The Campanian-Maastrichtian rudist bivalves succession in the Chiapas Central Depression, Mexico

摘要: Abstract The restudy of the Late Cretaceous rudist fauna Chiapas Central Depression, considered Campanian-Maastrichtian with no more precisions in literature, reveals that, fact, three successive assemblages occur: (1) a lower one, early and middle Campanian, uppermost part Sierra Madre Formation (distinguished as Suchiapa Formation); (2) Maastrichtian, upper Ocozocoautla Formation; (3) an late several horizons within Angostura Formation. Published data on planktic benthic foraminifers inoceramid bivalves, well new findings ammonites, helped bracketing age assemblages. Their stratigraphic position fits depositional model assuming basal carbonate platform fragmented into blocks each following different tecto-sedimentary evolution: drowned block constituting Tuxtla Gutierrez Basin, deepening towards neighbor raised receiving terrigenous material from emerged de Chiapas, after long hiatus, was filled up and, subsequently, marginal shallow platform, surrounded by detritic belt prograding basin, installed top; high where, insular installed.