Where it all began: Mundrabillia, Australia
Transcription
Where it all began: Mundrabillia, Australia
Meteorite Times Magazine Contents by Editor Featured Monthly Articles Accretion Desk by Martin Horejsi Jim's Fragments by Jim Tobin Meteorite Market Trends by Michael Blood Bob's Findings by Robert Verish IMCA Insights by The IMCA Team Micro Visions by John Kashuba Meteorite Calendar by Anne Black Meteorite of the Month by Editor Tektite of the Month by Editor Terms Of Use Materials contained in and linked to from this website do not necessarily reflect the views or opinions of The Meteorite Exchange, Inc., nor those of any person connected therewith. In no event shall The Meteorite Exchange, Inc. be responsible for, nor liable for, exposure to any such material in any form by any person or persons, whether written, graphic, audio or otherwise, presented on this or by any other website, web page or other cyber location linked to from this website. 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Meteorite Times Magazine Mundrabillia, Australia: Where it all began. by Martin Horejsi Where it all began: Mundrabillia, Australia The etched face of of this 69g end section of Mundrabillia brought joy to its owner, and the touchable wonders of space to hundreds if not thousands of students in its several decades as the cornerstone of my collection. Twenty or so years ago, I bought my first meteorite, an etched end section of Mundrabillia, and the magic began. The iron was purchased as a teaching aid to share with students who were learning about space science. The specimen came from David New and was chosen under his guidance as a nice, affordable example of a meteorite that would serve my needs well. He was right. But instead of being one of the many buyers of a meteorite who never make the turn to a former collector of meteorites, I followed his suggestions for the next decade buying almost everything he suggested. And he was never wrong as far as I was concerned. While the etched piece of Mundrabilla was my first meteorite, this was the first specimen card in my collection. Back in those days of long-distance telephone fees and no internet, meteorite were advertised in mailings, and inquires were made one at a time over the phone. It didn’t take the collector long to learn that what was listed in the mailed flyer was likely just a sample of what was available. Once on the phone with the dealer, the true scope of the potential offerings came into focus. Decision making back then contained the elements of one-on-one attention. If I was on the phone with David, then at that moment, I was first in line for whatever he had to offer. On more than one occasion I passed on buying a sample David suggested only to call back a few hours or a day later only to learn it had sold minutes after I hung up. Is that rust or dirt? On achondrites like Millbillillie its obvious, but on irons like Henbury, Boxhole and Mundrabillia its not so obvious. Mostly its rust. Sometimes it a combination of the two. And in those wonderful nonsanatized examples, its authentic Australian soil which just happened to be the only documented witness to the fall of Mundrabillia. For me, those early days of meteorite collecting were truly magical. For many of us, the only specimens we knew of where in museums and our own collections. It took the internet to provide a global venue for sharing our collections with each other. The internet has also dramatically changed our was of exchanging meteorites. Pictures are a must, and instead of a tens or hundreds possible buyers receiving a listing in the mail, there is no ceiling to the number of people who can view a meteorite offering, which of course also means the collector is considerably more savvy with market values and available specimens. But in the long run it is the relationships and stories the meteorites fostered that really make collecting a joy. As 2012 greets us, I will be again taking a break from writing my Accretion Desk columns with the detail I usually put in to my tales. Many projects are taxing my time so even carving out the small handful of hours needed to create an Accretion Desk has become a challenge. I want to enjoy spinning my meteorite yarns, and with m time constraints right now, I see no option but go to to a more simplified type of Accretion Desk. And I’m just as excited to see what that is as you are. Until next time…. The Accretion Desk welcomes all comments and feedback. [email protected] Meteorite Times Magazine Alamo Breccia 2011 by Jim Tobin As I write this I am hoping I will have enough new material to offer from our second visit to the Alamo Breccia that I did not say in the original Alamo Breccia article of November 2002. But, I guess I will start by saying that when we were there a few weeks ago I thought it had only been 8 years. Then I looked at the magazine back issues and found to my surprise that it had been ten years ago. I looked over the original article and said to myself that is pretty good, I clearly had more time in my life to do research and to spend on writing. But, I will give it a shot anyway again this month. The Alamo Breccia is a prominent layer of rock that can be traced visually for a long distance undulating from ridge to ridge and mountain to mountain over a wide area of Nevada. Mostly a gray color it is seen usually as two close together thick bands of rocks with some thinner layers added. Up close investigation shows these apparently separate layers to actually be from the same event. At the Hancock Summit site the exposures are easy to find visually. However, to get up onto the top of one of them is a good hike up steep terrain. You will be making your own path most of the way since there is not a real trail to follow. So pick a rate of climb that you are comfortable with and then make your way from boulder to boulder up to the top of the ridge. A portion of the rocks projects forward as a separate prominence. The remainder of the mountain rises behind you. From there you can stand and look out over the valley. I am really uncomfortable up on top of the ridge. I managed to get up there but did not stay long. I retreated to a spot just a little lower where I could collect specimens from the side of the exposure rather then off the very top. Paul up on top of the layer where I did not stay long On our way up we had determined to find the stromatolites. We had missed the best deposit the first trip. So after photographing the single petroglyph that I showed in last month’s article we made sure to find the stromatolites. We knew they were near the bottom of the mountain. We began hiking up a little more westward this trip and found the stromatolites pretty easy. We also immediately saw that there had been a lot of core sampling done since we were there last. In several places numerous cores had been removed. Paul suggested that there may have been so many done in order to provide each person in a large group a core of their own. That makes quite a bit of sense. There were more cores taken then needed for dating or other analysis, dozens. From the top of the ridge you get a great view out toward Area 51 and part way around the valley that leads ultimately after a few more mountains to Rachel, Nevada. As I said at the beginning the layer of Alamo Breccia can be visually traced from ridge to ridge and across the intervening valleys and washes. I had been noticing what I was sure was the continuation of the layers on the other side of the road from where we parked. After eating lunch we headed across the road. The Alamo Breccia there was tilted much flatter showing more surface of each layer. It was much like playing cards fanned out rather than the cliff-like exposure of the entire thickness on the other ridge. But, like the exposure of the morning hike if you when farther around the hill it too became a cliff as can be seen in the following picture. On the previous trip years ago we had hiked over to the next mountain in the other direction, about, I would say half a mile away southward from the high difficult ridge. There the rocks were slightly different again. In this part of Nevada it is not hard to find the Alamo Breccia. For example, when we returned to Rachel we drove off the road and parked to take some pictures of the abandoned mine that is outside town. As we were standing there I noticed that the rocks at our feet were mostly Alamo Breccia that had washed down out of the mountains near Rachel. The Tempeute Mountain deposit near there is 4×4 accessible with a serious hike at the end. Yet even miles away at the abandoned mine the ground is covered with mainly pieces of breccia. Your normal piece of Alamo Breccia from the Hancock Summit area is a gray stone with a distinct glassy feel and clink when struck. It is not rock that one would want to work with for very long without gloves. It is sharp often and wears out the skin fast when trying to pull it from the ground or even carry it. We put the pieces into back packs to get it to the 4×4 and then stored it in plastic tubs I had brought. We did not bring back really that much; a dozen pieces I guess from each of the two locations. Alamo Breccia is easy to work from a lapidary standpoint. It is not particularly hard and it polishes up nice. But, like most impact breccias it is prone to having cracks and to falling apart. Pieces will often crumble a little in the saw and portions may dislodge on the diamond lapping disks during smoothing. This has been the case with the interesting white crystal filled material from the site near the road. The crystal is rather fibrous and chunks cleave off very easy around the edges. It is stable in the middle of slices and as can be seen in the accompanying photo it is quite nice looking material. The Alamo Breccia rock unit is made up of several layers. At Hancock Summit there is a thick layer of huge mega blocks and giant boulders. In places the blocks are so large that it looks like a regular layer of gray rock rather then one made of blocks at all. Another layer consists of large clasts from say half an inch up to several inches with very little tiny broken rock in it. A third version is made up of material much more pulverized. It can contain little or no large clasts. There are many pieces which are a blending of these last two. Sometimes tiny breccia material will be found filling the gaps and cracks between the larger cobbles and boulders of broken rock. The shells and coral present at the impact site were incorporated into the rock as well. The Alamo Event as it is sometimes referred to was a very significant impact. The minimum area involved is on the order of 100,000 square kilometers. The rock layers are found to one extent or another at 25 different mountain ranges. Estimates for the cubic volume of rock transported by the event are all over the place. Estimates range from hundreds of cubic kilometers to a staggering 1000 cubic kilometers, to the unimaginable 2500 cubic kilometers. My geology training is pretty old at this point, though I have continued to use it over the years. Some impact products known today were not known when I was a student. So my descriptions of the layers as they are seen are my impression only and should be taken with a grain of salt. But, it is a difficult problem for professionals too as I read the written material. Several writers have made comments about not having access to places in the Area 51 portion of the impact region. Places that hold information necessary to aid the investigation of the Alamo Impact. Clearly the feel and sound of the rocks leads the visitor to the site to regard many of them as heat generated. However, the way that the beds themselves appear suggests water transport played a part. There is also the problem of differentiating what is immediate fall back material and what is later infill from subsequent land slide and tsunami activity. On top of these issues, you need to know in what zone the deposit you are looking at resides. In the case of the Hancock Summit sites where there are usually three or four outcrops marked on older study maps, you are outside the crater in one of the transitional zones. It is sometimes referred to as the Ring Realm. So any impressions of water reworking of material are certainly justified. The impact was into an ancient sea and the water was displaced , tsunami waves were formed, and then the water moved back into the sea after the event. Clearly some areas were stirred up considerably. There has been modeling by investigators that incorporates a series of tsunami waves being made along with collapse and landslide wave action as well. Presumably while all this was happening layers of broken rock ejecta and carbonate accretionary lapilli were being laid down. These however, are now incomplete layers disrupted and partially erased by the continuing water and settling processes. But, pockets of mostly small clast size breccia and scattered samples of the carbonate accretionary lapilli layer can be found if you hunt around a little. Some of the layers made up of large boulder size masses have fill material of finer grain size. I am guessing that this is reworked ejecta material that has settled and washed into the fracture spaces of the layer made up of boulders and megablocks. The most interesting material for me as a collector who is going to cut it up and polish it comes from the layer at or near the top made of mixed smaller size particles. This is the material which to me is so visually attractive when cut. Solid chunks of dolomite are in this writer’s opinion near the top of the list of boring rocks when cut. In the case of the ones involved in the Alamo Event they are plain dark gray to nearly black featureless stone. But, mix them up with a more than a dozen different limestones and other rocks, throw in a nice helping of fossil shells and you have a great impact breccia. At Hancock Summit this portion of the Alamo Breccia section is not very thick so you have to do some hunting around up on top to find the nice specimens. This layer of material is called in the literature the A Unit and varies from site to site greatly in thickness. I would estimate that up on the ridge it is only 1-2 meters thick. Though hunting around at the side of the cliff and the base of the ridge would probably yield many good specimen amongst the tallus that has fallen down. Across the road at the new spot we went to this trip the smaller grain breccia is spotty, less abundant but easier to get to. That is where we found the vein of breccia mixed with white crystalline rock. I hesitate to say that this was one of the well documented dikes associated with the Alamo Breccia at many locations. To me with the opportunity we had to briefly study the thing, it looked like a vein of rock that formed and filled a crack at a later time. I have not researched the dikes in the Alamo Breccia to see if they were immediate formations of injected material or later filled cracks running perpendicular to the bedding. The vein was an interesting feature however it came to be. I could probably be happy revisiting the Alamo Breccia sites every few years. Maybe come up with some alternating schedule. Meteor Crater one year, Alamo Breccia another with a couple other favorite areas for a couple years in between. Every time I go I find new material that I have only read about. As they say a picture is worth a lot of words so here is a small album of a few more pictures of the Alamo Breccia and the Hancock Summit location. Until next month, enjoy your meteorites and have a great up coming new year. Jim Meteorite-Times Magazine Meteorite Market Trends by Michael Blood Like 3 likes. Sign Up to see what your friends like. This Month’s Meteorite Market Trends by Michael Blood Please Share and Enjoy: Meteorite Times Magazine Franconia – Before the Gold Rush by Robert Verish An Article In Meteorite-Times Magazine by Robert Verish "Franconia - Before the Gold Rush" A reprint of my May 2004 article in the magazine titled, "Meteorite" This aerial view of Franconia Wash was taken by the author from 22,000 ft in May 2009. The view is south across the Sacramento Wash towards the Buck Mountains and is looking down the trend of the Franconia strewn field(?s?). There has been a renewed interest in the history of the various meteorites that have been found at Franconia, Arizona, within the Franconia (H5) strewn-field. For example, there is a new group of meteorite hunters that like to call themselves "TEAM HERSHEY" and have a discussion group named "Desertsunburn" that is moderated by an Arizona meteorite hunter and amateur researcher, Jim Wooddell. The thing about these hunters is that they like to hunt as a team, and their team leader, Jim, likes to document everything that they do in the field, particularly out at Franconia. To give you some idea, here is a link to one of their group-hunts that Richard Garcia coordinated and Jim documented, and that they called as, "The 1st Annual Franconia Birthday Hunt". As I said, Jim is conducting field research and researching the history of the Franconia strewn-field, and no doubt, if you ever made a meteorite find at that locality, he has probably contacted you for an interview. And if he hasn't contacted you, yet, there is no need to wait. Just email him, or go over to his DesertSunBurn YahooGroup and share your story with Jim and the other fellow meteorite hunters. Field workers, like Jim Wooddell, are aided in their research on the history of the Franconia Area Meteorites by utilizing Internet search-engines. But not everything that was published about Franconia Area Meteorites can be found on the Internet. In particular, magazine articles are not always reproduced on-line in "full text", unless a "reprint" should appear on a personal website. For instance, my first "printed" article about Franconia can't be viewed over the web. At least, so say the people that have come to me asking for a copy. And now this current interest in Franconia Area Meteorites has prompted me to make my old article more accessible. Hence, my subject this month will be a reprint of that article. And the subject of that original article was a description of the events that occured between the time that John Wolfe discovered the Franconia meteorite in 2002, and the peak of the "Gold Rush" to that meteorite locality in 2004. Now, for my "disclaimer": The following "reprinted" article from the May 2004 issue of the magazine titled, "Meteorite", has been reproduced in its entireity - meaning that it appears as it was originally published - with no corrections or updates. It DOES NOT represent our current understanding of this locality, let alone attempt to explain the variety of meteorites that have subsequently been found. For that matter, much about this locality is still being debated, and a common consensus has yet to form. This reprint is intended for historical-research purposes only. FRANCONIA – BEFORE THE GOLD RUSH -------------------------by Robert S. Verish There’s a “gold rush” going on right now in Mohave County, Arizona. It’s a meteorite gold rush and no, it’s not Gold Basin, it’s Franconia. And, as this event becomes known to the general public, the outcome of all this frenzied activity may affect meteorite hunting in Arizona, if not the entire western United States. The Franconia “gold rush” got into full swing soon after the 2004 Tucson Show. Reporting on events as recent as these is akin to writing about the 1849 California Gold Rush in May of 1849! It’s too soon for a comprehensive report. This article will focus on the events before the 2004 Tucson Show. Prior to that time, there were only a handful of people searching and documenting their efforts at Franconia. This article will describe those recovery If meteorites have fallen evenly over the surface of the Earth, then you may be asking, “Why does Mohave County have so many different meteorites”? In my opinion, it’s more a matter of geology, than of coincidence. Mohave County is special because the Colorado River flows through it. Back in its geologic past, either the sea level rose or there was a tectonic change, but something caused the Colorado River to back up and deposit finegrained lacustrine sediments that formed the now flat-floored valleys. When the Colorado River dropped down to its present level, it cut down through these layered sediments, and abandoned them from their source, never to have sediments deposited on their flat-topped surfaces again. Over time these surfaces developed desert pavements, which allowed meteorites to accumulate without becoming buried. I need to comment here - I realize that when meteorites impact the ground they usually bury themselves. But nearly all of the Franconia stones have been found exposed on the desert pavement. This contradiction has never been adequately explained. Nor is it within the scope of this article to propose an explanation, let alone prove one, but suffice it to say that when/if this contradiction is explained, it will most likely link these lacustrine sediments to this phenomenon. Mohave County is also special in that it has gold-bearing rock. The Colorado River eroded these exposures, to form placer gold deposits. When these gold fields and desert pavements are one and the same, all you need now to find meteorites are meteorite savvy gold prospectors. The first reported find of the Franconia (H5) meteorite was in 2002 on October 31st. And my involvement with this meteorite started that same day when the finder, John P. Wolfe, put in a phone call to notify me of his latest find. Within 3 days I, along with a couple members of my meteorite recovery team, were in the Franconia Wash inspecting the recovery site. It’s not that I had any doubts about John Wolfe’s find; it’s just that this is what I do in my spare time. document meteorites. And I study the surfaces that they were found on. (A quick search on Google for “Franconia will quickly show what I mean.) I first became acquainted with John, a gold-prospector-turned-meteorite-finder (with an uncanny ability to find new meteorites), a year earlier back at Gold Basin when I helped him get classified his 3.6kg fresh-fusion-crusted L6 meteorite that he had found in the middle of that strewn field. I have often traveled through Franconia on my way to Gold Basin, and many were the time that I said to myself, “Why go any farther? The surface here is even better than where I am headed!” So, I wasn’t surprised that John had made a find here in this part of the Colorado River valley. Not sure why John would regularly camp at Franconia, but he soon found the surface was not conducive to metal detecting for nuggets, yet was perfect for spotting dark-colored rocks. And this is the reason why John ended up finding the very first Franconia stone without the aid of a metal detector. He spotted it from a distance of over 50m. He stated that it helped that he was sitting on one of the many flat-topped ridges in this area while taking a break from his visual search for meteorites. From there he was able to look out over the eroding hog-backs and to slowly scan for exposed rocks that were “too dark”. It was on one of these hog-backs that he was able to spot the dark brown Franconia meteorite resting on the light-colored sediment. As noted earlier, John got me involved immediately, and the next day he and a few of his fellow gold prospectors started searching for more stones. My team members joined forces with them and a meteorite-recovery alliance was formed! But as each week went by without a second find being made, we eventually became discouraged. The reason we became discouraged is that even with a 6-man recovery team, not enough area was getting covered. The slow pace was at the heart of the problem. Because John and his fellow prospectors were experts in the use of metal detectors at Gold Basin, it was difficult for them to put down their metal detectors and to trust their eyes to do the hunting. The other team members were experienced dry lake searchers, on areas with few rocks. But in the pebbly alluvium they got bogged-down by the sheer number of rocks. They found it too difficult to “just scan” the desert pavement. Summer comes early in the Colorado River Valley cutting that recovery season short. There were milder areas elsewhere that needed to be searched. But over the summer John and his fellow prospectors solved the problem of how to cover more area while searching for meteorites. Each of them had acquired either an ATV or a dirt bike. Also over the summer, this same group worked together at other strewn fields perfecting their visual search methods while driving their off-road vehicles. This practice brought about a marked improvement in meteorite-recovery efforts. These advancements were more cultural than technological. And as a direct parallel, just as the Clovis point simultaneously appeared in the archeological record at numerous sites across the Americas, so too has the idea of searching for meteorites while riding on an ATV now become a widespread practice this past hunting season. In short, most prospectors are now using ATVs to search for meteorites. John continued to return to the Franconia area over the course of the next year. His perseverance paid off, but in the end, the opening up of the Franconia strewn field was more a matter of serendipity. John found his second Franconia stone along side a dirt road while he was driving his truck. He had driven this stretch of dirt road many times before, but this time the lighting must have been perfect because he spotted the dark-brown stone through his passenger-side window! (see figure) Had this “second” stone not been lying next to the dirt road, there is no telling how much longer it would have taken to find the Franconia strewn field. As it was, the second stone took 14 months to find. But now, with this second GPS coordinate, it took John less than 2 hours to find the third stone! And within the next 3 months, the vast majority of the stones from this strewn field were found. In addition, at least 3 other “different” meteorites (still pending classification) were found interspersed, or “over-lapping” this Franconia (H5) strewn field. Hence, whenever someone says that they found a Franconia meteorite, the typical response is, “Franconia! Yes, but which Franconia?” The importance of finding the second stone may have been overstated, because the primary factor for the rapid rate of recovery for the remaining stones is that nearly every prospector is now hunting for meteorites while driving on an ATV! But this “advance” has come with a “down-side”. The ATV’s can have a negative effect on the desert environment. And just as the arrival of early-man to the Americas had an impact on the numbers of large land mammals of that time, so has there been fallout over the cross-country use of ATVs in the search for meteorites. [Disclaimer: Neither I, nor any California member of my meteorite-recovery team, ever used an ATV or drove off-road in the Franconia, AZ area.] Some meteorite recovery lessons learned and observations from Franconia: 1) The bad news is that the time and effort needed to determine whether or not a strewn field exists may be greater than anticipated. In the case of Franconia, more than 1 year elapsed between finding the first and second stone 2 (approx. 1 man-year). 2) The good news is that since it has been shown that finds can be spotted while operating an off-road vehicle, a greater area can be searched in a shorter time period. In the case of Franconia, most of the finds were exposed at the surface. 3) The bad news is that concentrated usage of ATVs can have a negative impact on the desert environment. Prior to February 2004 a total of 20 chondritic stones have been reported and documented (see Table). Of these, 10 have been verified as being stones from the Franconia (H5) strewn field. The other 10 stones appear to be from 2 or 3 different falls. They are still pending classification. I have made available the data that I have accumulated to the labs conducting the classifications by publishing the Table included in this article. Since February 2, 2004, many more finds have been made, and continue to be found at Franconia by a greater, but unknown number of prospectors and land owners. The number of individual stones recovered has already surpassed 84 with the approximate TKW (Total Known Weight) exceeding 100kg. The details relating to that period of time will all have to be reported upon later – After the Gold Rush. The above article originally appeared in the May 2004 issue of Meteorite magazine. © 2004 by Meteorite magazine. The table below was submitted with the original draft to the editor of Meteorite, but it was not included with the published article. It is included here for completeness and for reader's convenience, but the same disclaimer for the reprinted article also applies to the following table - it is reprinted in its entireity - uncorrected and with no updates, and is intended for historical purposes. Name Field ID# Franconia F 002 F003-F008 F 009 F 010 F 011 F 012 F 013 F 014 F 015 F 016 F 017 F 018 F 019 F 020 Mass (g) 4255.0 57.0 33.0 3550.0 ~3000 3430.0 1850.0 1653.3 650.0 ~150 456.3 16 lbs. 816.0 6750.0 817.0 Found Pcs. GPS Finder mm/dd/yy 10/31/02 1 r John Wolfe 11/16/03 3 n/a Mike Miller 11/23/03 5 n/a Rubin Garcia 01/09/04 1 r John Wolfe 01/09/04 1 r anonymous 01/11/04 1 r John Wolfe 01/11/04 1 r Jim LaBarbera 01/11/04 1 r John Wolfe 01/18/04 14 r John Wolfe 01/18/04 ~5 r anonymous 01/18/04 1 r John Wolfe 01/23/04 1* n/a anonymous 01/28/04 1 r Larry Sloan 01/29/04 1 r John Wolfe 02/01/04 1 r Larry Sloan ? ? =After this point in time, the date of finds becomes uncertain, and only the number of stones and the total mass was properly recorded and is known for certain. There were 64 additional stones known to have been found, and as of March 20, 2004 - the TKW for the Franconia (H5) is ~102kg. Some of those "later" stones that were of importance: F 021 F 022 F023-F029 F030-F033 F034-F041 F041-F054 6963.0 ~2000 ~8500 14612 5975 4526 ~02/06/2004 ~02/15/04 Feb-Mar04 Feb-Mar04 Feb-Mar04 Feb-Mar04 F 055 3787.5 ~03/13/04 1 1* ~10 4 7 13 n/a n/a n/a n/a n/a n/a 1 n/a J. Schrader "Homer" S. Clary John Wolfe John Wolfe John Wolfe property owner Holder r (α) r (β) finder r b.m. r finder r r r r finder r r r (β) r r finder finder finder finder finder 1 * = these two stones are not paired to Franconia (H5), but they are most likely paired to each other! (α) = type specimen at UCLA (β) = type specimen at ASU b.m. = anonymous collector n/a = not available r = recorded & available upon request Typically, Franconia (H5) has many metal-grains (Ni-Fe), some quite large, and it is not unusual to find copper (Cu) in close association with troilite (tr). Photomicrograph in reflected-light of a thin-section from the Franconia initial discovery mass (3550g stone). The above "reprinted" article describes the events that preceded the Franconia meteorite "gold rush" in early 2004, and states that a proper accounting of this locality and its various meteorites will have to wait until "After the Gold Rush". But that "accounting" will still have to wait, because here we are - 8 years later - and the gold rush still continues! REFERENCES: Verish, R.S., 2004. "Franconia - Before the Gold Rush". in Meteorite 10:2.34. Search results for internet references to "Franconia Area Meteorites": Verish, R., 2003. "Just in time for the Tucson Show - A New Arizona Chondrite - Presenting the 'Franconia Meteorite'" , in Bob's Findings, an on-line article in Meteorite-Times Magazine for February 2003. Verish, R., 2007. "Another Buck Mountains (L6)", in Bob's Findings, an on-line article in Meteorite-Times Magazine for May 2007. Verish, R., 2007. "Dutch Flat (IIAB) - Another low-Iridium iron meteorite. But, is it paired to SikhoteAlin?", in Bob's Findings, an on-line article in Meteorite-Times Magazine for June 2007. Verish, R., 2008. "A Simple Technique to Improve Meteorite-Recovery.", in Bob's Findings, an online article in Meteorite-Times Magazine for November 2008. Verish, R., 2009. "Jim Smaller Memorial Meteorite Hunt", in Bob's Findings, an on-line article in Meteorite-Times Magazine for December 2009. Notkin, Geoffrey, 2004. "Franconia Meteorite Hunt — Photo Gallery". These images are also in an article that originally appeared in the August 2004 issue of Meteorite magazine. Meteoritical Bulletin: Entry for Franconia Basic information: Name: Franconia - This is an OFFICIAL meteorite name... References (related to the geology of the Franconia area): Metzger, D. G. and Loeltz, O. J., 1973, Geohydrology of the Needles area, Arizona, California, and Nevada: U.S. Geological Survey Professional Paper 486-J, 54 p. Roberts, P., 1992, Miocene Basin Evolution in the upper plate of the Whipple detachment fault, southwestern Arizona: unpublished M.S. thesis, Northern Arizona University, 136 p. Spencer, J. E. and Patchett, P. J., 1997, Sr isotope evidence for a lacustrine origin for the upper Miocene Pliocene Bouse Formation, lower Colorado River trough, and implications for timing of Colorado Plateau uplift: Geological Society of American Bulletin, Vol. 109, No. 6, p. 767-778. R. Tweed, Master's Thesis ... SJ, eds., Geology and mineral resources of the Buckskin and Rawhide Mountains, west-central Arizona: Arizona Geological Survey Bulletin 198, p. 47-50. Buck, WR ... www.lowell.edu/users/tweedr/thes_ref.html - 19k - Mar 16, 2004 - Cached - Similar pages Geologic Map of the Mojave Mountains Area, Mojave County, Western ... ... 2 of sheet 1). The low Buck Mountains lie northeast ... is Crossman Peak in the Mohave Mountains, at an ... 2 includes a brief discussion of the geology, cross sections ... geopubs.wr.usgs.gov/i-map/i2308/ GEOLOGIC MAP OF THE MOHAVE MOUNTAINS AREA, MOHAVE COUNTY, WESTERN ARIZONA, by K.A. Howard, J.E. Nielson, H.G. Wilshire, J.K. Nakata, J.W. Goodge, S.L. Reneau, B.E. John, and V.L. Hansen, in U.S.G.S. Miscellaneous Investigations Series I-2308, 1999 Aerial Photo from: GEOLOGIC MAP OF THE MOHAVE MOUNTAINS AREA, MOHAVE COUNTY, WESTERN ARIZONA, by K.A. Howard, J.E. Nielson, H.G. Wilshire, J.K. Nakata, J.W. Goodge, S.L. Reneau, B.E. John, and V.L. Hansen, in U.S.G.S. Miscellaneous Investigations Series I-2308, 1999 My previous articles can be found *HERE* For for more information, please contact me by email: Bolide*chaser Meteorite Times Magazine IMCA Insights – December 2011 by IMCA TEAM IMCA Insights – December 2011 The COMETS COlorado METeorites Society by Anne M. Black What better way to introduce the COMETS club, of which I am a member, than to use their own website: www.peaktopeak.com/comets Our History …as briefly told by Fred Hall, a founding member… “I met Anne Black and Mike Jensen at a restaurant for breakfast before I led a meteorite hunting trip to find some Johnstown meteorite. While seated in the restaurant, I mentioned that I was thinking of starting a meteorite club in Colorado. Mike and Anne looked at each other and Mike turned to me and said ‘We were thinking of doing the same!’ or something close to that. Mike started up the Yahoo site and we soon held our first meeting.” That was in 2000. What do we do? It’s all about meteorites. We collect them, look for them, read about them, dream about them… you name it, we do it. We try to meet once a month so we can swap stories, have a “show’n'tell” with the goodies that we have acquired (found or purchased), talk about what’s going on in the meteorite world and just have a good time with fellow meteorite enthusiasts and friends. Two things immediately stand out, the focus of the club is Meteorites, and the members meet in restaurants, in fact it is quite often a Mexican restaurant with very good margaritas. And one thing the Club is not is stuffy, or even organized. As stated above the COMETS club was created in 2000 but we never got around to creating any rules, or regulations, there are no officers, and no dues. We usually meet once a month, if there are enough members in town and available, and then we just chat about our favorite subject. We have organized a few meteorite-hunts, very few, in fact. The one to Johnstown mentioned above did not result in any findings, but it did get us out of town and we explored the small town of Johnstown, the church, the cemetery right behind it where they were preparing for a funeral when the meteorite fell on the 6th of July 1924. But all the members do rally and get to work once a year for the Denver Gem and Mineral Show, midSeptember. Occasionally one of the members will set up a display case in the Main Show in the Merchandise Mart; in 2008, Fred Olsen did a great double case featuring the Meteorites of Colorado, a display that was very well received. Thank you, Fred! The main focus of the whole group is our Auction and Get-together. It used to be held on two consecutive evenings but was consolidated into one long evening a couple years ago and is traditionally held in the warehouse of “Mineral Boxes and Supplies”. Fred Olsen, the owner and our resident (retired) geologist, moves all his boxes a bit out of the way, we set up a buffet with barbecue beef, pork and all the trimmings, and of course a keg of beer and some wines. When everyone has had plenty of time to eat, drink, look at the pieces offered in the auction, and most of all chat, we open the Auction. Not a very big auction, nothing really high-priced, the goal is mostly to cover the expenses. Food goes first! All ready for the Auction Mike Jensen is usually our Auctioneer Another group effort has been the renovation of the meteorite display in the Geology Museum of the School of Mines in Golden, just west of Denver, with the approval of Dr. Geller, the very friendly curator of the Museum. We donated one display, and Dan Wray has been very busy renovating several others. And of course we all helped with labels and specimens. Now, we highly recommend the Museum to any meteorite enthusiast coming to Denver. Dr. Geller (left) welcomes the COMETS members during another of our regular visits One of the 3 display cases housing the Meteorite Collection of the School of Mines, and a few of the COMETS members In conclusion, and because it is the season, we also have our own small Christmas party. For the last few years, it has been held in Roger’s large and pretty house. Thank you Roger! This year only a dozen members were in town, but size of the group is not everything. It is “pot luck” and this year the buffet was really international, from lasagna to an oriental salad and French wine. Of course no Christmas Party is complete without Christmas gifts All the COMETS members wish you all, wherever you are around the planet, a joyous end to 2011 and a very happy New Year 2012. Anne M. Black This article has been edited by Norbert Classen • IMCA Home Page • IMCA Code of Ethics • IMCA Member List • Join IMCA • IMCA Meteorite Info Meteorite Times Magazine Moorabie L3.8-an by John Kashuba A few of us were talking meteorites when one friend mentioned Moorabie. When I couldn’t recall the stone I was admonished to refresh my memory as soon as possible. I make amends with this column. Even before checking my small collection I consulted David Weir’s Moorabie page to see what the score was. He lays out the reasons for the “anomalous” classification and why the “L” designation is a bit tentative. Researchers make a good case for Moorabie being from an ordinary chondrite parent body other than the H, L and LL PBs. While the parent body was still plastic it sustained a deforming impact that oriented its components. This slice appears to have been compressed from the top and bottom. Moorabie L3.8-an. That same preferred orientation is apparent here with formerly spherical chondrules now ovoid. Moorabie L3.8-an. Cross polarized transmitted light (XPL) The fibers in this radial pyroxene chondrule appear to have been bent by the impact. Moorabie L3.8-an. XPL. Moorabie is strongly shocked, S4-5. This is unusual for an unequilibrated chondrite. The shock has tweaked the crystal lattice of this olivine fragment such that it does not go into extinction uniformly when the polarizing filters are rotated. Instead it darkens then lightens in a patchwork. XPL. This is a sequence of images of the same olivine fragment as it is viewed through stages of optical extinction in cross polarized transmitted light. This shock induced extinction pattern is called mosaicism. Moorabie L3.8-an. A distorted barred olivine chondrule. Moorabie L3.8-an. XPL. A 3 mm long porphyritic olivine chondrule, by far the dominant type of chondrule in Moorabie. XPL. At lower right is a radial pyroxene chondrule that was distorted, broken and altered before being sectioned for our viewing pleasure. Moorabie L3.8-an. XPL. A dark clast with fine mineral grains. Moorabie L3.8-an. XPL. Metal and brassy troilite (FeS). Moorabie is relatively troilite-rich. Field of view is 2 mm wide. Reflected light. A granular olivine chondrule containing metal blebs. Field of view is 2 mm wide. Reflected light and transmitted cross polarized light. Moorabie L3.8-an. The white surrounding the minerals in the center of this photo is glassy material, possibly maskelynite which is known to occur in melt pockets in Moorabie. Partially crossed polarized light. Meteorite Times Magazine Meteorite Calendar – December 2011 by Anne Black Please click on the meteorite calendar to view a larger image. Meteorite Times Magazine Dimmitt H3.7 from the Monnig Collection by Editor Our Meteorite of the Month is kindly provided by Tucson Meteorites who hosts The Meteorite Picture of the Day. 714.1 gram individual, from the Monnig Collection. H3.7 Impactika Submit Pictures to Meteorite Pictures of the Day Meteorite Times Magazine Bikolite Tektites, Philippine by Editor Click image for larger view. Meteorite Times Magazine Meteorite-Times Sponsors by Editor Please support Meteorite-Times by visiting our sponsors websites. Click the bottom of the banners to open their website in a new tab / window. Once a few decades ago this opening was a framed window in the wall of H. H. Nininger's Home and Museum building. From this window he must have many times pondered the mysteries of Meteor Crater seen in the distance. Photo by © 2010 James Tobin