Skip to content

Research at St Andrews

Petrogenesis and tectonic implications of Early Cretaceous andesitic–dacitic rocks, western Qinling (Central China): geochronological and geochemical constraints

Research output: Contribution to journalArticlepeer-review


Feifei Zhang, Peter A. Cawood, Yunpeng Dong, Yuejun Wang

School/Research organisations


40Ar/39Ar and zircon U–Pb geochronological and whole-rock geochemical analyses for the Laozanggou intermediate-acidic volcanic rocks from the western Qinling orogenic belt, Central China, constrain their petrogenesis and the nature of the Late Mesozoic lithospheric mantle. These volcanic rocks yield hornblende or whole-rock 40Ar/39Ar plateau ages of 128.3–129.7 Ma and zircon U–Pb age of 131.3 ± 1.3 Ma. They exhibit SiO2 of 56.86–66.86 wt.%, K2O of 0.99–2.46 wt.% and MgO of 1.03–4.47 wt.%, with Mg# of 42–56. They are characterized by arc-like geochemical signatures with significant enrichment in LILE and LREE and depletion in HFSE. All the samples have enriched Sr–Nd isotopic compositions with initial 87Sr/86Sr ratios ranging from 0.7112 to 0.7149 and ɛNd(t) values from −10.2 to −6.3. Such geochemical signatures suggest that these volcanic rocks were derived from enriched lithosphere-derived magma followed by the assimilation and fractional crystallization (AFC) process. The generation of the enriched lithospheric mantle is likely related to the modification of sediment-derived fluid in response to the Triassic subduction/collision event in Qinling orogenic belt. The early Cretaceous detachment of the lithospheric root provides a reasonable mechanism for understanding the petrogenesis of the Laozanggou volcanic sequence in the western Qinling orogenic belt.



Original languageEnglish
Pages (from-to)1507-1520
Number of pages15
JournalGeoscience Frontiers
Issue number4
Early online date27 Nov 2018
Publication statusPublished - Jul 2019

    Research areas

  • Ar/Ar and zircon U–Pb geochronology, Sr–Nd isotopes, Early Cretaceous, AFC process, Continental lithospheric mantle, Western Qinling orogenic belt

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by journal

  1. Compressional origin of the Aegean Orogeny, Greece

    Searle, M. P. & Lamont, T. N., 7 Aug 2020, In: Geoscience Frontiers. In press

    Research output: Contribution to journalArticlepeer-review

  2. Crustal reworking and orogenic styles inferred from zircon Hf isotopes: Proterozoic examples from the North Atlantic region

    Spencer, C. J., Kirkland, C. L., Prave, A. R., Strachan, R. A. & Pease, V., Mar 2019, In: Geoscience Frontiers. 10, 2, p. 417-424

    Research output: Contribution to journalArticlepeer-review

  3. Zircon geochronology reveals polyphase magmatism and crustal anatexis in the Buchan Block, NE Scotland: implications for the Grampian Orogeny

    Johnson, T. E., Kirkland, C. L., Viete, D. R., Fischer, S., Reddy, S. M., Evans, N. J. & McDonald, B. J., Nov 2017, In: Geoscience Frontiers. 8, 6, p. 1469-1478

    Research output: Contribution to journalArticlepeer-review

  4. From mantle to critical zone: a review of large and giant sized deposits of the rare earth elements

    Smith, M. P., Moore, K., Kavecsánszki, D., Finch, A. A., Kynicky, J. & Wall, F., May 2016, In: Geoscience Frontiers. 7, 3, p. 315-334 20 p.

    Research output: Contribution to journalArticlepeer-review

ID: 256733042