Macrofaunal Paleocommunities and Microfacies Analysis from the Upper Cretaceous in North Eastern Desert of Egypt  

作　　者：Saeed FAREED Yasser SALAMA Abdelaziz MAHMOUD 

机构地区：[1]Helwan University,Faculty of Sciences,Geology Department,Helwan,Cairo 11,Egypt [2]Beni-Suef University,Faculty of Sciences,Geology Department,Beni Suef 62511,Egypt

出　　处：《Acta Geologica Sinica(English Edition)》2025年第1期15-37,共23页地质学报(英文版)

摘　　要：The Upper Cretaceous successions of Wadi Umm-Khayshar,southern Galala Plateau,North Eastern Desert,Egypt,are composed of highly diversified faunas and subdivided from base to top into the Galala(Middle-Late Cenomanian),Maghra El Hadida(Latest Cenomanian-Late Turonian),Matulla(Coniacian-Santonian),and Sudr(Campanian-Maastrichtian)formations.Five ammonite biozones are recorded in the studied section:Neolobites vibrayeanus,Vascoceras cauvini(late Cenomanian),Vascoceras proprium,Choffaticeras segne,and Coilopoceras requienianum(Turonian)zones.The paleoenvironments of the Upper Cretaceous succession are interpreted based on detailed study and microfacies analysis that reflect a deposition in a homoclinal ramp platform ranging from intertidal to deep subtidal.The paleoecology of the Cenomanian-Turonian succession in the studied section is explained based on a detailed study of macrofaunal associations and sedimentary facies.Quantitative analysis(Q-mode cluster analysis,using the Raup-Crick Paired group method)of 1029 macrobenthic specimens,including 45 species of mollusks and echinoids yielded five macrofaunal associations(A-E)that are described and interpreted as remnants of communities.The nektonic elements are represented by 235 cephalopod specimens of 20 species;heatmap cluster analyses show the distribution of these specimens during the Upper Cenomanian-Turonian stages.Environmental parameters(substrate consistency,rate of sedimentation,water energy,surface-water productivity,and oxygen availability)controlled the distribution of the studied macrofauna.The five associations are divided into two major groups:low-stress associations(A,B,C,and D),and a highstress association(E).The low stress associations are recorded from two different habitats:(1)a high-energy,firm substrate habitat,dominated by epifaunal bivalves,large epifaunal gastropods and a regular echinoid;(2)a low-energy,soft substrate habitat dominated by infaunal bivalves and echinoids.The high stress association is dominated by only two species and recor

关 键 词：invertebrate paleontology AMMONITES Upper Cretaceous MICROFACIES Southern Galala NE Egypt 

分 类 号：Q915[天文地球—古生物学与地层学] P534.53[生物学—古生物学]