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- Peng, Jungang, et al.
(författare)
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The Triassic to Early Jurassic palynological record of the Tarim Basin, China
- 2018
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Ingår i: Palaeobiodiversity and Palaeoenvironments. - Berlin : Springer Berlin/Heidelberg. - 1867-1594 .- 1867-1608. ; 98, s. 7-28
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Tidskriftsartikel (refereegranskat)abstract
- The Tarim Basin, located in northwestern China, is an important oil-bearing region, and the extensive non-marine Mesozoic successions make this a key location for understanding environmental changes through the Triassic and Jurassic. Palynological analyses on samples from Lunnan-1 and Tazhong-1 drill cores from the northern and central part of the Tarim Basin reveal wellpreserved spore–pollen assemblages. Five palynological assemblages, i.e. Tarim Triassic 1 (TT1)–Tarim Triassic 4 (TT4) and Tarim Jurassic 1 (TJ1), spanning the Early Triassic to Early Jurassic were identified based on compositional changes, which are supported by ordination of samples using non-metric multidimensional scaling (NMDS). The Early Triassic assemblages possess abundant bryophytes and Densoisporites spp.-producers, which potentially represent a recovery succession following the end-Permian event. The Late Triassic spore–pollen assemblages are more similar to those of the North China Palynofloral Province compared to the South China Province. Based on our phytogeographic analysis, we propose that the western section of the boundary between the North and South China palynofloras should be placed at the southern margin of the Tarim Basin.
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| 3. |
- Peng, Jungang, et al.
(författare)
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Triassic palynostratigraphy and palynofloral provinces: evidence from southern Xizang (Tibet), China
- 2018
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Ingår i: Alcheringa. - Melbourne : Taylor & Francis. - 0311-5518 .- 1752-0754. ; 42, s. 67-86
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Tidskriftsartikel (refereegranskat)abstract
- Palynological analysis was carried out on Middle to Upper Triassic strata from Tulong, Nyalam County, southern Xizang (Tibet), China. Well-preserved miospore (pollen and spore) assemblages and sparse acritarch occurrences were identified. We recognized four formal and one informal biozones based on stratigraphically important taxa and compositional changes through the succession, in ascending order: the Triplexisporites Interval Zone (Anisian), the Staurosaccites quadrifidus Taxon-range Zone (upper Anisian to lower Norian), the Striatella Interval Zone (lower Norian), the Craterisporites rotundus Taxon-range Zone (middle to upper Norian) and the informal ‘Dictyophyllidites harrisii zone’ (Rhaetian). The zonation was supported by marine fossils (e.g., ammonoids and conodonts), and compositional similarity between the zones was examined using non-metric multidimensional scaling (NMDS). Correlation with other representative palynological sequences across Gondwana was also conducted. The presence of miospore taxa not previously recovered from the Late Triassic North and South China palynofloral provinces (e.g., Ashmoripollis reducta, Craterisporites rotundus, Enzonalasporites vigens, Minutosaccus crenulatus, Samaropollenites speciosus and Staurosaccites quadrifidus) calls for a new province in southwestern China, i.e., the Southern Xizang Province. It is proposed here that the modern expression of the northern boundary runs along the Yarlung Zangbo Suture, the remnant of the Tethys that separated the Indian Plate (southern Xizang) and the Lhasa Block during the Late Triassic. This new palynofloral province comprises typical elements of the Onslow Microflora, indicating the need for an extension of this microflora in southern Xizang, China.
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| 6. |
- Peng, Jungang, et al.
(författare)
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Triassic vegetation and climate evolution on the northern margin of Gondwana: a palynological study from Tulong, southern Xizang (Tibet), China
- 2019
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Ingår i: Journal of Asian Earth Sciences. - Amsterdam : Elsevier BV. - 1367-9120 .- 1878-5786. ; 175, s. 74-82
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Tidskriftsartikel (refereegranskat)abstract
- We present vegetation reconstructions based on an almost complete succession through the Triassic of Tulong, Nyalam County, southern Xizang (Tibet), China. The Permian and earliest Triassic samples were barren of palynomorphs, however, in overlying strata we identified well-preserved and diverse miospore assemblages. Seven pollen and spore zones spanning the Olenekian to the Rhaetian were recognized. These palynological zones were amalgamated into three floral stages that comprise distinct vegetation types: (1) an early Olenekian lycophyte dominated flora with common pteridosperms, indicative of a warm and dry climate; (2) a late Olenekian transitional flora composed of abundant conifers with low abundances of lycophytes, signifying a decrease in temperature and increase in humidity; (3) a Middle to Late Triassic mature conifer-dominated flora with diverse sphenophytes, ferns and cycadophytes, indicative of a stable, temperate and humid climate. The changes in vegetation and climate tentatively correlate with the rifting of northern Gondwana, suggesting that regional tectonics was a contributive driving factor to local floral community change.
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