Carboniferous and was deposited in a foreland basin setting. Integrating the published data and our new work, we suggest a new tectonic evolution model related to the Karamaili ocean‐continent transition process. During the Early Devonian, northward subduction of the Karamaili Ocean plate beneath the East Junggar Belt formed the Yemaquan arc. At this time, a passive margin sequence was deposited on the northern Junggar Block. During the Early Carboniferous, the closure of the Karamaili Ocean resulted from the collision between the Junggar Block and the East Junggar Belt. Foreland basins subsequently developed, forming an extensive unconformity in the accretionary wedge to the north and a disconformity in the relatively rigid and stable Junggar Block to the south. This significant difference in stratigraphic contact relationships confirms that regional convergence‐induced shortening deformation had no significant influence on the northern margin of the Junggar Block, suggesting the existence of a relatively rigid basement, probably an oceanic plateau, under the cover sediments of the Junggar Block.

Linking South China Plate to Arabian margin of Gondwana: Significance for Cambrian global plate reconstruction

Large-scale plate convergence processes led to the assembly of the Gondwana supercontinent during the Ediacaran–Cambrian. Herein, we present the results from petrological and geochemical studies on fine-grained sedimentary rocks belonging to the Lower Cambrian strata from the western part of South China Plate (SCP) in the Yangtze terrane, to reveal the location of SCP in the Gondwana supercontinent. Our results show that these rocks are of high compositional and textural maturity and belong to the same tectono-sedimentary cycle. The rare earth element (REE) distribution curve standardized by Post-Archean Australian Shale is similar to that for typical post-Archean shale. Characteristics of major and trace elements indicate that these fine-grained sedimentary rocks might mainly be derived from moderately felsic magmatic provenance with only a minor supply from mafic–ultramafic sources. Trace element ternary discriminant plots reveal the geotectonic setting as a continental island arc, although some passive margin sediments might have also been involved; R-type cluster analysis based on trace elements and REEs also shows that the tectonic setting of the sample provenance area is most likely to be that of continental island arcs and active continental margins. Combined with the published detrital zircon geochronological data of SCP and global tectonic-magmatic activity during the Cambrian, we propose that the Lower Cambrian clastic sediments in SCP were mainly supplied by the Cadomian island arc along the northern margin of Gondwana during the Ediacaran–Early Cambrian. Based on the above analysis, we believe that SCP might have been located closer to Arabian Plate than to Australian Plate.

FIRST DETRITAL ZIRCON GEOCHRONOLOGY DATA FOR CLASTIC ROCKS OF THE EAST SAKHALIN ACCRETIONARY TERRANE

First detrital zircon geochronology data and results of geochemical studies for clastic rocks of the Rymnik and Nabil zones of the East Sakhalin accretionary terrane, located within the region of the East Sakhalin Mountains, are presented. The studies have been carried out at the Center for Collective Use of Far Eastern Geological Institute of the Far East Branch of the Russian Academy of Sciences in Vladivostok. The established geochemical features suggest that the source of the clastic material of the zones was felsic rocks of the deeply eroded continental island arc or arcs. Although the geochemical characteristics are similar, there are sharp differences between the detrital zircons’ age distribution patterns of rocks of these zones. In the sandstone of the Nabil zone, 75 % of the zircon grains are of the middle Cretaceous age (94–108 Ma) with a peak of 96 Ma, 15 % are the middle Permian-Early Jurassic, and 10 % are the Precambrian (mainly Paleoproterozoic). The sandstone of the Rymnik zone has a more complex (polymodal) pattern of the detrital zircon age distribution, with a significant contribution of the Precambrian grains (37 %). Most of the grains belong to the Early Jurassic (peak 196 Ma) and the Early Cretaceous (peak 137 Ma), with 47 % of the Mesozoic grains. The likely provenances of the clastic material were the Middle Cretaceous volcanic arcs of the Asian eastern margin older complexes of the continent.

Detrital zircon geochronology of Late Cretaceous successions in the Ganzhou Basin, South China: evidence of a major tectonic transition

Abstract Situated within the southern segment of the South China Block, the Ganzhou Basin formed owing to subduction of the palaeo-Pacific plate beneath the South China Block. Late Cretaceous successions in this basin consist of fluvial and lacustrine facies red beds hosting abundant dinosaur and dinosaur egg fossils. This study reports detrital zircon geochronological data from a crystallized tuff and four sandstones found in the Late Cretaceous Ganzhou Group of the Ganzhou Basin. Age distributions included four major age subpopulations of predominantly Triassic, Devonian–Ordovician, Neoproterozoic and Paleoproterozoic ages. These indicate source material derived from Yanshanian and Triassic granitoids as well as from Kwangsian and Jiangnan orogens. Age signatures generally resemble those recorded in the adjacent Nanxiong Basin but also include distinctive features. Provenance signatures from successive units indicate a tectonic transition from intracontinental extension at c. 120 Ma to compression near the Cretaceous/Paleogene boundary. This tectonic transition was probably driven by continent–continent collision between the Indian and Eurasian plates, as well as by a shift in the subduction direction of the palaeo-Pacific plate beneath the Eurasian plate.

Geochronological constraints of the Huoshan Formation in the Lüliang area: Implication on the Great Unconformity in the central North China Craton

The Great Unconformity between the Precambrian basement and the Phanerozoic successions marks a major gap in the stratigraphic records globally. However, previous studies on the time, magnitude, and the spatial distribution of this unconformity in the North China Craton (NCC) mainly focused on the south‐eastern margin and were seldom investigated in the central area. In this study, we report detrital zircon geochronological data of the Huoshan Formation, a siliciclastic stratigraphic unit between the Archean‐Palaeoproterozoic metamorphic basement and Cambrian successions in the central NCC. The youngest age peak of 685 Ma suggests that the Huoshan Formation was formed in the post‐Ediacaran rather than the counterpart of the lower Palaeo‐Mesoproterozoic Changcheng Group. The detrital zircons of the quartz sandstone from the Huoshan Formation show varied age populations of 2,700–2,600 Ma, 2,600–2,500 Ma, 2,200–2,000 Ma, 1,900–1,800 Ma, and 700–600 Ma, which correspond to typical tectono‐thermal events of the NCC. First, the widely developed Precambrian tectono‐thermal events in the NCC were archived in the detrital zircons in the Huoshan Formation, for instance, the crustal growth event at 2,600–2,500 Ma and the 1,850–1,800 Ma magmatic and metamorphic events. Second, the age peaks younger than 1,000 Ma are not distinct in the NCC and are possibly from other terranes. The Great Unconformity represented by the boundary between the Huoshan Formation and the underlying Archean‐Palaeoproterozoic basement suggested a high topography and long‐term denudation in the Lüliang area during the transition from the Proterozoic to the Phanerozoic.

Sediment provenance analysis of the Permian from the Perth Basin using an automated Raman heavy mineral technique

The Early Permian in the onshore Perth Basin has experienced several significant discoveries in the last 8 years. Beginning with the play-opening Waitsia discovery (AWE), this was followed more recently by the Beharra Springs Deep (Beach Energy) and West Erregulla (Strike) discoveries. In addition, Late Permian sands (Dongara and Wagina sandstones) have long been recognised as excellent reservoirs in the basin. This study attempts to better understand the provenance of the Early and Late Permian sediments using automated Raman spectroscopy as a tool to identify variations in heavy mineral assemblages. Automated Raman spectroscopy analysis of heavy minerals minimises operator bias inherent in more traditional optical heavy mineral analyses. These data are integrated with publicly available chemostratigraphy data to enable a better understanding of sediment provenance variations with stratigraphy. In addition, publicly available detrital zircon geochronological data are incorporated to help further understand sediment sources. A transect of wells is investigated, from Arrowsmith-1 in the southernmost extent to Depot Hill-1 and Mt Horner-1 in the north. While the elemental (chemostratigraphy) data suggest some changes in sediment provenance through the Permian of the Perth Basin, the Raman heavy mineral data confirm a number of sediment provenance changes both at key formational boundaries (e.g. top Kingia sandstone) and complex sediment provenance variation within reservoir sandstone units. These results are integrated to demonstrate how sediment provenance holds the key to understanding controls on variable reservoir quality as well as understanding the early infill in this basin.

Constraining late paleozoic ice extent in the Paganzo basin of western Argentina: Provenance of the lower Paganzo group strata

The western margin of Gondwana records evidence of mid-Carboniferous glaciation (Visean- Bashkirian) in the strata of the Paganzo Basin and adjacent areas. Previous studies focused on constraining the orientations of ice flow and generalizing the extent and occurrence of glacial ice in the basin. However, there is uncertainty occurs concerning the location and extent of glaciation and the locations of glacial centers during deposition of the Guandacol Formation located in the western portion and the time correlative Malanzán Formation in the eastern parts of the basin respectively. Understanding these strata and the conditions that led to the deposition of these strata has important implications for understanding glaciation extent along the western margin of Gondwana during the late Paleozoic ice age. To refine the glaciation history, we present new paleocurrent, facies, and a comparative analysis of previously published and one new detrital zircon geochronology data set. Together, these data provide new insight into sediment dispersal patterns and glacial centers within the basin. Our data indicate that both units were deposited under cold climatic conditions that occurred across the entire basin, but that glaciers were restricted to the western portion of the basin. The facies analysis for both formations indicates very different depositional environments for the two units: glacial and glaciomarine environments in the west and non-glacial alluvial, alluvial fan and lacustrine and/or marine environments in the east. Detrital zircon geochronology indicates separate localized provenance signatures for the two formations. Furthermore, the detrital zircon populations allude to disconnected depositional centers. At Huaco, glacial flow in the Guandacol is oriented toward the northwest (i.e. 313°) and appears to be draining from an uplift that contains similar zircon age populations as the Sierra de Valle Fértil and Sierra de Pie de Palo ranges. In the Olta-Malanzán paleovalley system, drainage was off valley walls and down the valley axis (i.e. south and southwest) within the Sierras de Chepes region with limited sediment sourced from the east just beyond the paleovalley system. Paleoflow measurements reported from other known glacial localities along the western portion of the basin reflect a radial flow pattern within and away from deeply incised valleys that clearly point to upland glacial centers within the Cuyania and Precordilleran terranes.

Mesoproterozoic–Early Cretaceous provenance and paleogeographic evolution of the Northern Rocky Mountains: Insights from the detrital zircon record of the Bridger Range, Montana, USA

AbstractThe Bridger Range of southwest Montana, USA, preserves one of the most temporally extensive sedimentary sections in North America, with strata ranging from Mesoproterozoic to Cretaceous in age. This study presents new detrital zircon geochronologic data from eight samples collected across this mountain range. Multidimensional scaling and non-negative matrix factorization statistical analyses are used to quantitatively unmix potential sediment sources from these and 54 samples compiled from previous studies on regional correlative strata. We interpret these sources based on reference data from preserved strata with detrital zircon signatures likely representative of ancient sediment sources. We link these sources to their sinks along sediment dispersal pathways interpreted using available paleogeographic constraints. Our results show that Mesoproterozoic strata in southwest Montana contain detritus derived from the nearby craton exposed along the southern margin of the fault-bounded Helena Embayment. Middle Cambrian strata were dominated by the recycling of local sources eroded during the development of the Great Unconformity. In Devonian–Pennsylvanian time, provenance in southwest Montana shifted to more distal sources along the northeastern to southeastern margins of Laurentia, but more western basins received detritus from outboard sources along a tectonically complicated margin. By the Late Jurassic, provenance in the developing retroarc foreland basin system was dominated by Cordilleran magmatic arcs and fold-thrust belt sources to the west. Eastward propagation of the fold-thrust belt caused recycling of Paleozoic and Jurassic detritus into the foreland basin to dominate by the Early Cretaceous.

From a proximal-deposition-dominated basin sink to a significant sediment source to the Chinese Loess Plateau: Insight from the quantitative provenance analysis on the Cenozoic sediments in the Qaidam basin, northern Tibetan Plateau

A better understanding of the Cenozoic source to sink relationship between the Qaidam Basin and the surrounding regions allows us to reveal the topographic evolution of the northern edge of Tibetan Plateau in response to the India-Asian collision and the Asian aridification process. However, the depositional history and provenance of Paleogene strata in the southwestern/northeastern Qaidam Basin and the genetic linkage between the Qaidam Basin and Cenozoic Chinese Loess Plateau is still debated. Here we compile ca. 12,000 U-Pb zircon analyses from the Qaidam Basin, Chinese Loess Plateau and the surrounding regions, and conduct quantitative provenance analysis using a MATLAB-based Inverse Monte Carlo simulation technique. When integrated with variations in stratigraphic thickness and lithology across the basin, our analysis suggests the minor topographic relief separating the Qaidam Basin from the Hoh Xil Basin to the south, served as the major source for the sediments deposited in the SW Qaidam Basin since the Paleogene. The Qilian Shan to the north, the underlying Mesozoic strata and the local paleo-reliefs to the southwest within the basin shed materials into the NE Qaidam Basin during the Paleogene. This finding exemplifies the fact that detrital zircon geochronology alone would lead to an incorrect interpretation if independent sedimentary evidence is not considered. Based on U-Pb detrital zircon geochronology data from Pliocene-Quaternary and loess samples collected from various locations in both the Qaidam Basin and Chinese Loess Plateau, our quantitative estimate shows that approximately 30% of materials in the Chinese Loess Plateau are derived from the sediments in the Qaidam Basin, twice the previous estimate. This higher proportion of the Qaidam Basin source for the Chinese Loess Plateau highlights that using a spatially limited sample set from the Qaidam Basin would result in underrating its contribution to the sediments preserved in the Chinese Loess Plateau.

Provenance and tectonic setting of late Paleozoic sedimentary rocks from the Alxa Tectonic Belt (NW China): Implications for accretionary tectonics of the southern Central Asian Orogenic Belt

AbstractThe Central Asian Orogenic Belt has long been considered the largest Phanerozoic accretionary orogen in the world; it developed through the subduction and final closure of the Paleo–Asian Ocean. However, the architecture and duration of the accretionary orogenesis of the Central Asian Orogenic Belt are still controversial despite decades of investigation. In this study, we present field, compositional, and stratigraphically controlled detrital zircon geochronological data for late Paleozoic sedimentary rocks from the Alxa Tectonic Belt to constrain their provenance, tectonic setting, and the overall tectonic configuration of the southern Central Asian Orogenic Belt. A Devonian sample yields a unimodal age peak (ca. 424 Ma) and broad late Mesoproterozoic ages. A Carboniferous sample has Early Silurian (ca. 438 Ma) and Late Devonian (ca. 382 Ma) peaks along with Neoproterozoic to Archean ages. The Permian samples are dominated by Ordovician–Devonian and Carboniferous–Permian ages. They yield maximum depositional ages ranging from ca. 291 Ma to 248 Ma and contain abundant zircon ages that are close to their depositional ages. These data reveal Ordovician–Silurian and Carboniferous–Permian magmatic flare-ups separated by a Devonian magmatic lull in the southern Central Asian Orogenic Belt. The arc terranes in southern Mongolia, central Beishan, and northern Alxa provided major detritus for the late Paleozoic sediments. An abrupt shift of zircon εHf(t) values at ca. 400 Ma reveals significant late Paleozoic crustal growth and excludes southern Alxa as a source. Oceanic basins prevented detritus from southern Alxa from reaching northern Alxa during Permian–Early Triassic time. A geological and provenance comparison of Permian basins in the southern Central Asian Orogenic Belt reveals the existence of two separate forearcs ascribed to bipolar subduction of the Paleo–Asian Ocean. Combined with recent paleomagnetic data, this leads us to advocate for an archipelago-style accretionary process induced by subduction retreat for the late Paleozoic tectonic evolution of the southern Central Asian Orogenic Belt, which continued into Late Permian–Early Triassic.

Provenance and deformation history of the Eastern Thomson Orogen and implications for the Paleozoic evolution of the Tasmanides (Eastern Australia)

Cambrian deformation associated with the Delamerian Orogeny is most evident in the Delamerian Orogen (southwestern Tasmanides) but has also been documented in the Thomson Orogen (northern Tasmanides). The tectonic evolution of the Thomson Orogen in the context of the Delamerian Orogeny is poorly understood. In particular, tectonostratigraphic relationships between the different parts of the Thomson Orogen (Anakie Inlier, Nebine Ridge, and southern Thomson Orogen) are still unclear. New detrital zircon data from the Nebine Ridge revealed an age spectrum that is consistent with published geochronological data from the Anakie Inlier. These results, in conjunction with petrographic observations and the interpretation of geophysical data, suggest that along the eastern part of the Thomson Orogen, the ∼ NNE-trending Nebine Ridge represents the southward continuation of the ∼ N–S-trending Anakie Inlier. New detrital zircon geochronological data are also presented for metasedimentary rocks from both sides of the Thomson–Lachlan boundary. The results constrain the maximum age of deposition (Ordovician–Devonian), and show that both sides of the Thomson–Lachlan boundary received detritus from a similar provenance. This might suggest that the Thomson–Lachlan boundary did not play a major role as a crustal-scale boundary prior to the Devonian. We speculate that transpressional deformation along this ∼ E–W boundary, during the Early Devonian, was responsible for disrupting the original belt that connected the Delamerian Orogen (Koonenberry Belt) with the eastern Thomson Orogen (Nebine Ridge and Anakie Inlier).HighlightsThe Nebine Ridge is the southward continuation of the Anakie Inlier.The Anakie Inlier and Nebine Ridge represent a northern segment of the Cambrian Delamerian–Thomson Belt.∼E–W-trending crustal-scale structures at the southern Thomson Orogen were active during Devonian.

Detrital zircon U–Pb dating and Hf isotope study of late Palaeozoic sedimentary rocks in central–eastern Jilin Province, NE China: Constraints for tectonic evolution of the eastern segment of the Paleo‐Asian Ocean

This paper reports in situ U–Pb ages and Hf isotopic data on detrital zircons from Palaeozoic strata in central‐eastern Jilin Province, NE China, with the aim of constraining the timing of final closure of the Paleo‐Asian Ocean and the tectonic evolution of the eastern segment of the Central Asian Orogenic Belt (CAOB). Zircons from Middle to Late Permian Fanjiatun and Yangjiagou formations in central Jilin Province are characterized by four major groups of age populations (2.5–2.3 Ga, 1.9–1.7 Ga, 1.3–1.0 Ga, and Late Palaeozoic ages). The Paleo‐Mesoproterozoic and Cambrian zircons have positive εHf(t) values, suggesting that the source was mainly locally derived from the CAOB, whereas a lesser amount of Archean zircons with positive εHf(t) values, indicating that source from the North China Craton (NCC). The Phanerozoic zircons have both positive and negative εHf(t) values indicates that material from bidirectional provenances in the CAOB and the NCC. However, Late Permian Kaishantun Formation in eastern Jilin Province contain a single group of Phanerozoic zircons with positive εHf(t) values, distinct from known igneous zircons in the NCC, suggesting a local source. These observations, along with the results of previous studies on Middle–Late Permian igneous rocks in Jilin Province, indicate that the eastern segment of the Paleo‐Asian Ocean underwent the initial closure in central Jilin Province during the Middle Permian and the final closure in eastern Jilin Province in the Late Permian–Early Triassic. The detrital zircon geochronological data clearly record two stages of tectonic evolution and the scissor‐like closure model of the Paleo‐Asian Ocean in the eastern segment of the CAOB.

Detrital zircon provenance comparison between the Paleocene-Eocene Nangqian-Xialaxiu and Gongjue basins: New insights for Cenozoic paleogeographic evolution of the eastern Tibetan Plateau

Paleogeographic reconstructions of terranes can greatly benefit from the provenance analysis of sediments. A series of Cenozoic basins provide key sedimentary archives for investigating the growth of the Tibetan Plateau, yet the provenance of the sediments in these basins has never been constrained robustly. Here we report sedimentary petrological and detrital zircon geochronological data from the Paleocene-Eocene Nangqian-Xialaxiu and Gongjue basins. Sandstone detrital modes and zircon morphology suggest that the samples collected in these two basins were sourced from recycled orogen. Detrital zircon geochronology indicates that sediments in the Nangqian-Xialaxiu Basin are characterized by two distinct age populations at 220–280 Ma and 405–445 Ma. In contrast, three predominant age populations of 207–256 Ma, 423–445 Ma, and 1851–1868 Ma, and two subordinate age populations of ~50 Ma and ~2500 Ma, are recognized in the Gongjue Basin. Comparison with detrital zircon ages from the surrounding terranes suggests that sediments in the Nangqian-Xialaxiu Basin come from the neighboring thrust belts, whereas sediments from the Gongjue Basin are predominantly derived from the distant Songpan-Ganzi Terrane with minor contribution from the surrounding areas. A three-stage Cenozoic evolution of the eastern Tibetan Plateau is proposed. During the Paleocene, the Nangqian-Xialaxiu Basin appeared as a set of small intermontane sub-basins and received plentiful sediments from the neighboring mountain belts; during the Eocene, the Gongjue Basin kept a relatively low altitude and was a depression at the edge of a proto-Plateau; since the Oligocene, the Tibetan Plateau further uplifted and the marginal Gongjue Basin was involved in the Tibetan interior orogeny, indicating the eastward propagation of the Tibetan Plateau.

Petrography and detrital zircon U-Pb geochronology of sedimentary rocks of the Campo Alegre Basin, Southern Brazil: implications for Gondwana assembly

Abstract The Campo Alegre Basin is a volcano-sedimentary sequence covering an area of about 500 km2 , located at the northeast portion of Santa Catarina state (Brazil), and formed during the late stages of the Neoproterozoic era. Three main stratigraphic units compose this basin, the lowermost of which is the Bateias Formation, corresponding to the pre-volcanic stage. It is characterized by the fanglomeratic sediments at the basin’s northern boundary, which were deposited in a fluvial environment and progressively replaced by fluvial sandstones towards the south. Poorly sorted conglomerates and breccias compound the fanglomeratic facies, which comprises angular to subrounded fragments in a matrix ranging from sand fractions to fragments larger than gravel. The ubiquitous presence of volcanogenic and metamorphic fragments in the fanglomeratic facies strongly suggests that the Pien Magmatic Arc and a volcanic manifestation coeval with the earlier stages of the basin formation were important source areas, as well as the basin basement (the Luis Alves Terrane). In this sense, geological, petrographic, and detrital zircon geochronology data are combined in order to interpret the mechanisms that had acted during the deposition of these sedimentary rocks and to constraint the maximum depositional ages of Bateias Formation at ca. ~606 Ma.

Erratum for ‘The provenance of the Devonian Old Red Sandstone of the Dingle Peninsula, SW Ireland; the earliest record of Laurentian and peri-Gondwanan sediment mixing in Ireland,’ Journal of the Geological Society, London, 175, 411–424

Samples in this paper have been assigned formations based on the Geological Survey of Ireland shapefile released prior to the commencement of the study. However, the authors were not aware that, since obtaining the samples, an updated shapefile had been released. This update affects three of the four apatite samples assigned to the Lower Devonian Ballymore Formation. The location of samples Mb-1, Mb-4 and Mb-5 now places them well within the undifferentiated, Upper Devonian Slieve Mish Group. As outlined in our paper, the apatite ages were originally produced concurrently with apatite fission track analysis and were later used in our study to provide additional provenance information in support of the detrital zircon geochronological data. In the second paragraph of the discussion section we say the following: et al. (1999) obtained an age of 411 Ma for the Cooscrawn Tuff Bed in the Ballymore Formation, which is older than 22 of the 70 detrital apatites analysed in this formation. The reassignment of the three samples to the Upper Devonian Slieve Mish Group nullifies the above statement. However, our interpretation that the depositional age of the Ballymore Formation is younger than the 411 Ma age given by Williams et al. (1999) is predominantly based upon the evidence given by the six youngest detrital zircons from the formation which underlies the Ballymore Formation (i.e. the Slea Head Formation). These zircons give a concordia age of 405 ± 4 Ma. This suggests that the Ballymore Formation was more than likely deposited after 409 Ma. We do not believe that the reassignment of the three samples has any major impact on our provenance interpretations. The ∼420 Ma age of the majority of the apatites in samples Mb-1, Mb-4 and Mb-5 actually fits with the range of Palaeozoic detrital zircons in sample AK-17 which was taken from the Slieve Mish Group, thereby supporting minor input of rocks affected by end-Scandian metamorphism.

Geochronology and geochemistry of Permo-Triassic sandstones in eastern Jilin Province (NE China): Implications for final closure of the Paleo-Asian Ocean

In the eastern part of the Central Asian Orogenic Belt (CAOB) in northeastern (NE) China, scattered outcrops of molasse deposits mark the ending of an orogeny and are crucial for understanding the evolution of the Paleo-Asian Ocean (PAO). However, the timing of tectonic events and the relationships among these strata remain controversial. To better constrain these geologic events, a comprehensive study of the detrital zircon U-Pb geochronology and geochemistry of the sandstones of the Kaishantun (KST) Formation and Kedao (KD) Group in eastern Jilin Province, NE China, was conducted. The KST Formation is traditionally considered a molasse deposit. The sandstones display low CIA, PIA and high ICV values and low Th/U and Rb/Sr ratios, which suggest that the rocks were derived from an immature intermediate-felsic igneous source and experienced a simple sedimentary recycling history with relatively weak chemical weathering. LA-ICP-MS U-Pb dating of detrital zircons from two samples of the KST Formation yields ages of 748–252 Ma, suggesting that the KST Formation was deposited between 254.5 Ma and 252 Ma in Late Permian. The zircons were mainly derived from the continental northern part of the North China Craton (NCC). In contrast, the U-Pb dating of detrital zircons from five samples of the KD Group yields ages of 2611–230 Ma, suggesting that the KD samples were deposited in the Early to Middle Triassic (ca. 248–233 Ma). The detrital zircon ages for the KD samples can be divided into groups with peaks at 2.5 Ga, 1.8 Ga, 800–1000 Ma, 500 Ma and 440–360 Ma, which suggest that the samples were derived from bidirectional provenances in the Jiamusi-Khanka Block and the NCC. These new data, combined with previously published results, suggest that at least three orogenic events occurred in central-eastern Jilin Province during the Early Permian (270–262 Ma), Early Triassic (254–248 Ma) and Middle–Late Triassic (242–227 Ma). The final closure of the PAO occurred during 242–227 Ma in the Middle–Late Triassic along the Changchun-Yanji suture zone. The detrital zircon geochronological data clearly record plate convergence and the scissor-like closure of the PAO in the eastern CAOB.

Sediment routing systems in the second member of the Eocene Shahejie Formation in the Liaoxi Sag, offshore Bohai Bay Basin: A synthesis from tectono-sedimentary and detrital zircon geochronological constraints

Abstract Integration of three-dimensional (3D) seismic reflection data, well, core, and detrital zircon geochronological data from the second member of the Eocene Shahejie Formation in the Liaoxi Sag of the offshore Bohai Bay Basin offers a new insight of transportation and deposition of regional sediment delivery systems as well as tectonic influence of sediment routing, accumulation and distribution. Sequence stratigraphic work shows that the study interval generally corresponds to a complete third-order sequence, while well- and seismic-based tectono-stratigraphic and sedimentological signatures have demonstrated that several braided-river deltas sourced from the Yanshan Mountain and associated distal delta-lobes are shaped by the development of the F1 fault. Furthermore, the age distribution of detrital zircons sampled from subsurface cores and cuttings mainly represent two different age populations, virtually corresponding to two independent paleodrainages from the Yanshan Mountain. The correlation between the bedrock lithology and detrital zircon geochronological dataset as well as tectono-sedimentary evidences of regional sediment delivery systems have provided us with a general understanding of specific hypothetical sediment routes from the source domain with the high lithological diversity to the sink area under the control of extensional and strike-slip movement. This study also shows how to define and differentiate specific sedimentary delivery systems in a small oilfield scale from a source-to-sink perspective.