Weldona meteorite, Morgan County, Colorado, USAi
| Regional Level Types | |
|---|---|
| Weldona meteorite | Meteorite Fall Location |
| Morgan County | County |
| Colorado | State |
| USA | Country |
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Latitude & Longitude (WGS84):
40° 21' 0'' North , 103° 56' 59'' West
Latitude & Longitude (decimal):
Meteorite Class:
Meteoritical Society Class:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Weldona | 139 (2011) | 1.7km |
| Morgan Heights | 266 (2017) | 12.5km |
| Log Lane Village | 873 (2011) | 13.5km |
| Wiggins | 893 (2011) | 16.9km |
| Fort Morgan | 11,319 (2017) | 16.9km |
Ordinary chondrite (H4)
Found, 1934; 27.7 kg
The Weldona stone was ploughed up and reported soon after the spectacular Sioux County bolide of 8 August 1933 and its subsequent recovery had been widely reported. Scattered pits of 5-6 cm diameter were still visible on one side with smaller pits of 1-2 cm diameter pits on the other. Naked eye inspection reveals Fe-Ni metal, troilite, chondrules, and chondrule fragments within dark matrix. Nininger's description of the stone as 'crystalline' suggests that the stone is perhaps more 'equilibrated' than some H4 chondrites. Compositionally, olivine (Fa19) and low Ca-pyroxene ('bronzite') are characteristic of the H-chondrite geochemical group. Mineralogically the meteorite consists primarily of olivine and pyroxene accompanied by troilite and Fe-Ni metal. Accessory chromite, ilmenite, spinel, isocubanite, and mackinawite are also reported. Jull et al. (1993) report that Weldona has experienced minor weathering. A detailed petrographic and isotopic study of the two accessory sulfides (isocubanite, mackinawite) might be able to establish whether these minerals are preterrestrial phases or terrestrial weatherates. Important chronological markers include a 13.4 Ma cosmic ray exposure (CRE) age and a C-14 terrestrial exposure age of 6.0±1.3 ka.
The H-group chondrites (relatively high in total iron) are the largest group of ordinary chondrites and represent ~40% of the well-classified recovered meteorites. The H4 petrologic type represent less than 20 % of the total group. Weldona is the 28th largest of 5,333 meteorites classified exactly as H5 ordinary chondrite (as of 28 March 2017).
As with many meteorites collected by Harvey Nininger, the main mass has been kept at Arizona State University's Center for Meteorite Studies (Tempe) [6.8492 kg remained in 2016].
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsMineral List
8 valid minerals.
Meteorite/Rock Types Recorded
Note: data is currently VERY limited. Please bear with us while we work towards adding this information!
Select Rock List Type
Alphabetical List Tree DiagramDetailed Mineral List:
| ⓘ Chromite Formula: Fe2+Cr3+2O4 |
| ⓘ Copper Formula: Cu |
| ⓘ 'Fayalite-Forsterite Series' Description: Average olivine composition (Fa19) characteristic of H-group ordinary chondrites [Approximate Range of H-group means, Fa15-20]. |
| ⓘ Ilmenite Formula: Fe2+TiO3 |
| ⓘ Iron Formula: Fe |
| ⓘ Iron var. Kamacite Formula: (Fe,Ni) |
| ⓘ Isocubanite Formula: CuFe2S3 Description: A common terrestrial weatherate, but Ramdohr's practice in this listing was to report only those phases he deemed 'primary' (pre-terrestrial). |
| ⓘ Mackinawite Formula: FeS |
| ⓘ 'Pyroxene Group' Formula: ADSi2O6 Description: Ca-poor Pyroxene here is either 'Bronzite' or 'Clinobronzite' if the meteorite has been properly classified. Both phases are often present in H4 chondrites. |
| ⓘ Spinel Formula: MgAl2O4 |
| ⓘ Troilite Formula: FeS |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Copper | 1.AA.05 | Cu |
| ⓘ | Iron | 1.AE.05 | Fe |
| ⓘ | var. Kamacite | 1.AE.05 | (Fe,Ni) |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Isocubanite | 2.CB.55b | CuFe2S3 |
| ⓘ | Troilite | 2.CC.10 | FeS |
| ⓘ | Mackinawite | 2.CC.25 | FeS |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Chromite | 4.BB.05 | Fe2+Cr3+2O4 |
| ⓘ | Spinel | 4.BB.05 | MgAl2O4 |
| ⓘ | Ilmenite | 4.CB.05 | Fe2+TiO3 |
| Unclassified | |||
| ⓘ | 'Fayalite-Forsterite Series' | - | |
| ⓘ | 'Pyroxene Group' | - | ADSi2O6 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Chromite | Fe2+Cr23+O4 |
| O | ⓘ Ilmenite | Fe2+TiO3 |
| O | ⓘ Spinel | MgAl2O4 |
| O | ⓘ Fayalite-Forsterite Series | |
| O | ⓘ Pyroxene Group | ADSi2O6 |
| Mg | Magnesium | |
| Mg | ⓘ Spinel | MgAl2O4 |
| Mg | ⓘ Fayalite-Forsterite Series | |
| Al | Aluminium | |
| Al | ⓘ Spinel | MgAl2O4 |
| Si | Silicon | |
| Si | ⓘ Fayalite-Forsterite Series | |
| Si | ⓘ Pyroxene Group | ADSi2O6 |
| S | Sulfur | |
| S | ⓘ Isocubanite | CuFe2S3 |
| S | ⓘ Mackinawite | FeS |
| S | ⓘ Troilite | FeS |
| Ti | Titanium | |
| Ti | ⓘ Ilmenite | Fe2+TiO3 |
| Cr | Chromium | |
| Cr | ⓘ Chromite | Fe2+Cr23+O4 |
| Fe | Iron | |
| Fe | ⓘ Chromite | Fe2+Cr23+O4 |
| Fe | ⓘ Ilmenite | Fe2+TiO3 |
| Fe | ⓘ Iron | Fe |
| Fe | ⓘ Isocubanite | CuFe2S3 |
| Fe | ⓘ Iron var. Kamacite | (Fe,Ni) |
| Fe | ⓘ Mackinawite | FeS |
| Fe | ⓘ Troilite | FeS |
| Fe | ⓘ Fayalite-Forsterite Series | |
| Ni | Nickel | |
| Ni | ⓘ Iron var. Kamacite | (Fe,Ni) |
| Cu | Copper | |
| Cu | ⓘ Copper | Cu |
| Cu | ⓘ Isocubanite | CuFe2S3 |
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Denver BasinBasin
- Great Plains DomainDomain
- Yavapai TerraneVolcanic Arc
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