Proterozoic to Phanerozoic case studies of laser ablation microanalysis for microbial carbonate U–Pb geochronology

Jiang, Yuxiang; Hohl, Simon V.; Huang, Xiangtong; Yang, Shouye

doi:10.1016/j.gsf.2023.101736

Cited by 3 publications

(2 citation statements)

References 47 publications

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“…These analyses provide the most reliable age constraints for the strata. A stromatolite sample from the upper Kuangshishan Fm has been dated at 1,285.7 ± 66.6 Ma (Figure 2; Y. Jiang et al., 2024), using the LA–ICP–MS carbonate U‐Pb dating method, which provides an age constraint for the lower part of the Shennongjia Gp. Moreover, detrital zircon analyses of the sandstone of the Dayanping Fm have revealed a major age population around 1,400 Ma, with two youngest zircon grains yielded 207 Pb/ 206 Pb ages of 1,325 ± 8 Ma and 1,324 ± 27 Ma respectively, both being concordant well (Figure S1 in Supporting Information S1; H. Li et al., 2013), indicating that the strata are younger than ∼1,325 Ma.…”

Section: Geological Background and Samplingmentioning

confidence: 99%

New Paleomagnetic Results From the Late Mesoproterozoic Luanshigou Formation, Shennongjia Group in South China and Their Implications for the Pre‐Grenvillian Connections Between South China Blocks and Southwestern Laurentia

Liu,

Zhang,

et al. 2024

JGR Solid Earth

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The identification of the Grenvillian‐age ophiolite suites in the Yangtze block in recent years suggested that the northern Yangtze subblock (NYB) and the southern Yangtze subblock (SYB) were once separated by an ocean in late Mesoproterozoic. Although some paleogeographic models advocated the Pre‐Grenvillian connections between the south China blocks and Laurentia, none of them has been paleomagnetically tested. Here we report the new paleomagnetic results obtained from the ∼1,270 Ma purplish‐red muddy dolomite beds of the Luanshigou Formation, Shennongjia Group, NYB, providing new constraints for reconstructing the paleogeographic positions of the south China blocks in late Mesoproterozoic. A total of 447 samples underwent stepwise thermal demagnetization. Two components were identified. The low‐temperature component is interpreted as the recent viscous remnant magnetization. The high‐temperature component was obtained from 64 samples below 580°C and from 177 samples below 690°C, directed northeast‐up or southwest‐down, antipodally, positioning the paleomagnetic pole at 18.5°S, 74.4°E (dm/dp = 2.5/1.6°). Rock magnetic results demonstrate that the magnetic carriers in purplish‐red dolomite and pale‐pink dolomite are predominated by hematite and magnetite, respectively. The data quality is supported by an inverse baked contact test, a B‐class reversal test, and the paleomagnetic pole is distinct from any younger poles of the region. Based on the paleomagnetic results, aided by geological evidence, we propose a reconstruction in which the NYB was juxtaposed to southwestern Laurentia in the late Mesoproterozoic and suggest that the late Mesoproterozoic Miaowan‐Shimian ophiolite zone in the Yangtze block was likely an extension of the Grenville belt of Laurentia.

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Section: Geological Background and Samplingmentioning

confidence: 99%

New Paleomagnetic Results From the Late Mesoproterozoic Luanshigou Formation, Shennongjia Group in South China and Their Implications for the Pre‐Grenvillian Connections Between South China Blocks and Southwestern Laurentia

Liu,

Zhang,

et al. 2024

JGR Solid Earth

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“…The combination of mineral mapping with microscopy approaches or trace-element imaging by LA-ICP-MS, and single-spot analysis for isotope-ratio determination by LA-MC-ICP-MS allows for mineral- and zone-specific isotope-ratio dating. 6,13–15 More recently, whole mineral isotope imaging with LA-ICP-MS, has emerged as an approach to perform comprehensive in situ dating of mineral samples. 16,17…”

Section: Introductionmentioning

confidence: 99%