We are grateful to John White and Marie Huizing for procuring two photocopied articles from 1965 editions
of Rocks
and Minerals. The first article is entitled “Unusual Mineral Locality at Greenbelt, Maryland” by
French Morgan; the second is a follow-up article by Dr. Ernest E. Fairbanks, entitled
“Remarks on an unusual mineral
locality at Greenbelt, Maryland .”
The information in these articles proved essential for this post.
Maryland’s only significant phosphate mineral find resulted when in 1941, a knoll was leveled in order to erect a WWV Broadcasting Station near Greenbelt, in Prince George’s County. Today, the Visitor Center for the NASA Goddard Space Flight Center stands directly on the site. The above pictured image shows one of many unearthed phosphate-bearing concretion nodules that were collected there in the 1940’s.
It is notable that iron bearing sandstone concretions of similar
external visual appearance are common in Prince George’s County northeast of Washington,
DC. However, the only phosphate mineral
bearing concretions ever known to occur in the region are from this one
specific locality.
Out of curiosity, the late Dr. E. E. Fairbanks of the U.S.
Bureau of Mines procured a few of the concretions for examination. The verdict,
presumably based on visual observation, was that the phosphate material was
dufrenite. Dr. Fairbanks then provided a
number of concretions to Ward's Natural Science Establishment, which subsequently
sold them to various dealers and collectors labeled as dufrenite . Some concretions
also found their way to both the Smithsonian Museum of Natural History in
Washington, as well as the American Museum of Natural History in New York.
During World War II, the U.S. Government closed the area around
the towers to the public for safety reasons. However, by 1944, French Morgan and
several other members of the Mineralogical Society of the District of Columbia obtained
special permission to collect there. The group collected several dozen concretions
that apparently had rolled down a small hill from where grading for the radio
towers had taken place. Some of these concretions proved to be more interesting
than those found several years earlier.
In his 1965 article in Rocks and Minerals Morgan mentioned
finding limonite, goethite, opal (var.) hyalite, and beraunite during these later 1944 visits as well as
“red, yellow and white minerals as yet unidentified.” He also
noted “shrinkage cracks lined with microscopic crystals of an unknown
mineral.” Specimens of the crystals were submitted to the U.S. U. S.
Geological Survey, where according to article they “created no excitement.”
Not until late 1949 or early 1950 did the U.S. Geological Survey
become interested in the Greenbelt material. This was after and was probably
prompted by a 1949 article in American
Mineralogist by the late Dr.
Clifford Frondel entitled “The Dufrenite Problem.” Frondel's work confirmed that after analysis, the material
from the original 1941 find at Greenbelt
was in fact rockbridgeite rather than dufrenite. The article described
rockbridgeite as “indistinguishable from dufrenite in its general appearance
and confused with that species since earliest times.” Later in the article, Dr.
Frondel went even further to refer to rockbridgeite as “identical in appearance
with the fibrous varieties of dufrenite.”
Soon thereafter, the U. S. Geological Survey reported x-ray and
chemical analyses of a new and unknown species from within Greenbelt concretion
material. Subsequently, a new revision in Dana noted that a similar mineral had
been found in Russia. A brief description concluded that additional verification
was needed. The new Russian find received the name avovskite. More than a decade after this Russian
discovery and in the midst of the Cold War, Morgan’s article in Rocks and Minerals article noted that “attempt
(to obtain more information and/or a sample) has been made through diplomatic, scientific,
and other channels, but no trace of azovskite has been unearthed.”
Morgan also claimed in his
article that “at the very beginning,” he had been promised naming rights from
an unnamed source should a new species be uncovered. He suggested the new mineral be named named
fairbanksite (not to be confused with
the lead tellurite fairbankite ) in honor of Dr. Fairbanks. The only
reference to fairbanksite we have been able to locate is on Mindat, which
describes it as “unidentified microscopic crystals in shrinkage cracks in
concretions,” citing Hey’s Chemical Index of Minerals, 2nd
Edition 1962.
Even today, the
IMA describes the status of azovskite as “doubtful.” Fleischer's Glossary of
Mineral Species (2014) does not mention azovskite; nor does either edition
of Bernard and Hyrsl's Minerals
and their Localities. Mindat
states that azovskite “appears to be a gel” and “may be identical to delvauxite.”
Delvauxite, however, is amorphous and is not known to replace crystals of other
species, Still, it is interesting to
note brown globular material appearing in shrinkage cracks of Greenbelt concretions
that bear a visual resemblance to delvauxite. Delvauxite is not known to have
been reported from Maryland.
Catalogued in the Smithsonian collection are numerous “azovskite”
specimens, mostly from Greenbelt. The catalog states
or implies that none of the specimens was ever x-rayed. A curious and lengthy
PDF procured from the Internet describes azovskite as a mixture of santabarbaraite and goethite. Also observed on the Internet was an azovskite
specimen from Hagendorf, Germany, offered for sale by a European dealer who described it as
santabarbaraite and goethite on quartz. For
santabarbaraite to be replacing crystals of goethite hardly
seems a stretch. In fact, one of the Greenbelt azovskite specimens catalogued
in the Smithsonian collection names goethite as an associated mineral. Santabarbaraite,
on the other hand, has never been reported from anywhere in the Americas, much
less Maryland. Just as interesting is that the Smithsonian collection catalog
gives the Crimean Peninsula as the locality for one of the azovskite specimens.
According to Mindat, the Crimean
Peninsula boasts five santabarbaraite localities, far more than any other
region or country on earth where santabarbaraite is known to occur.
After Rocks
and Minerals published Mr. Moore’s article in 1965, Dr. Fairbanks submitted
his follow-up article entitled “Notes on the unusual mineral locality at
Greenbelt Maryland,” In addition to gratefully concurring with Mr. Morgan’s nomenclature suggestion, Dr. Fairbanks raised an additional point that 37 years later
would prove eerily prophetic. He stated:
It is definitely
odd that the small area in which the rockbridgeite concretions were found was
the only one in that area where phosphorous was relatively abundant. A very
prominent non-government geologist suggested that a huge dinosaur died here
furnishing the phosphorous.
In 2012, Smithsoniafgist and fossil hunter, Ray Stanford, was instrumental in the
discovery of two dinosaur tracks on the property of Goddard Space
Flight Center. A heavily-armored plant eater, the species was known to reach
the size of a small elephant. It received its name from the numerous spikes in
its armor. Stanford uncovered the tracks during excavation for the new building
pictured at left, photographed from the immediately adjacent Goddard Visitors
Center.
The most recent published research regarding the Greenbelt
concretions appears in Lawrence R. Bernstein’s 1980 Maryland Geological Survey
Publication Minerals of the Washington, D.C. Area, which evolved from an
earlier 1975 U.S. Geological Survey Professional Paper (Volume 475, parts 1-4)
by Mr. Bernstein. Therein Bernstein noted oral communication from Mary E Mrose of the U.S. Geological Survey
reporting cacoxenite, lipscombite,
phosphosiderite, and strengite in the concretions. Our research turns up no
other evidence that lipscombite, phosphosiderite, or strengite were ever
reported from Maryland. The same can be said for the beraunite that Morgan
claims to have collected between 1944 and 1949.
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