Detrital zircon geochronology and geochemistry of Jurassic sandstones in the Xiongcun district, southern Lhasa subterrane, Tibet, China: implications for provenance and tectonic setting

2018 ◽  
Vol 156 (4) ◽  
pp. 683-701 ◽  
Author(s):  
XINGHAI LANG ◽  
DONG LIU ◽  
YULIN DENG ◽  
JUXING TANG ◽  
XUHUI WANG ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Tectonic Setting ◽  
Oceanic Island ◽  
Island Arc ◽  
Igneous Rocks ◽  
Late Triassic ◽  
Chemical Index ◽  
Modal Abundance ◽  
Arc Setting ◽  
Detrital Zircon Ages

AbstractJurassic sandstones in the Xiongcun porphyry copper–gold district, southern Lhasa subterrane, Tibet, China were analysed for petrography, major oxides and trace elements, as well as detrital zircon U–Pb and Hf isotopes, to infer their depositional age, provenance, intensity of source-rock palaeo-weathering and depositional tectonic setting. This new information provides important evidence to constrain the tectonic evolution of the southern Lhasa subterrane during the Late Triassic – Jurassic period. The sandstones are exposed in the lower and upper sections of the Xiongcun Formation. Their average modal abundance (Q21F11L68) classifies them as lithic arenite, which is also supported by geochemical studies. The high chemical index of alteration values (77.19–85.36, mean 79.96) and chemical index of weathering values (86.19–95.59, mean 89.98) of the sandstones imply moderate to intensive weathering of the source rock. Discrimination diagrams based on modal abundance, geochemistry and certain elemental ratios indicate that felsic and intermediate igneous rocks constitute the source rocks, probably with a magmatic arc provenance. The detrital zircon ages (161–243 Ma) and εHf(t) values (+10.5 to +16.2) further constrain the sandstone provenance as subduction-related Triassic–Jurassic felsic and intermediate igneous rocks from the southern Lhasa subterrane. A tectonic discrimination method based on geochemical data of the sandstones, as well as detrital zircon ages from sandstones, reveals that the sandstones were most likely deposited in an oceanic island-arc setting. These results support the hypothesis that the tectonic background of the southern Lhasa subterrane was an oceanic island-arc setting, rather than a continental island-arc setting, during the Late Triassic – Jurassic period.

Provenance and tectonic setting of the Triassic clastic deposits in the Napo basin, South China: evidence from petrography, whole-rock geochemistry and detrital zircon U–Pb geochronology

2021 ◽  
pp. 1-20
Author(s):  
Lei Xia ◽  
Quan-Ren Yan ◽  
Zhong-Jin Xiang ◽  
Hong-Bo Zheng ◽  
Quan-Lin Hou ◽  
...  
Keyword(s):  
South China ◽  
Detrital Zircon ◽  
Middle Triassic ◽  
Tectonic Setting ◽  
Detrital Zircons ◽  
Island Arc ◽  
Late Permian ◽  
Magmatic Arc ◽  
Clastic Rocks ◽  
Arc Setting

Abstract The provenance and tectonic setting of the Lower–Middle Triassic clastic sediments from the Napo basin, South China, have been examined here using detrital modes, whole-rock geochemistry and detrital zircon U–Pb ages. Field investigations indicate that these sediments consist of fan delta, slope and turbidity fan facies with dominantly southward palaeocurrent directions. Detrital modes and geochemical characteristics of the clastic rocks indicate that they were derived from mixed magmatic arc and Palaeozoic successions in a continental island arc setting, with no significant sediment recycling. The U–Pb age spectra of sandstone detrital zircons from different stratigraphic positions are similar, with one major group (300–230 Ma), two subordinate groups (400–320 Ma and 480–420 Ma, respectively) and two scattered groups (1200–800 Ma and 2000–1700 Ma, respectively). Thus, we consider that the north late Permian – Middle Triassic volcanic rocks and the uplifted Palaeozoic sedimentary/volcanic sequences constituted the predominant sources. The detritus derived from the late Permian Emeishan mafic rocks is subordinate and limited. The pre-Devonian zircons are likely sedimentary-recycled or magmatic-captured instead of directly derived from the early Palaeozoic orogen (e.g. Yunkai massif) and Neoproterozoic Jiangnan orogen because of the topographic barrier of a magmatic arc and carbonate platform. Considering the spatial and temporal distribution characteristics of the volcanic arc and ophiolite, we suggest that the Triassic Napo basin was a fore-arc basin within a continental island arc setting, which developed in response to the northward subduction of the Babu–Cao Bang branch ocean beneath the South China Block.

scholarly journals GEODYNAMICS AND MAGMATISM OF THE PACIFIC-TYPE TRANSFORM MARGINS. ASPECTS AND DISCRIMINANT DIAGRAMS

2021 ◽  
pp. 3-24
Author(s):  
A.V. Grebennikov ◽  
◽  
A.I. Khanchuk ◽  
Keyword(s):  
Continental Margin ◽  
Tectonic Setting ◽  
Island Arc ◽  
Igneous Rocks ◽  
High Alumina ◽  
Plate Boundaries ◽  
Spreading Ridge ◽  
Convergent Margins ◽  
Oceanic Plate ◽  
Plate Movement

Transform margins represent lithospheric plate boundaries with horizontal sliding of oceanic plate, which in time and space replaced the subduction related convergent margins. This happened due to: spreading ridge–trench intersection (California; Queen Charlotte–Northern Cordilleran, West of the Antarctic Peninsula, and probably the Late Miocene–Pleistocene Southernmost South America) or ridge death along continental margin (Baja California); change in the direction of oceanic plate movement (Western Aleutian–Komandorsk; Southernmost tip of the Andes); and island arc-continent collision (New Guinea Island). Post-subduction magmatism is related to a slab window that resulted either from the spreading ridge collision (subduction) with a continental margin or slab tear formation, or slab break-off after subduction cessation due to other reasons. Igneous magmatic series formed in consequence of these events show diversity of tholeiitic (sub-alkaline), alkaline or calc-alkaline, high-alumina and adakitic rocks. The comprehensive geochemical dataset (more than 2400 analyses) on igneous rocks of the model transform and convergent geodynamic settings allowed to substantiate the most informative triple diagrams for the petrogenic oxides TiO2 × 10 – Fe2O3Tot – MgO and trace elements Nb – La– Yb. Mostly approved for the rock compositions with SiO2 < 63 wt. %, the new plots are capable of distinguishing igneous rocks formed above zones of subduction at an island arc and continental margin (related to convergent margins), from those formed in the tectonic setting of transform margins along continents or island arcs.

scholarly journals Permo-Carboniferous conglomerates in the Trinity Peninsula Group at View Point, Antarctic Peninsula: sedimentology, geochronology and isotope evidence for provenance and tectonic setting in Gondwana

2011 ◽  
Vol 149 (4) ◽  
pp. 626-644 ◽  
Author(s):  
JOHN D. BRADSHAW ◽  
ALAN P. M. VAUGHAN ◽  
IAN L. MILLAR ◽  
MICHAEL J. FLOWERDEW ◽  
RUDOLPH A. J. TROUW ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Detrital Zircon ◽  
Tectonic Setting ◽  
Detrital Zircons ◽  
View Point ◽  
Transport Distance ◽  
Clastic Sedimentary ◽  
Detrital Zircon Ages ◽  
The Antarctic ◽  
The Trinity

AbstractField observations from the Trinity Peninsula Group at View Point on the Antarctic Peninsula indicate that thick, southward-younging and overturned clastic sedimentary rocks, comprising unusually coarse conglomeratic lenses within a succession of fine-grained sandstone–mudstone couplets, are the deposits of debris and turbidity flows on or at the foot of a submarine slope. Three detrital zircons from the sandstone–mudstone couplets date deposition at 302 ± 3 Ma, at or shortly after the Carboniferous–Permian boundary. Conglomerates predominantly consist of quartzite and granite and contain boulders exceeding 500 mm in diameter. Zircons from granitoid clasts and a silicic volcanic clast yield U–Pb ages of 466 ± 3 Ma, 373 ± 5 Ma and 487 ± 4 Ma, respectively and have corresponding average εHft values between +0.3 and +7.6. A quartzite clast, conglomerate matrix and sandstone interbedded with the conglomerate units have broadly similar detrital zircon age distributions and Hf isotope compositions. The clast and detrital zircon ages match well with sources within Patagonia; however, the age of one granite clast and the εHf characteristics of some detrital zircons point to a lesser South Africa or Ellsworth Mountain-like contribution, and the quartzite and granite-dominated composition of the conglomerates is similar to upper Palaeozoic diamictites in the Ellsworth Mountains. Unlike detrital zircons, large conglomerate clasts limit possible transport distance, and suggest sedimentation took place on or near the edge of continental crust. Comparison with other upper Palaeozoic to Mesozoic sediments in the Antarctic Peninsula and Patagonia, including detrital zircon composition and the style of deformation, suggests deposition of the Trinity Peninsula Group in an upper plate basin on an active margin, rather than a subduction-related accretionary setting, with slow extension and rifting punctuated by short periods of compression.

Tectonic setting of late Archean bimodal volcanism in the Michipicoten (Wawa) greenstone belt, Ontario

1987 ◽  
Vol 24 (6) ◽  
pp. 1120-1134 ◽  
Author(s):  
Paul J. Sylvester ◽  
Kodjo Attoh ◽  
Klaus J. Schulz
Keyword(s):  
Greenstone Belt ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Depositional Environments ◽  
Oceanic Island ◽  
Island Arc ◽  
Basaltic Rocks ◽  
Bimodal Volcanism ◽  
Continental Arc ◽  
Convergent Plate Margin

The tectono-stratigraphic relationships, depositional environments, rock associations, and major- and trace-element compositions of the late Archean (2744–2696 Ma) bimodal basalt–rhyolite volcanic rocks of the Michipicoten (Wawa) greenstone belt, Ontario, are compatible with an origin along a convergent plate margin that varied laterally from an immature island arc built on oceanic crust to a more mature arc underlain by continental crust. This environment is similar to that of the Cenozoic Taupo–Kermadec–Tonga volcanic zone. Michipicoten basaltic rocks, most of which are proximal deposits compositionally similar ([La/Yb]n = 0.63–1.18) to modern oceanic island-arc tholeiites, are interpreted as having formed along the largely submerged island arc. Voluminous Michipicoten rhyolitic pyroclastic rocks ([La/Yb]n = 4.3–18.7, Ybn = 5.7–15.9) probably erupted subaerially from the continental arc, with distal facies deposited subaqueously on the adjacent oceanic island arc and proximal facies deposited in subaerial and shallow subaqueous environments on, or along the flanks of, the continental arc. The compositional similarity between the lower (2744 Ma) and upper (2696 Ma) volcanic sequences of the belt suggests that this island- and continental-arc configuration existed for at least 45 Ma. The Michipicoten belt may be a remnant of a larger, laterally heterogeneous volcanic terrane that also included the Abitibi greenstone belt.

scholarly journals U-Pb Detrital Zircon Ages and Geochemical Features of the Jingxing Formation, (Qamdo Basin, Tibet: Implications): Inferences for the Metallogenic Model of the East Tethys Evaporite

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 745
Author(s):  
Wenhua Han ◽  
Haizhou Ma ◽  
Weixuan Fang ◽  
Huaide Cheng ◽  
Yongshou Li ◽  
...  
Keyword(s):  
Trace Elements ◽  
Continental Margin ◽  
Detrital Zircon ◽  
Tectonic Setting ◽  
Active Continental Margin ◽  
Age Distribution ◽  
Major And Trace Elements ◽  
Jinsha River ◽  
The North ◽  
Detrital Zircon Ages

Qamdo basin is located between the suture zone of Jinsha River (Ailao Mountains) and that of Ban Gong Lake (Nujiang) in the eastern Tethys. Part of the Jingxing Formation is deposited in the southwest of the basin. In this study, two profiles were investigated from the north and south of Qamdo basin. The characteristics of detrital zircon LA-ICP-MS U-Pb age, and the main and trace elements of sandstone were analyzed. The characteristics of major and trace elements showed that the tectonic setting of the study area is mainly composed of a relatively stable active continental margin and a passive continental margin, showing characteristics of a continental island arc. The weathering degree of Jingxing Formation in the Qamdo area is lower than that in the Lanping-Simao area, which may be closer to the origin. The age distribution characteristics of detrital zircon grains indicate that the Qiangtang Block, Youjiang basin, and Yangtze area jointly constitute the provenance of the Qamdo-Lanping-Simao basin. Both basins may be part of a large marine basin with unified water conservancy connection before evaporite deposition. Metamorphic seawater from the Qamdo basin may migrate to the Lanping-Simao basin and even the Khorat basin, where evaporite was deposited.

Chapter 14: The Brucejack Au-Ag Deposit, Northwest British Columbia, Canada: Multistage Porphyry to Epithermal Alteration, Mineralization, and Deposit Formation in an Island-Arc Setting

2020 ◽  
pp. 289-311
Author(s):  
Warwick S. Board ◽  
Duncan F. McLeish ◽  
Charles J. Greig ◽  
Octavia E. Bath ◽  
Joel E. Ashburner ◽  
...  
Keyword(s):  
Volcanic Rocks ◽  
Lower Jurassic ◽  
Early Jurassic ◽  
Island Arc ◽  
Late Triassic ◽  
Low Grade ◽  
Coarse Aggregates ◽  
History Of ◽  
Arc Setting ◽  
Mineral District

Abstract The Brucejack intermediate-sulfidation epithermal Au-Ag deposit, located 65 km north of Stewart, BC, forms part of a well-mineralized, structurally controlled, north-south gossanous trend associated with Early Jurassic intrusions straddling the Late Triassic-Early Jurassic Stuhini-Hazelton Group unconformity in the Sulphurets mineral district. Mining of the deposit commenced in mid-2017 after a long history of exploration dating back to the 1880s. Mineralization is hosted in deformed Lower Jurassic island-arc volcanic rocks of the Hazelton Group exposed on the eastern limb of the Cretaceous McTagg anticlinorium. High-grade Au-Ag mineralization was formed from ~184 to 183 Ma in association with a telescoped, multipulsed magmatic-hydrothermal system beneath an active local volcanic center. Precious metal mineralization occurs as coarse aggregates of electrum and silver sulfosalts in steeply dipping, E- to SE-trending quartz-carbonate vein stockwork zones cutting low-grade intrusion-related phyllic alteration. Epithermal vein development is interpreted to have occurred during the waning stages of Early Jurassic sinistral transpression in a compressive arc environment, followed by a limited Cretaceous deformation overprint.

Early Mesozoic synrift Eagle Mills Formation and coeval siliciclastic sources, sinks, and sediment routing, northern Gulf of Mexico basin

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2631-2650
Author(s):  
Bruce C. Frederick ◽  
Mike D. Blum ◽  
John W. Snedden ◽  
Richard H. Fillon
Keyword(s):  
Gulf Of Mexico ◽  
Detrital Zircon ◽  
Early Jurassic ◽  
Late Triassic ◽  
The South ◽  
Northern Gulf Of Mexico ◽  
Early Mesozoic ◽  
Detrital Zircon Ages ◽  
Gulf Of Mexico Basin ◽  
Mexico Basin

Abstract The sedimentary architecture and provenance of the early Mesozoic incipient northern Gulf of Mexico basin remains controversial due to both lack of outcrop exposure and sample scarcity across the southern United States with subcrop depths approaching 6 km. The Eagle Mills Formation and coeval deposition across the northern Gulf of Mexico provides both a stratigraphic foundation for some ∼15-km-thick overlying Mesozoic and Cenozoic deposits, and a coeval pre-salt equivalent for southern synrift deposits, in one of the most economically significant hydrocarbon basins in the world. This study presents more than 3200 new detrital zircon U-Pb analyses from sixteen Late Triassic pre-salt, siliciclastic, subcrop well samples, and combines over 14,000 linear kilometers of 2-D multi-channel seismic reflection data, 1511 geophysical well logs, and biostratigraphic data from 2478 wells to construct basin-scale pre-salt isochore and structure maps spanning the northern Gulf of Mexico margin from Florida to the USA-Mexican border. The data show that incipient Gulf of Mexico paleodrainage pathways held individual distinctions between basement sources and tectonic controls in three primary regions across the northern Gulf of Mexico: (1) The western Gulf of Mexico paleodrainage extended from the Central Texas uplift highlands to the submarine Potosi Fan on the western margin of Laurentia with local tributary sources from the East Mexico Arc, Yucatán/Maya, and Marathon-Ouachita provinces as evidenced by inverse Monte Carlo unmixing of peri-Gondwanan (ca. 700–500 Ma), Appalachian/Ouachita (500–280 Ma), Grenville (1250–950 Ma), and Mid-Continent/Granite-Rhyolite Province (1500–1300 Ma) detrital zircon ages. Isochore and associated geophysical well and seismic data suggest that by Early Jurassic time this depocenter had shifted into the present-day western Gulf of Mexico as East Mexico Arc development continued. (2) Southerly drainage in the north-central Gulf of Mexico region bifurcated around the Sabine and Monroe uplifted terranes with southwestern flow characterized by peri-Gondwanan detrital zircon ages from late Paleozoic accreted basement or discrete flexural successor basins, and southeastern fluvial networks distinguished by traditional North American basement province sources including Grenville, Mid-Continent, and Yavapai-Mazatzal. (3) Eastern Gulf of Mexico regional paleodrainage, with regional southern flow dictated by the brittle extensional tectonics of the South Georgia Rift as well as the regional southern flexure of the South Florida Basin, resulted in almost all pre-salt detrital zircon siliciclastic ages from this region to be dominated by local Gondwanan/peri-Gondwanan aged sources including the proximal Suwannee terrane and Osceola Granite complex. These regional, synrift sediment provenance models provide the first critical allochthonous evidence of Late Triassic–Early Jurassic paleodrainage stemming from the Appalachian-Ouachita hinterlands into the incipient northern Gulf of Mexico basin with critical implications for pre-salt hydrocarbon exploration and carbon sequestration reservoir potential.

scholarly journals Detrital zircon geochronology along a structural transect across the Kahiltna assemblage in the western Alaska Range: Implications for emplacement of the Alexander-Wrangellia-Peninsular terrane against North America

Geosphere ◽  
2019 ◽  
Vol 15 (6) ◽  
pp. 1774-1808 ◽  
Author(s):  
Stephen E. Box ◽  
Susan M. Karl ◽  
James V. Jones ◽  
Dwight C. Bradley ◽  
Peter J. Haeussler ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Detrital Zircon ◽  
Upper Jurassic ◽  
Island Arc ◽  
Igneous Rocks ◽  
Japan Trench ◽  
Alaska Range ◽  
Magmatic Arc ◽  
The North ◽  
Modern Analogue

Abstract The Kahiltna assemblage in the western Alaska Range consists of deformed Upper Jurassic and Cretaceous clastic strata that lie between the Alexander-Wrangellia-Peninsular terrane to the south and the Farewell and other pericratonic terranes to the north. Differences in detrital zircon populations and sandstone petrography allow geographic separation of the strata into two different successions, each consisting of multiple units, or petrofacies, with distinct provenance and lithologic characteristics. The northwestern succession was largely derived from older, inboard pericratonic terranes and correlates along strike to the southwest with the Kuskokwim Group. The southeastern succession is characterized by volcanic and plutonic rock detritus derived from Late Jurassic igneous rocks of the Alexander-Wrangellia-Peninsular terrane and mid- to Late Cretaceous arc-related igneous rocks and is part of a longer belt to the southwest and northeast, here named the Koksetna-Clearwater belt. The two successions remained separate depositional systems until the Late Cretaceous, when the northwestern succession overlapped the southeastern succession at ca. 81 Ma. They were deformed together ca. 80 Ma by southeast-verging fold-and-thrust–style deformation interpreted to represent final accretion of the Alexander-Wrangellia-Peninsular terrane along the southern Alaska margin. We interpret the tectonic evolution of the Kahiltna successions as a progression from forearc sedimentation and accretion in a south-facing continental magmatic arc to arrival and partial underthrusting of the back-arc flank of an active, south-facing island-arc system (Alexander-Wrangellia-Peninsular terrane). A modern analogue is the ongoing collision and partial underthrusting of the Izu-Bonin-Marianas island arc beneath the Japan Trench–Nankai Trough on the east side of central Japan.

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