fond_Trilobiti

Esiste un sito negli USA, piu’ precisamente il “Penn Dixie Paleontological and Outdoor Education Center in Hamburg, New York”, che risulta essere uno tra i siti del devoniano piu’ importanti degli USA in quanto a quantità di rinvenimenti di faune marine dell’epoca ben conservate. Putroppo come in molte parti del mondo, gli interessi economici prevalgono spesso e volentieri su quelli culturali e scientifici; questo sito infatti risulta attualmente minacciato dalla costruzione di svincoli autostradali e centri commerciali. Il direttore del museo di Hamburg (uno dei pochi che permette di raccogliere e tenere i fossili che si rinvengono sul sito dell’ex cava, mi ha chiesto  di lanciare un segnale di aiuto internazionale nella speranza di evitare questo scempio nella speranza di salvaguardare i terreni per la ricerca scientifica ed il collezionismo.
Un ulteriore esempio di collaborazione tra scienza e collezionismo privato, che dovrebbe farci da esempio a noi italiani....
Segue il testo in inglese, parzialmente modificato per rispettare l’impaginazione del presente sito e limitarne il volume, non me ne vogliano gli autori.... che ringrazio per la segnalazione, cioè Nando Musmarra e Diana Fattori


 Mom, there is a trilobite in my sandwich !!!
by Diana Fattori and Nando Musmarra

niagara

During  our recent trip in United States, after visiting the always exciting Big Apple, Nando and  I decided to rent a car, then we travelled toward west to visit  Niagara Falls. The roaring waters were really impressive, but being fossils’ lovers we were looking for an opportunity to go around  for fossils. So we turned our car south and we went to the Buffalo Museum of  Science looking for inspiration. Because the museum lies in a very fossiliferous Devonian area, the specialties are  mainly fossils from that geologic period, like trilobites and brachiopods from the area around the city of Hamburg.

location02

For this reason, we decided to stop for the night in Hamburg, who claims to be the city that given the birth and the name to the hamburger, the backbone of every American meal.
From the Genghis Khan’s soldiers that softened the meat by placing it under the saddles of their horses while riding into the battle, to the emigrants by the German Hamburg-Amerika boat line in the 1850s, many people did claim to be the first to soft, to mince, to cook the hamburger, the tasty dish based on minced meat.
Well, we don’t know where the truth is, anyway the sandwiches we had in a restaurant in Hamburg were absolutely delicious: the hamburgers were marinated to perfection, medium cooked with a pink colour at centre, surrounded by pickles, Idaho potatoes and side of a big, tasty blooming onion.
Obviously, there is more than an hamburger in the region where Hamburg lies. While in the area,  we discovered the wonderful Middle Devonian spot very close to the city, the famous Penn Dixie Quarry.

Location of Penn Dixie Paleontological and Outdoor Education Center in Hamburg, New York. Map provided by J. C. Bastedo

This site is a former quarry that once was the source of calcareous shale excavated and used for cement aggregate by the Penn Dixie Cement Company. After quarry operations ceased in the 1960, weathering forces began to expose 380 million-year-old Devonian fossils preserved within the Windom Shale.  This highly fossiliferous unit underlies the entire site and provides an inexhaustible supply of fossils.  In addition to the Windom Shale, several limestone units outcrop on the surface. All  those units contain a big variety of fossils.

fauna

380 millions years ago the region was 20 to 30 degree south of the equator, the actual Hamburg area was covered by a warm tropical sea providing an environment conducive for a variety of invertebrate and vertebrate animals. The shales and limestones that formed during this period preserved the remains of the diverse and abundant fauna that occupied these seas. The following discussion of the units present on the site begins with the Wanakah Shale at the north end through the West River Shale to the south.

The Wanakah Shale is a gray calcareous shale that weathers to a sticky clay. It is a popular area for fossil collecting (Brachiopods, bryozoans, trilobites, gastropods, pelecypods, echinoderms, corals, sponges, ostracodes, and some pyritized fossils).

The Tichenor Limestone (1.5 to 2 feet thick) has pyrite coated surface that exhibits a reddish-rusty color. This layer is often referred to as “crinoid heaven” due to the countless number of pelmatozoan columnals.
The Tichenor Limestone contains corals, brachiopods, pelecypods, trilobites, bryozoans, and echinoderms, all of which are difficult to remove from the hard limestone.

The Windom Shale is a dark gray, calcareous mudstone with several thin argillaceous limestones, concretionary beds, phosphate nodules and sticky clay (Beuhler and Tesmer, 1963).

fauna2

The Penn Dixie site has the most complete exposure of Windom Shale in New York State, approximately 42 feet thick, that contains a variety of corals, brachiopods, pelmatozoan columnals, bryozoans, trilobites, gastropods, pelecypods, cephalopods, and more rarely fish remains, plant material, and blastoid and crinoid calices. The upper Windom has a variety of pyritized fossils that include brachiopods, pelecypods, cephalopods, trilobites, and blastoids

The North Evans Limestone is a dark-gray crinoidal limestone that is 1.5 to 4 inches thick. Erosional lag concentrations of hiatus concretions, pelmatozoan fragments, conodonts, fish plates, teeth, and mandibles, along with some brachiopod valves, are present. Carbonized plant remains are also found in this unit.

The Genundewa Limestone is a nodular, dark-gray to light gray poorly bedded limestone, which has been referred to as the “Styliolina Limestone”.. Carbonized wood can be frequently found, but other examples of the fauna are more difficult to obtain.
The West River Shale is dark gray to black in color. Most of this unit is covered by overburden at Penn Dixie. Conodonts, cephalopods, pelecypods, and fish remains have been reported from the West River Shale at other localities in Western New York.

Paleogeography

Stratigraphy of Penn Dixie quarry

In the Penn Dixie quarry is easy to find the trilobite  Phacops rana (especially enrolled specimens!) washed out of the shale after a good rainstorm. Also multiple complete trilobites on a slab are common in the quarry.
The site was purchased by the Town of Hamburg in 1995 to preserve the former quarry and its associated wetlands saving one of the richest sites of 380-million-year-old Devonian Era fossils in the eastern United States. Now the site is owned and operated by The Hamburg Natural History Society, Inc (HNHS) a non-profit educational corporation and by the Outdoor Education Center of Hamburg, New York. The society was founded to promote the study of the natural sciences, astronomy (a seismographic and climatological station are  planned to be included in the center) and ornithology (there are more than 140 bird’s species nesting and living in the quarry) with a particular emphasis on field activities associated with the geological and biological sciences.

Unlike conventional museums or research facilities, the Penn Dixie Site is an outdoor educational facility where visitors of all ages are encouraged to collect and take home the 380 million year old fossils.  There is a small fee to collect in the quarry (6.00$ each adult; you can also consider to join the Society for one year for 20.00 $  like individual or 35.00$ like family and then collecting for free as many times as you like).
The Society reprinted an old exceptional book “Geology and Paleontology of Eighteen Mile Creek” by Amadeus W. Grabau, the book is very useful for identify the Penn Dixie fossils. Grabau was a distinguished geologist and paleontologist, he was the first professor of paleontology at the Columbia University. He moved to China where he became chief paleontologist of the National University of Peking. He was also closely connected with discoveries of Peking man.
The  Executive Director of Penn Dixie Education Center is Jerold Bastedo, if any of you readers will visit the area out from the visiting schedules, it is a good idea contact him to arrange a visit to the quarry. Mr. Bastedo loves to have visitors from all around the world,  he will be happy to fix for you a day to collect enrolled trilobites, beautiful spirifers, corals and others Devonian fossils. Penn Dixie staff and volunteer guides will direct visitors to the better collecting areas on the site.
If you are planning a trip in eastern United States, remember to include the area around Hamburg: good food and Devonian fossils. Is your appetite whetted?
 The Penn Dixie society  website is www.penndixie.org
(All photo by Nando Musmarra except as noted)

Phacops rana

Phacops rana collected by Jon Luellen and prepared by Gerry Kloc. Collected from the Lower Windom Shale at Penn Dixie. The trilobite is 5 cm. long.  Photo provided by J. C. Bastedo