- a young meteorite impact crater in the old volcanic landscape of Nicaragua?
By Leo Kowald, Gelsenkirchen, Germany, April 2006
Abstract (2006):
The "Crater of Pantasma" in Nicaragua has not been noticed by the science so far.
A volcanic origin is suggesting but not proven (is there any unpublished evidence?).
Without the volcanic vicinity a meteoric origin would be evident.
Impact material has obviously not yet been searched for.
Update 2010:
An expedition in July 2009 by the Nicaraguan Astronomers has confirmed the impact-theory.
The Geologist Jean H. Cornec (Denver, USA) wrote, that he has found 800.000 year old Tektites 500 km north-west in Belize, 500 km north-west.
This year in February I travelled with
"
Pan y Arte",
an organization of the Austrian actor
Dietmar
Schönherr,
for two weeks through Nicaragua.
"
Pan y Arte"
supports cultural projects in Nicaragua like the
"
Casa
de los tres Mundos" in Granada and
"
Musica en los Barrios" in Managua.
When I prepared for this journey, during a "flight" with
"
Google Earth" over
the northern landscape of Nicaragua, I casually found a large
circular valley
with a diameter of about 12 km, whose centre is at 13.22 degrees north and 85.57 degrees west.
Nicaragua, a country with approximately 5.5 million inhabitants, lies
in the middle of the central American land bridge and is part of the
geologically young
Caribbean plate, which was formed, when
the plates of South- and Northamerica moved together.
In the west, near the Pacific coast line there is active volcanism in form of
a chain of volcanoes, calderas and lagoons, which is caused by
the subduction of the Pacific sea floor under the
Caribbean plate.
In this zone there are often violent earthquakes, by which on
12/23/1972
the capital Managua was nearly completely destroyed.
The eastern part of the country drops slightly to the Atlantic Ocean.
The central and northern part take mountains with up to over 2000 m high summits,
which were created in the Tertiary (chronologically after the Mexican Chicxulub impact) by volcanic activity.
There, approximately 70 km south of the border to Honduras,
in the district of
Jinotega,
you can find that circular valley, the "
Valle de Pantasma".
It is passed from SSW to NNE by the "Rio Pantasma", a tributary of the "Rio Coco" (also called "Rio Segovia"),
with "Las Praderas" in its centre which is the main village of the municipality
"
Santa Maria de Pantasma",
with about 40,000 inhabitants. In the poor, but obviously fertile and
agriculturally intensely used valley the people cultivate corn, grain, fruit and coffee
and raise cattle.
Sad celebrity attained the place on October 18, 1983 by the
"
Massacre of Pantasma", in which 47 men, women and children were assassinated
during an assault on the agricultural cooperatives of the valley by CONTRA terrorists,
who werde financed and armed by the United States under president
Ronald Reagan against the Sandinist government.
Exactly three years later, on October 19, 1986 an anti-
tank mine blew up a truck on the main street from Pantasma to Jinotega
killing 11 and maiming 33 civilians. On Monday, March 23, 1987 Members of the US-American
"First
Veteran Peace Action Team”, lead by the Vietnam veteran
S. Brian Willson started a one-week
and 73-miles "Peace
Walk" on this road passing the Pantasma Valley in order to focus public attention on
the CONTRA terror, that was very cruel particularly in this part of the country.
(*1)
Since 2004 the terrain is cleared from the landmines
in that area and the "civil" war is definitely terminated since 1990.
But prudence and the assistance of a guide are strongly recommended, if one wants to travel there.
The floor of the valley rises from NNE to SSW from 400 m to over 500 m.
In front of the outlet of the Pantasma river at the northern edge a plain has been formed,
which looks like a puddle in a flat bowl, which stands on an inclined table
(see accompanying, triple super elevated Google picture). Because of the inclination, the
500 m line crosses the valley, why its circular shape is often not visible in maps.
In E, S and W the circle is somewhat bumped out,
which is obviously caused by well recognizable ravine-
like slope washings with related debris deposits
at the edge of the valley, which lie under the highest summits of the 600 m to 1100 m
high surrounding ring of mountains.
The valley interrupts the flank of an about 1000 m high mountain plateau,
which drops by some 100 m toward NE, where also the gradient of the
floor points to.
My journey through Nicaragua did not lead me into the proximity of the crater and I could look at it only by
"Google Earth",
maps and this beautiful shade relief, which was kindly sent to me by Dr. Wilfried Strauch,
director of the geologic institute
"INETER" (Managua, Nicaragua).
On this certainly still insufficient base I believe as an amateur astronomer, who saw many pictures of volcanic and
impact craters
on the moons and planets of the solar system, I find that the "Valle de Pantasma" was obviously
caused by a meteorite impact.
After the rule "crater by 20" the meteorite should have had a diameter of
more than 500 m.
I would even call the crater a typical sample of a meteorite impact, if the central
uplift would not be missing, which is however often not present in very large impact craters
(over 5 km). In this rainy area it can be covered with sediments in the meantime.
In a distance of 10 km off the crater there are some hills, that could refer to an
ejection ring, that is however not clearly recognizable in that rough region.
Its embedding into the landscape is nearly identical to the 5 km large
and 50 million years old impact crater of Goat Paddock
in Australia. Its size and shape reminds at the 10 km large and about one million years old crater of
Lake Bosumtwi
in Ghana.
The Crater of Pantasma fulfills all outer conditions of a meteorite crater.
I find that, beside the circular shape, the inclination toward the spacious form of the mountain slope is remarkable.
The arbitrary position of the crater in the landscape corresponds to the arbitrariness of a meteorite impact.
I beleive, that its spectacularity itself already shows that it does not have to do something
with the volcanic structures in that area; it is simply extraordinary.
It must be substantially younger than its environment. Its narrow northern mountain-
bow also
doesn't look like a rim of a collapsed caldera. In my opinion this crater can only be
caused by a big explosive event before 1 or 2 million years
bigger than the explosions of Krakatoa
Tambora and
the Lake of Laach
( ⇒ Wikipedia: Explosive Calderas).
After
R. Weyl, the era of active volcanism in this region however has ended
already more than 5 million years ago (tertiary volcanism).
But I have to admit, that I don't really have enough knowledge about geology
to estimate the probability of a volcanic origin.
(*2)
Despite intense investigations I haven't found any traces of
a Crater of Pantasma or Las Praderas in the Internet.
In "
The Geology of Central America" by Richard Weyl (ISBN 3-443-11001-0)
the valley is not mentioned.
In contrast to the 120 km more southern lain extinct volcano
"
Las Lajas",
which is called - despite its substantially smaller caldera of 7 km -
"the largest volcano of possible Quaternary age east of the Nicaraguan graben", it doesn't appear in
relevant lists
of volcanic objects.
Unlike the other craters it is not part of one of the two volcano chains
(the young south-
western and the elder nort-eastern of the nicaraguan graben).
Also our competent Nicaraguan guide did not know anything about it.
It seems to me, that the crater has not been noticed at all by the international science community so far.
Only Dr. Strauch from INETER wrote me, that he already had noticed the crater,
but his geologists had thought, that it is volcanic.
Although meteorites are not much concerned about the geologic properties of their target areas,
the probability, that this is "only" an unusual volcanic object, is rather high.
But there is no literature or at least a discussion about it, although the
crater should be interesting enough even as a volcanic object.
I suppose that the Nicaraguan geologists for comprehensible reasons have much trouble
with the research and the forecast of dangerous seismic and volcanic activity,
and simply not much time for less important questions.
The question "volcanic or meteoric" can be decided certainly only
by geologists by minerals
(
shatter cones,
suevites,
tektites),
that have to be found in or near the Pantasma Valley.
Therefore it would be fantastic, if a geologist went there soon to answer that question!
In the language of the Miskitos "Pantasma" means "small man" or "flat head".
The Spanish word "Fantasma" comes from the Greek "Phantasma" and means "ghost".
Should I only be fooled by a Phantasma?
Dear Visitors!
If you have questions, critics or recommendations, please do not hesitate to
send me a Mail!
Foot Notes:
*1) S. Brian Willson's Video Clip,
9 minutes (2.3MB): http://www.peace.ca/brianwillson.wmv.
S. Brian Willson,
who organized the Peace Walk, is the Vietnam veteran who lost his
legs when run over (with full intention!) by a naval train in Concord,
California, carrying weapons that were headed for Central America.
Brian is one of the most spiritual, courageous and honest
activists who Wages Peace against violent foreign policies.
He is a hero in Central America where the people understand that he has stood up for
their rights as equal human beings. Brian says that he doesn't want
Mothers and Fathers and Children to be killed and maimed in our name with our
tax money! (Singer, actor) Kris Kristofferson gives him a special
introduction. Brian's web site: http://www.brianwillson.com
features his autobiography and a series of essays he has written.
I recommend getting on his web site and reading everything he has to offer!
|
*2) The basement of northern Nicaragua is still a great problem stratigraphically.
Enclosed tuffits (mainly basic, partly also intermediate to acid) appear of importance
for both petrology and sedimentology. Not in the least they are guide horizons for a
more accurate mapping. The vast regional distribution, commonly proved yet, suggests
that the composition of the basement is considerably uniform and it seems that they
do not belong to different periods and formations. Structurally the region is exceedingly complicated.
The folding direction as regards plication and overthrusts is mainly to the North,
but partly also to the East.
Probably the ldquoTotogalpa formationrdquo (fanglomerates, conglomerates and sandstones,
mainly reddish) which follows disconformably over the basement, already indicated, belongs
to the sequence of tertiary tuffites, agglomerates, lavas etc. as they conformably form a
formation of uniform composition. The relation of basement to lower Cretaceous
(marine Albian; ldquoMetapanrdquo), which follows immediately to the south, is less clear.
The lower Cretacious shows intensive and complicated folding at Siuna and it appears
almost unmetamorphosed (? basement in a wider sense).
The marine sediments (upper Cretacious - Miocene) of South Nicaragua are orogenetically
only slightly efected (folding direction to E-N). To the North follows a thick serie of
Tertiary and Quarternary volcanites (initially mainly submarinal, later on continental).
Together with the NW/SE lineaments (Nicaragua depression, lines of volcanoes, coast
line in the SW etc.) also NS directed ones clearly appear (coastline in the East).
This direction can be found e. g. in the ldquogranite ridge of Susucayanrdquo and the
accompanying faults in the vicinity. These latter structures may have taken an active
part in the development of the flexured border of the Nicaraguan depression NW of Managua.
("Geologische
Problematik und Strukturanalyse Nikaraguas" by Bruno Engels, 1965)
|
Sources:
Richard Weyl: "Die Geologie Mittelamerikas", Borntraeger, 1961 (ISBN 3-443-11001-0)
„Sterne und Weltraum“, May,
July 2006
INETER, Managua, Nicaragua
topographic map 1:50.000 Quisuto (Crater-NW)
Topographic map 1:50.000 Las Praderas (Crater-NE)
Topographic map 1:50.000 San Rafael del Norte (Crater-SW)
Topographic map 1:50.000 Asturias (Crater-SE)
Topographic map 1:50.000 Jinotega
Köberl and Sharpe: Review of impact cratering
Crater Size Calculator
University of Texas: Caribbean Plate Project
NSF press release 96-009
Doxler, Cunningham: An Ocean Drilling Journey, RICE University
Raik Bachmann: The Caribbean Plate and the question of its formation
Earth Impact Database
Günther Weber: "Die trotzigen Mühen um die Freiheit"
Nicaraguas Bauern kämpfen um ihr Land. Berichte aus dem Tal von Pantasma, Edition Nahua, 1986
Equipo Envio:
"Pantasma: las cooperativas, blanco de la contrarrevolución"
Equipo Envio:
"Una guerra contra el mundo"
Bernadette Schiefer:
"Nicaragua: Requiem für eine Revolution", 2004
Maria Mies: "Globalization from Below,
Resistance and new Perspectives", 2001
The
Reagan Doctrine: Third World Rollback
S. Brian Willson: „On Third World Legs“, 1992;
Mark Becker: "Walking through the New Nicaragua", 1986
Links:
Pan y Arte, Münster
Casa de los Tres Mundos, Granada, Nicaragua
ORO Travel, Managua, Nicaragua
Informationsbüro Nicaragua e.V., Wuppertal
Nicaragua-Forum, Heidelberg
Wikipedia.en: Pantasma
Google Earth Community
NASA Basic Science Studies II: Impact Cratering
Terrestrial Impact Craters
List of Terrestrial Impact Crater Structures
Google Earth Placemark "Pantasma Valley"
Google Maplandia: Las Praderas
S. Brian Willson: How the U.S. Purchased the 1990 Nicaragua Elections
Richard Leonardi: Los Campesinos
Imprint
