Ostracoda and foraminifera from Paleocene (Olinda well), Paraíba Basin, Brazilian Northeast

ABSTRACT Paleocene ostracods and planktonic foraminifera from the Maria Farinha Formation, Paraíba Basin, are herein presented. Eleven ostracod species were identified in the genera Cytherella Jones, Cytherelloidea Alexander, Eocytheropteron Alexander, Semicytherura Wagner, Paracosta Siddiqui, Buntonia Howe, Soudanella Apostolescu, Leguminocythereis Howe and, probably, Pataviella Liebau. The planktonic foraminifera are represented by the genera Guembelitria Cushman, Parvularugoglobigerina Hofker, Woodringina Loeblich and Tappan, Heterohelix Ehrenberg, Zeauvigerina Finlay, Muricohedbergella Huber and Leckie, and Praemurica Olsson, Hemleben, Berggren and Liu. The ostracods and foraminifera analyzed indicate an inner shelf paleoenvironment for the studied section. Blooms of Guembelitria spp., which indicate either shallow environments or upwelling zones, were also recorded reinforcing previous paleoenvironmental interpretations based on other fossil groups for this basin.

【摘要】本文报道了产自帕拉伊巴盆地玛丽亚·法林哈组的古新世介形类与浮游有孔虫化石。本次研究共鉴定出11个介形类物种，分属圆星介属(Cytherella Jones)、似星介属(Cytherelloidea Alexander)、始翼星介属(Eocytheropteron Alexander)、半密星介属(Semicytherura Wagner)、副肋介属(Paracosta Siddiqui)、本顿介属(Buntonia Howe)、苏丹介属(Soudanella Apostolescu)、豆星介属(Leguminocythereis Howe)，以及疑似隶属于帕塔维介属(Pataviella Liebau)的类群。本次研究发现的浮游有孔虫分属以下7个属：盖姆贝利特虫属(Guembelitria Cushman)、微皱球虫属(Parvularugoglobigerina Hofker)、伍林虫属(Woodringina Loeblich and Tappan)、异卷虫属(Heterohelix Ehrenberg)、泽维虫属(Zeauvigerina Finlay)、穆里科赫伯格虫属(Muricohedbergella Huber and Leckie)以及前穆里虫属(Praemurica Olsson, Hemleben, Berggren and Liu)。经分析的介形类与有孔虫化石表明，本次研究的层段形成于内陆架古环境。本次研究还记录了盖姆贝利特虫属(Guembelitria spp.)的化石繁盛现象，该现象可指示浅水环境或上升流区，进一步佐证了此前基于该盆地其他化石类群得出的古环境解释。