H Ordinary Chondrites

Dashoguz (41°59'4" N, 59°41'6" E)

Fell 1998 September 5
Ordinary chondrite (H5)

A meteor trail was witnessed near the city of Dashoguz, Turkmenistan. After a search of several weeks, a very small crater (depression) with ~7 kg of meteorite fragments was found. Kakabay Annaniyazov recovered fresh, grey fragments from the rim of the crater and weathered, brown fragments from within the water-fill crater. Classification and mineralogy (T. Bunch and J. Wittke, NAU): olivine Fa17.5; pyroxene Fs15.3; plagioclase An14. Shock stage S3; weathering grade, W0/1 for the grey fragments, W4 for the brown fragments. Specimens: type specimen, 21.2 g and one thin section, NAU; main mass with anonymous purchaser.

New Orleans (29°56.8305' N, 90°6.5855' W)

New Orleans, Louisiana USA
Fell 2003 September 23. approx. 16:05 hrs (CST)
Ordinary chondrite (H5)

On the afternoon of September 23rd 2003, a meteorite tore through the two-storey home of Ray and Judy Fausset, who were not at home at the time. Neighbors said that they heard a "terrific noise." Two observations of a fireball were recorded. The main mass of the meteorite was found in the crawl space under the house. Powdery meteorite debris and fragments were found along the penetration path throughout the house. A total mass of 19,256 g was recovered from the Fausset house, the three largest fragments weighing 2966 g, 1292 g and 1001 g. Some additional material (~100 g) was also recovered in the surrounding neighborhood. Description and classification (S. Nelson, Tulane University; R. Jones and A. Brearley, UNM; T. Bunch and J. Wittke, NAU): The meteorite is light grey with a black fusion crust, and very friable. Abundant metal and troilite are visible on broken surfaces, as well as some thin (mm-thick) impact melt veins. Classification and mineralogy: The meteorite is very fragmented on a sub-mm scale. Mean compositions of olivine, Fa17.6; orthopyroxene, Fs15.4Wo1.4; clinopyroxene, Fs10.4Wo24.8; plagioclase, An12.8Or5.6; metal, Ni = 6.7 wt %, Co = 0.83 %. Minor chromite and phosphate are present. The meteorite broke a pipe and many fragments sat in water for several days. Because of this and the humid climate in New Orleans, light oxidation of interior metal within small fragments (<100 g) was evident within a week of the fall. Shock level, S1. Specimens: 82 g, UNM; 63 g, NAU; main mass with owner.

New Orleans H5. Arrow points to hole in roof. Image source: http://www.marmet-meteorites.com/sitebuildercontent/sitebuilderpictures/.pond/new.orleans.2.jpg.w560h420.jpg

Northwest Africa 2058

Ordinary chondrite (H melt rock)

Five fresh, fully crusted stones with unusually smooth fusion crust (total weight of 80.1 g) were purchased in Zagora, Morocco in 2001. Classification and mineralogy (T. Bunch and J. Wittke, NAU): melt mass of >90 vol. % that consists mostly of euhedral olivine crystals (<0.01 mm) with minor orthopyroxene and micron- to submicron-size metal spherules set in feldspathic glass. Within this mass are mm size elongated metal-sulfide nodules of eutectic texture. These nodules together with connecting metal veins form a network subparallel to the flow direction of the melt mass. No apparent vesiculation. Relict olivine (Fa17.1-18.4) and orthopyroxene (Fs15.8-16.5) chondrule fragments (<0.05 mm in diameter) are randomly distributed throughout the melt mass. Nodule metal: Ni, 7.8 wt %; Co, 0.75 %; Cr, 0.37 % and P, 0.57 %. Shock level, S6; weathering grade, W2/3. Specimens: type specimen, 17.1 g, NAU; main mass, Hupé.

Northwest Africa 2390

Northwest Africa
Purchased July 2004
Ordinary Chondrite (melt breccia, recrystallized)

A 231 g stone was purchased in Erfoud, Morocco. Description and classification (J. Wittke and T. Bunch, NAU): lightly shocked, brecciated L4 host with massive, recrystallized shock melt. Large, isolated metal-sulfide blebs display typical melt-eutectic texture. Recrystallized silicates are fine-grained (<0.02 mm) and show only localized flow fabric. Host olivine, Fa25.3; orthopyroxene, Fs21.1. Recrystallized olivine and pyroxene are moderately equilibrated and more consistent with an H composition than with L composition, Fa15.4-18.9; orthopyroxene, Fs11.0-15.3. Either reduction of silicate FeO occurred during melt/recrystallization or the impactor/target chondrite types were dissimilar. Shock level, S2-6; weathering grade is W2. Specimens: type sample, 22.3 g, NAU; main mass, Burkhard.

Thumb Butte

Mojave County, Arizona, USA
Find: 1 March 2008
Ordinary chondrite (H3.8)

History: Mr. Todd Parker found a 104 g stone on a small, alluvium-covered flat just west of Thumb Butte and 4 miles east of Bullhead City, Mojave Co., Arizona.
Physical characteristics: The single stone is mostly covered by moderately weathered reddish-brown fusion crust.
Petrography (T. Bunch and J. Wittke, NAU): Chondrules have sharp outlines with a mean diameter of ~0.4 mm. Matrix is slightly recrystallzed with some remnant calcic glass. Chondrule mesostasis is clear to turbid and several chondrules are armored with metal and minor FeS. Contains olivine, orthopyroxene, kamacite, FeS, taenite, merrillite, Cl-apatite, chromite and a trace of plagioclase. Fresh interior with reddish staining, weathering grade is W1. Shock level is S2.
Mineral compositions: Olivine, Fa17.3-24; orthopyroxene, Fs15.7-19.1Wo1.5-2.3; taenite Ni = 41.2 wt%; chromite, Cr/(Cr+Al) = 0.86.
Classification: Ordinary chondrite (H3.8).
Type specimen: 20 g are on deposit at NAU. Mr. Todd Parker holds the main mass.

Thumb Butte. Image © T.E. Bunch 2010

Photographs of H Chondrites

NWA 3115. Image © T.E. Bunch 2005