Meteor Crater

Impact Earth

Locations

  • Field locations include:

    • Los Angeles

    • Death Valley National Park

    • Long Beach

    • Anaheim

    • San Diego

    • Las Vegas

    • Mexicali

    • Tijuana

    • St. George

    • Arizona (Phoenix, Mesa, Tucson, Nogales)

    • Baja

    • Gila National Forest

    • 8mSanta Fe

    • Albuquerque

    • New Mexico (Las Cruces, El Paso)

Impact Craters

  • Coon Butte (also known as Barringer Crater or Meteor Crater)

  • San Francisco volcanic field: Contains 600 volcanoes with ages ranging from 6 million years to less than 1,000 years.

  • Canyon Diablo Crater

  • Meteor Crater: Formation occurred approximately 50,000 years ago.

    • During this time, the area was inhabited by mammoths, mastodons, ground sloths, bison, and mountain goats.

Biological Effective Peak Effect

  • Overpressure (psi) and Radial Distance (km) relationship with lung damage and lethality:

    • Lung Damage Threshold: 8-15 psi, 6.5-9.3 km

    • Severe: 20-30 psi, 4.9-5.9 km

    • Lethality Threshold: 30-50 psi, 3.8-4.9 km

    • 50% Lethality: 50-75 psi, 3.2-3.8 km

    • 100% Lethality: 75-115 psi, 2.7-3.2 km

Beringia and Early Settlement

  • Beringia: Region including the Cordilleran and Laurentide ice sheets.

  • Ice-free corridor

  • Folsom and Clovis: Early settlement areas.

  • Earliest dated settlement (Clovis) approximately 13,000 years ago.

Hopi and Navajo Traditions

  • No identified Hopi or Navajo traditions about the formation of Meteor Crater.

Canyon Diablo and Historical Context

  • Related to Volz trading post.

  • Atchison, Topeka and Santa Fe Railway bridge over Canyon Diablo (1883-1903).

Albert E. Foote

  • Mentioned in the context of the American Association for the Advancement of Science in 1891.

Iron Meteorite Composition

  • Metallic Iron (N/A), Nickel (1,000x⨁1,000 x \bigoplus), Gold (120x⨁120 x \bigoplus), Platinum (2,700x⨁2,700 x \bigoplus)

  • ⨁\bigoplus = Earth Crust

Canyon Diablo - Meteorite Distribution

  • Meteorite finds vary in weight and location relative to the crater.

Grove Karl Gilbert (1843 – 1918)

  • Prominent geologist of the late 19th century.

  • Explored the American West.

  • Founder of modern Geomorphology.

  • One of the first Planetary Geologists.

  • Investigated the Coon Butte Crater in November 1891.

Gilbert's Investigation and Hypotheses

  • Gilbert's Study of the Moon's Features

  • Addressed the Philosophical Society of Washington December 10, 1892

  • Gilbert hypothesized that if the crater was produced by a collision, a stellar body would lie beneath the bowl, which would not be the case if the crater resulted from an explosion.

Ball-In-Mud Impact Crater Model

  • Impactor Size ~ Crater Size

  • Impact Speed "Slow"

  • Impactor buried under crater

Gilbert's Experiments and Findings

  • Experiments with clay balls suggest a crater 4,000 feet in diameter could be produced by a swift-moving meteor with a diameter of 1,500 feet (19-38% of crater size).

  • Magnitude of hollow and rim were both found to be 82 million yards.

  • The stellar body would likely be composed of iron, detectable by a compass needle, but no such mass was found.

Magnetic Survey

  • Magnetic surveys were conducted to detect a buried iron mass.

  • Instruments tested at the Washington Navy Yard.

Conclusions from Gilbert's Investigation

  • Crater likely resulted from a volcanic steam explosion rather than a meteorite impact.

  • Volume of the crater should exceed ejected material if caused by a meteorite.

  • Meteorite iron should create magnetic anomalies.

  • Meteorite fragments found on the rim were considered coincidental.

Maar Formation

  • Maar forms due to explosive reactions when magma contacts permafrost or groundwater.

Daniel Barringer (1860 - 1929)

  • Mining Engineer

  • Discovered the Commonwealth silver mine, amassing a fortune.

  • Advocated for the impact theory of the crater's formation, opposing Gilbert's steam explosion theory.

Barringer's Evidence Against Steam Explosion

  • No rocks of igneous origin in or around the crater.

  • No evidence of solfataric activity.

  • Finding of unaltered sandstone in place.

  • Ejected rock fragments deposited in reverse stratigraphical order.

  • Crater situated in an area with a high concentration of iron meteorites.

Barringer's Beliefs and Mining Operations

  • Barringer believed a metallic mass lay in the bottom of the crater.

    • Believed the buried meteorite had a mass of 100 million tons.

    • Worth more than 1billionin1903dollars(1 billion in 1903 dollars ( > $25 billion 2018).</p></li></ul></li><li><p>Conductedextensivedrillingoperationsfrom1903−1905tolocatethemeteoritemass.</p></li></ul><h4id="d03b6498−da7b−4fd4−b933−b3f6e2212cdd"data−toc−id="d03b6498−da7b−4fd4−b933−b3f6e2212cdd"collapsed="false"seolevelmigrated="true">Barringer′sMiningOperationsMap</h4><ul><li><p>Mapshowcasingvariousshafts,claims,andgeologicalfeaturesaroundMeteorCrater.</p></li></ul><h4id="8c25d653−c64f−41a5−be0b−95d6d9feebe2"data−toc−id="8c25d653−c64f−41a5−be0b−95d6d9feebe2"collapsed="false"seolevelmigrated="true">CraterDrilling</h4><ul><li><p>Drillingoperationswereconductedbetween1903and1905usingaHeatondrilloutfit.</p></li><li><p>By1905,5holeshadbeendrilled(Deepest 1,000feet).</p><ul><li><p>Nometeoritemassfound.</p></li><li><p>Mostdrillholesfilledwithwater.</p></li><li><p>Cost:.</p></li></ul></li><li><p>Conducted extensive drilling operations from 1903-1905 to locate the meteorite mass.</p></li></ul><h4 id="d03b6498-da7b-4fd4-b933-b3f6e2212cdd" data-toc-id="d03b6498-da7b-4fd4-b933-b3f6e2212cdd" collapsed="false" seolevelmigrated="true">Barringer's Mining Operations Map</h4><ul><li><p>Map showcasing various shafts, claims, and geological features around Meteor Crater.</p></li></ul><h4 id="8c25d653-c64f-41a5-be0b-95d6d9feebe2" data-toc-id="8c25d653-c64f-41a5-be0b-95d6d9feebe2" collapsed="false" seolevelmigrated="true">Crater Drilling</h4><ul><li><p>Drilling operations were conducted between 1903 and 1905 using a Heaton drill outfit.</p></li><li><p>By 1905, 5 holes had been drilled (Deepest ~ 1,000 feet).</p><ul><li><p>No meteorite mass found.</p></li><li><p>Most drill holes filled with water.</p></li><li><p>Cost:30,000 (1million2025).</p></li></ul></li><li><p>In1906onelastshaftwasdrilledinthecenter.</p><ul><li><p>Hitwaterat200feet.</p></li><li><p>Wasabandonedbyspring1906.</p></li><li><p>Cost:1 million 2025).</p></li></ul></li><li><p>In 1906 one last shaft was drilled in the center.</p><ul><li><p>Hit water at 200 feet.</p></li><li><p>Was abandoned by spring 1906.</p></li><li><p>Cost:55,000 (1.8million2025)</p></li></ul></li></ul><h4id="3c231496−abc8−4608−b866−3738496f55c5"data−toc−id="3c231496−abc8−4608−b866−3738496f55c5"collapsed="false"seolevelmigrated="true">Barringer′sNewStrategy</h4><ul><li><p>Proposedtunnelingandshaftconstructionbasedonstratauplift.</p></li></ul><h4id="3734fa1b−163e−49a4−8be2−0c7f1ef317b5"data−toc−id="3734fa1b−163e−49a4−8be2−0c7f1ef317b5"collapsed="false"seolevelmigrated="true">CrossSectionofMeteorCrater</h4><ul><li><p>Visualrepresentationofthecrater′sgeologyandproposedexplorations.</p></li></ul><h4id="7cd62abc−d369−43e4−9276−938c482d0522"data−toc−id="7cd62abc−d369−43e4−9276−938c482d0522"collapsed="false"seolevelmigrated="true">MiningEffortsandFinancialTroubles</h4><ul><li><p>InApril1928,afinalshaftwasstartedjustoutsidethesouthrimofthecrater.</p></li><li><p>InJune1929,at600feet,waterpouredintotheshaft.</p><ul><li><p>Aseriesofwaterpumpswereusedtodraintheshaft.</p></li></ul></li><li><p>InJuly1929,at713feet,thepumpsfailed,andthedrillingwasabandoned.</p></li><li><p>Barringerhadspentover1.8 million 2025)</p></li></ul></li></ul><h4 id="3c231496-abc8-4608-b866-3738496f55c5" data-toc-id="3c231496-abc8-4608-b866-3738496f55c5" collapsed="false" seolevelmigrated="true">Barringer's New Strategy</h4><ul><li><p>Proposed tunneling and shaft construction based on strata uplift.</p></li></ul><h4 id="3734fa1b-163e-49a4-8be2-0c7f1ef317b5" data-toc-id="3734fa1b-163e-49a4-8be2-0c7f1ef317b5" collapsed="false" seolevelmigrated="true">Cross Section of Meteor Crater</h4><ul><li><p>Visual representation of the crater's geology and proposed explorations.</p></li></ul><h4 id="7cd62abc-d369-43e4-9276-938c482d0522" data-toc-id="7cd62abc-d369-43e4-9276-938c482d0522" collapsed="false" seolevelmigrated="true">Mining Efforts and Financial Troubles</h4><ul><li><p>In April 1928, a final shaft was started just outside the south rim of the crater.</p></li><li><p>In June 1929, at 600 feet, water poured into the shaft.</p><ul><li><p>A series of water pumps were used to drain the shaft.</p></li></ul></li><li><p>In July 1929, at 713 feet, the pumps failed, and the drilling was abandoned.</p></li><li><p>Barringer had spent over600,000 (20million2025)inminingthecrater.</p></li><li><p>Nolargeburiedmeteoritemasswaseverdiscovered.</p></li><li><p>BarringerdiedofaheartattackonNovember30,1929.</p></li></ul><h4id="bb598272−8523−4561−925f−0a0ca1c2df9f"data−toc−id="bb598272−8523−4561−925f−0a0ca1c2df9f"collapsed="false"seolevelmigrated="true">Post−BarringerEra</h4><ul><li><p>TheBarringerCraterCompanycontinuedoperations.</p></li><li><p>HarveyNiningerattemptedtonationalizeMeteorCraterin1948.</p></li></ul><h4id="aabf0d41−b138−4ef8−994a−a220d62b6d17"data−toc−id="aabf0d41−b138−4ef8−994a−a220d62b6d17"collapsed="false"seolevelmigrated="true">RecognitionasanImpactCrater</h4><ul><li><p>MeteorCraterrecognizedastheplanet′sfirstprovenimpactcraterin1960.</p></li><li><p>Prototypeforstudyingallimpactcratersinourgalaxy.</p></li><li><p>Firstprovenandbest−preservedimpactsiteonEarth.</p></li></ul><h4id="25015ce2−1fd9−4f8f−b734−a146a342e1fd"data−toc−id="25015ce2−1fd9−4f8f−b734−a146a342e1fd"collapsed="false"seolevelmigrated="true">Ives′ExperimentsImitatingLunarCraters(1919)</h4><ul><li><p>Calculationssuggestingthatameteorstrikingthemoonwouldbeaveryefficientbomb.</p></li></ul><h4id="7209e947−0427−4309−ab0c−05ba74ac6984"data−toc−id="7209e947−0427−4309−ab0c−05ba74ac6984"collapsed="false"seolevelmigrated="true">VelocityCalculations</h4><ul><li><p>Velocityofanobjecthittingthegrounddroppedfromaheightofd:</p><ul><li><p>20 million 2025) in mining the crater.</p></li><li><p>No large buried meteorite mass was ever discovered.</p></li><li><p>Barringer died of a heart attack on November 30, 1929.</p></li></ul><h4 id="bb598272-8523-4561-925f-0a0ca1c2df9f" data-toc-id="bb598272-8523-4561-925f-0a0ca1c2df9f" collapsed="false" seolevelmigrated="true">Post-Barringer Era</h4><ul><li><p>The Barringer Crater Company continued operations.</p></li><li><p>Harvey Nininger attempted to nationalize Meteor Crater in 1948.</p></li></ul><h4 id="aabf0d41-b138-4ef8-994a-a220d62b6d17" data-toc-id="aabf0d41-b138-4ef8-994a-a220d62b6d17" collapsed="false" seolevelmigrated="true">Recognition as an Impact Crater</h4><ul><li><p>Meteor Crater recognized as the planet's first proven impact crater in 1960.</p></li><li><p>Prototype for studying all impact craters in our galaxy.</p></li><li><p>First proven and best-preserved impact site on Earth.</p></li></ul><h4 id="25015ce2-1fd9-4f8f-b734-a146a342e1fd" data-toc-id="25015ce2-1fd9-4f8f-b734-a146a342e1fd" collapsed="false" seolevelmigrated="true">Ives' Experiments Imitating Lunar Craters (1919)</h4><ul><li><p>Calculations suggesting that a meteor striking the moon would be a very efficient bomb.</p></li></ul><h4 id="7209e947-0427-4309-ab0c-05ba74ac6984" data-toc-id="7209e947-0427-4309-ab0c-05ba74ac6984" collapsed="false" seolevelmigrated="true">Velocity Calculations</h4><ul><li><p>Velocity of an object hitting the ground dropped from a height of d:</p><ul><li><p>v = \sqrt{2gd}</p></li><li><p>g=localgravity</p></li></ul></li><li><p>Example:d=100km,v=1,400m/s(3,000mph)</p></li><li><p>WhendisVERYlarge:</p><ul><li><p></p></li><li><p>g = local gravity</p></li></ul></li><li><p>Example: d = 100 km, v = 1,400 m/s (3,000 mph)</p></li><li><p>When d is VERY large:</p><ul><li><p>v = \sqrt{\frac{2GM}{R} (\frac{d}{R + d})}</p></li><li><p>Vapproaches</p></li><li><p>V approaches\sqrt{\frac{2GM}{R}}</p></li></ul></li></ul><h4id="502daecf−b76e−4482−848f−9cf69e149bbd"data−toc−id="502daecf−b76e−4482−848f−9cf69e149bbd"collapsed="false"seolevelmigrated="true">EscapeVelocity</h4><ul><li><p></p></li></ul></li></ul><h4 id="502daecf-b76e-4482-848f-9cf69e149bbd" data-toc-id="502daecf-b76e-4482-848f-9cf69e149bbd" collapsed="false" seolevelmigrated="true">Escape Velocity</h4><ul><li><p>V_{escape} = \sqrt{\frac{2GM}{R}}$$

    • Earth's Escape Velocity = 11.2 km/s (25,000 mph)

    • An object falling to Earth from a large distance will hit with a minimum velocity of 11.2 km/s.

    Energy Release and Impact Dynamics

    • Small masses moving at high speeds can release a large amount of energy.

    • Meteor Crater Impactor:

      • Diameter = 50 meters

      • Composition = Iron

      • Mass = 500,000 tons (1 billion lbs) ~1% Crater diameter

    • Energy of Impact: 8 million tons of TNT

    • Energy to Destroy Impactor: 0.0001 tons of TNT

    • Impactor destroyed on impact; no large mass survived.

    Atmospheric Effects

    • Atmospheric drag slows the incoming projectile.

    • Pressure on the projectile reaches the