Lead-lead dating is a method for dating geological samples, normally based on 'whole-rock' samples of material such as granite. For most dating requirements it has been superseded by uranium-lead dating U-Pb dating , but in certain specialized situations such as dating meteorites and the age of the Earth it is more important than U-Pb dating. There are three stable "daughter" Pb isotopes that result from the radioactive decay of uranium and thorium in nature; they are Pb, Pb, and Pb. These daughter isotopes are the final decay products of U and Th radioactive decay chains beginning from U, U and Th respectively. With the progress of time, the final decay product accumulates as the parent isotope decays at a constant rate. This can be expressed by the following decay equations:.
The meteorite is classified as an iron meteorite and the estimated impact time is 50, years ago. Fragments of the meteorite have been actively collected since the mid s and there is evidence that fragments were collected and used by pre-historic Native Americans.
Therefore, troilite found in Canyon Diablo represents the primeval lead isotope composition of the solar system, dating back to +/- Byr. Stony meteorites however, exhibited very high Pb/ Pb versus Pb/ Pb ratios, indicating that these samples came from the crust or mantle of the planetesimal. Together, these samples define an isochron, whose slope gives the age of meteorites . The Canyon Diablo iron meteorites arrived 49, years ago when an asteroid plunged into North Central Arizona, forming Meteor Crater. Thousands of meteorite fragments of the asteroid were scattered by the explosion over the area. By relating known relationships among noble gas isotope ratios, the cosmic ray exposure age can be ascertained for the Canyon Diablo object. The oldest isochron provides evidence for a collision in space m.y. ago, while a secondary isochron of m.y. is suggestive of a more recent collision.
The biggest fragment is the Holsinger Meteorite with a mass of kg, which is on display in the Meteor Crater Visitor Center on the rim of the crater. The total known mass is on the order of 30, kg.
Fragments of the meteor have been collected around the crater and in Canyon Diablo which lies 3 to 4 miles west of the crater. The meteorite is classified as an iron meteorite and the estimated impact time is 50, years ago. The Canyon Diablo date has been backed up by hundreds of other dates, from both terrestrial samples and other meteorites. The meteorite samples, however, show a spread from to billion years ago. This is interpreted as the duration of formation of the solar nebula and its collapse into the solar disk to form the Sun and the planets. In , American geologist Clair Patterson used uranium-lead dating of the Canyon Diablo meteorite, shown here, to calculate that it was billion years old. The meteorite is a fragment of an asteroid that hit modern-day Arizona about , years ago.
Canyon Diablo Iron Meteorite. Thousands of meteorite fragments of the asteroid were scattered by the explosion over the area. They were named the Canyon Diablo meteorites after the river gorge near the crater and they are among the most historically significant meteorites available to collectors.
Made of nickel-iron with inclusions of graphite and other minerals they are classified as Coarse Octahedrite Iron Meteorites. The smaller fragments show the effects of being torn apart by the tremendous crater-forming explosion.
Canyon Diablo Iron Meteorite Individual - Grams - Meteor Crater, Arizona. $ +$ shipping. Make Offer - Canyon Diablo Iron Meteorite Individual - Grams - Meteor Crater, Arizona. gram CANYON DIABLO IRON METEORITE SPECIMEN from . Its location, about km west of the Canyon Diablo find, and the absence of a known and verified meteorite crater in the area, strongly suggest it is a piece of transported Canyon Diablo meteorite. Superficially the piece looks very much like Canyon Diablo individuals, with small pockets of adhering clay in surface flutings. Jun 19, Dating the Earth via Canyon Diablo Meteorite (help needed) Discussion in 'Creation & Evolution' started by ENominiPatri, Jun 19, Jun 19, #1. ENominiPatri Regular Member. +7 Atheist Single. Hey hey what's up everybody? I'm not asking for dating advice to score with our planet, I am actually writing a book and want to demonstrate.
The meteorite sampleshowever, show a spread from 4. This is interpreted as the duration of formation of the solar nebula and its collapse into the solar disk to form the Sun and the planets. This 50 million year time span allows for accretion of the planets from the original solar dust and meteorites.
The moon, as another extraterrestrial body that has not undergone plate tectonics and that has no atmosphere, provides quite precise age dates from the samples returned from the Apollo missions. Rocks returned from the moon have been dated at a maximum of around 4.
Martian meteorites that have landed upon Earth have also been dated to around 4. Lunar samples, since they have not been disturbed by weathering, plate tectonics or material moved by organisms, can also provide dating by direct electron microscope examination of cosmic ray tracks.
Classroom Aid - Meteorite Lead-Lead Dating
The accumulation of dislocations generated by high energy cosmic ray particle impacts provides another confirmation of the isotopic dates.
Cosmic ray dating is only useful on material that has not been melted, since melting erases the crystalline structure of the material, and wipes away the tracks left by the particles.