The present work focuses on the upper Cretaceous (Cenomanian-early Campanian) carbonate successions in selected wells from northwestern Iraq. These are represented by Gir Bir Turonian), Wajna (late Santonian) and Mushorah (early Formations. succession has affected early burial near-surface, unconformity-related deep diagenesis cementation, neomorphism, dolomitization, dedolomitization, silicifi...

The Pennsylvanian Minturn Formation in north-central Colorado exhibits a complex stratigraphic architecture of fan-delta deposits that developed in association with high topographic relief in a tectonically active setting. The formation records a wide range of environments including alluvial fan, fluvial, deltaic, and open marine settings. This field trip will examine outcrops of a remarkable ~...

[1] In clay-rich sediment, microstructures and macrostructures influence how sediments deform when under stress. When lithology is fairly constant, anisotropy of magnetic susceptibility (AMS) can be a simple technique for measuring the relative consolidation state of sediment, which reflects the sediment burial history. AMS can reveal areas of high water content and apparent overconsolidation a...

Wanganui Basin, New Zealand, contains one of the most complete late Neogene marine stratigraphic records in the world. The ca. 2 km thick basin-fill for the last ca. 2.5 Ma comprises 47 superposed cyclothems which correspond to successive 5th (100 ka) and 6th (41 ka) order glacio-eustatic, sea-level fluctuations on the palaeo-New Zealand shelf since oxygen isotope stage 100. Stages 100 to 5 are...

Buchanan et al. (1) assert that the radiocarbon record from the United States and Canada does not support the extraterrestrial impact hypothesis, but their claims do not hold true for the California archaeological record. Fluted projectile points marking Paleoindian occupations have been reported from no fewer than 51 locations in California (2), and no fewer than 38 sites have produced radioca...

Lower Pliocene temperate carbonates exhibit landward-downlapping beds at the southern margin of the Carboneras Basin in south-eastern Spain. This rarely documented stratal geometry resulted from the accumulation of bedded bioclastic carbonate sand and gravel by longshore currents along a spit platform located a few hundred metres from the palaeoshoreline. The top of the spit platform was covere...

Sedimentologic, paleogeographic, stratigraphic, structural and tectonic studies in a paleo/mesoproterozoic metasedimentary succession (Espinhaço Megasequence, southeastern Brazil) indicates deposition in a rift-sag basin. Four basin evolution stages are recognized (prerift, rift, transitional and flexural). The four stages can be represented by six unconformity-bounded tectonosequences. The unc...

A method for in situ U–Pb isotopic analyses by secondary ion mass spectrometry (SIMS) has been developed for uranium minerals with a range of chemical compositions. This method combines the advantages of conventional U–Pb dating (i.e., use of concordia) and in situ analysis, and therefore is ideally suited for the study of chemically complex and fine-grained uranium oxides associated with urani...

A 22m long sediment core from Lake Yamozero on the Timan Ridge in northern Russia has provided evidence of intriguing climatic shifts during the last glacial cycle. An overall shallowing of the lake is reflected in the lower part of the cores, where pollen indicates a transition from glacial steppe vegetation to interstadial shrub-tundra. These beds are capped by a well-defined layer of compact...

Some writers, speakers, and students have problems with clear usage of stratigraphic terminology, a topic made more acute by the appearance of the complex 1983 North American Stratigraphic Code, its 2005 revision, and new editions of the International Stratigraphic Guide. The basic categories of stratigraphic units are: 1) material; 2) non-material; 3) hybrid. Examples are the well-known rock (...