sábado, 29 de abril de 2017

Interesting Geoformation at Fort San Severino, Matanzas, Cuba

Por: Johanset Orihuela

In this post, I will attempt to merge two of my favorite sciences, historical archaeology, and geology, by discussing a geological formation underlying the already attractive fort San Severino in the picturesque bay of Matanzas, northwestern Cuba.
Underlying all architectural structures there are geological formations. They serve as the foundation for the structures that we build on them or as a quarry for the myriad of construction materials and necessary natural resources derived from them. They are true substructures to our daily existence and a constant reminder of the importance of geology in our everyday life.

Figure 1: View of Fort San Severino's position in the northern coastline of Matanzas bay.

Background on Fort San Severino

Fort San Severino is a 322-year-old Spanish colonial fort, and the oldest surviving architectural structure in the city of Matanzas (fig.1, 2). The city of Matanzas is itself a tricentennial port city on the north coast of Cuba that acquired world fame during the sugar boom of the 19th century (Hernandez, 2006). I will dedicate a whole post on this marvelous city and its history later (hint hint).
San Severino was planned as a component within the military protection belt of the region of Havana. This region had a geopolitical span that included the small population of Matanzas (Alfonso, 1854). The bay of Matanzas was spottily underpopulated then but had frequent illicit trade along with sporadic pirate attacks. This illicit commerce and pirate raids, in a way, prompted the Spanish crown for its protection (Alfonso, 1854). The most famous incident is without a doubt that of the Dutch privateer Piet Hein when his ships attacked and possessed the Spanish treasure fleet (the Silver Fleet or Silverloot) right on the bay in 1628. Other previous, but of nevertheless interesting occurrences include that of the Veracruz fleet who took refuge in the bay running from Jacques de Sore in 1555, and the capture of Francesco Estroce by Pedro Menendez Marquez in 1580 (Dominguez, 1959). An instance in which the bay of Matanzas served as a military-strategic locality.

Figure 2: Fort San Severino, where the masonry merges into the underlying Jaimanitas Formation at Santa Ana bastion; photo looking North.

Plans for the construction of the fort began in the 1680s, but the first stone was not placed until the fall of 1693 when the city was officially founded (Alfonso, 1854; Hernandez, 2006). In fact, this post is about its building stones, its masonry, and the Jaimanitas formation, which is its underlying geological setting. The Jaimanitas formation was originally called coastal "Seboruco" by Alexander Humboldt, and other geographers of the 18th and 19th century, but not described until 1940 (Lexicon, 2014:47). Both the masonry and the Jaimanitas Fm. are biogenic fossil-rich limestones formed in shallow warm marine environments, and its coastal span is also the geological substrate to other coastal military forts around the bay. 
There are many ways to classify limestone. This is usually done based on its composition and content. Limestone is a carbonate sedimentary rock most commonly formed in warm and shallow clear waters, formed from the accumulation and compaction of reef debris, bits of coral, shells, alga, sand, and even fish fecal pellets within a Calcium carbonate matrix. The definitions given below are a form of lithological classification, which pertains to the macroscopic aspect of the rock or simply those aspects visible to the naked eye. In the petrographic sense or the microscopic characteristics of the rock, such limestones are named for the particulates or clasts that make them up and the type matrix or cement that holds everything together (fig. 2, 3). 

Figure 3: Part of the East wall section. The stone masonry lies over the uplifted Pleistocene reef that is the Jaimanitas Fm. Bullet holes are visible in this section, a reminder of its military past. Note how the limestone was shaved to accommodate the masonry.

Fort San Severino sits on the Jaimanitas Formation, an uplifted coralline limestone formed underwater from coral reef rubble, sand, and microscopic microorganisms during the latter part of the Pleistocene epoch, between 180,000 and 82,000 thousand years ago. This formation surrounds the coastal parameter of the bay of Matanzas, and most of the Cuban archipelago (Cabrera and Penalver, 2003). 
Recent uplifting due to plate movements and the resulting adjusting and readjusting of consequent fractures of the rock has raised or uplifted some of these massive reef biomes above present sea level, providing a geological setting to the region where fort Severino lies. One can now walk on what used to be coral reefs 5-10 meters below water during the Pleistocene (fig. 2, 3).


Geologic formations are the basic units of lithostratigraphy (from the Greek lithos = meaning rock, and the Latin stratum = layer), which is a technical term for the science that studies rock layers, their age, and their origins. There are many practical and intellectual benefits for human society in their study. In the practical sense, knowing about rock beds and their possible age is essential for a bundle of everyday practicalities such as basic materials, the discovery of fossil fuels or minerals, and many other resources that right now many take for granted. Geology is inseparably linked to human social and economic development and advance. Formations are often composed of several types of rocks, but with distinctive, identifiable characteristics as a whole. The limestone of the Jaimanitas Fm. is generally a fossiliferous limestone, meaning that its composition is comprised of fossilized organisms, mostly extant, which also gives it the name of organogenic limestone (Lexicon, 2014:47). When these layers of sediment form and consolidate into rock they record within themselves clues to the conditions of the environment that allowed for their formation.
The association of some Quaternary fossils characterizes the Jaimanitas formation, although index fossils are not yet assigned to it specifically (Cabrera and Penalver, 2003). These fossils include colonies of scleractinian corals such as Acropora and Diploria species (fig. 4) and the mollusk shells of the large queen conch Strombus gigas visible in figure 5. These fossils dot the sea walls and masonry that encases the fort.

Figure 4: Fossilized colony of the brain coral Diploria sp. in situ within the reef rubble on the fort's old natural sea wall.

Interesting Problem

The stones that make up the masonry of the fort are also composed of what seems to be the same limestone which generally makes up the Jaimanitas fm. But here is a contradicting problem. Local legends and some accounts recount that the stones used for the construction of the fort, quarried by slaves and prisoners, came from the hills north of the fort, and thus not from the surrounding coastal rock which is the Jaimanitas fm (Hernandez, 2006: 40). The Jaimanitas formation does not extend far away from the coast, and could not have been quarried anywhere else, except in its proximal coastal settings. Moreover, the first formation that pinches out into the hills rising behind the fort, which is the Canimar formation, is made up of marl, a softer and older limestone. Could these legends be wrong, and instead the rocks were mostly quarried right on where the fort was built?
Documentation shows this is likely so. Few letters sent from the general Severino de Manzaneda to the king of Spain Charles II (in Spanish Carlos 2) dating between 1693 and 1694 hint at the extraction, in situ, of the Jaimanitas limestone using explosives (AGI/Santo Domingo, 457; Hernandez, 2006: 42). Some of these documents suggest the recycling of the rock excavated from the leveling of the moat was used as a building material as well. In one of the letters Severino mentions its usefulness because of the rock's hardness, he calls them "piedras durisimas" or really hard stones (Hernandez, 2006: 42). This could explain why most of the masonry observed at the fort resembles the Jaimanitas fm.Yet, these are just observations that have not been properly tested. To confirm them, one would have to sample all these geological formations and compare them lithologically and petrologically to several samples from the fort's base rock and masonry. But that will be a project for the future. 

Figure 7: Fossilized queen conch Strombus gigas on one of Severino's walls.

Addendum: November 24, 2016

It was recently brought to my attention (thanks to Odlanyer Hernández, an archaeologist friend, and colleague) that the conclusion reached here from my observations were in fact tested and published in the 1980's and 90's by a local researcher Samuel Gerardo. Gerardo found that the rocks could have indeed only come from the coastal limestones of the Jaimanitas fm. and not the softer rocks from other forms surrounding the bay. 
I want to end with words from S. Hernandez's book on Fort San Severino (my translation from Spanish) because I think with them she captures the essence, a bit of the romanticism and nostalgia associated with the investigation of such antique structure where so many things happened to human lives for so many years:

"...This investigation is just a start point, this theme is not extinct and the research must continue. Unearthing and unraveling the anecdotes and occurrences impregnated on the walls of the old fort is just a matter of time. The waters of the bay no longer wash its shore, but the sea is visible from its interior..."


Alfonso, Pedro. 1854. Historias de un Matancero: apuntes para la historia de Cuba, con relacion a la ciudade de San Carlos y San Severino de Matanzas. Marsal y Ca., Matanzas.

Archivo General de Indias (AGI)/Santo_Domingo, 457: Severino al Rey: feb. 1693 and 3 de nov. 1694.

Cabrera, Miguel and Leandro L. Penalver. 2003. Contribucion a la estratigrafia de la formacion Jaimanitas y su relacion estratigrafica con las demas formaciones del Pleistoceno superior. Memorias GEOMIN, 2003, La Habana, March 24-28, ISBN 959-7117-11-8.

Dominguez, F. J. Ponte, 1959. Matanzas: Biografia de Una Provincia.

Hernandez Godoy, Silvia. 2006. El Castillo de San Severino: Insomne Caballero del Puerto de Matanzas. Ediciones Matanzas, Matanzas, Cuba.

Stratigraphic Lexicon of Cuba. 2014. Instituto de Geologia y Paleontologia, Editorial Centro Nacional de Informacion Geologica.

viernes, 28 de abril de 2017

Arqueología de la Arquitectura en el Castillo de San Severino

Por: Boris Rodríguez

Entre los días 24 y 28 de abril del 2006 se realizó el I Taller de Arqueología de la Arquitectura en el Castillo de San Severino, Museo de la Ruta del Esclavo en Matanzas. Este taller fue impartido por un equipo de investigadores del Gabinete de Arqueología de la Oficina del Historiador de la Ciudad de La Habana, integrado por los arqueólogos Roger Arrazcaeta Delgado, Lisette Roura Alvarez y Adrián Labrada Milán. El objetivo del mismo fue el adiestramiento de especialistas de la Dirección Provincial de Patrimonio, así como implementar por vez primera esta novedosa metodología en el estudio de las fortificaciones cubanas.

Odlanyer Hernández-de-Lara indica algunos de los cambios ocurridos en la fortaleza. Lo acompañan, de izquierda a derecha: Adrián Labrada, Boris Rodríguez, Silvia Hernández y Roger Arrazcaeta.

Este edificio militar fue la más importante fortificación que conformaba el cinturón defensivo de la ciudad de Matanzas durante los siglos XVIII y XIX, y constituye el único exponente de los actos fundacionales de la misma que ha sobrevivido. Los inicios de su construcción datan de 1692 y en sus más de 300 años ha sufrido procesos transformadores de diferentes magnitudes: desde la voladura de sus baluartes en 1762 –durante la toma de La Habana por los ingleses– y su posterior reconstrucción, en la que se llevaron a cabo cambios internos y externos a la fortaleza, las constantes y necesarias reparaciones, readaptaciones para prisión, hasta el deterioro paulatino causado por agentes naturales, ya sean la lluvia, el aire salino de la bahía y la vegetación, entre otros. Todo ello conllevó a continuas alteraciones de su estructura, impuestas por necesidades funcionales y espaciales, las cuales se hicieron patentes con la adición de nuevos muros y paredes – tabiques, recrecimientos, demoliciones parciales, y transformaciones.

Roger Arrazcaeta y Odlanyer Hernández-de-Lara analizan la dinámica constructiva de San Severino.

Si bien, algunos hechos aparecen registrados documentalmente, otros que también cambiaron en diversa medida la fisonomía constructiva de esta fortificación no quedaron asentados en las fuentes escritas, y además, en ninguno de los casos es sencilla la determinación de transformaciones, pérdidas y adiciones al edificio, lo cual sólo es posible con el uso combinado de la metodología de la Arqueología de la Arquitectura. Esta se ha aplicado con éxito en inmuebles ubicados en el Centro Histórico de la Habana Vieja, aportando datos imprescindibles para la interpretación y restauración de dichas edificaciones.

En esa ocasión, los trabajos se volcaron hacia el estudio de la planimetría histórica existente, así como de los inventarios ejecutados por los ingenieros militares que trabajaron en la fortificación durante las remodelaciones y transformaciones de la misma. Igualmente, se identificaron un total de 445 unidades estratigráficas básicas, las cuales constituyen el punto de partida para los ulteriores trabajos de Arqueología de la Arquitectura. Todo ello contribuirá al estudio de las reconstrucciones en los baluartes, cambios de pavimentos, tapiado de vanos, sustitución de puertas y ventanas, sustitución de carpintería por herrería, reparación y destrucción de muros, emplazamiento de nuevos armamentos, construcción de vías de acceso y cambios de ubicación de los servicios sanitarios, entre otros. Este análisis también nos permitirá identificar zonas de gran potencial arqueológico, con vistas a efectuar excavaciones y estudiar la cultura material correspondiente con los componentes humanos que residieron en este inmueble. No obstante, el futuro levantamiento fotogramétrico del inmueble agilizará sobremanera estos trabajos, dotándolos de una mayor calidad en el registro arqueológico.