Additional occurrence report on early Carboniferous radiolarians from southern peninsular Thailand (original) (raw)
Related papers
Paleontological Research, 2007
A Late Devonian to Early Carboniferous radiolarian fauna is present in chert and siliceous shale of a chert-clastic section along the Khong River, Pak Chom area, at the Thai-Lao border of northeastern Thailand. The radiolarian fauna is composed of Stigmosphaerostylus variospina, Astroentactinia stellata, Astroentactinia multispinosus, Archocyrtium wonae, Archocyrtium riedeli, and other species and corresponds to the Famennian (Late Devonian) to Tournaisian (Early Carboniferous) radiolarian fauna reported from northwestern Europe, Australia, northern and southern Thailand, and southern China. Ten radiolarian species belonging to four genera including one unidentified genus are investigated. The radiolarian-bearing sequence was probably deposited in a pelagic or hemipelagic environment within the Paleotethys Ocean during Late Devonian to Early Carboniferous time. Furthermore, this chert-clastic section of Pak Chom area is thought to be deposited on the Nakhon Thai Block and subducted beneath the Indochina Block. This suggests that the age of subduction and accretion of the Naknon Thai Block is thought to have occurred at least after Early Carboniferous indicated by the occurrence of Late Devonian to Early Carboniferous radiolarians.
Paleontological Research, 2009
Lower Permian (Asselian to Sakmarian) radiolarians and conodonts are identified from the bedded chert of the Chanthaburi area along the Sra Kaeo Suture Zone in eastern Thailand. The radiolarian and conodontbearing bedded chert including radiolarian species such as Parafollicucullus bulbosus, P. lomentarius, P. u-formus, Pseudoalbailella scalprata, and others is exposed as large-size exotic blocks within the Thung Kabin mélange. This radiolarian fauna further includes Triplanospongos musashiensis, Triaenosphaera minuta, Latentifistula texana, Latentibifistula asperspongiosa and others, which have previously been reported from the Middle to Upper Permian. Except for these Middle to Upper Permian species, this radiolarian fauna is quite similar to those from Japan, Oregon, South China, West Texas, Cis-Urals and Central and Northeastern Thailand. Asselian to Sakmarian conodont faunas represented by Streptognathodus constrictus which have been reported from the Southern Urals and South China, and several sponge spicules are also contained in this bedded chert. Occurrence of these Lower Permian conodonts is the first record from the Sra Kaeo Suture Zone. This radiolarian-and conodont-bearing bedded chert was probably deposited in the Palaeotethys /or Palaeotethyan back-arc basin which is thought to have been a pelagic environment at low latitudes of the Southern Hemisphere.
Paleozoic and Mesozoic Radiolarian Faunas in Thailand
Radiolarian biostratigraphy of the Devonian to Triassic sequences have been undertaken in several areas of Thailand. Radiolarian-bearing rocks in these areas consist of various colored chert, siliceous shale, calcareous shale and tuffaceous siliceous shale. Fourteen Devonian to Triassic radiolarian zones are proposed in this study. These radiolarian zones can be correlated with other Devonian to Triassic radiolarian zones that were reported from several areas in the world. Based on lithostratigraphy, sedimentary structures and radiolarian biostratigraphy, radiolarian-bearing rocks in Thailand are divided into two types which have been accumulated in hemipelagic and pelagic environments.
Late Permian to Middle Triassic Radiolarian Faunas from Northern Thailand
Journal of Paleontology, 2000
Moderately well-preserved Late Permian to Middle Triassic radiolarians are identified in chert beds that occur in the Shan-Thai Block of northern Thailand. These radiolarians are identical to the faunas of the Late Permian Neoalbaillella ornithoformis and N. optima Assemblage Zones and the Triassic Parentactinia nakatsugawaensis and Triassocampe coronata Assemblage Zones reported in chert sequences of Japan. We discovered the radiolarian faunas, apparently indicating Late Permian and Early Triassic ages, in almost continuous sequences of chert and shale exposed in the north of Chiang Mai. The occurrence of these radiolarian faunas provides important data to solve the P/T (Permian/Triassic) boundary in pelagic sequences. Our present discovery also furnishes significant data to reconstruct the paleobiogeography of Mainland Thailand during Late Permian to Middle Triassic times. Fifty species belonging to 35 genera, including three unidentified genera, are investigated taxonomically. Four new species Pseudospongoprunum? chiangdaoensis, Cenosphaera igoi, Cenosphaera? rugosa, and Tlecerina? apsornae are described.
Journal of Earth Science, 2017
Annulotriassocampe multisegmantis Archaeocenosphaera sp. Muelleritortis cochleata cochleata M. cochleata tumidospina M. expansa M. sp. Pseudostylosphaera coccostyla coccostyla P. imperspicua Archaeocenosphaera sp. cf. A. laseekensis A. sp. Acanthosphaera sp. Paronaella sp. Annulotriassocampe companilis A. multisegmantatus A. sulovensis A. sp. Parauesticyrtium sp. A P. sp. cf. P. illyicum Striatriassocampe nodoannulata Triassocampe deweveri T. coronata T. scalaris T. sp. Orbiculiforma sp. cf. O. gazipasaensis O. karnica Pseudogodia? sp. Canoptum inornatus C. levis C. sp. Japonocampe nova Corum kraineri Spongserrula rarauana Spongosilicarmiger sp. Pseudostylospaera sp. Praeheliostaurus sp. Figure 7. Plot of radiolarian occurrences in the Santisuk (ST) and Den Chai sections (DC).
Middle Triassic radiolarian faunas from Chiang Dao, Northern Thailand
Palaeoworld, 2011
Middle Triassic radiolarians were obtained from a bedded chert sequence in Chiang Dao, northern Thailand. Sixty-four species were identified into two assemblages, which indicate two stratigraphic levels including lower Illyrian (lowermost upper Anisian) and upper Illyrian (uppermost Anisian). The occurrence of upper Anisian radiolarians in our study indicates the former existence of a relatively deep marine environment in northern Thailand with a seaway between eastern and western Palaeotethys. The stratigraphic units containing bedded chert in this area were formerly dated on the basis of fossil evidence and petrological similarities. However, the strata in the study area are possibly not part of a continuous stratigraphic sequence, but consist of tectonic slices. The fossil age from any slice indicates only the geological age of the given slice, and adjacent slices are often of different ages. Parts of the sequence formerly mapped as Carboniferous and Permian are Middle Triassic in the study area. The sequence covers the Carboniferous to Middle Triassic and can be correlated with the eastern zone of the Changning-Menglian Belt in southwestern Yunnan, China.
Journal of Asian Earth Sciences, 2002
Early to Late Triassic (Spathian to Carnian) radiolarians were obtained from the bedded chert sequence of the Mae Sariang Group distributed in northern Thailand. Based on the similarity of radiolarian fauna and petrographical characteristics, it is inferred that the ®negrained siliceous and calcareous sediments of the Mae Sariang Group are equivalent to those belonging to the eastern marginal facies of the Sibumasu Block. Moreover, the occurrence of an early (?) Carnian radiolarian assemblage from bedded chert shows that the closure of the Paleotethys Ocean between the Sibumasu and Indochina Blocks in northern Thailand occurred after the early Carnian. q
Occurrence of paleozoic and early mesozoic radiolaria in Thailand (preliminary report)
Journal of Southeast Asian Earth Sciences, 1993
Almtraet-Paleozoic and Early Mesozoic radiolarians are newly recovered from chert and associated fine-grained clastic rocks in Thailand. This study clarifies the geologic age of these radiolarian rocks and their paleogeographical and geotectonic significance. Devonian, Early Carboniferous and Permian radiolarians were found in the "Fang Chert" which outcrops along the Chiang Mai-Fang Road, upper north Thailand. Early Carboniferous radiolarians were recovered from a sequence of tuffaceous shale and chert exposed in the Pak Chom area along the Mekong River, and well-preserved Late Devonian and Early Carboniferous radiolarians were also recovered from cherts exposed along the Pak Chom-Loei Road near Phu Laem, north of Loei, in northeast Thailand. These Devonian to Carboniferous radiolarian faunas are apparently identical with those reported from eastern and western Australia. Well-preserved Early Triassic conodonts and radiolarians were obtained from a limestone exposed near Patthalung, southern Thailand. Most of the radiolarian species of this fauna show close atfinity with those reported from the Upper Paleozoic rocks, and are new species except for some spicule-type forms. Based on the above-mentioned newly obtained micropaleontological evidence, the geotectonic significance of these radiolarian rocks are briefly discussed in relation to the paleogeography of the Palaeo-Tethys Ocean, Sibumas and Indochina Terranes, and Australia during the Late Devonian to Middle Permian times.
Permian radiolarian faunas from Thailand and their paleogeographic significance
Journal of Asian Earth Sciences, 2002
Chert and ®ne-grained clastic rocks in Thailand contain rich Permian radiolarian faunas. We have discriminated eight radiolarian assemblages in these rocks; Pseudoalbaillella bulbosa (Upper Carboniferous to lowermost Permian; Gzhelian to Asselian), Pseudoalbaillella simplex (lowermost Permian; Asselian), Pseudoalbaillella lomentaria (Lower Permian; Asselian to Sakmarian), Pseudoalbaillella scalprata (Lower Permian; Sakmarian), Follicucullus monacanthus (Middle Permian; Wordian), Follicucullus porrectus (upper Middle to lowermost Upper Permian; Capitanian to lower Wuchiapingian), Neoalbaillella ornithoformis (Upper Permian; Wuchiapingian), and Neoalbaillella optima (Upper Permian; Changsingian) assemblages in stratigraphic order. These radiolarians have a potential to contribute to understanding the history of the Paleotethys. Based on the radiolarian biostratigraphy and lithological characteristics, Lower to lower Upper Permian radiolarian-bearing cherts are thought to have been deposited in a pelagic environment in a deep basin far from land. The uppermost Permian radiolarian-bearing cherts, however, reveal differences in their depositional environments. In northern Thailand the uppermost Permian to Middle Triassic radiolarian chert was deposited in a pelagic basin, while in eastern Thailand the uppermost Permian chert and the conformably overlying clastic rocks show a change in depositional environment across the P±T boundary, from a deep pelagic or hemipelagic, to shallow seas in the Triassic. q
Palaeoworld
Abstract The first radiolarian fauna obtained from Permian carbonates in Thailand is of late Kungurian age and is present in the basal beds of the carbonate–mudstone–chert Phap Pha Formation, Ratburi Group. This succession contains several species of the radiolarian Pseudoalbaillella, and some sponge spicules. The radiolarian fauna consists of abundant Pseudoalbaillella aidensis and P. elegans together with P. fusiformis, P. longtanensis, P. m. rhombothoracata and P. sp. A. Other species include P. cf. aidensis, P. cf. elongata, P. cf. fusiformis, P. cf. ishigai, P. cf. lomentaria, P. cf. longicornis, P. cf. longtanensis, P. cf. ornata, P. cf. simplex, P. cf. m. scalprata, P. cf. m. postscalprata, P. cf. u–forma m. I, P. cf. u–forma m. II, and P. spp. The radiolarian assemblage suggests its correlation to the P. longtanensis Zone which, in turn, is correlated to the P. ishigai Zone of late Kungurian age. The occurrence of an abundant but generically low–diversity radiolarian fauna suggests restricted physical conditions and, with other evidence, suggests deposition along a cool deglaciating or deglaciated continental margin with an abundance of silica possibly provided by glacial meltwaters. The abundant chert in the Phap Pha Formation is part of the widespread Permian Chert Event.