کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4689157 | 1636034 | 2015 | 11 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Provenance of Late Carboniferous to Jurassic sandstones for southern Taimyr, Arctic Russia: A comparison of heavy mineral analysis by optical and QEMSCAN methods Provenance of Late Carboniferous to Jurassic sandstones for southern Taimyr, Arctic Russia: A comparison of heavy mineral analysis by optical and QEMSCAN methods](/preview/png/4689157.png)
• We report the first framework-grain petrography and heavy mineral analysis data of a complete late Paleozoic to Mesozoic siliciclastic successions in Taimyr, Arctic Russia.
• We reveal provenance changes of the Taimyr siliciclastic sedimentary rocks through late Carboniferous to early Cretaceous.
• We correlate the provenance changes with regional tectonic events: Uralian orogeny, the Siberia Traps and the Mesozoic transpression.
• The Taimyr fold and thrust belt underwent at least two uplift events.
• The comparison of heavy mineral data obtained from four samples by conventional optical point counting method and by QEMSCAN suggests that QEMSCAN has great potential for application to heavy mineral analysis.
Sandstone framework-grain petrography, optical and QEMSCAN (Quantitative Evaluation of Minerals by Scanning Electron Microscopy) heavy mineral analysis carried out on 40 samples collected from east and west southern Taimyr are used to constrain the provenance and tectonic history of Late Carboniferous to Late Jurassic siliciclastic sequences. The tectonic settings of provenance evolved gradually from a mix of volcanic arc and recycled orogen to craton interior. Much of the detritus in the Late Paleozoic to Mesozoic siliciclastic succession came from proximal sources with contributions from multi-type source rocks including acid igneous rocks, basalts, sedimentary rocks and low to medium-grade metamorphic rocks. Carboniferous to Permian sandstones contain low-diversity suites of heavy minerals, including apatite, tourmaline, zircon, rutile, Cr-spinel, monazite and titanite. Cr-spinel indicates probable influx from exposed ophiolitic basement. Abundant euhedral zircon and apatite suggest a volcanic arc source related with Uralian collision. The appearance of garnet in the early Triassic signals the unroofing of a metamorphic source. The abrupt increase of clinopyroxene in Middle to Late Triassic sandstones indicates the influx of detritus from basic rocks related with Siberian Trap magmatism. The decrease of Cr-spinel and an abundance of staurolite in Jurassic samples indicate that unroofing of an ophiolitic source ceased and that stripping of a different thrust sheet containing plenty of staurolite-bearing metamorphic rocks commenced.
Journal: Sedimentary Geology - Volume 329, November 2015, Pages 166–176