The brackish-water bivalve Waagenoperna Tokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features ...The brackish-water bivalve Waagenoperna Tokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology of Waagenoperna therefore yields information on the palaeoenvironment of the area. The restriction of Waagenoperna to marine and brackish-water settings suggests that the sea water once reached these areas during the Sinemurian. This paper discusses the palaeogeographic implications and suggests an ingression of the sea water from the west to the western and southern part of the Junggar Basin. Additionally, the two Waagenoperna species collected from the Haojiagou section in the Junggar Basin are taxonomically documented.展开更多
The Lower Cretaceous mixed siliciclastic-carbonate successions of the Boulouha Formation at the type locality in the Dahar escarpment of southern Tunisia have yielded a new discovered assemblage of bivalves which cont...The Lower Cretaceous mixed siliciclastic-carbonate successions of the Boulouha Formation at the type locality in the Dahar escarpment of southern Tunisia have yielded a new discovered assemblage of bivalves which contains Anomia laevigata (Sowerby);Modiolus sp. cf. M. dahuashuensis (Yu et Li);Astarte sp.;and ?Mytilus sp.. The temporal distribution of the Anomia laevigata (Sowerby) and Modiolus sp. cf. M. dahuashuensis (Yu et Li) is limited to the Aptian formations of northeastern China, Japan and Korea, thus we suggest a Hauterivian-Barremian age for the Boulouha Formation. Henceforth, the new biostratigraphic data are used to improve a regional chronostratigraphic correlation between the lower Cretaceous strata of the Saharan Platform domain and those coeval from the Chotts domain.展开更多
基金supported by the Bureau of Geological Survey of China(1212011120116)the National Natural Science Foundation of China(40632010,41102005,91114201,and J0930006)the National Basic Research Program of China (2012CB821906)
文摘The brackish-water bivalve Waagenoperna Tokuyama, 1959 is reported from the Lower Jurassic Badaowan Formation at four localities, along the southern margin and western margin of the Junggar Basin. Taphonomic features recorded in the field indicate that it occurs in autochthonous or parautochthonous assemblages. The autecology of Waagenoperna therefore yields information on the palaeoenvironment of the area. The restriction of Waagenoperna to marine and brackish-water settings suggests that the sea water once reached these areas during the Sinemurian. This paper discusses the palaeogeographic implications and suggests an ingression of the sea water from the west to the western and southern part of the Junggar Basin. Additionally, the two Waagenoperna species collected from the Haojiagou section in the Junggar Basin are taxonomically documented.
文摘The Lower Cretaceous mixed siliciclastic-carbonate successions of the Boulouha Formation at the type locality in the Dahar escarpment of southern Tunisia have yielded a new discovered assemblage of bivalves which contains Anomia laevigata (Sowerby);Modiolus sp. cf. M. dahuashuensis (Yu et Li);Astarte sp.;and ?Mytilus sp.. The temporal distribution of the Anomia laevigata (Sowerby) and Modiolus sp. cf. M. dahuashuensis (Yu et Li) is limited to the Aptian formations of northeastern China, Japan and Korea, thus we suggest a Hauterivian-Barremian age for the Boulouha Formation. Henceforth, the new biostratigraphic data are used to improve a regional chronostratigraphic correlation between the lower Cretaceous strata of the Saharan Platform domain and those coeval from the Chotts domain.
