Preface Introduction Purpose Antarctic Geology Fluorite Formation Conclusion International Agreements Dr. Grunow Interview Sue Rose Interview Visiting Antarctica Antarctic Links Until Next Time Endnotes Article Contributors Photo & Graphics Credits Suggested Reading Webliography Invitation to Members Past Minerals of the Month		Antarctic Fluorite (Photo by Sue Rose, USPRR)	Radar Satellite image of Antarctica (NASA)
		Who knew our seventh continent was home to...
		...an unspoiled treasure: Antarctic Fluorite!
		The above images are courtesy of Dr. Thomas Fleming (Left) ©2005 and Dr. Bill McIntosh (Right) ©2005

Preface    

    In this followup article to Fluorite: A Global Quest for the Perfect Crystal, I endeavor
to expand on the exotic occurrence of fluorines and fluorites found as extreme rarities on
the frozen continent of Antarctica.  Scientists have discovered fluorine gas, flouride mineral
assemblages, and loose crystalline samples of this amazing mineral during some geologic
reconnaissance missions.  Our task today, is to seek out possible fluorite deposits, or
potential formational conditions to advance our theory that these crystal finds are not unique.
I hope you packed you extreme winter gear, and a mind open to phenomenal possibilities.  
So, here were go!

Introduction

     Under the Earth’s cryosphere (ice sheets) hides a fantastic treasure: Antarctic Fluorite. 
In newly discovered occurrences, intrepid scientific researchers have found samples of polar
this gem.  

     Up to now, this researcher has found only references in academic papers to fluorite’s
existence on the frozen continent.  And some important officials had put me on the right path. 
Recently, I was contacted by Sue Rose, Assistant Curator for the United State Polar Rock
Repository (USPRR) at the Byrd Polar Research Center at Ohio State University.  She was
able to track down a sample, and forwarded some photos to me for this article.  In fact,
Ms. Rose and Curator, Dr. Anne Grunow, have consented to interview on the workings of the
Repository and their experiences.  (see: Interviews, below)

     Since the Repository opened in 2003, in this author’s estimation, the performance of the
staff to put in place a comprehensive research library, thousands of cataloged specimens with
a searchable database online, a laboratory, and educational facility in just a short time, is a
grand accomplishment.  I applaud them for their diligence in their mission to assist researchers,
and to make the writing of this article possible.

Purpose

     The purpose of this article is to inform, in an educational manner, those interested in Antarctic
exploration, and in particular, those who wish to further study the mineral Fluorite (CaF₂) in all its
forms from our seventh continent.

What will be Covered?

     In this article, I will cover some of the known fluorite occurrences in Antarctica and related
geology, interviews with Antarctic scientists and curators, concerning their adventures and work,
the peculiar challenge of polar exploration, and the status quo of conserving the continent for
scientific endeavor.  I will tie all this into a theme, focusing upon Antarctic Fluorite. 

     I intend to stay clear of the political discussion surrounding the future uses for the frozen
continent, save to mention a brief history of the international agreements that provide the climate
for unfettered scientific pursuits.

 What Is Known?

     Today, only scientists and researchers can collect fluorite samples for geologic study.  As
much of the landmass has yet to be explored, we do not know how much fluorite exists there;
or, have we fathomed much about its particular genesis.  It has already been determined that
all three types of rock have formed there: igneous, sedimentary, and metamorphic that could
contain fluorine or fluorite.

     Since Antarctica comprises about nine percent of the Earth’s landmass today, a vast
territory of 5.4 million square miles needs to be covered.  With glaciers covering this polar
regime and chilly weather extremes, exploration may prove difficult, though not impossible. 
So, we will need our extreme cold-weather gear!

     We are on the bridge to amassing knowledge on the geological processes of Antarctica. 
In recent decades, specific research has been aimed at certain rocks and minerals related to
each respective process.  For example, much interest today is focused upon the magmatic
components of the Mt. Erebus volcano.  Our focus is the unexplored world of Antarctic Fluorite. 
So, let’s explore!  Put on you parkas, and join the team.  I’ll dispatch our helicopter!

Our helicopter awaits. Photo by Tim Vermaat		Our Cold-weather Clothing issue Photo by Emily Desmaris		"Mt. Erebus from the sea ice" Photo by Rich Karstens

Antarctic Geology

     From the magma source of the Mt. Erebus volcano to the cooler carbonatites, calcsilicates,
and karst anomalies, the mineral fluorite has been proven present in all of these varied geologies.

     To my understanding, fluorite was first found by Drs. Zeller and Dreschoff in the 1980s as
recounted by Professor David Elliot of Ohio State University.  So, for at least 15 years, the book
of Antarctic Fluorite was opened to study.  Let’s see what more we can find.

     Jutting into the cryosphere we can easily view the Transantarctic Mountains from our perch at
McMurdo Station.  In the shadow of these massive peaks lay fluorite, some deposited by glaciers
or by erosion into lakes, others were created hydrothermally.  We will fly there first.

Arrival at McMurdo Station on January 1, 2000 (Photos by Thomas Fleming)

     “This behemoth mountain chain stretches from Victoria Land to Coats Land. “Its basement
rocks, similar to rocks found in Australia, S Africa, and South America, give credibility to the
theory of continental drift.”[i]

     We will meetup after our initial flyby of the volcano at the base to discuss how what we have
seen relates to plate tectonics, specifically, ancient Pangea and Gondwanaland.

Transantarctic Mountains & Glaciers (Photo by Thomas Fleming, January 6, 2003)		Flyby of the Mount Erebus Crater (Photo by Clive Oppenheimer, 2003)		Map of Gondwanaland & Laurasia

Some Field Study Parameters

     To search for specific fluorite deposits and sources, we must rely both on geologic
reconnaissance and some supposition by theory, as we have limited documented samples
found to date. And, as we have about 91% of the world’s landmasses to search for specimens
and mining from known fluorite locales, the only need we have as a global community is to
study fluorite as a part of understanding the geologic processes hidden under this icy,
harsh-weathered continent.  The limitations of weather, rough travel, the cryosphere, funding,
and a highly specialized interest, only offer a gap to be filled in our potential knowledge as
study-priority dictates.  The quest to understand fluorite in Antarctica will take some time.

Packing provisions (Photo by Thomas Fleming)

This is our starting point.  Before we leave the relative comfort of McMurdo Station on our next jaunt, we must narrow down our search areas to optimize our research resources at our first team meeting.  Also, our geologic reconnaissance mission must be setup and scheduled.      Only after we line up provisions and equipment, can we engage the harsh, cold summer weather (November through February) of the official research season.  This seems like more prep-work than our past excursions, but believe me, to survive and find fluorite, it will all be well worth it.  (If you have any doubts, review the history of the earliest expeditions gone wrong.  Today, with the best modern equipment, and highly-trained support personnel, we can concentrate on finding our fluorite with a prudent stance.)

A Brief History of Geologic Expeditions

     In addition to the more recent Antarctic expeditions that I refer to below, an abbreviated
history of geologic and milestone explorations would give us a foundation for understanding.

     To see more information on these explorers and many more, visit our Explorers page.[ii]

An Antarctic/Pangean Primer

     Accepted by most modern geologists, the proven theories of Continental Drift and of Plate
Tectonics have been the subject of a few recent science-fiction/disaster movies, notably,
“The Core”.  Even the modern remake of Jules Verne’s “Journey to the Center of the Earth”
remarks on such processes to propel the plot forward.  In real science, however, Alfred
Wegner proposed the theory of Continental Drift, and named Pangea (“all earth”) back in 1915.

     For our purposes, a simple comprehension of the basic process as related to the ancient
supercontinent of Pangea will suffice.  We will use Antarctica as a keystone to our puzzle.

     A supercontinent is a landmass that consists of interacting continents that float on their
respective mobile plates, as a teacup sits on its saucer.  Our crustal ‘teacups’ ride on a liquid
core.  During Pangea’s time, the Earth rotated faster, and our younger planet’s plate border
geology worked simultaneously at many locations (continents) at once.  Our example
highlights the boundaries of Antarctica as it “touched” and separated from South America,
Africa, the Indian subcontinent, Australia, New Guinea, and New Zealand.  The southernmost
of the two emerging supercontinents is known as Gondwanaland (breaking apart about
200-245 mya).  This narrows or focus down to about half of the world’s landmasses. 

                 (Courtesy of the University of Texas)  

How did Antarctica form?

     Here is the current thinking: “Scientist[s] theorize that many millions of years ago, all
the land in the world formed a single continent, called Pangea. According to continental
drift theory, this supercontinent broke up between two hundred million and two hundred
and forty-five million years ago into a northern continent, Lurasia, and a southern continent,
Gondwanaland. About one hundred eighty million years ago, Gondwanaland and Lurasia
also started breaking apart. The present day continents began to form and, through
continental drift, started moving toward their present positions on the earth today, and
that's how Antarctica became its own continent.”[iii] 

     For our purposes, imagine fluorite deposits having formed at intercontinental boundaries. 
Then, picture each continent slowly moving away from each other.  Finally, envision today,
a map with many of the world’s known, large fluorite deposits—some being mined.   This is
our frame of reference.  From knowing where to locate fluorite, and how to match the
continents together, as if in solving a jigsaw puzzle, can we infer where we might find
coastal Antarctic fluorite deposits.

     Thus, by comparing the relative geologies of it’s former Pangean neighbors, we can
infer onto Gondwanaland areas in Antarctica to search.  Our goal is to find and compare
fluorite from locations that correspond in chemistry, morphology, and paragenesis.   We
can build upon the work of geologists who have compared topographies, stratigraphies,
and orogenies on other rocks and minerals as the basis for our work.

Dr. Thomas Fleming

One such scientist is Antarctic explorer, Dr. Thomas Fleming, of Southern Connecticut University.  He has studied volcanism as it relates to the breakup of a more recent (~180 mya), smaller supercontinent, Gondwanaland.  As magma may have erased some of Pangea’s geological remnants, it formed new geological records from which to interpolate fresher boundaries to study.  Drs. Fleming and Grunow have worked together on at least one expedition.[iv]      In a recent correspondence Dr. Fleming had told me that he has not yet encountered fluorite in Antarctica.  He did say that some of the common secondary minerals he has worked on in the Jurassic basalts there are: calcite, stilbite, mesolite, apophyllite, and heulandite.

      Apophyllite does have fluorine, and calcite is associated with fluorite.  So,
we can consider that the presence of fluorine from igneous rocks at least establishes the
discovery of fluorine in Antarctica.

    Another Antarctic geologist, Dr. Edward Grew of the University of Maine, told me that
he has worked on “several fluorine-bearing minerals, including wagnerite, fluorapatite, and
florian biotite.  I have not seen fluorite in my Antarctic specimens. In general fluorite is a
rare mineral in the type of rocks study; fluorine is incorporated in the above listed phosphate
and silicate minerals instead of combining with calcium to form fluorite.”

     Professor Alan F. Cooper of the Geology Dept., University of Otago, New Zealand,
posted an online lecture called: "Geological Evolution Of The Transantarctic Mountains,
Southern Victoria Land, Antarctic”.  He referenced the finding at his Pipecleaner Glacier
camp in the foothills of the Royal Society Range.  In a highly alkaline pluton of some size
that ages within the Ross Orogeny, “we found a cross-cutting dyke-like intrusion composed
of the minerals calcite (CaCO3), fluorite (CaF2) and biotite (a complex mica).”[v]

Possibly Fluorite (unconfirmed) from Pipecleaner Glacier area (From the USPRR, Photo by Sue Rose)

     Thus far, three active explorers can reference recent findings of fluorine-bearing minerals. 
Our aim is to tie-together the ancient continental boundaries with matching fluorite deposits. 
Though this is highly unlikely, given that most fluorite is of secondary origin, and that our
proofing is the reverse of their methods, perhaps the raw materials and conditions at those
boundaries were conducive towards an independent, yet nearly simultaneous formation. 
We can at least explore the latter.

     Many biologists assume that lifeforms are opportunistic, that wherever conditions are
suitable for life, life will exploit them, if it is present.  Geology supports life, and life creates
some geology.  For example, hot springs support microbes.  Also, decaying plant matter
acidifies groundwater to create the limestone erosional-component of carbonic acid, thus
forming karst caves.

     And, that all of the processes of a planet are combined into one interdependent entity
or ecosphere (the Gaia Hypothesis).  Geologists can assume that wherever similar
conditions exist for a geologic process to occur, that it will occur.  Accepting that two
continental boundary conditions can give paragenesis to a secondary mineral, fluorite, we
can assume that fluorine will form with hydrothermal, or other type calcium to form fluorite.

     Perhaps we might find evidence in off-shore sediments and sedimentary rocks.  Dr.
Bernie Gunn, who studies Ross Sea sediments, communicated to me as a supposition
that “…there should be fluorites in the Ross group metasediments as their are things
like scapolite…”

Antarctic Fluorite Supposition

     With the find of these rare purple-white fluorite crystals comes the question of how
they were formed, and what is their source.  Other specimens, now cataloged, have
been tentatively identified as fluorite (PRR-4607, PRR-4608, and PRR-4609 ).  All of the
suspected calcium fluoride appears to be purple-white, as well.  They were all found near
the same database reference "Fluorite Locality" of Radian and Pipecleaner Glaciers.

     This near coastal locale supports our thought that Australian or South American
deposits may be analgous in color, and perhaps in more, such as in iron (Fe) content. 
I have not yet found reference to any such comparison published to date, so maybe
we will have to conduct the quantitative analyses ourselves in the future.  

     As there are about 3,733 confirmed fluorite locales and mines, as compiled by
Mr. Jolyon Ralph of England on his online database, mindat.org, we have a wide
range of occurences to compare over the globe.

Most likely set down by glacial deposition, these purple-white fluorite crystals, (above: front view; below: back view), were found in the Radian Glacier and Pipecleaner Glacier, Royal Society Range, Southern Victoria Land.  These photos were taken by Assistant Curator, Sue Rose,of the United States Polar Rock Repository (USPRR), especially for this article.

     Now, with the premise of joining geologies put forth, we can now induce that known
fluorite occurrences in the other Gondwanaland (and now independent) continents will
point us toward other analogous Antarctic deposits.

Map of Known Antarctic Fluorite Locations

     For example, Namibia on the African continent was once located near East
Antarctica, as well as “joined” to the now southern tip of South America.   Green
(perhaps iron-bearing) fluorite crystals have been collected from Erongo, Namibia. 
The Okorusu Mine in Namibia has offered some beautifully translucent purple
cubes![vi]

     The landmass of the nations of Argentina, Uruguay, and Brazil once bordered our
search area.  Some fine purple, white, and yellow fluorites have been found in Mendoza,
Catamarca, and San Luis, Argentina.[vii] 

     Some small, clear purple cubes have been found as a rarity at a Linopolis mine in
Minas Gerais, Brazil, as well.[viii]

Fluorite with Quartz, Ancash, Peru (Photo courtesy fo Isaias Casanova, IC Minerals)		Green Fluorite, Erongo, Namibia (Photo courtesy of Dick Nelson  ©2005)

    One could suggest that a working knowledge of the REE, Strontium-rich fluorites
of the Okorusu fluorite deposit in Namibia could be applied to the related carbonatitic
stratigraphy of Antarctica.[ix]

     Concerning pegmatites, the Tubuleiro granites in Santa Catarina, Brazil have been
studied for their ratios of Sr 87: Sr 86.[x]

     The USGS has established a model for summarizing our argument with an example
in a 1995 publication.  “Known metalliferous fold belts in Africa, Australia, and South
America appear to have continuations in Antarctica, based on general concepts of
plate tectonics. Although much evidence is circumstantial, a reasonable basis exists
for projecting various high probability areas of ore-grade mineralization in Antarctica.  
Some copper-bearing plutons on the Antarctic peninsula have distinct similarities to
the Andean porphyry copper bodies. The Dufek Massif, a major intrusion near the
African end of the Transantarctic Mountains, bears some resemblance to, and is
potentially larger than, the Bushveld Complex in South Africa.”[xi]

     To prospect important scientific locations of fluorite in the 1970s, the USGS
found that “[e]xtensive products of mineralization on King George Island, including
pyrite, hydrothermally altered rock, and large veins have led some investigators to
speculate that there maybe a porphyry-type copper deposit at depth on King
George Island.”[xii]

     Rare earth elements have been found there, as well.  This suggests that fluorite
by association, may be found there.

Fluorine and Mount Erebus

     To date, mostly the coastal regions of this icy continent have been explored for
geology.  One such region is volcanically active: Mount Erebus.  It is convenient for
our study to view and measure its emissions from our McMurdo base nearby.  If we
are intrepid enough, perhaps we can tag along with a team of volcanologists for an
up-close view.

Aerial view of Mt. Erebus cone (Photo by Clive Oppenheimer, 2003)		Lava crater at Mt. Erebus (Photo by Dr. Bill McIntosh, 1983)		Team conferring (Photo by Thomas Fleming)

     Fluorine Gas may act as a signal to fluorite formation near or within the Mt. Erebus
volcanic chain.  The heat from near-surface magma could instigate a hydrothermal
paragenesis even now, if it has not already.

     A 1993 scientific paper notes that naturally occurring fluorine gas has escaped into
Earth’s atmosphere.  G. Zreda-Gostynska and P. R. Kyle have written on fluorine
emissions from Mt. Erebus.[xiii]

     Mount Erebus is Antarctica’s only active volcano.  Its 12,450ft/3,800 m snow packed
peak is a fetching view from one’s room at McMurdo.  “One of only three volcanoes in the
world that has a permanent lava lake, Erebus vents significant amounts of chlorine, sulfur
dioxide and fluorine, contributing to the growing diameter of the area's infamous ozone
hole.”[xiv]

     It is not only through the actions of mankind that fluorine cycles through our environment. 
Nature may have it’s own “fluorine cycle”.

     We won’t talk about the environmental impact of fluorine deposited by volcanic emissions,
as nature itself is the environment.  Our goal is to establish that the element fluorine exists
as part of the geology of Antarctica.  And by various geophysical measurements, it does.

     In nature, fluorine dissolves in surface water and underground streams, as well.  The Long
Term Ecological Research team (LTER) lead by W. Berry Lyons and Kathy Welch of the Byrd
Polar Research Center at Ohio State University, has measured fluorine concentrations by ion
chromatography.  Some may be from dissolved solids.  “This dataset shows concentrations
of lithium, sodium, potassium, magnesium, calcium, iron, chlorine, bromine, silicon, fluorine,
sulfate, and hydrogen ions found in various streams of the McMurdo Dry Valleys.”[xv]

     One could suppose that some of the fluorine may enter, or has already taken part in fluorite
formation, given the calcium-rich karst-nature of underground streams and caves in some areas

     Other meta-analytic studies agree that measurable fluorine gas has been emitted, and point
to fluorine emissions as affecting the environment, as well:

Kyle, P.R., Sybeldon, L.M., McIntosh, W.C., Meeker, K., and Symonds, R.B., 1994, "Sulfur
dioxide emission rates from Mount Erebus, Antarctica", in Kyle, P.R., ed., Volcanological
and Environmental Studies of Mount Erebus, Antarctica: Antarctic Research Series, v. 66,
p. 69-82.  http://vulcan.wr.usgs.gov/Projects/Emissions/gas_pubs.html

Kyle, P., Preface, Volcanological and Environmental Studies of Mount Erebus, Antarctica,
Antarctic Research Series, American Geophysical Union, 66, edited by P. Kyle, xiii-xiv, 1994.
http://www.ees.nmt.edu/Geop/mevo/publications/publications.html

     For a specific example, the mineral Rosenbergite, AlF3·3(H2O), consists of 48.40%
Fluorine as found on Mt. Erebus, Ross Island, Antarctica.[xvi]

     Even meteorites from outer space are evidenced to have been contaminated by fluorine
as result of their contact with the Antarctic continent.  “There are several sources for the
terrestrial enrichment of F on Antarctic meteorites conceivable [2]. The previous hypothesis,
assuming sea salt aerosols to be the main source [4], has become rather remote after
recent research results [5]. Thus, besides continental dust and layers of volcanic ash
emerging in blue-ice ablation zones [6,7], the constant volcanic exhalations of Mt. Erebus
(Ross Island), with their exceptionally high concentration of F [8], are proposed to play an
important role as a dominant source for the terrestrial F enriched in Antarctic meteorites.”[xvii]

     Study of Byrd ice cores have shown that “[t]he finding of high halide concentrations in
Antarctic ice is somewhat unusual.  For example, gas emissions from the high halogen
Antarctic volcano Mt. Erebus have been found to have a comparable Cl/F ratio of 2.5, but a
very low Cl/S ratio of 1…”[xviii] 

     Therefore, a natural stream of fluorine has possibly been fed into the atmosphere,
measurable over geologic time.  As volcanism and subduction is a cycle, perhaps the
separate components or fluidic magma and gases, such as fluorine, can be suggested
as such.

Fluorite Formation

Igneous Occurrences

     In a Bulgarian Academy of Sciences publication, B. Zidarova and N. Zidarova, called
“Main elements of the common geogenetic model for deposits of the Fluorite Formation”,
they mentioned simple aspects of Bulgarian geology that may be applied to our
understanding of the mechanism of fluorine emissions and fluorite formation under the
auspices of Mt. Erebus.

     “[F]luorine is most probably resulting from degasification of the Upper Mantle, while
the remaining components (Ca, Si, Al, and others) coming from the embedding rocks.”[xix]  
And that, the “…morphogenetic type of the deposits: [is] vein type in silicate rocks and
stratiform type in carbonate rocks.”[xx]  It is safe to say that calcium exists on the
continent, as evidenced by karst, and silicon and aluminum are there by virtue of their
commonality as components of the Earth’s crust.

     Another paper by B. Zidarova, “REE in the fluorite as indicators of the mineral-forming
environment”, lays the groundwork for interpolating the presence of fluorite, based on the
occurrence of other related minerals, and vice-versa.

     During the Devonian (“Age of Fishes”), most major landmasses were engulfed by shallow
seas.  This higher sea-level most likely affected Antarctica, as well, since fossil fishes have
been excavated in recent years.  Granting that much sea-floor deposition of minerals allowed
for Devonian dolomites to form, a study of Bosnian strata showed some subordinate
components to include calcite, fluorite, and quartz.  Some paragenetic carbonates have also
formed with trace amount of REE (Eu), which we know makes fluorite fluoresce blue under
certain wavelengths of ultraviolet light.[xxi]

     The Earth’s carbon cycle also pulls other reactive elements and compounds proportionally
into and out of the ground.  From geos- to bathos- to atmosphere (skyward), varying
proportions of carbon isotopes are plied into related processes.  Calcium carbonate
exchanges its carbonate anion for one of fluorine.  Igneous carbonatite formation is no
exception.

     “Carbonatites are intrusive carbonate-mineral-rich igneous rocks, many of which contain
distinctive abundances of apatite, magnetite, barite, and fluorite, that may contain economic
or anomalous concentrations of rare earth elements, phosphorus, niobium, uranium, thorium,
copper, iron, titanium, barium, fluorine, zirconium, and other rare or incompatible elements.
They may also be sources of mica or vermiculite. Carbonatites may form central plugs within
zoned alkalic intrusive complexes, or as dikes, sills, breccias, and veins.  Examples…
Phalaborwa, South Africa; Jacupiranga, Brazil; Kovdor, Russia.  Spatially and (or) genetically
related deposit types.  Vein deposits of thorium, fluorite, or rare earth elements may be
associated with carbonatites.”[xxii]

Metamorphic Occurrences

     Many other papers speak on Antarctic halogen-bearing materials in magmatic fluid
interaction, and may be related to metamorphic assemblages in marbles and calcsilicates. 
Some argue that similar rock types may be matched Central Dronning Maud Land to India
and Africa in the ascertaining of Gondwanaland borders.[xxiii] 

     One study, “Humite- and scapolite-bearing assemblages in marbles and calcsilicates
of Dronning Maud Land, Antarctica and their implications on Gondwana reconstructions”
by Piazolo, S., and Markl, G. (1999) J. Metam. Geol., 17, 91-107, highlights our halogen
as occurring on the opposite end of the Antarctic continent from our base at McMurdo.  
We will have to fly there soon, crossing the geographic south pole, to investigate.

Overlooking McMurdo on January 5, 2000 (Photo by Thomas Fleming)		Rare rock outcropping (Photo by Thomas Fleming)

     These scientists state that, “This study investigates marbles and calcsilicates in
Central Dronning Maud Land (CDML), East Antarctica. The paleogeographic positioning
of CDML as part of Gondwana is still unclear; however, rock types, mineral assemblages,
mineral textures, and P-T conditions observed in this study are remarkably similar to the
Kerala Khondalite Belt in India.”[xxiv]

     As a result, “[d]uring retrogression, highly fluoric humite group minerals (humite,
clinohumite, chondrodite) replaced forsterite and garnet rims formed at the expense of
scapolite during reactions with wollastonite, calcite or clinopyroxene but without
involvement of anorthite.” (ibid.)

Sedimentary Occurences

     Now, for the sedimentary record.   Italian Antarctic scientists have derived that
“[t]he lake sediment of Tarn Flat contains calcite, fluorite and silicate minerals with
a low level of salts of marine origin. The sediment derives from local materials,
modified in silicate fraction and enriched in inorganic salts.”[xxv]

     Dr. Bernie Gunn has also suggested that fluorite might be found in some bathic
metasediments, thus covering both terrestrial and marine occurrences.

Antarctic microbes and fluorite

     Some exobiologists and planetary geologists even try to link Martian geology
to Earth analogs in theories of similar or related formation of fluorite.  Clues to
ancient extremofile life on Earth may support the relevant topic of past life on Mars.  
At the edge of hydrothermal environments, in rich, mineral-laden waters, fluorite
spheres have been found on Earth.[xxvi]  These can only form, per scientists, in
water containing organic compounds.  Therefore, if such spheres were found
either on Mars or in Antarctica, microbial life may have been extant at one time. 

     Though the scope of our article relates to fluorite formation, and evidence of
cold-loving microbes have been found on our extreme, frozen continent today[xxvii],
then the possibility exists heat-loving life of a geologically warmer paleoclime
(such as in the Devonian), that fluorite spheres may be found in Antarctica. 
Looking for biomarkers in such places as ancient travertine and aragonite
deposits may give us the evidence we need to support our claim.  Let’s setup a dig!

     The supposition seems a bit of a stretch for fluorite, but the logic is usually
enough to justify funding NASA’s exobiology research; therefore, it has great
relevance to the scientific community—and we who are interested in its study. 
Perhaps the results of our Antarctic Fluorite study could be used by NASA
scientists to build a model of discovery for future interplanetary missions. 
Wouldn’t it be great to be an Antarctic professional, publishing geologist now?

Limestone

Skelton Group

     Limestone outcrops, both metamorphosed and unmetamorphosed, have been
observed in the past decade or so around the Skelton Glacier, near our home base. 
Some show deformation and available calcite.

     “For thirty miles along the lower Skelton Glacier which lies SW of McMurdo Sound,
are calcareous greywackes and argillites (mainly on Teal Island, on the southern coast)
and, further up glacier continuous intricately folded limestone intercalated at intervals
with post-tectonic hornblende granodiorite is well seen at Anthill and other spurs of the
Worcester Range which project north towards the Skelton fiord. On the north bank, near
the Cox Glacier, deglaciated gently rolling terrane shows folded limestone weaving back
and forth in intricate patterns. The greywackes contain secondary chlorite, actinolite,
clinozisite with detrital quartz-albite and interstitial calcite.”[xxviii]

     Regarding fluorite formation, we have found some geothermally-altered rock, as
“[t]hey have been contact metamorphosed by the Skelton Granodiorite to spotted
slates, biotite hornfelses and hornblende hornfelses with the secondary amphibole
phenocrysts containing numerous quartz inclusions.”[xxix]

     “The limestones are saccharoidal, contain thin bands of argillite and are also
contact metamorphosed.”[xxx]

     Nearby, at the Byrd Glacier, one of the purported sites of fluorite crystal discovery,
a “[r]ecent field study of the Byrd Group immediately south of Byrd Glacier adds to our
understanding of this tectonically important suite of Cambrian rocks in the Transantarctic
Mountains. Folded and unmetamorphosed, the Byrd Group is comprised of Early
Cambrian Shackleton Limestone (interpreted as a shallow-water, carbonate shelf)…”[xxxi] 

     Perhaps, fluorite arrived here either by glacial deposition, or erosional forces.  Its
source may be far up the glacier, or even nearby, released from vugs, around our initial
search area.

     It is important to find limestone and dolostone topographies or stratigraphies in our
quest, as it is helpful that “[t]he discovery of karsted surfaces, including terra rossa soils
and breccias, at several horizons within the formation demonstrates that the carbonate
shelf was repeatedly emergent.”[xxxii]

     In addition, “[f]olded Shackleton Limestone is crosscut by a set of dikes that are
fractured and faulted.”[xxxiii]

     This formation can be studied on the surface, thus supporting our contention of a
suitable environment in which fluorite might form.

Dr. Thomas Fleming

     Professor Tom Fleming theorizes that Connecticut, New England, and the South
Pole were once part of the same ancient landmass (Gondwanaland, 200 mya), as
rocks from these locations are chemically similar.  He has compared the ages of these
similar rocks from Antarctica to those in southern Africa and Australia.[xxxiv]

     One example would be the Wise Fluorite mine in New Hampshire.  It could be
parallel to Avalon and African fluorites due to their paragenetic sources being attached
at one time.  Though, Antarctic fluorite might only be a chemical parallel.   This is
sufficient for our argument.

     Of the only ten percent of visible rock outcroppings, some tree and fish fossils have
been found to help bridge the gap of comparably dating materials.  "’From a geologist's
perspective, these rock outcroppings are important windows into what goes on there,’
Fleming says.”[xxxv]

Left: Scientists studying rock outcrop; Right: Dr. Fleming (Photos courtesy of Thomas Fleming)

     If there is a wind-chill factor on the day of our expedition, exposure would kill us
quickly.  Antarctic temperatures hover around –5 F, going up to about 32 F on a good
summer’s day.  Though 20 hours of sunlight per day reach these outcrops, it’s the
temps that will hit us first.  Professor Fleming warns, "Don't even bother to go out.
You don't stand a chance."[xxxvi]

Karst Caves and the Fluorine Cycle

     Vladimir Maltsev has published an article on the Cupp-Coutunn karst Cave System
at the Kugitangtau Ridge in Turkmenistan.  His study points toward fluorite formation in
these caves.  It forms “…using elements of the inner circulation of water and of chemical,
as well as biochemical, factors such as the bacterial cycle of sulfur, the secondary fluorine
cycle supported by the former sulfur cycle…”[xxxvii] 

     Its morphology may be unique, or may be a process hidden from us in our Antarctic
studies thus far.  “Fluorite is distributed as large quantities of veined mineral rock debris
and as poorly colored crystals (up to 5cm) of the thermal phase (80-100 degrees centigrade
of formation temperature) on the walls and also as modern dark violet crystals (up to 1mm)
on calcite and gypsum speleothems.”[xxxviii]

     Karst caves and depositional features usually do not include fluorine on a large scale. 
“The first class contains crystallictite crusts of fluorite originating in a very uncommon way
connected with the double process in thin water films, through which hydrofluoric acid, if it
is present in the air, reacts with calcite or gypsum.”[xxxix]

     A hydrothermal stage reworks deposits, finally creating fluorite rosettes after a third stage
of deposition.  “Sulfuric acid, involved in the biogenic cycle of sulfur, reacts with fluorite,
expelling hydrofluoric acid into the air. Some crystals are dissolved along fractures up to
3 - 5cm in depth. The hydrofluoric acid the reacts with the calcite or gypsum of speleothems,
forming new fluorite.”[xl]

     In the natural fluorine cycle, karst caves can produce metamorphic fluorite via low
temperature thermal activity.  The mechanism is related to the sulfur cycle, in that
hydrofluoric acid forms, reacts with the calcium carbonate to form CaF₂, calcium fluorite. 
Perhaps such activity has recently occurred in limestone caves near Mt. Erebus.

Conclusion

     In our quest for the unspoiled beauty of Antarctic Fluorite, we have searched boldly
from the ground and the air to ascertain the most likely locations in this polar frozen
desert.  We have built upon the work of serious scientists and intrepid explorers to
greet the chance of finding our crystalline rarities.

     One could suggest from our novel supposition that fluorite does indeed exist, in
many forms,  on our southernmost continent.  Before we undertook our most chilling
journey yet, one might have thought that Antarctica was a lifeless, snow-covered,
anti-paradise.  On the contrary, we have discovered through our bold inquiries that
our seventh continent does have life, is alive geologically, and has recorded a lively
past.  I hope this experience has inspired you to research further in peace.

International Agreements

     The Antarctic Treaty is an international agreement for the peaceful use of the
continent of Antarctica.  Articles 2 and 3 state that the area is to be used in “freedom
of scientific investigation” and in the spirit of “international scientific cooperation”. 
Since then, several new instruments have been signed to protect specific resources
there.  For example, the more recent Protocol on Environmental Protection to the
Antarctic Treaty (1991) offers to conserve marine living resources by treaty.

     Specifically, the Madrid Protocol subsequently setup a “mining ban - a
moratorium on all commeric[i]al mineral exploitation for at least 50 years. It also
introduces strengthened and legally binding measures governing waste disposal,
marine pollution and the conservation of flora and fauna.”[xli]

     There are most likely other international agreements and historical territorial
claims; however, this article intends to recognize only the pure scientific pursuits
and sharing involving the current twelve exploring nations.  Many of the researchers
publish regularly online and in print through their academic institutions, grant programs,
and respective Antarctic Surveys.

     Antarctica is rich in history, both the nearly 100 years of exploration and millions
of years of geologic times past.  Many of the surveys have websites and journals.   I
will list a few for you as suggested reading and links areas below.  So, we’ll just focus
on the history of fluorite science here.

United States Polar Rock Repository (USPRR)

Dr. Anne Grunow, Curator and Research Scientist, USPRR		Ms. Sue Rose, Assistant Curator and Geologist, USPRR

     One such organization that supports the greater advancement of Antarctic science
is the United States Polar Rock Repository (USPRR).  Under the auspices of the
Byrd Polar Research Center (BPRC) at Ohio State University, and funded by the
National Science Foundation (NSF), the staff at the USPRR maintain researchable
collections of Antarctic rock & mineral specimens in a modern facility.

     As many of the world’s great museums house magnificent specimens of rock and
minerals, very few maintain an Antarctic display or collection.  Of the several curators
I have contacted, none had a specimen of fluorite from Antarctica.  This includes the
British Museum of Natural History and the Smithsonian Institution. 

     I was fortunate enough to be guided to Curator, Dr. Anne Grunow and Assistant
Curator, Sue Rose of the USPRR.  Ms. Rose supplied me with photos of the only
confirmed samples of fluorite cataloged into the repository’s database to date.

     We, as amateur geologists, may have only experienced direct benefits from the
NSF by watching certain funded science television programs on public TV, such as
NOVA.  The success of this article would not have been possible without their funding
to the USPRR.  Thank you, National Science Foundation.

     Intrepid professionals, such as Dr. Anne Grunow of the USPRR, have visited our
South Pole’s ‘desert’ many times.  She has published papers on her geologic
reconnaissance and research results. Today, she is the Curator at the Repository.

     Dr. Grunow has agreed to an interview about her journeys and the Antarctic science
she has performed.  Ms. Rose also shares some of her experiences as a curator and
geologist.