scholarly journals Burial and Exhumation History of the Lujing Uranium Ore Field, Zhuguangshan Complex, South China: Evidence from Low-Temperature Thermochronology

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 116
Author(s):  
Yue Sun ◽  
Barry P. Kohn ◽  
Samuel C. Boone ◽  
Dongsheng Wang ◽  
Kaixing Wang
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
South China ◽  
Thermal History ◽  
Fission Track ◽  
Thermal Evolution ◽  
Negative Relationship ◽  
The Tibetan Plateau ◽  
Uranium Ore ◽  
Production Area

The Zhuguangshan complex hosts the main uranium production area in South China. We report (U-Th)/He and fission track thermochronological data from Triassic–Jurassic mineralized and non-mineralized granites and overlying Cambrian and Cretaceous sandstone units from the Lujing uranium ore field (LUOF) to constrain the upper crustal tectono-thermal evolution of the central Zhuguangshan complex. Two Cambrian sandstones yield reproducible zircon (U-Th)/He (ZHe) ages of 133–106 Ma and low effective uranium (eU) content (270–776 ppm). One Upper Cretaceous sandstone and seven Mesozoic granites are characterized by significant variability in ZHe ages (154–83 Ma and 167–36 Ma, respectively), which show a negative relationship with eU content (244–1098 ppm and 402–4615 ppm), suggesting that the observed age dispersion can be attributed to the effect of radiation damage accumulation on 4He diffusion. Correspondence between ZHe ages from sandstones and granites indicates that surrounding sedimentary rocks and igneous intrusions supplied sediment to the Cretaceous–Paleogene Fengzhou Basin lying adjacent to the LUOF. The concordance of apatite fission track (AFT) central ages (61–54 Ma) and unimodal distributions of confined track lengths of five samples from different rock units suggest that both sandstone and granite samples experienced a similar cooling history throughout the entire apatite partial annealing zone (~110–60 °C). Apatite (U-Th-Sm)/He (AHe) ages from six non-mineralized samples range from 67 to 19 Ma, with no apparent correlation to eU content (2–78 ppm). Thermal history modeling of data suggests that the LUOF experienced relatively rapid Early Cretaceous cooling. In most samples, this was followed by the latest Early Cretaceous–Late Cretaceous reheating and subsequent latest Late Cretaceous–Recent cooling to surface temperatures. This history is considered as a response to the transmission of far-field stresses, involving alternating periods of regional compression and extension, related to paleo-Pacific plate subduction and subsequent rollback followed by Late Paleogene–Recent India–Asia collision and associated uplift and eastward extrusion of the Tibetan Plateau. Thermal history models are consistent with the Fengzhou Basin having been significantly more extensive in the Late Cretaceous–Early Paleogene, covering much of the LUOF. Uranium ore bodies which may have formed prior to the Late Cretaceous may have been eroded by as much as ~1.2 to 4.8 km during the latest Late Cretaceous–Recent denudation.

scholarly journals The Tectonic event of the Zaire-Hala’alate thrust belt in Junggar Basin,China

2021 ◽  
Vol 937 (4) ◽  
pp. 042090
Author(s):  
Jinghui Ma ◽  
Lishang Nie ◽  
Changcheng Han
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Thermal History ◽  
Fission Track ◽  
Junggar Basin ◽  
Tectonic Activity ◽  
Thrust Belt ◽  
Tectonic Event ◽  
Intensity Effect ◽  
Activity Intensity

Abstract The Yanshanian tectonic activity intensity effect of The Zaire- Hala’alate thrust belt, which is located in the northwest margin of Junggar Basin, have been in dispute for a long time. The distribution characteristics of the FT peak age in the narrower time domain is the key to understanding the dynamic mechanism of this important intracontinental deformation. In this study, apatite fission track dating and thermal history simulation analysis were carried out on 6 samples collected from this area. The results show that the fission track ages are mainly distributed in three intervals, corresponding to the geological ages of 130∼128Ma, 92∼89Ma and 72Ma, reflecting the obvious cooling and uplifting events in the three periods. At the same time, the thermal history simulation shows that the region experienced three rapid uplift events in the Early Cretaceous, the Early Late Cretaceous and the Late Cretaceous-Eocene. The comprehensive study shows that the main thrust fold in this area started from the end of Early Cretaceous, and the tectonic movement was the most intense in Late Cretaceous. As a whole, Tectonic activity migrated from south to north, which shows a retro-thrust expansion from the basin to the orogenic belt.

scholarly journals Polyphase evolution of Pelagonia (northern Greece) revealed by geological and fission-track data

Solid Earth ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 285-302 ◽  
Author(s):  
F. L. Schenker ◽  
M. G. Fellin ◽  
J.-P. Burg
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Fission Track ◽  
Regional Scale ◽  
Normal Faults ◽  
Recent Sediment ◽  
Northern Greece ◽  
Rapid Cooling ◽  
Fission Track Ages ◽  
Pelagonian Zone

Abstract. The Pelagonian zone, situated between the External Hellenides/Cyclades to the west and the Axios/Vardar/Almopias zone (AVAZ) and the Rhodope to the east, was involved in late Early Cretaceous and in Late Cretaceous–Eocene orogenic events whose duration and extent are still controversial. This paper constrains their late thermal imprints. New and previously published zircon (ZFT) and apatite (AFT) fission-track ages show cooling below 240 °C of the metamorphic western AVAZ imbricates between 102 and 93–90 Ma, of northern Pelagonia between 86 and 68 Ma, of the eastern AVAZ at 80 Ma and of the western Rhodope at 72 Ma. At the regional scale, this heterogeneous cooling is coeval with subsidence of Late Cretaceous marine basin(s) that unconformably covered the Early Cretaceous (130–110 Ma) thrust system from 100 Ma. Thrusting resumed at 70 Ma in the AVAZ and migrated across Pelagonia to reach the External Hellenides at 40–38 Ma. Renewed thrusting in Pelagonia is attested at 68 Ma by abrupt and rapid cooling below 240 °C and erosion of the gneissic rocks. ZFT and AFT in western and eastern Pelagonia, respectively, testify at ~40 Ma to the latest thermal imprint related to thrusting. Central-eastern Pelagonia cooled rapidly and uniformly from 240 to 80 °C between 24 and 16 Ma in the footwall of a major extensional fault. Extension started even earlier, at ~33 Ma in the western AVAZ. Post-7 Ma rapid cooling is inferred from inverse modeling of AFT lengths. It occurred while E–W normal faults were cutting Pliocene-to-recent sediment.

Closure of the Bangong–Nujiang Tethyan Ocean in the central Tibet: Results from the provenance of the Duoni Formation

2019 ◽  
Vol 89 (10) ◽  
pp. 1039-1054 ◽  
Author(s):  
Zhicai Zhu ◽  
Qingguo Zhai ◽  
Peiyuan Hu ◽  
Sunlin Chung ◽  
Yue Tang ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Late Cretaceous ◽  
Suture Zone ◽  
The Tibetan Plateau ◽  
Tectonic History ◽  
Magmatic Rocks ◽  
Two Samples ◽  
Delta Sequence ◽  
History Of ◽  
Central Tibet

ABSTRACT The closure of the Bangong–Nujiang Tethyan Ocean (BNTO) and consequent Lhasa–Qiangtang collision is vital to reasonably understanding the early tectonic history of the Tibetan Plateau before the India-Eurasia collision. The timing of the Lhasa–Qiangtang collision was mainly constrained by the ophiolite and magmatic rocks in previous studies, with only limited constraints from the sedimentary rocks within and adjacent to the Bangong–Nujiang suture zone. In the middle segment of the Bangong–Nujiang suture zone, the Duoni Formation, consisting of a fluvial delta sequence with minor andesite interlayers, was originally defined as the Late Cretaceous Jingzhushan Formation and interpreted as the products of the Lhasa–Qiangtang collision during the Late Cretaceous. Our new zircon U-Pb data from two samples of andesite interlayers demonstrate that it was deposited during the latest Early Cretaceous (ca. 113 Ma) rather than Late Cretaceous. Systemic studies on the sandstone detrital model, heavy-mineral assemblage, and clasts of conglomerate demonstrate a mixed source of both Lhasa and Qiangtang terranes and ophiolite complex. Clasts of conglomerate contain abundant angular peridotite, gabbro, basalt, chert, andesite, and granite, and minor quartzite and gneiss clasts also exist. Sandstones of the Duoni Formation are dominated by feldspathic–lithic graywacke (Qt25F14L61 and Qm13F14L73), indicative of a mixture of continental-arc and recycled-orogen source origin. Detrital minerals of chromite, clinopyroxene, epidote, and hornblende in sandstone also indicate an origin of ultramafic and mafic rocks, while garnets indicate a metamorphosed source. Paleocurrent data demonstrate bidirectional (southward and northward) source origins. Thus, we suggest that the deposition of the Duoni Formation took place in the processes of the Lhasa–Qiangtang collision during the latest Early Cretaceous (∼ 113 Ma), and the BNTO had been closed by this time.

Low-temperature thermochronologic constraints on the tectonic evolution of the Subei and Shibaocheng areas, northern Tibetan Plateau

2020 ◽  
Author(s):  
Jianfeng Li ◽  
Zhicheng Zhang ◽  
Yue Zhao
Keyword(s):  
Tibetan Plateau ◽  
Thermal History ◽  
Tectonic Evolution ◽  
Fission Track ◽  
The Tibetan Plateau ◽  
Apatite Fission Track ◽  
Northern Tibetan Plateau ◽  
Mountain Belt ◽  
Altyn Tagh ◽  
Local Uplift

<p>        The northern Tibetan Plateau, between the Kunlun and the Altyn Tagh faults, contains high relief topography, such as the Eastern Kunlun Range, the Altyn Tagh Range and the Qilian mountain belt, and plays an important role in researching the tectonic evolution and topographic growth of the Tibetan Plateau. We present new apatite fission track (AFT) and <sup>40</sup>Ar/<sup>39</sup>Ar thermochronologic data from the Subei and Shibaocheng areas near the eastern Altyn Tagh fault. Two Cenozoic exhumation phases have been identified from our AFT thermochronology. The AFT cooling ages of ~ 60–40 Ma farther away from the faults represented a slow widespread denudation surface as response to the Indo-Eurasia collision and signified that the Subei and Shibaocheng areas denudated as a whole in the northern Tibetan Plateau. Another phase with AFT cooling ages between about 20.5 Ma to 13.6 Ma on the hanging walls near the faults, located in the Danghenanshan and Daxueshan Mountains, recorded widespread fault activities resulted from local uplift and exhumation in late Miocene (~ 8 Ma) acquired from AFT thermal history modeling. A Cretaceous exhumation (~ 120–70 Ma) acquired from AFT thermal history modeling may have made great contributions to the growth of the pre-Cenozoic northern Tibetan Plateau.</p>

scholarly journals Post-Variscan thermal history of the Intra-Sudetic Basin (Sudetes, Bohemian Massif) based on apatite fission track analysis

2019 ◽  
Vol 108 (8) ◽  
pp. 2561-2576 ◽  
Author(s):  
Dariusz Botor ◽  
Aneta A. Anczkiewicz ◽  
Stanisław Mazur ◽  
Tomasz Siwecki
Keyword(s):  
Standard Deviation ◽  
Late Cretaceous ◽  
Bohemian Massif ◽  
Fission Track ◽  
Thermal Evolution ◽  
Vitrinite Reflectance ◽  
Length Distribution ◽  
Track Length ◽  
Second Phase ◽  
Apatite Fission Track

Abstract The Intra-Sudetic Basin, a ~ 12 km deep Variscan intramontane basin, has the best preserved post-orogenic sedimentary record available at the NE margin of the Bohemian Massif. Apatite fission track (AFT) analyses have been performed on 16 sedimentary and volcanic samples of Carboniferous to Cretaceous age from the Intra-Sudetic Basin to improve understanding of the post-Variscan thermal evolution. AFT central ages range from 50.1 ± 8.8 to 89.1 ± 7.1 Ma (Early Eocene to Coniacian), with 13 of them being Late Cretaceous. The mean track length values range from 12.5 ± 0.4 to 13.8 ± 0.5 (except for one sample 14.4 ± 0.2) µm. This relatively short mean track length together with the unimodal track length distributions and rather low standard deviation (0.8 to 1.7 µm) in most samples indicate a long stay in the partial annealing zone during slow cooling. However, in the northern part of the Intra-Sudetic Basin, samples show a wider track length distribution (standard deviation of 1.8 to 2.1 µm) that could indicate a more complex thermal evolution possibly related to Mesozoic reheating. Vitrinite reflectance data combined with thermal models based on the AFT results indicate that the Carboniferous strata reached maximum palaeotemperatures in the latest Carboniferous to Early Permian time, corresponding to a major coalification event. The second phase of temperature rise occurred due to Late Mesozoic sedimentary burial, but it had no influence on maturation of the Carboniferous organic matter. Final cooling phase in the Late Cretaceous–Paleogene was related to tectonic inversion of the Intra-Sudetic Basin, which occurred after deposition of a significant thickness of Cenomanian–Turonian sediments. Thermal modelling demonstrates that ~ 4 km thick cover of Upper Cretaceous sediments is required to obtain a good match between our AFT data and modelled time–temperature paths. This outcome supports a significant amount of Late Cretaceous–Paleogene inversion within the Variscan belt of Central Europe.

Fission-track thermochronology of the Oman Mountains continental windows, and current problems of tectonic interpretation

2006 ◽  
Vol 177 (3) ◽  
pp. 127-134 ◽  
Author(s):  
Omar Saddiqi ◽  
André Michard ◽  
Bruno Goffe ◽  
Gérard Poupeau ◽  
Roland Oberhänsli
Keyword(s):  
Late Cretaceous ◽  
Fission Track ◽  
Thermal Evolution ◽  
Low Grade ◽  
Isostatic Rebound ◽  
Oman Mountains ◽  
Relative Extension ◽  
Fission Track Thermochronology ◽  
Eclogite Facies

Abstract The Oman Mountain belt offers a unique case study of an Alpine orogen where blueschist- and eclogite-facies metamorphism developed in continental rocks beneath an ophiolite in the absence of continental collision. We present hereafter the first systematic, fission-track (FT) study of the subophiolitic Jebel Akhdar and Saih Hatat windows in the central-southern Oman Mountains. Nineteen samples out of 28 yielded significant zircon and/or apatite FT results. All of the 9 samples from NE (internal) Saih Hatat, where metamorphism occurred at ca. 300°C < T < 550°C (low-grade blueschist to low-grade eclogite facies), yielded FT zircon ages at 66-70 Ma. Four samples from SW Saih Hatat (front of the Fe-Mg carpholite zone, ca. 280°C < T < 300°C) yielded 69-93 Ma dates, and 4 samples from Jebel Akhdar (ca. 250°C < T < 280°C) yielded 80-96 Ma dates, which reflects partial resetting of the zircon FT chronometre at T ≤ ca. 280°C. As eclogite metamorphism of the deepest Saih Hatat units is dated at ca. 80 Ma [Warren et al., 2003], we deduce an early cooling rate of 30°C/Ma for these units. Late thermal evolution is constrained by apatite FT length optimization analysis and includes, i) cooling under 60°C until 60-58 Ma (rate close to 10°C/Ma); and ii) heating over 80°C at ca. 20-8 Ma. The Oman Mountains tectonic building is currently accounted for by contrasting models involving one or two subductions. Taking into account the structural and geophysical data on the Saih Hatat metamorphic pile, we interpret the reported thermal evolution in the framework of the classical, one subduction model: i) Permian rifting and Mesozoic spreading; ii) late Cretaceous intra-oceanic subduction followed by continental margin subduction/ophiolite obduction; iii) late Late Cretaceous-Paleocene synorogenic exhumation of the subducted units through extrusion within the subduction channel (relative extension), then isostatic rebound and extensional inversion of the obduction thrust; and iv) Neogene compression resulting in rejuvenation of the basal thrust beneath the continental windows, which are considered to be parautochthonous.

Sign in / Sign up

Export Citation Format

Share Document