An extraterrestrial event at the Cretaceous–Tertiary boundary

  title={An extraterrestrial event at the Cretaceous–Tertiary boundary},
  author={Jan Smit and Jan Gh Hertogen},
Closely spaced samples from an uninterrupted calcareous pelagic sequence across the Cretaceous–Tertiary boundary reveal that the extinction of planktonic Foraminifera and nannofossils was abrupt without any previous warning in the sedimentary record, and that the moment of extinction was coupled with anomalous trace element enrichments, especially of iridium and osmium. The rarity of these two elements in the crust of the Earth indicates that an extraterrestrial source, such as the impact of a… Expand
A unique geochemical record at the Permian/Triassic boundary
A 330-metre core drilled through the marine Permian/Triassic boundary in the Carnic Alps of Austria allows closely correlated studies of geochemistry, petrography and palaeontology across theExpand
Siderophile-enriched sediments from the Cretaceous–Tertiary boundary
Siderophilic element concentrations are high in sediments from the Cretaceous–Tertiary boundary. An extraterrestrial source is indicated. Concentrations are too high to be understood in terms of theExpand
An Iridium Abundance Anomaly at the Palynological Cretaceous-Tertiary Boundary in Northern New Mexico
An iridium abundance anomaly, with concentrations up to 5000 parts per trillion over a background level of 4 to 20 parts per trillion, has been located in sedimentary rocks laid down under freshwaterExpand
Sanidine spherules at the Cretaceous–Tertiary boundary indicate a large impact event
The hypothesis that a catastrophic impact of an extraterrestrial body caused the terminal Cretaceous mass extinctions of dinosaurs, planktonic foraminfera and other species is now accepted asExpand
Oceanic anoxia at the Cretaceous/Tertiary boundary supported by the sulfur isotopic record
Abstract A temporary and drastic increase in 34S/32S ratio of whole rock sulfide has been recognized just at the Cretaceous/Tertiary boundary within the continuous marine sedimentary sequence of theExpand
Trace element patterns at a non-marine Cretaceous–Tertiary boundary
At the fossil-pollen-defined Cretaceous–Tertiary boundary in the Raton Basin of New Mexico and Colorado, an iridium abundance anomaly and excess scandium, titanium, and chromium are associated with aExpand
High noble metal concentrations in a late Pliocene sediment
A 2.3-Myr-old layer in a sediment from the Antarctic Ocean contains Ir and Au at levels comparable with those at the Cretaceous–Tertiary boundary. A sizable fraction of the noble metals is containedExpand
Records of post Cretaceous-Tertiary boundary millennial-scale cooling from the western Tethys: A smoking gun for the impact-winter hypothesis?
The record of both dinoflagellate cysts and benthic foraminifera across the Cretaceous-Tertiary boundary at El Kef, Tunisia, reveals a brief expansion of the Boreal bioprovince into the westernExpand
Sudden death at the end of Mesozoic
Abstract A paleoecological analysis of the fossil record before and after the Cretaceous/Tertiary boundary indicates that the widespread extinctions and biological stresses around the boundary areExpand
Isotopic evidence for the Cretaceous-Tertiary impactor and its type.
High-precision mass spectrometric analysis of chromium in sediment samples from the Cretaceous-Tertiary (K-T) boundary coincident with the extinction of numerous organisms on Earth confirms theExpand


Magnetostratigraphy, biostratigraphy and geochronology of Cretaceous–Tertiary boundary sediments, Red Deer Valley
Integrated magnetostratigraphic and biostratigraphic data for continental Cretaceous–Tertiary boundary sediments in Alberta allow a correlation with recognised sea floor magnetic anomalies 29 and 30.Expand
The terminal Cretaceous event: A geologic problem with an oceanographic solution
The Danian coccolithosphores and planktonic foraminifers probably developed in an isolated and brackish Arctic Ocean during Late Cretaceous time, and when the Greenland Sea–Norwegian Sea passageExpand
Magnetostratigraphy of the Cretaceous–Tertiary boundary in the San Juan Basin, New Mexico
Magnetostratigraphy of a terrestrial sedimentary sequence in the San Juan Basin reveals that the Cretaceous–Tertiary boundary, recognised by the highest stratigraphic occurrence of dinosaurs, isExpand
Upper Cretaceous–Paleocene magnetic stratigraphy at Gubbio, Italy I. Lithostratigraphy and sedimentology
An essentially complete section of middle Cretaceous to Paleocene, calcareous, pelagic sediments is exposed at Gubbio, in the Umbrian Apennines of Italy. This, the first of five papers, presents theExpand
Evidence for Global Synchronism in Mantle Plume Convection, and Possible Significance for Geology
Volume estimates and age dating of basic, non-orogenic igneous deposits suggest synchronous discharge from many hot spots, identified as mantle plumes. The discharge fluctuations seem to mirror theExpand
Sources for gold, palladium and iridium in deep-sea sediments
Abstract Deep-sea sediment cores, one from the Caribbean (calcareous ooze) and three from the Pacific-Antarctic basin (Globigerina ooze, siliceous ooze and pelagic clay) were analysed for Au, Pd, IrExpand
Injection events in ocean history
The reconnection, with the world ocean, of temporarily isolated ocean basins results in injection either of hyper-saline waters favouring abyssal stratification and stagnation, or of brackish WatersExpand
A Terminal Mesozoic "Greenhouse": Lessons from the Past
In late Mesozoic, the deep oceanic waters may have been triggered into releasing vast amounts of carbon dioxide into the atmosphere in a chain reaction of climatic warming and carbon dioxide expulsion, which may be duplicated by human combustion of the fossil fuels and by forest clearing. Expand
The Enigma of the Extinction of the Dinosaurs
One of the more interesting contributions of paleontology to general knowledge is evidence that giant reptiles were once the dominant life forms on our planet. During the past two centuries some 5000Expand
Primary production, isotopes, extinctions and the atmosphere
Abstract Phytoplankton photosynthesis has controlled the atmospheric carbon dioxide-oxygen balance since the early Precambrian when algal abundance became sufficient to convert the reducingExpand