A combined biostratigraphic study of dinoflagellate cysts and foraminifera was carried out on Early Cretaceous subsurface well cutting sediments from well A (DNG) (2800–2746 m depth) from the Krishna-Godavari Basin, India. The last appearance datum of marker species of dinoflagellate cysts and planktonic foraminifera was considered for the construction of the biostratigraphic framework. The study shows dominance of Early Cretaceous marker dinoflagellate cysts Cassiculosphaeridia magna, Cribroperidinium perforans, Hystrichodinium voigtii, Kleithriasphaeridium eoinodes , and planktonic foraminifera Hedbergella aptiana, Hedbergella mitra, Hedbergella praelippa, Hedbergella tardita, Microhedbergella miniglobularis and Hedbergella mitra species. In addition to this, the dinoflagellate cyst data were compared with the dinoflagellate biozones of Austral and Tethyan provinces. Based on earlier micropalaeontological records from the Krishna-Godavari Basin and the present study, a latest Barremian-early Aptian age has been determined for the earliest marine transgression in the Krishna-Godavari Basin. The early marine incursion during late Barremian-earliest Aptian in the Krishna-Godavari Basin compared to Albian age in Cauvery Basin suggests the opening of east coast from north to south.

中文翻译：

---

印度 Krishna-Godavari 盆地最早海侵事件的年龄：来自甲藻囊肿和浮游有孔虫生物地层学的证据

对来自印度 Krishna-Godavari 盆地的 A 井 (DNG)（深度 2800-2746 m）的早白垩世地下井切割沉积物进行了甲藻囊肿和有孔虫的组合生物地层研究。生物地层框架的构建考虑了甲藻包囊和浮游有孔虫标记物种的最后一次出现数据。该研究表明，早白垩世标记甲藻囊肿 Cassiculosphaeridia magna、Cribroperidinium perforans、Hystrichodinium v​​oigtii、Kleithriasphaeridium eoinodes 和浮游有孔虫 Hedbergella aptiana、Hedbergella mitra、Hedbergella minipra、Hedbergella minis 和 Hedbergella minis 占优势。除此之外，将甲藻囊肿数据与澳大利亚和特提斯省的甲藻生物区进行了比较。根据 Krishna-Godavari 盆地早期的微古生物学记录和本研究，已确定 Krishna-Godavari 盆地最早海侵的最新巴雷米阶-早 Aptian 年龄。与 Cauvery 盆地的 Albian 时代相比，Krishna-Godavari 盆地的晚 Barremian-最早的 Aptian 期间的早期海洋入侵表明东海岸从北向南开放。