Conodonts, radiolarians and ostracodes in the Permian E-Lert Formation, Loei Fold Belt, Indochina Terrane, Thailand

Abstract

Conodonts are rare in the Permian carbonates of Indochina but abundant conodonts and ostracodes have been obtained from turbiditic limestones of the Permian E-Lert Formation along with radiolarians from overlying cherts, all deposited on the margins of the interplatform Nam Duk Basin. Conodonts are typically Tethyan and are very similar to faunas from Sicily and south China. They include Hindeodus gulloides, Pseudohindeodus oertlii, Mesogondolella siciliensis and Sweetognathus subsymmetricus which indicate a probable late Kungurian – Roadian age range although a Wordian age cannot be excluded. M. siciliensis, which has a high blade and small cusp supposedly typical of warm-water conodonts, is found in deep (<500 m) carbonate turbidites in Thailand and in very deep deposits in Oman and Sicily, but generally not in shallow-water tropical limestones in Thailand, Oman and Sicily. The chert sequence yields a radiolarian fauna consisting of 11 confidently assigned species of which Albaillella asymmetrica, A. sinuata, Tormentum delicatum and Latentifistula patagilaterata suggest a latest Kungurian – earliest Roadian age, deposited at a palaeodepth of c. 500 m. Ostracodes consist of 16 genera and 23 species which belong to Shivaella, Paraberounella, Carinaknightina, Paraparchites, Shemonaella, Bairdia, Cryptobairdia, Bairdiacypris?, Spinocypris, Pseudobythocypris, Baschkirina, Microcheilinella, Basslerella, Polycope and Cyathus, of which Shivaella elertensis sp. nov. Chitnarin is newly described. The ostracodes are a palaeoecologically mixed assemblage comprising external platform and deeper-water forms, suggesting that the limestone turbidites were deposited on the proximal part of the slope. Cyathus caperata and C. elliptica show a palaeobiogeographic link to south China.

Permian (Artinskian to Wuchapingian) conodont biostratigraphy in the Tieqiao section, Laibin area, South China

“…Guangxi in South China, as well as from Thailand and Oman (Mei et al, 2002 and this study; Henderson and Mei, 2003;Metcalfe and Sone, 2008;Burrett et al, 2015). The assertion that Sw. subsymmetricus is restricted to the Roadian (Kozur, 1993) is incorrect.…”

“…Seven subordinate zones are established at Tieqiao, representing interval zones based on occurrences of long ranging species. The subordinate zones are less effective for stratigraphic correlation but can provide a valuable reference for cases when a single conodont assemblage is obtained from an age-ambiguous lithologic unit (e.g., Burrett et al, 2015). In the following section, we first describe the ranges of these subordinate zones in the Tieqiao section, followed by comments on the range of the zonal species.…”

“…monocornus might be facies-related, and its presence in Wordian to lower Capitanian strata elsewhere (Li et al, 1989) cannot be excluded. (Burrett et al, 2015). In west Texas, the species was recovered from the upper part of Road Canyon Fm., representing a late Roadian age (Kozur and Mostler, 1995).…”

Morphological characteristics of a dimorphic pair of Albaillella sinuata Ishiga and Watase: Dimorphism in the lineage of the Permian Albaillellaria (Radiolaria)

“…This type has been reported in the Cisuralian-Guadalupian in Japan (e.g. Hori, 2004;Ishiga, 1990;Ishiga et al, 1986;Ishiga, Kito, & Imoto, 1982a, 1982bIshiga & Suzuki, 1984;Ito & Matsuoka, 2015a;Kametaka, 2006;Kurihara & Kametaka, 2008;Nakae, 2001;Sano, 1988;Ujiié & Oba, 1991;Yamamoto, 1985), United States (Blome & Reed, 1992), China (Sun, Xia, & Liu, 2002;Wang, Cheng, & Yang, 1994;Wang, Luo, Kuang, & Li, 1998;Wang, Luo, & Yang, 2012;Wang & Yang, 2011;Xia & Zhang, 1998;Xie, Yang, Liu, & Feng, 2011;Zhang, Henderson, Xia, Wang, & Shang, 2010), Russia (Rudenko & Panasenko, 1990), and Thailand (Burrett, Udchachon, Thassanapak, & Chitnarin, 2015;Sashida, Igo, Hisada, Adachi, et al, 1998;Sashida, Igo, Hisada, Nakornsri, & Ampornmaha, 1993;Sashida & Salyapongse, 2002). Albaillella sinuata co-occurred with the Lopingian radiolarian assemblage in southwest Japan (Kuwahara, 1997;Kuwahara & Yao, 1998;Mitsumura & Kamata, 2009;Takemura & Yamakita, 1993); however, Takemura and Yamakita (1993)…”

Rediscovering the Lys collection in the Muséum national d'Histoire naturelle (Paris, France): first report on Middle Permian ostracods from occidental Hindu Kush, Afghanistan

“…Forel M.-B.rin et al 2012;Burrett et al 2015), questionably from the Middle Permian of SouthChina (Zazzali et al 2015) and from the Changhsingian, Late Permian of South China(Yi 2004; Crasquin et al 2010) andIran (Forel et al 2015). The juvenile and adult specimens document the relatively conservative morphology of Cyathus sp.…”