Itqiy meteorite | |
---|---|
Type | Chondrite (ongoing scientific debate) |
Class | Enstatite chondrite (ongoing scientific debate) |
Group | EH7-an (ongoing scientific debate) |
Parent body | NWA2526-Itqiy [1] |
Composition | Enstatite (78 %), meteoric iron (22 %), sulfides. [2] |
Country | Western Sahara [3] |
Coordinates | 26°35′27″N 12°57′8″W / 26.59083°N 12.95222°W [3] |
Observed fall | Yes [3] |
Fall date | 1990 [3] |
Found date | 1990 + 2000-07 [3] |
TKW | 0.410 kilograms (0.90 lb) [3] + 4.310 kilograms (9.50 lb) [3] |
The Itqiy meteorite is an enstatite-rich stony-iron meteorite. It is classified as an enstatite chondrite of the EH group that was nearly melted and is therefore very unusual for that group. [2] [4] Other classifications have been proposed and are an ongoing scientific debate.
Itqiy was initially attributed to a 1990 fireball in Western Sahara. One stone was recovered by a nomad, and a second stone was recovered in July 2000 by Marc, Luc, and Jim Labenne who were searching for meteorites in the same location. [3] The meteorite was analyzed in 2001. [5] Later work showed that the meteorite had fallen nearly 6,000 years ago and was not associated with any recent fireball. [6]
Itqiy is a stony meteorite consisting of 78% enstatite and 22% meteoric iron. The meteoric iron is kamacite with 5.77% nickel. Small amounts of other minerals include troilite, Mg-Mn-Fe sulfides and Fe-Cr sulfides. [2] [7]
The meteorite was described as an "ungrouped stony meteorite" in 2000, and reclassified as an "ungrouped enstatite meteorite" in 2001. [2] [7] In 2006, Itqiy was classified as a member of the EH enstatite chondrites, with a petrologic type of 7, emphasizing that it was a strongly metamorphosed EH chondrite. [2]
Itqiy represents a rock that formed through partial melting of an EH chondrite. This process removed the more volatile minerals like plagioclase. [8] In 2010-1 it was proposed that Itqiy, QUE 94204, QUE 97289, QUE 97348, NWA 2526 and possibly Yamato 793225 form a new group from the same parent body that should be called "primitive enstatite achondrites". [8] [9]