Franconia – Before the Gold Rush

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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 efforts and report on their findings.   

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 fine-grained 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.     I 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?”

2

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 (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.

 

Name -	Mass	Found	Pcs.	GPS	Finder	Holder
Field ID#	(g)	mm/dd/yy
Franconia	4255.0	10/31/02	1	r	John Wolfe	r (α)
F 002	57.0	11/16/03	3	n/a	Mike Miller	r (β)
F003-F008	33.0	11/23/03	5	n/a	Rubin Garcia	finder
F 009	3550.0	01/09/04	1	r	John Wolfe	r
F 010	~3000	01/09/04	1	r	anonymous	b.m.
F 011	3430.0	01/11/04	1	r	John Wolfe	r
F 012	1850.0	01/11/04	1	r	Jim LaBarbera	finder
F 013	1653.3	01/11/04	1	r	John Wolfe	r
F 014	650.0	01/18/04	14	r	John Wolfe	r
F 015	~150	01/18/04	~5	r	anonymous	r
F 016	456.3	01/18/04	1	r	John Wolfe	r
F 017	16 lbs.	01/23/04	1 *	n/a	anonymous	finder
F 018	816.0	01/28/04	1	r	Larry Sloan	r
F 019	6750.0	01/29/04	1	r	John Wolfe	r
F 020	817.0	02/01/04	1	r	Larry Sloan	r (β)
		?
? =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	6963.0	~02/06/2004	1	n/a	J. Schrader	r
F 022	~2000	~02/15/04	1 *	n/a	"Homer"	r
F023-F029	~8500	Feb-Mar04	~10	n/a	S. Clary	finder
F030-F033	14612	Feb-Mar04	4	n/a	John Wolfe	finder
F034-F041	5975	Feb-Mar04	7	n/a	John Wolfe	finder
F041-F054	4526	Feb-Mar04	13	n/a	John Wolfe	finder
F 055	3787.5	~03/13/04	1	n/a	property owner	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