|JILIN (KIRIN) CITY, JILIN PROVINCE, MANCHURIA,
CHINA Stone. Olivine-bronzite chondrite (H5). "CM" REF:
P. 181, "ARNs" REF: P. 145. FELL: 1976, March 8, 1500 hours.
The "Catalogue of Meteorites" reports that: "After a fireball and several explosions, a shower of stones fell, totaling about 4 tons, with the largest individual weighing 1770 Kg., analysis 28.6% total iron". This event is also described in "Cosmic Debris - Meteorites in History", by John G. Burke, P. 227 (1986), as follows: "On March 8, 1976, the largest stone meteorite ever recorded as having come to Earth fell at Jilin (Kirin), Manchuria. The total weight was approximately 2 metric tons, and the mass of the largest piece was 1.77 metric tons." An earthquake, measuring 1.7 on the Richter scale, was recorded upon impact of this mass. A map showing the distribution of fragments from this shower of H5 chondrites appears in "Meteorites - Their Record of Early Solar-System History", by John T. Wasson, P. 9, Fig. I-5 (1985).
The physical appearance of these specimens is of a light gray stone matrix with thin, dark gray veinlets included. As mentioned above, there is a high percentage of iron present in this H5 chondrite. The silvery-metallic iron inclusions are practically indistinguishable from the light gray stone matrix, in specimens with no cut surfaces, however, all examples show a very strong response to a magnet. With 10X magnification, small Troilite inclusions can also be seen scattered throughout the light gray stone matrix. Chondrules are usually +/- l mm size, scattered, yet visible with l0X magnification over the uncut surfaces of the matrix.
Item 7005 has one unpolished, saw cut surface which exhibits rich distribution of metallic inclusions over the entire cut surface. Items 7004, 7006 ad 7007. are natural, uncut fragments without fusion crust. Item 7007 is a large, uncut specimen with one end showing a natural break, as illustrated in the accompanying photos. This natural break is probably the result of the specimenís initial contact with the Earth. Ablation marks, demonstrating oriented flight, are exhibited on two sides of the specimen. None of the primary black fusion crust is present, however, a secondary fusion crust has begun to form. This secondary fusion crust was created after the explosion of the original mass of this huge stone meteorite, upon entry to the Earthís atmosphere. Secondary fusion crust is formed on meteorites when inner fragments of the meteorite are subjected to the intense heat generated by their flight through the Earthís atmosphere.
Copyright 1998-2017 by Mineralogical Research Co.
All rights reserved.