Late middle Cambrian (Cambrian Series 3) trilobite faunas from the lowermost part of the Sesong Formation, Korea and their correlation with North China

2013 ◽  
Vol 87 (6) ◽  
pp. 991-1003 ◽  
Author(s):  
Tae-Yoon Park ◽  
Ji-Hoon Kihm ◽  
Duck K. Choi
Keyword(s):  
North China ◽  
Abrupt Change ◽  
Middle Cambrian ◽  
Taebaeksan Basin ◽  
Late Cambrian ◽  
Lowermost Part ◽  
Taebaek Group

The Sesong Formation is a member of the Taebaek Group, Korea, which extends from late Cambrian Series 3 to middle Furongian in age. Recent studies on the trilobites of the Sesong Formation have contributed significantly to the revision of the biostratigraphy. However, trilobites in the lower part of the formation, which may include the “Stephanocare Zone”, have remained essentially overlooked since the establishment of the biozone, making it difficult to correlate with the equivalent biozones of North China. Here we report trilobite faunas from the lower part of the Sesong Formation in two different sections, the Seokgaejae and the Jikdong sections, which yield two species of Jiulongshania among other species. Species of Jiulongshania have been known to occur successively in North China, so are useful for detailed correlation. Specimens of Stephanocare richthofeni are fragmentary and rarely occur in association with Jiulongshania regularis, while Jiulongshania species occur throughout the studied intervals. Accordingly, it is reasonable to extend the previously established Jiulongshania Zone of the uppermost part of the underlying Daegi Formation into the lower part of the Sesong Formation. By doing so, the Jiulongshania Zone is correlated with the Blackwelderia Zone of North China with confidence. The lowermost part of the Sesong Formation in the Jikdong section yields a fauna including J. regularis, which implies that the boundary between the Daegi and Sesong formations is diachronous within the Taebaeksan Basin. The Daegi/Sesong formation boundary in Korea is comparable to the Zhangxia/Gushan boundary in North China in that it displays an abrupt change from a carbonate-dominant facies to a shale-dominant facies. The correlation employing the Jiulongshania species indicates that the facies shift occurred significantly earlier in Shandong, North China than in the Taebaeksan Basin, Korea.

Dikelocephalid trilobites from theEosaukiafauna (Upper Furongian) of the Taebaek Group, Korea

2011 ◽  
Vol 85 (2) ◽  
pp. 279-297 ◽  
Author(s):  
Seung-Bae Lee ◽  
Duck K. Choi
Keyword(s):  
South China ◽  
North China ◽  
Generic Concept ◽  
Upper Cambrian ◽  
Taebaeksan Basin ◽  
Biostratigraphic Correlation ◽  
Lowermost Part ◽  
Taebaek Group

TheEosaukiafauna is proposed for the upper Furongian trilobite assemblage from the interval spanning from the upper part of the Hwajeol Formation to the lowermost part of the Dongjeom Formation in the Taebaek Group, Taebaeksan Basin, Korea. It is characterized by the dominance of dikelocephalid trilobites comprisingEosaukia micropora, E. bella, E. acuta, Mictosaukiacf.M. globosa, andTaebaeksaukia spinatan. gen. n. sp. Taxonomic reappraisal of the genusMictosaukiathat has been employed as an upper Cambrian index taxon in eastern Gondwana reveals that more than half of the species ofMictosaukiabelong inEosaukia.This study clarifies the generic concept ofEosaukia, which provides a more reliable biostratigraphic correlation for the upper Furongian strata in eastern Gondwanan regions. TheEosaukiafauna is correlated with the“Mictosaukia”faunas from the upper Fengshanian of North China, upper Taoyuanian of South China, and upper Payntonian of Australia.

scholarly journals Satunarcus, a new late Cambrian trilobite genus from southernmost Thailand and a reevaluation of the subfamily Mansuyiinae Hupé, 1955

2020 ◽  
Vol 94 (5) ◽  
pp. 867-880
Author(s):  
Shelly J. Wernette ◽  
Nigel C. Hughes ◽  
Paul M. Myrow ◽  
Apsorn Sardsud
Keyword(s):  
North China ◽  
New Genus ◽  
Sedimentary Rocks ◽  
Cladistic Analysis ◽  
New Genus And Species ◽  
Natural Group ◽  
Middle Cambrian ◽  
Current Definition ◽  
Late Cambrian ◽  
Cambrian Trilobite

AbstractThe Ao Mo Lae Formation of the Tarutao Group crops out on Thailand's Tarutao Island and contains a diverse assemblage of late Furongian trilobite taxa, including several endemic forms. This study presents a new genus and species, Satunarcus molaensis, discovered at two locations on the island. A cladistic analysis of the kaolishaniid subfamily Mansuyiinae in light of Satunarcus and similar genera known from across upper Cambrian equatorial Gondwanan rocks suggests that the subfamily is polyphyletic in its current definition, and thus is not a natural group. Separating Mansuyia Sun, 1924 from the other taxa conventionally placed in Mansuyiinae permits recognition of a previously unrecognized monophyletic subfamily Ceronocarinae new subfamily. As established herein, this kaolishaniid subfamily contains Satunarcus n. gen. and all genera previously recognized as Mansuyiinae. with the exception of Mansuyia itself. Ceronocarinae n. subfam. occur in middle Jiangshanian to middle Cambrian Stage 10 sedimentary rocks from Australia, South China, North China, and Sibumasu, with most genera endemic to Australia.UUID: http://zoobank.org/618c5136-73f0-4912-a7d3-e56559d2a76c

Ontogeny of the Ptychaspidid TrilobiteQuadraticephalus elongatusKobayashi, 1935 from the Furongian (Late Cambrian) Hwajeol Formation, Korea

2013 ◽  
Vol 87 (3) ◽  
pp. 379-390 ◽  
Author(s):  
Ji-Hoon Kihm ◽  
Tae-Yoon Park ◽  
Duck K. Choi
Keyword(s):  
Developmental Stage ◽  
Morphological Changes ◽  
Equilibrium Phase ◽  
Special Focus ◽  
Taebaeksan Basin ◽  
Late Cambrian ◽  
Frontal Part ◽  
Accumulation Phase ◽  
Taebaek Group ◽  
Number Of Segments

The development of the trilobite pygidium involves both an articulation process at the frontal part and the formation of new segments at the rear end, and hence the development of the meraspid pygidium entails complicated morphological changes. This study deals with the ontogeny of the Furongian (late Cambrian) ptychaspidid trilobite,Quadraticephalus elongatus(Kobayashi, 1935), from the Hwajeol Formation of the Taebaek Group, Taebaeksan Basin, Korea, with a special focus on the segmentation process during the meraspid pygidial development. Compared to the ontogeny of a ptychaspidid trilobite,Asioptychaspis subglobosa(Sun, 1924), which is assumed to be an ancestral species ofQ. elongatus, the convexity of the cranidium ofQ. elongatusincreased in a slower rate; the yoked free cheek ofQ. elongatussplits to form a ventral median suture in a later developmental stage; and, a rim-like ridge, which disappeared in the early holaspid pygidium ofA. subglobosa, was maintained in the late holaspid period ofQ. elongatus. These morphological changes with growth imply that paedomorphosis was involved in the evolution ofQ. elongatus. Eleven stages are recognized for the meraspid pygidial development, which began with an accumulation phase during which the number of segments increased from three to seven, followed by an equilibrium phase with seven segments, and ended up with a depletion phase during which the number of segments within the pygidium decreased to four. During the depletion phase, the pygidial length did not increase or even slightly decreased. The onset of the epimorphic phase, in which the total number of trunk segments does not increase anymore, precedes the onset of the holaspid period, demonstrating that the developmental mode ofQ. elongatusis protomeric.

Trilobites of thePseudokoldinioidiaFauna (Uppermost Cambrian) from the Taebaek Group, Taebaeksan Basin, Korea

2007 ◽  
Vol 81 (6) ◽  
pp. 1454-1465 ◽  
Author(s):  
Seung-Bae Lee ◽  
Duck K. Choi
Keyword(s):  
Species Diversity ◽  
South America ◽  
South China ◽  
North China ◽  
Eastern Asia ◽  
Taebaeksan Basin ◽  
Cambrian Trilobite ◽  
Taebaek Group

ThePseudokoldinioidiaFauna is a newly documented uppermost Cambrian trilobite assemblage from the Dongjeom Formation of the Taebaek Group, Taebaeksan Basin, Korea. It is characterized by low species diversity comprising six trilobite taxa:Micragnostus chiushuensis, Koldinioidia typicalis, leiostegiid genus and species indeterminate,Pseudokoldinioidia perpetis, Onychopyge borealis, and pilekiid genus and species indeterminate. Of these, special attention has been paid toPseudokoldinioidia perpetis, which was originally assigned toMissisquoia, an index fossil for the uppermost Cambrian in Laurentia.Pseudokoldinioidiais restricted to eastern Asia, whereasMissisquoiais confined to Laurentia. The appearance of thePseudokoldinioidiaFauna is interpreted as contemporaneous with the base of the‘Missisquoia’ perpetisZone of North China, which in turn is correlated with the base of theMissisquoia typicalisSubzone of Laurentia. The associatedKoldinioidiaandOnychopygemake it possible to compare thePseudokoldinioidiaFauna of Korea and North China with the latest Cambrian trilobite assemblages of South China, Australia, South America, and Mexico, and also suggests an interesting biogeographic connection among these areas in the latest Cambrian.

scholarly journals Paleomagnetic insights into the Cambrian biogeographic conundrum: Did the North China craton link Laurentia and East Gondwana?

Geology ◽  
2020 ◽  
Author(s):  
Hanqing Zhao ◽  
Shihong Zhang ◽  
Maoyan Zhu ◽  
Jikai Ding ◽  
Haiyan Li ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Tilt Test ◽  
Strong Ties ◽  
Middle Cambrian ◽  
The North ◽  
Late Cambrian ◽  
Small Shelly Fossils ◽  
Paleomagnetic Pole

Redlichiid trilobite and small shelly fossils indicate strong ties of the North China craton (NCC) to Gondwana during the early Cambrian, while recent discoveries of the characteristic fossils of Laurentia in Wuliuan shales in the eastern NCC imply its possible connection with Laurentia during the middle Cambrian. Here we report a new paleomagnetic pole at 31.8°S, 140.4°E (radius of 95% confidence cone of paleomagnetic pole, A95, = 5.3°), obtained from the Wuliuan (ca. 505 Ma) Hsuchuang Formation, by averaging our new data and existing virtual geomagnetic poles acquired from different parts of the NCC. A positive regional tilt test and the presence of geomagnetic reversals demonstrate that the remanence was primary. The paleomagnetic data permit placing the NCC near 20°N between Laurentia and Australia at ca. 505 Ma, suggesting that the NCC may have played the role of biogeographic link between East Gondwana and Laurentia in the middle Cambrian. Low-latitudinal westward ocean currents may have facilitated faunal migrations from Laurentia to East Gondwanan blocks via the NCC as well as the newly formed tectono-paleogeographic archipelago, which likely further enhanced biological exchange in the late Cambrian.

scholarly journals Diversified calcimicrobes in dendrolites of the Zhangxia Formation, Miaolingian Series (Middle Cambrian) of the North China craton

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ming-Xiang Mei ◽  
Muhammad Riaz ◽  
Zhen-Wu Zhang ◽  
Qing-Fen Meng ◽  
Yuan Hu
Keyword(s):  
North China ◽  
Cyanobacterial Mats ◽  
Third Order ◽  
Depositional Sequence ◽  
Middle Cambrian ◽  
Forming Mechanism ◽  
The North ◽  
Biological Affinity ◽  
History Of ◽  
Group 3

AbstractAs a type of non-laminated microbial carbonates, dendrolites are dominated by isolated dendritic clusters of calcimicrobes and are distinct from stromatolites and thrombolites. The dendrolites in the upper part of the Miaolingian Zhangxia Formation at Anjiazhuang section in Feicheng city of Shandong Province, China, provide an excellent example for further understanding of both growth pattern and forming mechanism of dendrolites. These dendrolites are featured by sedimentary fabrics and composition of calcified microbes as follows. (1) The strata of massive limestones, composed of dendrolites with thickness of more than one hundred meters, intergrade with thick-bedded to massive leiolites, formimg the upper part of a third-order depositional sequence that constitutes a forced regressive systems tract. (2) A centimeter-sized bush-like fabric (shrub) typically produced by calcified microbes is similar to the mesoclot in thrombolites but distinctive from clotted fabrics of thrombolites. This bush-like fabric is actually constituted by diversified calcified microbes like the modern shrub as a result of gliding mobility of filamentous cyanobacteria. Such forms traditionally include: the Epiphyton group (which actually has uncertain biological affinity), the Hedstroemia group which closely resembles modern rivulariacean cyanobacteria, and the possible calcified cyanobacteria of the Lithocodium–Bacinella group. (3) Significantly, dense micrite of leiolite is associated with sponge fossils and burrows, and is covered by microstromatolite. The Lithocodium–Bacinella group is a controversial group of interpreted calcified cyanobacteria in the Cambrian that has also been widely observed and described in the Mesozoic. Therefore, dendrolites with symbiosis of leiolites in the studied section provide an extraordinary example for further understanding of growing style of bush-like fabrics (shrubs) of the dendrolites dominated by cyanobacterial mats. Furthermore, the present research provides some useful thinking approaches for better understanding of the history of the Early Paleozoic skeletal reefs and the microbe–metazoan transitions of the Cambrian.

Taebaek Group (Cambrian-Ordovician) in the Seokgaejae section, Taebaeksan Basin: a refined lower Paleozoic stratigraphy in Korea

2004 ◽  
Vol 8 (2) ◽  
pp. 125-151 ◽  
Author(s):  
Duck K. Choi ◽  
Sung Kwun Chough ◽  
Yi Kyun Kwon ◽  
Seung-Bae Lee ◽  
Jusun Woo ◽  
...  
Keyword(s):  
Lower Paleozoic ◽  
Taebaeksan Basin ◽  
Taebaek Group

Origin of megarhythms in flysch sequences of the Quebec Appalachians

1979 ◽  
Vol 16 (7) ◽  
pp. 1518-1523 ◽  
Author(s):  
Jean Lajoie
Keyword(s):  
Deep Sea ◽  
Source Area ◽  
Rock Composition ◽  
Middle Cambrian ◽  
Late Cambrian ◽  
External Domain ◽  
Vertical Evolution ◽  
Metamorphic Terranes ◽  
Sea Fan ◽  
Stratigraphic Evolution

The cyclic and positive sequences observed in the External Domain of the Quebec Appalachians between L'IsIet and Grosses Roches have been interpreted as facies of deep-sea fans that result from progradation. In these conglomerate-bearing sequences, the composition of the detritus changes up-section, which suggests that uplift of the source area played an important role in their vertical evolution. In early and (or) Middle Cambrian time, the source consisted of sedimentary, igneous, and metamorphic terranes. This provenance was rejuvenated in Late Cambrian – Early Ordovician time, and the Lower – Middle Cambrian shelf wa.s uplifted. The stratigraphic evolution of composition observed in these flysch sequences cannot be explained by deep-sea fan progradation.In recent years the general trend in flysch-sequence analysis has been away from tectonic and towards sedimentological interpretations. The stratigraphic evolution of flysch sequences may be due to both tectonic and sedimentary processes. Studies of rock composition, generally neglected by most workers, could be used to make the distinction.

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