Cretaceous Planktonic Foraminifers and Depositional Environments from the Ontong Java Plateau with Emphasis on Sites 803 and 807

Abstract

Cretaceous planktonic foraminifers from Ocean Drilling Program (ODP) Leg 130 consist of two age groups: one dominantly Aptian in age and the other dominantly Maastrichtian. The oldest dated sediments from Ontong Java Plateau occur at ODP Site 807 and are assigned to the early Aptian Globigerinelloides blowi Zone. The assemblage correlates closely with Aptian foraminifers from Deep Sea Drilling Project (DSDP) Site 289 and a younger Aptian assemblage from DSDP Site 288 where drilling ended before reaching basement. Planktonic foraminifers from ODP Site 803 suggest a late Aptian to early Albian age and are overlain by radiolarians of late Albian age. These ages are in conflict with a radiometric age of about 90 Ma for basement at the site. The dominantly Maastrichtian group occurs at Site 807 and consists of poorly preserved, mostly small-sized specimens that range in age from perhaps the latest Campanian to the Cretaceous/Tertiary boundary. Age assignments are made difficult by pervasive dissolution and resedimentation that extends into the Paleogene.Deposition of the Aptian limestone at Site 807 took place at lower bathyal depths beneath the foraminiferal lysocline but above the calcite compensation depth (CCD). Deposition then continued beneath the CCD until the late Campanian or Maastrichtian when carbonate sedimentation resumed. Within the Maastrichtian, deposition again took place at lower bathyal depths at or above the rapidly dropping CCD until the Cretaceous/Tertiary boundary when the CCD apparently rose. Small planktonic foraminifers accumulated in winnowed and redeposited fine-grained sediments whereas larger planktonic foraminifers were deposited largely in mass-flow deposits that increase in number upsection through the Maastrichtian. The increased pulses of larger planktonic foraminifers followed by the abrupt occurrence of laminated sediments, an abundance of small, globular planktonic foraminifers, and an increase in radiolarians in the latest Maastrichtian likely were the result of northward plate motion into more productive waters and different current systems. At Site 803, deposition beneath the CCD continued from the earliest sediments above the basalt until the Eocene. Carbonate sedimentation during the late Albian to early Santonian, however, is recorded atop the plateau at Site 288.The extensive hiatuses in the Cretaceous sequence from the Ontong Java Plateau correlate in part with times of widespread hiatuses in the Pacific Basin. Evidence of pervasive mechanical erosion during the Cenomanian to Santonian and the Campanian to Maastrichtian on the top of the plateau perhaps were caused by the longitudinal position of the plateau relative to western boundary currents and eddy effects above the plateau.

Impact origin for the greater Ontong Java Plateau?

“…(a) Model-predicted paleodepths of preexisting oceanic crust (SS92) [35] at time of OJP formation at V120 Ma [2,3], range of uplift of oceanic crust predicted by speci¢c OJP dynamic (Uplift-Max) [15] and isostatic (Uplift-Min) [17] plume models. For individual DSDP and ODP sites, we compare model-predicted paleodepth ranges for the top of OJP crust (open symbols with bars) to paleodepth ranges of Aptian sediment directly overlying OJP basalts interpreted from paleoenvironmental data (¢lled symbols with bars) [13,39,40], with elevation of ¢nal £ood basalt emplacement at V120 Ma predicted by either water-corrected isostasy (for calculations below sea level) ( . Crustal thickness values from [5], and ages of preexisting crust estimated from extrapolating Mesozoic marine magnetic anomalies in the Nauru Basin ( Fig.…”

“…For the OJP, the error bars represent the mass £ux range assuming an emplacement rate from 1^5 Myr. (c) Total subsidence vs. age for OJP basalts (error bars on symbols denote range interpreted from [39,40,87]). Subsidence curves are from: BL and PS77 [34], and SS92 [35].…”

“…Predicted total subsidence of V120 Ma oceanic crust ranges from V3000 to V3800 m [34,35]. Paleoenvironments interpreted from sediment immediately overlying basalt at ¢ve out of six OJP drill sites [13,39,40] and basalt eruption depths calculated from H 2 O and CO 2 concentrations in basaltic glasses [41] show that OJP crust, when reconstructed to account for sediment loading, subsided only 1000^2800 m, signi¢cantly less than either typical oceanic lithosphere [34,35] or other oceanic plateaus and submarine ridges [37,38,42] (Fig. 2c).…”

Biozonation and Paleobathymetry on Foraminifera Upper Cretaceous Deposites of Central Iran Basins (Isfahan, Baharestan Section)

“…Since beaches have unstable situation and benthic foraminifera which have more strength and can bear the situation are seen in these areas (Sliter and Leckie, 1993) [13], (Li and Stinnesbeck, 1999) [14].…”

Maastrichtian-Thanetian planktonic foraminiferal biostratigraphy and remarks on the K-Pg boundary in the southern Kocaeli Peninsula (NW Turkey)

“…On the other hand, identification of planktonic foraminifera in thin section is a longestablished and widely used method for dating of the Upper Cretaceous and Palaeocene marine sequences. Although axial sections of the Upper Cretaceous and Palaeogene planktonic foraminifera were well illustrated together with photographs of isolated specimens by classical work of Postuma (1971), biostratigraphic subdivisions based on thin section analysis have been subjected to relatively few studies, including those of Sliter (1989Sliter ( , 1999, Sliter and Leckie (1993), Premoli Silva and Sliter (1995), and Robaszynski et al (2000) for the Upper Cretaceous and van Konijnenburg et al (1998) for the Palaeogene. These pioneering works are commonly followed by various researchers to establish biostratigraphic zonation in some Upper Cretaceous and Palaeocene sections in Turkey and Northern Cyprus (e.g., Özkan-Altıner and Özcan, 1999;Sarı and Özer, 2002;Sarı, 2006Sarı, , 2009Sarı, , 2013Hakyemez and Özkan-Altıner, 2010).…”