排序方式： 共有3条查询结果，搜索用时 62 毫秒
1
1.
Kmar Ben İsmail-Lattrache Kamel Boukhalfa Pratul Kumar Saraswati Mohamed Soussi Luigi Jovane 《Geodinamica Acta》2013,26(1-2):94-121
The orthophragminids in lower Bartonian Reineche Limestone member, a fossiliferous shallow-marine unit exposed in Cap Bon peninsula in Tunisia, are represented by 17 species assigned to Discocyclinidae Galloway 1928 and Orbitoclypeidae Brönnimann 1946. These taxa, associated with nummulitids and alveolinids, belong to the lineages of Discocyclina Gümbel 1870, Nemkovella, 1987, Orbitoclypeus Silvestri 1907, and Asterocyclina Gümbel 1870, described for the first time from north Africa lying at the southern margin of Tethyan ocean during Paleogene. We identified Nemkovella evae, previously not recorded in upper Lutetian/lower Bartonian and younger Eocene deposits of northern Tethyan platforms, and erected a new subspecies, N. evae reinechensis n. ssp. A comparison of Reineche orthophraminids, assigned to orthophragmines zone (OZ) 12 and shallow benthic zone (SBZ 17), to the well-described coeval assemblages at northern Tethyan platforms in Italy, Hungary, Turkey, and to those in Kutch Basin in the Indian subcontinent suggests that some species are confined to certain paleogeographic domains. Orbitoclypeus haynesi, the only orbitoclypeid and the most abundant orthophragminid in lower Bartonian deposits in Kutch, appears to be the most common orbitoclypeid in Reineche Limestone. In Europe, this species is not known and is replaced by Orbitoclypeus varians, the most common orbitoclypeid in middle Eocene of central Europe. Both species occur in varying proportions in marine successions in Turkey. Asterocyclina sireli, identified so far only in Turkey, occurs in Reineche Limestone and in lower Bartonian deposits in Kutch. This species is recorded for the first time in the Indian subcontinent. Relying on present study, as well as our recent studies in Kutch Basin, we conclude that the generic and specific diversity of orthophragminids decreases eastward from the peri-Mediterranean region to Indian subcontinent and to the western Pacific. 相似文献
2.
Nowrad Ali Ali Osman Yücel Muhammad Hanif Syed Irfanullah Hashmi Farhat Ullah 《Geodinamica Acta》2018,30(1):31-62
The Pirkoh and Drazinda formations in the Sulaiman Range, central Pakistan, yielded assemblages of (early) Bartonian orthophragminids, characterized predominantly by discocyclinids with a significant number of species probably endemic to Indian Subcontinent. The rarity of Asterocyclina and the absence of Orbitoclypeus and Nemkovella are noteworthy. Ten species of Discocyclina Gümbel and two species of Asterocyclina Gümbel, referable to the Shallow Benthics Zone (SBZ) 17 are described for the first time from Pakistan. The discocyclinids, i.e. Discocyclina praeomphalus, D. sulaimanensis, D. kutchensis, along with the new taxa established here, D. zindapirensis sp. nov., D. rakhinalaensis sp. nov., and D. pseudodispansa sp. nov., seem to be confined to the Indo-Pakistani region (Eastern Tethys). The Discocyclina dispansa, D. discus, D. nandori, and D. augustae lineages known from Western Tethys are also common in the Indian Subcontinent, as are asterocyclinids, such as Asterocyclina sireli and A. stellata. The upper part of the Drazinda Formation (‘Pellatispira beds’), referable to latest Bartonian and/or the early Priabonian, is poor in orthophragminids and is characterized by the occurrence of reticulate Nummulites, Heterostegina, Pellatispira and Silvestriella. The records of ‘Lepidocyclina of Caribbean affinity’ with large embryons from the Eocene of the Indian Subcontinent correspond to misidentified Discocyclina discus. 相似文献
3.
Ercan Özcan İftikhar Ahmed Abbasi Katica Drobne Abiraman Govindan Luigi Jovane Kamel Boukhalfa 《Geodinamica Acta》2016,28(3):160-184
The upper member of the Jafnayn Formation in Wadi Rusayl and Al Khoud, Seeb Area in north Oman contains Nemkovella stockari Less & Özcan, 2007, an Early Eocene orthophragminid recorded here for the first time from the Arabian Peninsula. N. stockari, the only orthophragminid identified in Jafnayn Formation, is quite distinct from any other species from Tethys in having spiral and orbitoidiform chambers around the isolepidine embryon developed before the onset of annular chambers. The Oman specimens exhibit equal-sized principal auxiliary chambers and symmetrical spirals and are assigned to N. stockari bejaensis Özcan, Boukhalfa & Scheibner, 2014, an advanced form of the N. stockari lineage. The associated alveolinids, revised in this study, rotaliids and other age-diagnostic foraminiferal taxa in the transgressive basal part of the upper member have enabled us to revise the age as middle Ilerdian (Early Eocene), assignable to SBZ 7/8 and 8; OZ 3/4. Integrating a new record of this species from Arabian Plate margin in Belen, S Turkey, and previous records from north Africa, N. stockari appears to be a diagnostic marker for the Early Eocene along the southern peri-Tethys platforms, facilitating the Tethyan correlation by orthophragminids. The palaeobiogeographic distribution of N. stockari is discussed. 相似文献
1