Impact Theory of Mass Extinctions and the Invertebrate Fossil Record

  title={Impact Theory of Mass Extinctions and the Invertebrate Fossil Record},
  author={Walter Alvarez and Erle G. Kauffman and Finn Surlyk and Luis W. Alvarez and Frank. Asaro and Helen V. Michel},
  pages={1135 - 1141}
There is much evidence that the Cretaceous-Tertiary boundary was marked by a massive meteorite impact. Theoretical consideration of the consquences of such an impact predicts sharp extinctions in many groups of animals precisely at the boundary. Paleontological data clearly show gradual declines in diversity over the last 1 to 10 million years in various invertebrate groups.Reexamination of data from careful studies of the best sections shows that, in addition to undergoing the decline, four… 

A Geochemical Perspective on the Causes and Periodicity of Mass Extinctions

Evidence that extraordinary tectonism took place prior to and at the Cretaceous–Tertiary boundary (K–TB) is sufficient to account for the environmental changes that led to mass extinctions.

The End-Permian Mass Extinction

  • D. Erwin
  • Geography, Environmental Science
  • 1990
Teichert’s description of a gradual extinction at the close of the Permian reflects one view of our expanding knowledge of late Permian biostratigraphy and the end-Permian mass extinction. From this

Molluscan extinction patterns across the Cenomanian-Turonian Stage boundary in the western interior of the United States

  • W. Elder
  • Environmental Science
  • 1989
High-resolution stratigraphic analysis of 18 sections spanning the Cenomanian–Turonian Stage boundary in the western interior of the United States has allowed determination of the magnitude and

Aftermath of the Cretaceous-Tertiary extinction: Rate and nature of the early paleocene molluscan rebound

A preliminary analysis of the first 150.000 years of the Paleocene molluscan rebound interval in the Brazos River area, Texas reveals a rapid diversity increase comprised of a roughly equal blend of

Continental flood basalts drive Phanerozoic extinctions.

Refinements of the geological timescale driven by the increasing precision and accuracy of radiometric dating have revealed an apparent correlation between large igneous provinces (LIPs) and

Phanerozoic Overview of Mass Extinction

Mass extinctions are episodes of accelerated extinction of variable magnitude that affect widespread taxa and cause at least temporary declines in their diversity. Although such episodes are often

Extinction of late Eocene to Oligocene molluscs; relationship to shelf area, temperature changes, and impact events

  • T. Hansen
  • Environmental Science, Geography
  • 1987
The Eocene-Oligocene boundary is widely cited as the "other" example (besides the Cretaceous-Tertiary boundary) of a known relationship between mass extinctions and bolide impacts. The stratigraphic

Taxonomic selectivity and continuous variation in mass and background extinctions of marine taxa

  • Michael L. McKinney
  • Environmental Science, Geography
  • 1987
It is shown that except for the late Permian event, mass-extinction rates for each taxon were often not higher than many of their 'normal' background rates evincing continuous variation between them.



Terminal Cretaceous Events

  • T. Worsley
  • Geology, Environmental Science
  • 1971
SEVERAL explanations have been offered (see refs. 1–3) for the abrupt faunal extinctions at the end of the Cretaceous and, with the advent of the JOIDES Deep Sea Drilling Project, it was hoped that

Sudden death at the end of Mesozoic

End-Cretaceous Brachiopod Extinctions in the Chalk of Denmark

The results of a detailed study of the brachiopods of the most complete Cretaceous-Tertiary boundary in Denmark, Nye Kl∅v, show an extinction pattern for this marine invertebrate group compatible

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 as

The Cretaceous-Tertiary Transition

It seems more likely that an explanation for the changes during the Cretaceous-Tertiary transition will come from continued examination of the great variety of terrestrial events that took place at that time, including extensive volcanism, major regression of the sea from the land, geochemical changes, and paleoclimatic and paleoceanographic changes.

Extraterrestrial Cause for the Cretaceous-Tertiary Extinction

A hypothesis is suggested which accounts for the extinctions and the iridium observations, and the chemical composition of the boundary clay, which is thought to come from the stratospheric dust, is markedly different from that of clay mixed with the Cretaceous and Tertiary limestones, which are chemically similar to each other.

A Major Meteorite Impact on the Earth 65 Million Years Ago: Evidence from the Cretaceous-Tertiary Boundary Clay

The major extinction of life on the earth at the end of the Cretaceous Period may be related to the meteorite impact, as the enriched noble metals in the clay are present in cosmic proportions, indicating that the impacting celestial body had not undergone gross chemical differentiation.

Environmental Effects of an Impact-Generated Dust Cloud: Implications for the Cretaceous-Tertiary Extinctions

A model of the evolution and radiative effects of a debris cloud from a hypothesized impact event at the Cretaceous-Tertiary boundary suggests that the cloud could have reduced the amount of light at

Evidence for a Major Meteorite Impact on the Earth 34 Million Years Ago: Implication for Eocene Extinctions

A deep-sea core from the Caribbean contains a layer of sediment highly enriched in meteoritic iridium. This layer underlies a layer of North American microtektites dated at 34.4 million years ago and

Iridium Anomaly Approximately Synchronous with Terminal Eocene Extinctions

The iridium anomaly and the tektites and microtektites are supportive of a major bolide impact about 34 million years ago, and other workers have deduced that the microtekkites are part of the North American strewn tektite field, which is dated at about34 million years before present.