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Late Cretaceous-Early Tertiary dinoflagellates and acritarchs from the Kashi area, Tarim Basin, Xinjiang Province, China
| Mao Shaozhi and Norris, G. | |
| 1988 | |
| Royal Ontario Museum, Life Sciences Contributions vol.150 pp.1-93 pl.16 | |
| Late Cretaceous-Early Tertiary dinoflagellates and acritarchs from the Kashi area, Tarim Basin, Xinjiang Province, China |
Mao Shaozhi and Norris, G., 1988; Late Cretaceous-Early Tertiary dinoflagellates and acritarchs from the Kashi area, Tarim Basin, Xinjiang Province, China. Royal Ontario Museum, Life Sciences Contributions vol.150 pp.1-93 pl.16 Annotated abstract: The Upper Cretaceous Yingjiesha Group and the Lower Tertiary Kashi Group comprise transgressive and regressive sequences and outcrop in the piedmont of the western Kunlun Mountains and Tianshan Mountains on the western margin of the intracratonic Tarim Basin. They have yielded dinoflagellate and acritarch assemblages comprising 176 species distributed amongst 82 genera. Six Oppel zones are distinguished and correlated: Zone A: Cyclonephelium brevispinatum Zone (Cenomanian to Turonian) Zone B: Alterbidinium emulatum Zone (Turonian to Coniacian or Santonian) Zone C: Canningia reticulata Zone (post-Coniacian) Zone D: Phelodinium anisos Zone (Late Paleocene) Zone E: Turbiosphaera filosa Zone (Late Eocene) Zone F: Deflandrea intrasphaerula Zone (Early Oligocene) The assemblages resemble those from coeval strata in Australia, North America, and Europe but also contain apparently endemic elements. Nearshore dinoflagellate assemblages tend to be dominated by proximate cysts or those with short processes, whereas offshore assemblages are characterized by numerous and diverse skolochorate cysts. The lower part of the Yingjiesha Group is a fine-grained clastic and shelly facies and represents a shift from nearshore conditions from Cenomanian to Coniacian. A widespread regression occurs in the latest Cretaceous, marked by gypsiferous mudstones and massive evaporites containing only sparse dinoflagellate assemblages. The lower part of the Tertiary Kashi Group also exhibits gypsiferous sediments and sparse but distinctive dinoflagellate floras. A major transgression is recorded in the middle to upper Paleocene Qimugen Fm and another in the Upper Eocene Wulagen Fm, with diverse and abundant skolochorate dinocysts accompanying calcareous perforate foraminifera in grey and green mudstones, marls, and shelly limestones. The intervening regressive intervals are generally characterized by gypsiferous mudstones, massive gypsum, dolostones, reddish mudstones with calcareous perforate and sparse agglutinating foraminifera, and a few poorly preserved dinocysts, acritarchs, and terrestrial angiosperm pollen. The following new taxa are described: Alterbidinium emulatum Batiacasphaera hystrieosa Ceratiopsis speciosa subsp. elongata Canningia kukebaiensis Cerbia formosa Cleistosphaeridium radiculopsis Deflandrea intrasphaerula D. musculopsis Eurydinium tempestivum Florentinia laciniata subsp. propria Kisselovia fusiformis K. wulagenensis Millioudodinium (?) aequum M. (?) venulosum Palaeohystrichophora granulata Phelodinium anisos Pseudoalterbia concinna Sentusidinium stipulatum Talimudinium scissurum gen. et sp. nov. Trithyrodinium sabulum Wetzeliella crassa Xuidinium laevigatum gen. et sp. nov., and one new combination, Coronifera minor (Yu and Zhang).