The Triassic to Early Jurassic palynological record of the Tarim Basin, China
- 1.3k Downloads
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 well-preserved 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.
KeywordsPhytogeography Palaeovegetation Biostratigraphy Spores and pollen Triassic and Jurassic Tarim Basin
Geological setting and previous studies
During the Triassic, China was composed of widely separated terranes with major blocks represented by the North China Block, the South China Block and the smaller blocks that later formed the Qinghai–Xizang Plateau. The Tarim Block was at the time part of the North China Block following its collision with the Central Asian Orogenic Belt in the Late Carboniferous and was thus incorporated into southwestern part of the Eurasia Plate (Carroll et al. 1995; Zhang et al. 2013). The Tarim Basin, located in NW China, is the country’s largest sedimentary basin. The basin is enclosed by the Tianshan Mountains to the north, the Kunlun Mountains to the southwest and the Altun Mountains to the southeast (Fig. 1c). Sedimentary successions were deposited on a crystalline basement of Archaean and Proterozoic metamorphic complexes (Wang et al. 1992). Following four marine transgressions and regressions prior to the Late Permian, the basin subsided passively during the Late Permian to form an intracontinental basin (Kang and Kang 1996). With the exception of Upper Permian strata, the majority of the Palaeozoic successions are marine, and the Mesozoic and Cenozoic sequences are dominantly non-marine (Zhang et al. 2000). The Tarim Basin has been subdivided based on regional stratigraphy and tectonic features (e.g. Wang et al. 1992). Huang et al. (2002) provided a composite regional stratigraphic classification of 11 stratigraphic sub-regions for the basin (Fig. 1c). The studied cores, Lunnan-1 and Tazhong-1, are located in the Tabei and Taklimakan sub-regions, respectively (Fig. 1c).
Triassic outcrops are distributed irregularly across the northern and southwestern margins of the basin, and subsurface strata have been recovered in northern, central and southwestern areas (Li et al. 2001). In the Tabei sub-region, Triassic successions comprise the Lower Triassic Ehuobulake Formation, the Middle Triassic Karamay Formation and the Upper Triassic Huangshanjie Formation. Jurassic strata are represented by Lower and Middle Jurassic deposits (Li et al. 2001; Cao et al. 2001). Within the Taklimakan sub-region, the Lower Triassic Ehuobulake Formation and the Middle to Upper Triassic strata are present (Li et al. 2001; Cao et al. 2001).
In Tazhong-1 (Fig. 3), the Ehuobulake Formation lies unconformably on Permian strata and is overlain by the Karamay Formation from which no fossils have been recovered in this core. The Huangshanjie Formation was not recorded in Tazhong-1. The Ehuobulake Formation in Tazhong-1 is composed of dark-grey mudstones with interbedded black mudstones. The successions host miospores, megaspores and acritarchs (Li et al. 2001). The Karamay Formation comprises two lithological units: the lower portion is represented by grey-white to grey-green siltstones and grey-brown to grey-purple mudstones; the upper part comprises dark-purple sandstones, greyish-purple to greyish-brown siltstones and mudstones.
Palynological studies of core Lunnan-1 include the investigations of Yong et al. (1990) and Zhan (1991). Yong et al. (1990) provided a list of taxa through the core from intervals 5039–5009.5 m (Early Triassic) and 4789–4771 (no age assignment). Zhan (1991) carried out a palynological assessment of the interval 5039–4655 m (Triassic). Li et al. (2001) documented the composition and abundance data of spore–pollen assemblages of the Lunnan-1 and Tazhong-1 cores.
Material and methods
Sample preparation and data collection
A total of 22 core samples were collected for palynology: 18 from Lunnan-1 and four from Tazhong-1 (Fig. 3). Samples were prepared using standard HCl and HF palynological processing techniques in the palynological laboratory of Nanjing Institute of Geology and Palaeotology, Chinese Academy of Sciences (NIGPAS). Counts of ca. 200 specimens were carried out to produce relative abundance data. Raw count data are provided in Supplementary Table 1. Selected specimens were photographed using a Zeiss Axio microscope (Scope A1 system) under transmitted light. To improve environmental reconstructions, basic palynofacies analysis was undertaken for all samples of Lunnan-1. Black and brown woods (sensu Batten 1996; Li and Batten 2005) and miospores were counted and plotted. Counts of ca. 300 particles per sample were carried out before calculating relative abundances. Slides are stored in NIGPAS.
The ordination technique non-metric multidimensional scaling (NMDS) was carried out to assess compositional variation between palynological samples through time. NMDS is a non-parametric ordination technique that uses ranked distances to assess the degree of similarity between samples. In the ordination, samples that plot close together are compositionally similar and samples that plot far apart are compositionally dissimilar. The commonly used Bray-Curtis dissimilarity metric was used (e.g. Harrington 2008; Slater and Wellman 2015; Slater and Wellman 2016), and repeated runs were carried out for two dimensions until a convergent solution was established. NMDS was carried out in PAST (Hammer et al. 2001) using relative abundance (percentage) data. We also conducted correspondence analysis (CA) and detrended correspondence analysis (DCA) using the same data set. Clustering of samples in CA and DCA ordinations was highly similar to the NMDS ordination displayed here, indicating that the results are robust.
General vegetation patterns
Spores and pollen were grouped botanically (following e.g. Rouse 1957; Delcourt et al. 1963; Couper 1958; Balme 1995; van Konijnenburg-van Cittert 1993; Batten and Dutta 1997; Song et al. 2000; Mander et al. 2010; Mander 2011; Hermann et al. 2011; Raine et al. 2011; Bonis and Kürschner 2012) to assess broad temporal vegetation changes (Supplementary Table 2). Floras comprise a mixture of bryophytes, lycophytes, sphenophytes, ferns, pteridosperms, conifers and monosulcate pollen-producers (Fig. 11). Macrofloral studies of coeval deposits from the Tarim Basin have recovered cycadophytes and ginkgophytes (Li et al. 2001); thus, monosulcate pollen probably originates from a mixture of these groups.
Bryophyte, lycophyte and fern abundances vary considerably through Lunnan-1, whilst other groups remain comparatively stable (Fig. 11). Bryophytes are represented by Limatulasporites limatulus, Nevesisporites vallatus and Annulispora spp. (Fig. 10) and are abundant in the Lower Triassic strata (ca. 20%) but become increasingly rare within the Middle and Upper Triassic successions (Fig. 11). Lycophytes are represented by Densoisporites spp., Aratrisporites spp., Lycopodiumsporites (al. Retitriletes) spp. and Anapiculatisporites spp. (Fig. 10). Lycophytes are markedly more abundant in the Middle Triassic (ca. 40%) and are moderately more abundant in the Upper Triassic (ca. 15%) compared to the Lower Triassic (ca. 10%) (Fig. 11). Within this group, Aratrisporites spp. dominate in the Middle Triassic and Lycopodiumsporites spp. dominate in the Lower Jurassic (Fig. 10). Ferns are represented by Biretisporites potoniaei, Leiotriletes spp., Punctatisporites punctatus, Todisporites spp., Concavisporites toralis, Dictyophyllidites harrisii, Osmundacidites spp., Verrucosisporites spp., Apiculatisporis spp., Baculatisporites comaumensis and Striatella spp. (Fig. 10). Ferns are highly abundant throughout the section, and abundances increase from ca. 30% in the Lower Triassic and ca. 40% in the Middle Triassic to ca. 70% in the Upper Triassic. Pollen from seed ferns and conifers include taeniate bisaccate pollen, Alisporites spp. and Abietineaepollenites spp. Monosulcate pollen-producers (e.g. cycadophytes and ginkgophytes) occur consistently in low abundance through the section (Fig. 11).
Tarim Triassic 1 Assemblage (TT1)
Core and interval:
Lunnan-1, 5050–5011 m; Tazhong-1, 2498–2437 m.
High abundances of Limatulasporites limatulus, Densoisporites spp. and Lunatisporites pellucidus. Aratrisporites spp. are rare. Fern spores are dominated by Leiotriletes spp., Punctatisporites punctatus and Osmundacidites spp.
Tarim Triassic 2 Assemblage (TT2)
Core and interval:
Lunnan-1, 4948–4879 m.
Abundant Aratrisporites spp. and Calamospora mesozoica. Limatulasporites limatulus, Densoisporites spp. and Lunatisporites spp. show marked decreases in Tarim Triassic 2 (TT2). Parataeniaesporites pseudostriatus and Lycopodiacidites kuepperi are new incoming taxa.
Abundant Aratrisporites spp. together with a marked decline in abundances of Densoisporites spp., Limatulasporites spp. and bisaccate taeniate pollen grains are indicative of a younger age than Early Triassic, and possibly Middle Triassic (e.g. Helby et al. 1987; Qu and Wang 1986; Liu 2003). The presence of Parataeniaesporites (al. Colpectopollis spp.) indicates a Middle to Late Triassic age (Liu et al. 1981). The low abundances of Dictyophyllidites spp. and Concavisporites spp. tentatively suggest a Middle Triassic age (e.g. Qu 1980; Qu and Wang 1986).
Tarim Triassic 3 Assemblage (TT3)
Core and interval:
Lunnan-1, 4840–4800 m.
Abundant Aratrisporites spp. and an increase in abundance and diversity of Striatella spp. and Apiculatisporis spp. Dictyophyllidites harrisii and Concavisporites toralis occur in low abundances.
Apiculatisporis spp., Acanthotriletes microspinosus, Lophotriletes spp. and Anapiculatisporites spp. are common in Middle Triassic strata and abundant in Upper Triassic strata of northern China (e.g. Qu 1980; Qu and Wang 1986; Liu 2003); Dictyophyllidites harrisii and Concavisporites toralis are abundant in Upper Triassic strata, e.g. in the Junggar (Qu and Wang 1986) and Ordos basins (Qu 1980). Based on the increase of spiny trilete spores (e.g. Apiculatisporis spp., Acanthotriletes microspinosus, Lophotriletes spp. and Anapiculatisporites spp.), the low abundance of Dictyophyllidites harrisii and Concavisporites toralis and the absence of Lunatisporites spp. and Limatulasporites spp., we interpret this assemblage as late Middle Triassic in age. It should be noted that the uppermost part of the Karamay Formation has been interpreted as Upper Triassic in previous studies (e.g. Zhang et al. 2004), however, based on the palynology of samples LN-1-23 and LN-1-20 we suggest that it is Middle Triassic.
Tarim Triassic 4 Assemblage (TT4)
Core and interval:
Lunnan-1, 4782–4771 m.
Dictyophyllidites harrisii and Concavisporites toralis are abundant with moderately abundant Apiculatisporis spp. and Aratrisporites spp. Striatella spp. and Quadraeculina anellaeformis occur in low abundances. Lycopodiumsporites spp. and Cyathidites minor are present.
Late Triassic based on abundant Dictyophyllidites harrisii and Concavisporites toralis, as well as common Aratrisporites spp. and spiny trilete spores. This assemblage is similar to Late Triassic assemblages of North China elsewhere, e.g. the Junggar Basin (Qu and Wang 1986, 1990; Sha et al. 2011, 2015) and the Ordos Basin (Qu 1980; Liu et al. 1981). However, Zebrasporites spp. have not been recovered in this assemblage. The first occurrence of this genus was regarded as the base of Ashmoripollis reducta Oppel Zone in Australia spanning from Rhaetian to ?Hettangian (Helby et al. 1987). Thus, the lack of this genus tentatively suggests an early Late Triassic (Carnian to Norian) age for Tarim Triassic 4 (TT4).
Tarim Jurassic 1 Assemblage (TJ1)
Core and interval:
Lunnan-1, 4649–4641 m.
Abundant Lycopodiumsporites spp., Dictyophyllidites harrisii, Cyathidites spp. and Pinuspollenites spp.
This assemblage displays high compositional similarity with the Cyathidites–Cerebropollenites–Pinuspollenites assemblage of Zhan (1991), specifically regarding the abundances of Lycopodiumsporites spp., Cyathidites spp. and Pinuspollenites spp. The interval 4649–4641 m of Lunnan-1 possesses the megaspores Kuqaia radiata and Kuqaia concentrica indicating an Early Jurassic age (Li 1993).
Non-metric multidimensional scaling
The palynofacies of Lunnan-1 is dominated by black and brown wood remains with small quantities of other components (Fig. 11). There is little compositional variation between samples, indicating a relatively stable depositional setting. The acritarch Veryhachium sp. was recorded in LN-1-30 and LN-1-43, indicating possible marine influence. The algae Botryococcus spp. is present in most samples, indicating a fresh–brackish depositional setting (e.g. Batten and Grenfell 1996) (for raw palynofacies count data, see Supplementary Table 5).
Temporal vegetation change
The succeeding early Middle Triassic assemblage (TT2) continues with pollen dominance and a considerable reduction of bryophytes. Aratrisporites spp. is the dominant lycophyte genus replacing Densoisporites spp., which potentially represents a “normal” succession dynamic rather than abrupt environmental changes. Other lycophytes also emerged and, together with a broad range of ferns, formed a shade-tolerant understory. The middle story comprises ginkgoes/cycads and tree ferns (e.g. Cyatheaceae), and the upper storey comprises a conifer canopy (Fig. 14). The following late Middle Triassic assemblage TT3 continues with an increase in abundances of Aratrisporites spp.-producing lycophytes and monosulcate pollen-producers. Fern abundances increase slightly from TT2 into TT3 (Fig. 14). This vegetation change shows that bryophytes decreased from the Early to the Middle Triassic, and their niche was filled by the Aratrisporites spp.-producers, subsequently followed by ferns. Seed ferns (represented by taeniate bisaccates) reduced markedly in the Middle Triassic (TT2–TT3) compared to the Early Triassic (TT1).
The Late Triassic assemblage (TT4) is strongly dominated by ferns, including abundant Leiotriletes spp., Dictyophyllidites harrisii and Concavisisporites toralis-producers. Conifers are slightly less abundant, and Vitreisporites pallidus-producers are markedly less abundant in TT4 compared to TT3. In summary, the vegetation change from TT2–TT3 to TT4 is characterised by a shift from an ecosystem dominated by Aratrisporites-producers (lycophytes) and conifers, to a fern-dominated ecosystem with less conifers in the Late Triassic as reflected in the TT4 assemblage.
This Early Jurassic assemblage is characterised by high relative abundances of lycophyte (Lycopodiumsporites spp.-producers) spores together with bisaccate conifer pollen, including Pinuspollenites spp. (Fig. 14). The contact between the Triassic and Jurassic strata in Lunnan-1 is unconformable, and the interval of this hiatus possibly comprises part of/all of the Rhaetian based on the age assignments of palynological assemblages provided here. Relatively limited vegetational changes are noted with respect to broad botanical groups across the Triassic–Jurassic interval; however, the spore peak (Fig. 10) in TT4 (Late Triassic) and a substantial increase in Lycopodiumsporites spp. within the Lycophyta group in TJ1 (Early Jurassic) were identified. These signals possibly reflect the local climatic and/or habitat changes, considering the lack of a conformable “boundary”. They also potentially represent local vegetation responses to the T–J extinction, although spore/pollen peaks are typically recognised within or above extinction event intervals (e.g. Ruckwied et al. 2008; Ruckwied and Götz 2009; Larsson 2009; Götz et al. 2009, 2011; Vajda et al. 2013; Vajda and Bercovici 2014).
Late Triassic palynofloral provinces of China
Two Late Triassic palynofloral provinces encompassing North and South China, respectively, were proposed by Qu et al. (1983) and subsequently followed by numerous authors (e.g. Qu et al. 1987; Sun et al. 1995; Song et al. 2000; Liu 2003; Shang 1998, 2011). The South China province possesses several key taxa (e.g. Ovalipollis, Ricciisporites, Rhaetipollis, Camerosporites, Kyrtomisporites, Verrusaccus and Granosaccus) that are absent or in very low abundances in the North China Province, which is characterised by cosmopolitan taxa (e.g. Apiculatisporis and Striatella). Ovalipollis, Ricciisporites and Kyrtomisporites have been reported from the North China Province: (i) Jiang et al. (2006) recorded Ovalipollis from the Shaanxi province in low abundance (1%) without presenting images, (ii) Chen (1998) documented Ricciisporites from the southwestern region of the Tarim Basin without statistics or images and (iii) Huang (1993) reported Kyrtomisporites from the northwestern region of the Junggar Basin in low abundances (<1%) without presenting images. The very low abundances and scattered distribution of these important taxa await more information for confirmation.
The Late Triassic palynoflora of the Tabei sub-region of the Tarim Basin (Lunnan-1) lacks key taxa typically present in the South China Province. This suggests that the Tabei sub-region of the Tarim Basin should be incorporated into the North China Province, which is similar to the marginal Kuqa sub-region studied by Liu (2003). It should be noted that no Late Triassic palynofloras have been recovered from the southern part of the Tarim Basin; hence, the phytogeographic affinity of the southern area of this basin is uncertain. Here, based on the new evidence from the Tabei sub-region, we tentatively regard the whole basin as a single Late Triassic phytogeographic region within the North China Province, with the boundary running along the southern margin of the Tarim Basin (Fig. 15). More data from the southern areas are required to explore the phytogeographic affinity of the whole basin and to resolve the precise position of the North–South palynofloral province boundary.
Well-preserved Triassic and Early Jurassic spore–pollen assemblages have been recovered from Lunnan-1 and Tazhong-1 cores of the Tarim Basin, China. Through the sections, five palynological assemblages (TT1–TT4 and TJ1) were recognised based on compositional changes, supported by NMDS analysis. The age of the studied assemblages ranges from Early Triassic (Olenekian) to Early Jurassic. The vegetation reconstruction for the Triassic of the Tarim Basin shows that, based on palynology, the effects of two mass extinction events are reflected in the vegetation composition. The Early Triassic assemblages in the TT1 zone are characterised by abundant bryophytes and Densoisporites spp.-producers, a well-known marker for the Early Triassic recovery succession following the end-Permian event (Vajda and McLoughlin 2007). Two spore peaks recorded in the Upper Triassic and Lower Jurassic potentially reflect vegetation responses to the T–J extinction. However, the unconformable nature of this succession makes such interpretations tentative. Our phytogeographic analysis based on the palynological data shows that the Late Triassic palynofloras of the Tarim Basin are more similar to those of North China. This calls for an update of the boundaries of the regional vegetation provinces, and we support that the western section of the boundary between the North and South China palynofloras should follow the southern margin of the Tarim Basin.
This work was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (Grant No.: XDB03010103 and XDB18000000), the China Scholarship Council (201504910609) and the Swedish Research Council (Grant VR 2015-04264). This is also a contribution of IGCP project 632. We thank Pollyanna von Knorring for contributing to the landscape illustration (Fig. 14). Annette E. Götz and Mike Pole are gratefully acknowledged on their very constructive reviews that considerably improved the manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Akikuni, K., Hori, R., Vajda, V., Grant-Mackie, J., & Ikehara, M. (2010). Stratigraphy of Triassic-Jurassic boundary sequences from the Kawhia coast and Awakino gorge, Murihiku Terrane, New Zealand. Stratigraphy, 7, 7–24.Google Scholar
- Batten, D. J. (1996). Chapter 26A. Palynofacies and palaeoenvironmental interpretation. In J. Jansonius & D. C. McGregor (Eds.), Palynology: principles and applications, 3 (pp. 1011–1064). Utah: Publisher Press.Google Scholar
- Batten, D. J., & Grenfell, H. R. (1996). Chapter 7D. Botryococcus. In J. Jansonius & D. C. McGregor (Eds.), Palynology: principles and applications, 1 (pp. 205–214). Utah: Publishers Press.Google Scholar
- Cao, Z. Y., Li, W. B., Liu, Z. S., Chen, J. H., Cao, M. Z., & Xiao, S. H. (2001). Jurassic. In Z. Y. Zhou (Ed.), Stratigraphy of the Tarim Basin (pp. 236–260). Beijing: Science Press.Google Scholar
- Carroll, A. R., Graham, S. A., Hendrix, M. S., Ying, D., & Zhou, D. (1995). Late Paleozoic tectonic amalgamation of northwestern China: sedimentary record of the northern Tarim, northwestern Turpan, and southern Junggar Basins. Geological Society of America Bulletin, 107(5), 571–598.CrossRefGoogle Scholar
- Chen, R. L. (1998). The discovery of Late Triassic strata and its geological significance in the southwestern Tarim Basin. Experimental Petroleum Geology, 20(4), 329–331.Google Scholar
- Couper, R. A. (1958). British Mesozoic microspores and pollen grains. A systematic and stratigraphic study. Palaeontographica B, 103, 75–179.Google Scholar
- Delcourt, A. F., Dettmann, M. E., & Hughes, N. F. (1963). Revision of some Lower Cretaceous microspores from Belgium. Palaeontology, 6(2), 282–292.Google Scholar
- Götz, A. E., Ruckwied, K., & Barbacka, M. (2011). Palaeoenvironment of the Late Triassic (Rhaetian) and Early Jurassic (Hettangian) Mecsek Coal Formation (south Hungary): implications from macro- and microfloral assemblages. Palaeobiodiversity and Palaeoenvironments, 91, 75–88.CrossRefGoogle Scholar
- Hammer, Ø., Harper, D. A. T., & Ryan, P. D. (2001). PAST: paleontological statistics software package for education and data analysis. Palaeontologia Electronica, 4(1), 1–9.Google Scholar
- Helby, R., Morgan, R., & Partridge, A. D. (1987). A palynological zonation of the Australian Mesozoic. In P. A. Jell (Ed.), Studies in Australian palynology (pp. 1–94). Sydney: Association of Australasian Palaeontologists.Google Scholar
- Huang, P. (1993). Triassic sporopollen assemblages from northwestern margin of Junggar Basin, Xinjiang. Acta Micropalaeontologica Sinica, 10(4), 369–395.Google Scholar
- Huang, Y. Y. (1986). Triassic system in the north part of Tarim Basin and its oil prospecting. Oil and Gas Geology, 7(1), 32–41.Google Scholar
- Huang, Z. B., Wu, S. Z., Zhao, Z. X., Li, M., Tan, Z. J., & Du, P. D. (2002). The composite regional stratigraphic classification in Tarim Basin and its circumferences. Xinjiang Petroleum Geology, 23(1), 13–17.Google Scholar
- Jiang, D. X., Wang, Y. D., & Wei, J. (2006). Palynoflora and its environmental significance of the Late Triassic in Tongchuan, Shaanxi Province. Journal of Palaeogeography, 8(1), 23–33.Google Scholar
- Kang, Y. Z., & Kang, Z. H. (1996). Tectonic evolution and oil and gas of Tarim basin. Journal of Southeast Asian Earth Sciences, 13(3–5), 317–325.Google Scholar
- Larsson, L. M. (2009). Palynostratigraphy of the Triassic–Jurassic transition in southern Sweden. Geologiska Föreningen i Stockholm Förhandlingar, 131(1–2), 147–163.Google Scholar
- Li, W. B. (1993). Kuqaia—a new palynomorph taxon. Acta Micropalaeontologica Sinica, 10(1), 71–76.Google Scholar
- Li, J. G., & Batten, D. J. (2005). Palynofacies: principles and methods. Acta Palaeontologica Sinica, 44(1), 138–156.Google Scholar
- Li, W. B., Chen, J. H., Cao, Z. Y., Xiao, S. H., & Cao, M. Z. (2001). Triassic. In Z. Y. Zhou (Ed.), Stratigraphy of the Tarim Basin (pp. 208–235). Beijing: Science Press.Google Scholar
- Liu, Z. S. (1996). Biota and environment of Early Triassic in Duwa area of Tarim Basin. Xinjiang Petroleum Geology, 17(3), 242–254.Google Scholar
- Liu, Z. S. (1999). Triassic palynological assemblages from the northern margin in Tarim Basin of Xinjiang, NW China. Acta Palaeontologica Sinica, 38(4), 474–504.Google Scholar
- Liu, Z. S. (2003). Triassic and Jurassic sporopollen assemblage from the Kuqa depression, Tarim Basin of Xinjiang, NW China. Palaeontologia Sinica 190, New Series A, 14, 1–244.Google Scholar
- Liu, G. S., & Wei, L. (2007). Triassic palynological assemblages from Yuqi, Tarim Basin. Geology and Mineral Resources of South China, 2007(4), 56–63.Google Scholar
- Liu, Z. S., Shang, Y. K., & Li, W. B. (1981). Triassic and Jurassic sporo-pollen assemblages from some localities of Shaanxi and Gansu, North-West China. Bulletin of Nanjing Institute of Geology and Palaeontology, Academia Sinica, 3, 131–210.Google Scholar
- Qu, L. F. (1980). Triassic spores and pollen. In Institute of Geology, Chinese Academy of Geological Sciences (Ed.), Mesozoic stratigraphy and palaeontology of the Shaanxi-Gansu-Ningxia Basin (pp. 115–143). Beijing: Geological Publishing House.Google Scholar
- Qu, L. F. (1989). Early Triassic sporo-pollen. In Institute of Geology and Mineral, Xinjiang Bureau of Geology & Mineral Resources, Institute of Geology, Chinese Academy of Geological Sciences (Eds.), Research on the boundary between Permian and Triassic in Tianshan Mountain of China (pp. 36–39). Beijing: China Ocean Press.Google Scholar
- Qu, L. F., & Wang, Z. (1986). Triassic sporopollen. In Institute of Geology, Chinese Academy of Geological Sciences & Institute of Geology, Xinjiang Bureau of Geology and Mineral Resources (Eds.), Permian and Triassic strata and fossil assemblages in the Dalongkou area of Jimsar, Xinjiang (pp. 111–173). Beijing: Geological Publishing House.Google Scholar
- Qu, L. F., & Wang, Z. (1990). Triassic palynological assemblages in North Xinjiang. In Institute of Geology, Chinese Academy of Geological Sciences & Research Institute of Petroleum Exploration and Development, Xinjiang Petroleum Administration (Eds.), Permian to tertiary strata and palynological assemblages in the north of Xinjiang (pp. 37–56). Beijing: China Environmental Science Press.Google Scholar
- Qu, L. F., Yang, J. D., Bai, Y. H., & Zhang, Z. L. (1983). A preliminary discussion on the characteristics and stratigraphic division of Triassic spores and pollen in China. Bulletin of the Chinese Academy of Geological Science, 5, 81–94.Google Scholar
- Qu, L. F., Zhang, W. P., & Yu, J. X. (1987). Advance in Mesozoic palynological researches for thirty years. Professional Papers of Stratigraphy and Palaeontology, 17, 65–91.Google Scholar
- Raine, J. I., Mildenhall, D. C., & Kennedy, E. M. (2011). New Zealand fossil spores and pollen: an illustrated catalogue, 4th edition. GNS Science miscellaneous series no. 4. http://data.gns.cri.nz/sporepollen/index.htm.
- Ruckwied, K., Götz, A. E., Pálfy, J., & Török, Á. (2008). Palynology of a terrestrial coal-bearing series across the Triassic/Jurassic boundary (Mecsek Mts, Hungary). Central European Geology, 51(1), 1–15.Google Scholar
- Ruckwied, K., & Götz, A. E. (2009). Climate change at the Triassic/Jurassic boundary: palynological evidence from the Furkaska section (Tatra Mountains, Slovakia). Geological Carpathica, 60(2), 139–149.Google Scholar
- Sha, J. G., Vajda, V., Pan, Y. H., Larsson, L., Yao, X. G., Zhang, X. L., Wang, Y. Q., Cheng, X. S., Jiang, B. Y., Deng, S. H., Chen, S. W., & Peng, B. (2011). Stratigraphy of the Triassic–Jurassic boundary succession of the southern margin of the Junggar Basin, northwestern China. Acta Geologica Sinica, 85(2), 421–436.CrossRefGoogle Scholar
- Sha, J. G., Olsen, P. E., Pan, Y. H., Xu, D. Y., Wang, Y. Q., Zhang, X. L., Yao, X. G., & Vajda, V. (2015). Triassic–Jurassic climate in continental high-latitude Asia was dominated by obliquity-paced variations (Junggar Basin, Ürümqi, China). Proceedings of the National Academy of Sciences of the United States of America, 112(12), 3624–3629.Google Scholar
- Shang, Y. K. (1998). Late Triassic palynoflora provinces of China. Acta Palaeontologica Sinica, 37(4), 427–445.Google Scholar
- Shang, Y. K. (2011). Late Triassic palynology of Yunnan and Guizhou, China. Palaeontologica Sinica 196, New Series A, 16, 1–276.Google Scholar
- Shen, S. Z., Crowley, J. L., Wang, Y., Bowring, S. A., Erwin, D. H., Sadler, P. M., Cao, C. Q., Rothman, D. H., Henderson, C. M., Ramezani, J., Zhang, H., Shen, Y. A., Wang, X. D., Wang, W., Mu, L., Li, W. Z., Tang, Y. G., Liu, X. L., Liu, L. J., Zeng, Y., Jiang, Y. F., & Jin, Y. G. (2011). Calibrating the end-Permian mass extinction. Science, 334, 1367–1372.CrossRefGoogle Scholar
- Song, Z. C., Shang, Y. K., Liu, Z. S., Huang, P., Wang, X. F., Qian, L. J., Du, B. A., & Zhang, D. H. (2000). Fossil spores and pollen of China, 2: the Mesozoic spores and pollen (pp. 1–170). Beijing: Science Press.Google Scholar
- Sun, G., Meng, F. S., Qian, L. J., & Ouyang, S. (1995). Triassic floras. In X. X. Li (Ed.), Fossil floras of China through the geological ages (pp. 305–342). Guangzhou: Guangdong Science and Technology Publishing House.Google Scholar
- van de Schootbrugge, B., Quan, T. M., Lindström, S., Püttmann, W., Heunisch, C., Pross, J., Fiebig, J., Petschick, R., Röhling, H.-G., Richoz, S., Rosenthal, Y., & Falkowski, P. G. (2009). Floral changes across the Triassic/Jurassic boundary linked to flood basalt volcanism. Nature Geoscience, 2, 589–594.CrossRefGoogle Scholar
- Vajda, V., Calner, M., & Ahlberg, A. (2013). Palynostratigraphy of dinosaur footprint-bearing deposits from the Triassic-Jurassic boundary interval of Sweden. Geologiska Föreningen i Stockholm Förhandlingar., 135(1), 120–130.Google Scholar
- Vajda, V., & Bercovici, A. (2014). The global vegetation pattern across the Cretaceous–Palaeogene mass extinction interval: a template for other extinction events. Global and Planetary Change, 122, 29–49.Google Scholar
- Xu, Y. L., Yang, G. D., & Zhao, Y. Y. (1996). Triassic palynology and division of sequence stratigraphy from northern Tarim Basin. Geoscience, 10(4), 437–447.Google Scholar
- Yong, T. S., Song, L. X., Yu, Y. D., & Yu, X. Q. (1990). The Mesozoic stratum of the well Lunnan-1 in Tarim Basin. Xinjiang Petroleum Geology, 11(2), 132–135.Google Scholar
- Zhan, J. Z. (1991). The Mesozoic stratigraphic divisions from the well Lunnan no. 1 and its fossil evidences. Xinjiang Petroleum Geology, 12(4), 293–300.Google Scholar
- Zhang, S. B., Huang, Z. B., Zhu, H. C., et al. (2004). Subsurface Phanerozoic stratigraphy of the Tarim Basin (pp. 1–300). Beijing: Petroleum Industry Press.Google Scholar
- Zhu, H. C. (1996). Discovery of the earliest Triassic spores and pollen from southwest Tarim and Permian-Triassic (P–T) boundary. Chinese Science Bulletin, 41(24), 2066–2069.Google Scholar
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.