Copyright - Tom Phillips - M.Bandli - Historic Meteorites
Mystery Alexis A. Julien 19th Century Thin-section
19th century thin-section meets 20th century microscope
My new quest to identify this mystery meteorite leads me to thin-section guru Tom Phillips. Tom was kind enough to help me out with micrographs of this antique TS. The Julien TS was so thick that it required a 750 watt lamp to pump enough light through. When Tom sent me back these images, I was absolutely stunned:
My quest to locate historic meteorites leads me to an antique thin-section and a petrology artists named Alexis Julien. Julien was more than a thin-section maker - he was curator of geology at Columbia University's prestigious School of Mines from 1895. He was also an expert in stone building and Vice President of the New York Academy of Sciences.
One can only imagine the crude techniques involved with making a thin-section in the 1800's. The preparer would have to carefully polish a glass-mounted sliver of material down to ~30 microns - thin enough to transmit light and be viewed through a microscope. How were such precise things accomplished so long ago and how would they look viewed with today's technology?
19th century meteorite thin-sections also present a common problem. Very few of them were labeled with the crucial information needed to identify the name of the meteorite from which they were born. Most say 'Meteoritic Stone' or simply 'Meteorite,' leaving no dates or localities. Luckily, this Julien sample holds some obvious clues, but may raise more questions than answers.
Above: the entire thin-section. Note the thin rind of fusion crust on the lower-right edge.
To think that scientists and geologists gazed upon this very thin-section well over one hundred years ago is incredible. Tom was likely the first to view it in a very long time.
Now back to the mystery. Here is what we know:
1. Chondrite - Likely a petrologic type of 4-5.
2. Alexis Julien lived from 1840 -1919.
3. Iowa has three official chondrites to its name prior to his passing. Marion, 1847 (L6), Homestead, 1875 (L5), and Forest City, 1895 (H5).
4. There is a '61' and 'Iowa Ct' noted on the bottom of the label. Here is where it gets tricky. The MetBull has a single doubtful stone listed in its fall database named 'Iowa City' and as falling in 1861. Is it possible the '61' means 1861 and the 'Iowa Ct' means Iowa City? Could this be a section of Iowa's lost meteorite? Or does 'Ct' mean County, as in Amana, Iowa County, now known as Homestead?
And so I call upon the Met-List and all meteorite junkies to help me with this one. What do you think?
A big thanks to Tom Phillips for his amazing work and technique. You can view his work here: www.meteorite.com/meteorite-gallery/
