Detrital zircon (U–Th)/He thermochronometry of the Mesozoic Daba Shan Foreland Basin, central China: Evidence for timing of post-orogenic denudation

ABSTRACT Detrital zircon U-Pb and (U-Th)/He ages from latest Cretaceous–Eocene strata of the Denver Basin provide novel insights into evolving sediment sourcing, recycling, and dispersal patterns during deposition in an intracontinental foreland basin. In total, 2464 U-Pb and 78 (U-Th)/He analyses of detrital zircons from 21 sandstone samples are presented from outcrop and drill core in the proximal and distal portions of the Denver Basin. Upper Cretaceous samples that predate uplift of the southern Front Range during the Laramide orogeny (Pierre Shale, Fox Hills Sandstone, and Laramie Formation) contain prominent Late Cretaceous (84–77 Ma), Jurassic (169–163 Ma), and Proterozoic (1.69–1.68 Ga) U-Pb ages, along with less abundant Paleozoic through Archean zircon grain ages. These grain ages are consistent with sources in the western U.S. Cordillera, including the Mesozoic Cordilleran magmatic arc and Yavapai-Mazatzal basement, with lesser contributions of Grenville and Appalachian zircon recycled from older sedimentary sequences. Mesozoic zircon (U-Th)/He ages confirm Cordilleran sources and/or recycling from the Sevier orogenic hinterland. Five of the 11 samples from syn-Laramide basin fill (latest Cretaceous–Paleocene D1 Sequence) and all five samples from the overlying Eocene D2 Sequence are dominated by 1.1–1.05 Ga zircon ages that are interpreted to reflect local derivation from the ca. 1.1 Ga Pikes Peak batholith. Corresponding late Mesoproterozoic to early Neoproterozoic zircon (U-Th)/He ages are consistent with local sourcing from the southern Front Range that underwent limited Mesozoic–Cenozoic unroofing. The other six samples from the D1 Sequence yielded detrital zircon U-Pb ages similar to pre-Laramide units, with major U-Pb age peaks at ca. 1.7 and 1.4 Ga but lacking the 1.1 Ga age peak found in the other syn-Laramide samples. One of these samples yielded abundant Mesozoic and Paleozoic (U-Th)/He ages, including prominent Early and Late Cretaceous peaks. We propose that fill of the Denver Basin represents the interplay between locally derived sediment delivered by transverse drainages that emanated from the southern Front Range and a previously unrecognized, possibly extraregional, axial-fluvial system. Transverse alluvial-fluvial fans, preserved in proximal basin fill, record progressive unroofing of southern Front Range basement during D1 and D2 Sequence deposition. Deposits of the upper and lower D1 Sequence across the basin were derived from these fans that emanated from the southern Front Range. However, the finer-grained, middle portion of the D1 Sequence that spans the Cretaceous-Paleogene boundary was deposited by both transverse (proximal basin fill) and axial (distal basin fill) fluvial systems that exhibit contrasting provenance signatures. Although both tectonic and climatic controls likely influenced the stratigraphic development of the Denver Basin, the migration of locally derived fans toward and then away from the thrust front suggests that uplift of the southern Front Range may have peaked at approximately the Cretaceous-Paleogene boundary.

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The Numidian Sand Event in the Burdigalian Foreland Basin System of the Rif (Morocco) in a source-to-sink perspective

10.5194/egusphere-egu21-15312 ◽

2021 ◽

Author(s):

Anas Abbassi ◽

Paola Cipollari ◽

Maria Giuditta Fellin ◽

Mohamed Najib Zaghloul ◽

Marcel Guillong ◽

...

Keyword(s):

Detrital Zircon ◽

Large Population ◽

Foreland Basin ◽

Source Area ◽

Western Mediterranean ◽

Early Miocene ◽

Calcareous Nannofossils ◽

External Zone ◽

Field Evidence ◽

Basin System

During the Tertiary evolution of the Western Mediterranean subduction system, the orogenic accretion at the Maghrebian margin let the stacking of three main tectonic zones of the Rif fold-and-thrust belt: 1) the Internal Zone; 2) the &#8220;Maghrebian Flysch&#8221; Nappes; and 3) the&#160; External Zone. In this context, a migrating foreland basin system developed between the Maghrebian orogenic belt and the adjacent African Craton.&#160;A comprehensive reconstruction of the foreland basin system of the Rif Chain for each phase of its accretional history is still missing. In this work, by integrating field observations with quantitative biostratigraphic data from calcareous nannofossils assemblages, sandstone composition, and detrital zircon U-Pb geochronology from selected stratigraphic successions, we reconstruct the foreland basin system that in the early Miocene developed in front of the growing Rif orogen. The analyzed successions are representative of (1) the &#8220;Beliounis Facies&#8221;, made of quartz-arenites and litharenites (Numidian-like &#8220;mixed succession&#8221;), from the Predorsalian Unit; (2) the &#8220;M&#233;rinides Facies&#8221;, made of a Numidian-like &#8220;mixed succession&#8221;, from the &#8220;Maghrebian Flysch Basin&#8221;; and (3) the classical &#8220;Numidian Facies&#8221;, exclusively made of quartzarenites, from the Intrarifian Tanger Unit.The petrographic analyses and the detrital zircon U-Pb ages show the provenance of the quartzarenites of the &#8220;Numidian Facies&#8221; from the African Craton, whereas the sublitharenites and feldspathic litharenites, of both the &#8220;M&#233;rinides Facies&#8221; and &#8220;Beliounis Facies&#8221;, show provenance from a cratonic area and the growing and unroofing Rif Chain, respectively.&#160;The Alpine signature of the detrital grains sedimented into the foredeep deposits of the early Miocene orogenic system of the Rif Chain is from the feldspathic litharenites of both the M&#233;rinides Facies and the Beni Ider Flysch. Both show Mesozoic and Cenozoic U-Pb zircon populations, with a large population of zircons centered at ca. 32 Ma. The U and Th concentration, the Th/U ratio, and the REE pattern of this population of zircons suggest a possible source area from Oligocene doleritic rock intrusions, similar to the magmatic dyke swarms (diorite) cropping out in the Malaga region ( SE Spain).The biostratigraphic analyses pinpoint the same age for the arrival of the quartz grains in the Numidian, M&#233;rinides, and Beliounis deposits, indicating about 1 Myr for their sedimentation (ca. 20-19 Ma, early Burdigalian). Together with field evidence, the biostratigraphic results point to an autochthonous deposition of the Numidian Sandstones on top of the Tanger Unit, allowing to delineate the early Burdigalian foreland basin system of the Rif Chain. The foreland depozone involved the Tanger Unit and received the &#8220;Numidian Facies&#8221; deposits&#160;; the foredeep depozone hosted about 2000 m of the &#8220;M&#233;rinides Facies&#8221; and the Beni Ider Flysch, and developed on the so-called &#8220;Flysch Basin Domain&#8221;; and, finally, the wedge-top depozone, characterized by the &#8220;Beliounis Facies&#8221;, developed on top of the Predorsalian Unit.The Numidian Sandstones and the Numidian-like deposits analyzed in Morocco show the same age of similar deposits from Algeria, Tunisia, and Sicily, suggesting a comparable early Burdigalian tectono-sedimentary evolution along the southern branch of the Western Mediterranean subduction-related orogen.

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Resolving the history of early fault slip and foreland basin evolution along the Wyoming salient of the Sevier fold-and-thrust belt: Integrating detrital zircon geochronology, provenance modeling, and subsidence analysis

Tectonics, Sedimentary Basins, and Provenance: A Celebration of the Career of William R. Dickinson ◽

10.1130/2018.2540(23) ◽

2018 ◽

Cited By ~ 1

Author(s):

A. Gentry ◽

W.A. Yonkee ◽

M.L. Wells ◽

E.A. Balgord

Keyword(s):

Detrital Zircon ◽

Foreland Basin ◽

Fault Slip ◽

Basin Evolution ◽

Zircon Geochronology ◽

Thrust Belt ◽

Detrital Zircon Geochronology ◽

Fold And Thrust Belt ◽

Subsidence Analysis ◽

History Of

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Dating lacustrine carbonate strata with detrital zircon U-Pb geochronology

Geology ◽

10.1130/g48070.1 ◽

2020 ◽

Author(s):

Emily S. Finzel ◽

Justin A. Rosenblume

Keyword(s):

Detrital Zircon ◽

Relative Proportion ◽

Foreland Basin ◽

Depositional Environments ◽

Detrital Zircons ◽

Sediment Flux ◽

Coarse Grained ◽

Southwestern Montana ◽

Tectonically Active ◽

Lacustrine Carbonate

Carbonate lacustrine strata in nonmarine systems hold great potential for refining depositional ages through U-Pb dating of detrital zircons. The low clastic sediment flux in carbonate depositional environments may increase the relative proportion of zircons deposited by volcanic air fall, potentially increasing the chances of observing detrital ages near the true depositional age. We present U-Pb geochronology of detrital zircons from lacustrine carbonate strata that provides proof of concept for the effectiveness of both acid-digestion recovery and resolving depositional ages of nonmarine strata. Samples were collected from Early Cretaceous foreland basin fluvial sandstone and lacustrine carbonate in southwestern Montana (USA). Late Aptian–early Albian (ca. 115–110 Ma) maximum depositional ages young upsection and agree with biostratigraphic ages. Lacustrine carbonate is an important component in many types of tectonic basins, and application of detrital zircon U-Pb geochronology holds considerable potential for dating critical chemical and climatic events recorded in their stratigraphy. It could also reveal new information for the persistent question about whether the stratigraphic record is dominated by longer periods of background fine-grained sedimentation versus short-duration coarse-grained events. In tectonically active basins, lacustrine carbonates may be valuable for dating the beginning of tectonic subsidence, especially during periods of finer-grained deposition dominated by mudrocks and carbonates.

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