There are meteorites out there that set the bar. If you ask a meteorite collector to describe how nicely colored and translucent the olivines are in a new pallasite, they can compare it to those in Fukang or Esquel. But what do you compare an impact melt breccia to, that maybe has more in common visually to foundry slag than to most meteorites? Cerro Del Gato; Cat Mountain that’s what.
Chondritic Impact Melt Breccias are stunning and unique in appearance. They are also very underrepresented in ordinary chondrites. Characterized by their metals and sulfides largely consolidated into eutectic blebs within wispy rivers of grey melt surrounding shock-darkened rounded breccia clasts. Add to that their affinity to spalling crust and looking on the exterior, rather un-meteoritic, and they are the Edvard Munch’ s ‘The Scream’ of the meteorite world in my opinion.
Being first, or nearly so is a leg up when it comes to gaining standard bearing notoriety. Cat Mountain was a lucky cat in that regard. If you search meteorites containing “melt” as part of the classification, filter by year found, and dig into the actual first classification date; you come up with a list of mostly Antarctic meteorites. Most were found in the 80s and not classified till the early 2000s. Just four other meteorites are on the listing with a find date before 2000, Caldwell (1961 Kansas find, classified simply as chondrite, till 1997), Muckera 007 (1991 Australia find, classified as just L till 2006), NWA 002 (an Al Haggounia 001 pairing classified as EL6 till 2016 reclassification to EL-melt rock) and Sahara 99362 (found in 1999 and not classified till 2018 as l5-melt breccia). Note Cat Mountain wasn’t even one of the four, more on that later.
Cat Mountain like many of the other meteorites that are eventually classified as melts shares in common, this long status in an unclassified state. In the case of Cat Mountain, the finder, William Goldups, refused to let a sample be taken, the prospective meteorite sitting on his mantle untouched. Upon his passing, the meteorite was sent for examination. This was some 10 or so years after its finding. At the Lunar and Planetary Laboratory, UofA the single stone find was classified as an L5-imp melt breccia in 1993. This puts it towards the head of the pack for ‘melt’ classifications I could find.
Gaining standard bearing status isn’t only about being first, is helps to have a great story. In the case of Cat Mountain, besides remaining on his mantle untouched for a decade, the find details are quite interesting, though as enigmatic as the animal it is named after. For instance, I noted the wait for classification was around a decade, that is because the true find date of this meteorite is a bit of a mystery. Bob Haag, who conversed with the original finder lists the finding as 1978, the Meteoritical Bulletin puts the find date as 1981 in the basic information but references the MB 75 write-up that has a range of 1980-1982. Other details are also a mystery, such as one accounting having the meteorite pass the Goldups’s son, while another to one of his friends, a detail that may be important for accounting for mass, considering the Meteoritical Bulletin lists 784 grams as “with the finder”. Then there is getting back to the fact that Cat Mountain is no longer in the Meteoritical Bulletin as an L5 impact-melt breccia (in modern classification terms an L5 melt breccia, which would make it 1 of 46, instead it’s simply an L5, 1 of 12,934 with no explanation to the change.
Cat Mountain’s interesting story starts well before its finding, and subsequent complex terrestrial tale. David Kring, who did the classification, produced a couple of papers on Cat Mountain. The following information is taken from his 1996 publication and provides a detailed look at the impact melt breccias creation and subsequent cataclysmic history that got it to earth. Using noble gas analysis, and the structure of the material, Krang points out a history that is rife with impacts, one at 880 MYA which created a greater than kilometer-wide crater, within this impact structure rounded clasts of L5 shocked material were surrounded by completely melted rock which quickly cooled to form an impact melt breccia. A second impact, which Kring theorized happened 500 MYA threw a substantial chunk of the impact melt breccia out of the crater. A third collision some 20 MYA broke off a small meter or so sized chunk and put it into an earth crossing orbit where it experienced its final collision.
The interesting things about Cat Mountain don’t stop there, however. Cat Mountain is every meteorite aficionado’s dream find, the stone that one happens upon during the everyday grind. William Goldups, just happened upon the 2.7 Kg mass while walking the same path he walked daily between his house and his preferred spot for buying a newspaper and morning coffee as the story goes. He reckons it had to have fallen within 24 hours of finding it as it was in a small impact crater in the sandy desert not there the previous day. A new crater on your morning walking path is something to take note of. Even before you have had your morning coffee.
Other things add to the lure of Cat Mountain. No history jaunt for a 90’s classified meteorite would be complete without a review of what was said about it on the Meteorite List email forum. So doing a little digging I found the following. A couple of meteorite hunters while out looking for additional pieces of Cat Mountain a year after it was classified failed to find any more, but found a bit over a kilo of a new meteorite nearby, that was classified as Snyder Hill. A subsequent trip turned up a pecan size additional piece which ended up with Bob Haag alluding to there being more out there. Fast forward some 15 years, and while hunting as a reunion opportunity to celebrate Snyder Hill, Dave Johnson found a third piece of Cat Mountain weighing 107 grams. Finally, later that year a 168-gram, or 170-gram piece, (depending on which source you go by) was found bringing the grand total of finds to four. Not to be less interesting than Schrödinger’s cat, the box containing the larger piece was apparently lost in transit while being sold. A Meteorite List thread on the loss led me to what may be the oddest thing I have ever watched on the platform. If the curiosity gets the better of you like it did the fabled cat, just YouTube search “kitty cat mountain meteorite”. Just remember curiosity also killed the cat…
In conclusion, there are certainly more recent finds of impact melts out there, ones that rival and maybe surpass Cat Mountain on looks, but not on story, history, or scientific impact.
