The hippuritid rudist bivalves from the Peters Hill Limestone, Jamaica, Barrettia coatesi (Chubb 1968) and Torreites tschoppi Mac Gillavry1937, are revised. B. is shown to be a primitive species of similar in development ruseae Chubb 1968 Clifton but more advanced that an undescribed sp. St Ann's Great River coral bed, Jamaica. T. likely represents youngest specimen this has been figured larger...

A magnetostratigraphy for ∼ 60 m of Koobi Fora Formation sediment in Area 104 was derived from 46 oriented samples that produced well-resolved characteristic magnetizations from progressive thermal demagnetization. Approximately 59 m below the Morte Tuff, previously dated to ∼ 1.51 Ma (millions of years ago), the Olduvai-Matuyama boundary (∼ 1.78 Ma) was found to be at the level of marker bed A...

Chronostratigraphic data available for the preliminary age model for the upper 700 m for the AND-1B drill core include diatom biostratigraphy, magnetostratigraphy, 40Ar/39Ar ages on volcanic material, 87Sr/86Sr ages on calcareous fossil material, and surfaces of erosion identifi ed from physical appearance and facies relationships recognised in the AND-1B drill core. The available age data allo...

Carbonate-rich sedimentary rocks of the western Anabar region, northern Siberia, preserve an exceptional record of evolutionary and biogeochemical events near the Proterozoic/Cambrian boundary. Sedimentologically, the boundary succession can be divided into three sequences representing successive episodes of late transgressive to early highstand deposition; four parasequences are recognized in ...

Abstract In its subsurface, the Browse Basin on Australian Northwest Shelf accommodates one of largest Miocene–Pliocene carbonate platform provinces Earth. This study presents a comprehensive three-dimensional (3-D) documentation and investigation Neogene carbonates based analysis 15 3-D seismic reflection volumes covering ca. 33,000 km2 22 industry boreholes. Eight basin-wide marker horizons t...

Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses about its age span the entire Holocene epoch and previous attempts at direct radiocarbon dating ha...