BEST BETS FOR FINDING FRAGMENTS OF METEORS

We know that extraterrestrial materials fall randomly on Earth; it is simply easier to find them in deserts where they are well preserved (due to lack of weathering) and concentrated on a plain background so that they are easily recognized. Successful meteorite searches in cold and hot deserts have dramatically increased the number of meteorite finds.

While Antarctica is the premier cold desert hunting ground, researchers have been using remote sensing images to look at Earth's other ice sheet, Greenland, for evidence of meteorite stranding surfaces. Their work suggests that Greenland would be an excellent place for future meteorite hunts.

Several hot desert regions are yielding huge numbers of meteorites, namely the Sahara Desert (Algeria and Libya), the Nullarbor Plains (Western and South Australia), Mojave Desert (Southern California), and high plains of Texas and New Mexico.

The three most productive areas in the Sahara are the Reg el Acfer in Algeria (at least 320 meteorites), Dar al Gani (at least 256 meteorites) and Hammahah al Hamra (at least 520 meteorites) in Libya. Over 200 specimens have been collected from an unknown Saharan location (undisclosed by the private collectors). An additional 280 meteorites have been collected in Australia's Nullarbor Region.

BRYSON BURKE
Home
Mission
Board
History
Business Plan
Latest Information
Building Our Drill
Innovation
Photo Album
Satellite Weather
Free News - Sign Guestbook

INVESTING
Investment
Stock Quotes

COMMUNICATION
Press Releases
Newsletter
Current Information
Contact

SITE GEOLOGY
Geology Reports
Site Geologic History
Magnetic Maps Index
Heavy Minerals Index
Grenville Province Index

DIAMOND POLITICS
Blood Diamonds
Kimberley Process

DIAMOND GEOLOGY
Indicator Minerals
Kimberlites
Decay of Kimberlites
Kimberlites & Magnetics
Placer Deposits
Magnetic Reversal
Crustal Thickness
How Diamonds are Made
Glaciation Issues
Mineral Transport Index
Doing the Map Work
Gathering Samples
World Mining Index
Excavation and Recovery
Mining Corporations
Mining News Magazines
Environmental Issues
Diamonds in Space
World's Only MineCam
Live Volcano Geo-Cams

EXPLORATION
Site Exploration History
Topography Map Index
Location Map
Claim Maps Index

DIAMONDS
Diamonds and Graphite
Diamond Formation
Grading Diamonds
Price of Diamonds
Industrial Diamonds
Drilling Equipment
Medical Use of Diamonds
Gemstones
Birthstones
Hall of Fame

DIAMONDS IN CULTURE
Good Books on Diamonds
Cremains to Diamonds
Diamonds in Lawsuits
Irish Diamonds
Unusual Diamond News
Diamonds in the Media
Famous Jewelers
In Advertisements
Top Twenty Cut Diamonds
Top Diamonds
Diamond Lore
Theft/Hoaxes/and Fraud
Religion Index
Diamond/ Culture Index
Television
Movies
Games - Play Now
Music
Weddings
Royals
Our Darlings
Diamond Animal Index

INTERACTIVE
Reflection/Refraction Index
Crossword Puzzle Index
Which Is A Diamond I
Which is a Diamond II
Become a Gemologist

Origins: Solar or Presolar

The average abundance of nano-diamonds in chondritic meteorites is ~400 ppm. They are between 1 and 10 nm in diameter with a log-normal size distribution. The average diameter is ~3 nm.

Although their bulk 13C/12C composition is solar, they are widely assumed to be presolar in origin because of their association with a noble gas carrier, specifically an anomalous Xe-HLcomponent that has been linked to a supernova origin. The abundance of Xe is such that only 1 in 106 nano-diamonds contains a Xe atom.

Since it is not yet possible to measure the isotopic composition of a single nano-diamond, it is an unclear whether all nano-diamonds are indeed presolar. The relative abundance of nano-diamonds in asteroidal versus cometary materials may provide insight about their origins because presolar grains should be more abundant in the most primitive parent bodies located at large heliocentric distances.

We have examined HF acid-etched thinsections of Orgueil (CI) and Murchison (CM) meteorites, two unmelted "CM-like" polar micrometeorites, and 9 chondritic IDPs. Eight of the 9 IDPs are anhydrous chondritic porous (CP) particles, 4 are cluster particles one of which is hydrated

More on Diamond Origins in Meteorites

Found Spring 2000
~28° N., ~16° E.
A single 40.03 g ureilite meteorite was found in the Libyan Sahara Desert. Like most ureilites, DaG 868 is composed of grains of olivine (82 vol%) and pigeonite (11 vol%) along with carbonaceous material forming rims and veins. The small amount of metal present has been extremely weathered. The olivine in DaG 868 has a high CaO content and a high fayalite value of 20.6, which places it in Berkley's subgroup I.

In contrast to most other ureilites, DaG 868 contains unshocked olivine without undulose extinction, but still contains sub-millimeter-sized diamonds in the graphite present within pigeonite crystals. These diamonds have a solar signature inferred by their C and N isotope compositions. It is thought that diamonds found in ureilites, as well as those found in iron meteorites, were formed by impact shock pressures, or through chemical vapor deposition processes. While DaG 868 has forced a reconsideration of diamond origins, a new mechanism, catalytic transformation of graphite to diamond, is currently under consideration to account for the production of diamonds in DaG 868. Under conditions of relatively low-pressure and high temperature, certain molten metals can serve as solvent catalysts leading to diamond formation. Consequently, DaG 868, along with ALH 78019 and ALH 78262, may represent a unique group of weakly shocked, diamond-bearing ureilites.

Other sub-millimeter-sized diamonds of solar origin are found in unshocked meteorites, such as the enstatite chondrite Abee. By contrast, diamonds present in primitive chondrites are nanometer-sized, and contain anomalous C and N, reflecting a circumstellar origin. Remarkably, two different types of diamonds are found in the meteorite Acfer 214; nanometer-sized diamonds similar to those found in primitive chondrites, and larger, micron-sized diamonds with unique isotopic characteristics, combustion temperatures, and C/N ratios. The above specimen of DaG 868 is a 0.39 g partial slice with crust.