Extraterrestrial Cause for the Cretaceous-Tertiary Extinction

1980/06/06 by Luis W. Alvarez, Walter Álvarez, Frank Asaro +1 · 4,029 citations
Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · Physics and Astronomy · #Abundance (ecology) #Asteroid #Astro and Planetary Science #Astrobiology #Biological dispersal #Chondrite #Cretaceous #Earth science #Ecology #Extinction (optical mineralogy) #Extinction event #Extraterrestrial life #Geochemistry and Elemental Analysis #Geology #Geomagnetism and Paleomagnetism Studies #Meteorite #Paleontology #Physics #Range (aeronautics) #Volcano

paper · doi:10.1126/science.208.4448.1095

published in Science 208(4448), 1095-1108 (American Association for the Advancement of Science)

openalex publication_date 1980/06/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01

Abstract

Platinum metals are depleted in the earth's crust relative to their cosmic abundance; concentrations of these elements in deep-sea sediments may thus indicate influxes of extraterrestrial material. Deep-sea limestones exposed in Italy, Denmark, and New Zealand show iridium increases of about 30, 160, and 20 times, respectively, above the background level at precisely the time of the Cretaceous-Tertiary extinctions, 65 million years ago. Reasons are given to indicate that this iridium is of extraterrestrial origin, but did not come from a nearby supernova. A hypothesis is suggested which accounts for the extinctions and the iridium observations. Impact of a large earth-crossing asteroid would inject about 60 times the object's mass into the atmosphere as pulverized rock; a fraction of this dust would stay in the stratosphere for several years and be distributed worldwide. The resulting darkness would suppress photosynthesis, and the expected biological consequences match quite closely the extinctions observed in the paleontological record. One prediction of this hypothesis has been verified: 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. Four different independent estimates of the diameter of the asteroid give values that lie in the range 10 +/- 4 kilometers.

Citations

• Gold, palladium and iridium in marine sediments
• Geochemistry
• Accretion rate of cosmic matter from iridium and osmium contents of deep-sea sediments
• Primary production, isotopes, extinctions and the atmosphere

Cited by

• Oceanic minerals: Their origin, nature of their environment, and significance
• The Earth expansion theory and its transition from scientific hypothesis to pseudoscientific belief
• Ammonites on the Brink of Extinction: Diversity, Abundance, and Ecology of the Order Ammonoidea at the Cretaceous/Paleogene (K/Pg) Boundary
• An Archean Impact Layer from the Pilbara and Kaapvaal Cratons
• Iridium‐bearing sublimates at a hot‐spot volcano (Piton De La Fournaise, Indian Ocean)
• High noble metal concentrations in a late Pliocene sediment
• Volatile fluxes during flood basalt eruptions and potential effects on the global environment: A Deccan perspective
• K‐Pg extinction: Reevaluation of the heat‐fire hypothesis
• Generation and propagation of a tsunami from the Cretaceous-Tertiary impact event
• Reflections on the tropical deforestation crisis
• Shocked Quartz in the Cretaceous-Tertiary Boundary Clays: Evidence for a Global Distribution
• Multiple factors in the origin of the Cretaceous/Tertiary boundary: the role of environmental stress and Deccan Trap volcanism
• Deccan traps mantle degassing in the terminal Cretaceous marine extinctions
• Global climate change driven by soot at the K-Pg boundary as the cause of the mass extinction
• Production of sulphate-rich vapour during the Chicxulub impact and implications for ocean acidification
• The Chicxulub impact event and its environmental consequences at the Cretaceous–Tertiary boundary
• Energy, volatile production, and climatic effects of the Chicxulub Cretaceous/Tertiary impact
• The extinction of the dinosaurs
• Evidence suggesting gradual extinction of latest cretaceous Dinosaurs
• The eruptive tempo of Deccan volcanism in relation to the Cretaceous-Paleogene boundary
• Numerical Modeling of the Largest Terrestrial Meteorite Craters
• Assessing the record and causes of Late Triassic extinctions
• Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction
• Mass extinction of lizards and snakes at the Cretaceous–Paleogene boundary
• Organic matter from the Chicxulub crater exacerbated the K–Pg impact winter
• Biological Extinction in Earth History
• The age of the Kaali meteorite craters and the effect of the impact on the environment and man: evidence from inside the Kaali craters, island of Saaremaa, Estonia
• The role of extinction in evolution.
• Understanding the Complexity of Economic, Ecological, and Social Systems
• Periodicity of extinctions in the geologic past.
• Large igneous provinces and mass extinctions
• How Large Igneous Provinces affect global climate, sometimes cause mass extinctions, and represent natural markers in the geological record
• Phanerozoic Overview of Mass Extinction
• End-Cretaceous extinction in Antarctica linked to both Deccan volcanism and meteorite impact via climate change
• Press-pulse: a general theory of mass extinction?
• Sudden and Gradual Molluscan Extinctions in the Latest Cretaceous of Western European Tethys
• End-Permian impactogenic earthquake and tsunami deposits in the intracratonic Paraná Basin of Brazil
• Mass extinctions of life and catastrophic flood basalt volcanism
• Analyses of shocked quartz at the global K-P boundary indicate an origin from a single, high-angle, oblique impact at Chicxulub
• PHANEROZOIC BIODIVERSITY MASS EXTINCTIONS
• The evidence for and against astronomical impacts on climate change and mass extinctions: a review
• Mass extinctions over the last 500 myr: an astronomical cause?
• An Extraterrestrial Impact at the Permian-Triassic Boundary?
• Rapid eruption of Siberian flood-volcanic rocks and evidence for coincidence with the Permian–Triassic boundary and mass extinction at 251 Ma
• Knowledge gaps and missing links in understanding mass extinctions: Can mathematical modeling help?
• Impact Theory of Mass Extinctions and the Invertebrate Fossil Record
• The terrestrial impact cratering record
• Impact Event at the Permian-Triassic Boundary: Evidence from Extraterrestrial Noble Gases in Fullerenes
• Rarity in mass extinctions and the future of ecosystems
• Revising the age for the Baptistina asteroid family using WISE/NEOWISE data
• The role of the Mediterranean region in the development of sedimentary geology: a historical overview
• Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling
• Mass extinctions past and present: a unifying hypothesis
• Resolving the age of the Puchezh-Katunki impact structure (Russia) against alteration and inherited 40Ar* – No link with extinctions
• Volcanic origin for Younger Dryas geochemical anomalies ca. 12,900 cal B.P.
• Geochemical evidence for volcanic signatures in sediments of the Younger Dryas event
• Mass Survival of Birds Across the Cretaceous- Tertiary Boundary: Molecular Evidence
• Small near-Earth asteroids in the Palomar Transient Factory survey: A real-time streak-detection system
• Impacts on the Earth by asteroids and comets: assessing the hazard
• Evolution of the atmosphere
• NEOWISE OBSERVATIONS OF NEAR-EARTH OBJECTS: PRELIMINARY RESULTS
• The hazard of near-Earth asteroid impacts on earth
• Earth Impact Effects Program: A Web-based computer program for calculating the regional environmental consequences of a meteoroid impact on Earth
• The stratigraphy of mass extinction
• Constraints on the thermal energy released from the Chicxulub impactor: new evidence from multi-method charcoal analysis
• Nuclear Winter: Global Consequences of Multiple Nuclear Explosions
• Does extinction wield an axe or pruning shears? How interactions between phylogeny and ecology affect patterns of extinction
• The Politics of Atmospheric Sciences: “Nuclear Winter” and Global Climate Change
• Accelerated diversifications in three diverse families of morphologically complex lichen-forming fungi link to major historical events
• The Global Boundary Stratotype Section and Point for the base of the Danian Stage (Paleocene, Paleogene, Tertiary, Cenozoic) at El Kef, Tunisia — Original definition and revision
• Successive Refinements in Long‐Term Integrations of Planetary Orbits
• On the formation and evolution of asteroid belts and their potential significance for life
• How to kill (almost) all life: the end-Permian extinction event
• Are Insects Heading Toward Their First Mass Extinction? Distinguishing Turnover From Crises in Their Fossil Record
• Extinction and recovery patterns of the vegetation across the Cretaceous–Palaeogene boundary — a tool for unravelling the causes of the end-Permian mass-extinction
• Confidence intervals for pulsed mass extinction events
• Bedout: A Possible End-Permian Impact Crater Offshore of Northwestern Australia
• Is plate tectonics needed to evolve technological species on exoplanets?
• Chondritic Meteorite Fragments Associated with the Permian-Triassic Boundary in Antarctica
• Magmatism at rift zones: The generation of volcanic continental margins and flood basalts
• Impact induced melting and the development of large igneous provinces
• Stratigraphy of the Anthropocene
• Flood Basalts and Mass Extinctions
• Extinction: End‐Triassic Mass Extinction
• Extinctions, scenarios, and assumptions: Changes in latest Pleistocene large herbivore abundance and distribution in western North America
• Political Ecology in the Extreme: Asteroid Activism and the Making of an Environmental Solar System
• Environmental changes in the Late Ordovician-early Silurian: Review and new insights from black shales and nitrogen isotopes
• The “Shiva Hypothesis”: Impacts, mass extinctions, and the galaxy
• Historic Eruptions of Tambora (1815), Krakatau (1883), and Agung (1963), their Stratospheric Aerosols, and Climatic Impact
• DNA evidence for a Paleocene origin of the Alcidae (Aves: Charadriiformes) in the Pacific and multiple dispersals across northern oceans
• Chicxulub impact tsunami megaripples in the subsurface of Louisiana: Imaged in petroleum industry seismic data
• The first day of the Cenozoic
• The Cretaceous‐Paleogene boundary deposit in the Gulf of Mexico: Large‐scale oceanic basin response to the Chicxulub impact
• Scientist as detective: Luis Alvarez and the pyramid burial chambers, the JFK assassination, and the end of the dinosaurs
• Evolutionary Traits that Enable Scleractinian Corals to Survive Mass Extinction Events
• Seismic stratigraphic evidence of a pre-impact basin in the Yucatán Platform: morphology of the Chicxulub crater and K/Pg boundary deposits
• Evidence of Carboniferous arc magmatism preserved in the Chicxulub impact structure
• Frontiers in large igneous province research
• The 21st Century Singularity and its Big History Implications: A re-analysis
• Foraminiferal turnover across the Eocene–Oligocene transition at Fuente Caldera, southern Spain: No cause–effect relationship between meteorite impacts and extinctions
• A possible K-T boundary bolide impact site offshore near Bombay and triggering of rapid Deccan volcanism
• George Bellas Greenough's 'Theory of the Earth' and its impact on the early Geological Society
• The Central Atlantic Magmatic Province at the Triassic–Jurassic boundary: paleomagnetic and 40Ar/39Ar evidence from Morocco for brief, episodic volcanism
• Sulfur, chlorine and fluorine degassing and atmospheric loading by the Roza eruption, Columbia River Basalt Group, Washington, USA
• The Cretaceous-Tertiary biotic transition
• MODELING THE PERFORMANCE OF THE LSST IN SURVEYING THE NEAR-EARTH OBJECT POPULATION
• Evolution and Extinction Dynamics in Rugged Fitness Landscapes
• Thalassotitan atrox, a giant predatory mosasaurid (Squamata) from the upper Maastrichtian phosphates of Morocco
• Chicxulub central zone structure and stratigraphy—PEMEX exploration drilling program
• Rapid eruption of the Deccan flood basalts at the Cretaceous/Tertiary boundary
• The Neoproterozoic assembly of Gondwana and its relationship to the Ediacaran–Cambrian radiation
• Fingerprinting the Cretaceous-Paleogene boundary impact with Zn isotopes
• Large igneous provinces and silicic large igneous provinces: Progress in our understanding over the last 25 years
• Earth: Atmospheric Evolution of a Habitable Planet
• Dynamical erosion of the asteroid belt and implications for large impacts in the inner Solar System
• Prospects for Detection of Catastrophic Collisions in Debris Disks
• Bentonites in the Chalk of central eastern England and their relation to the opening of the Northeast Atlantic
• An Iridium Abundance Anomaly at the Palynological Cretaceous-Tertiary Boundary in Northern New Mexico
• Hydrothermal vents and prebiotic chemistry: a review
• Prolonged 187Os/188Os excursion implies hydrothermal influence after the Chicxulub impact in the Gulf of Mexico
• Dinosaur [wikipedia]
• Extinction event [wikipedia]
• History of paleontology [wikipedia]
• Iridium [wikipedia]
• Luis Walter Alvarez [wikipedia]