IN PARTNERSHIP WITH THE DEPARTMENT OF GEOLOGY OF THE NATIONAL
AUTONOMOUS UNIVERSITY OF MEXICO UNAM AN INVESTIGATION ON T HE
ORIGINS OF TOBA VOLCÁNICA OPENED A DEEPER INSIGHT ON A STONE
THAT IS WIDELY USED IN MEXICAN CULTURE.
The stone has the false common name “cantera” (spanish word for quarry) and there is no public
understanding of its origin and composition. This scientific investigation is driven by the studio‘s
strong desire to research materials and share public knowledge.
The image shows a partial view of the Construction Materials Collection placed on its plinths. Source: Album “Photography Workshop No. 2”, p. 51, ca. 1916. Photographer: D.N. Chavez. Photographic collection of the Historical Heritage of the Institute of Geology - UNAM (AHIG).
When the National Geological Institute started in 1888, its work was divided into collections:
minerals, rocks, construction, ornamentation materials, paleontology, and technological geology.
In the Department of „Mineralogy, Petrography and Construction Materials“, the study of rocks,
lamination, microscopic study, cutting, polishing, study of quarries and igneous rocks used for
construction material (andesites, breccias and tuffs) was carried out. Likewise, experiments to
calculate the elasticity, compression rupture and resistance, degree of porosity and absorption
capacity of the rocks, its density per cubic meter, texture, resistance and action to sudden changes
in temperature where studied.
The image shows the Library of the Geological Institute of Mexico in 1917, a space where the Historical Collection of the Institute of Geology of the UNAM is currently housed. Source: Album “Photography Workshop. File No. 2 ”, p. 3 3 , Photographic Collection of the Historical Herritage of the Institute of Geology - UNAM (AHIG).
The Historical Collection of the Institute of Geology of the UNAM (AHIG) is the area responsible
for safeguarding, conserving and disseminating the institutional historical memory, generated
from its origins, in addition to promoting and disseminating a documentary culture based
on the regulatory frameworks of transparency and access to information. The value of the
Historical Heritage lies in the possibility of preserving essential information for the production
of knowledge about the past and in a historical perspective on issues that matter in the present.
The protected testimonies allow us to understand the national history of scientific, agricultural,
mining, industrial and economic development related to non-renewable resources, as well as the
experiences that guided the formation of the scientific and technical elites, the scientific and
extractive policies, the networks between the geological community in the country and with the
world.
In such a way that this space, located in the heart of the building, has maintained its vocation
since the beginning of the 20th century. The extreme dates of the collections it houses are from
1888 to 1950: historical documentary archive, photographs, maps, collection of construction
materials buckets and more than 8,000 prints (brochures, theses, periodicals, books, general works
and encyclopedias).
The enclosure that houses the UNAM Geology Museum was built exclusively to house the National
Geological Institute to carry out the geological study of the territory from three points of view:
scientific, technical and industrial, to build the geological and mining cartography of Mexico and
create the nation‘s Geological and Paleontological Museum. The design and construction of the
building, between 1900 and 1904, corresponded to the architect Carlos Herrera López, and it was
officially inaugurated on September 6, 1906 when the 10th National Geological Congress was held
in Mexico. Since 1970, the building exclusively houses the Museum of the Institute of Geology
of the UNAM. It has five rooms: Main Room, Paleontology, Mineralogy, Petrography, and Earth
System, which exhibit an estimated collection of 30,000 specimens (fossils, rocks, minerals, and
Mexican and foreign meteorites).
The following photomicrographs are taken, the first (left) in parallel light and the second (right) with crossed nicols,
detail of a plagioclase phenocryst of composition Andesina - Labradorite, disseminated on a matrix, with a twinned
texture, corrosion, poikilitic with rounded and gulf crystals.
A rock formed by processes of extrusive igneous origin, that means; they were formed on the
surface of the Earth, originated by a volcanic body, this rock made up of various components of
stone origin (rocks, minerals, gases and a large amount of amorphous material), due to its sudden
cooling and solidification, shows kinematic traces of flow, deformation and empty vesicles that
trapped gases (volatile elements). Now a material that is used and employed as dimensional rock.
SPECIAL THANKS TO:
Engineer Juan Carlos Cruz, for the petrographic studies, to Engineer Óscar Irazaba
for access to the Museum's collections and to Dr. Lucero Morelos for the historical photographs and
texts.
ABOUT UNAM GEOLOGY INSTITUTE
The Institute of Geology (IGl) is a dependency of the National Autonomous University of Mexico
(UNAM) that belongs to the Subsystem of Scientific Research (SIC). It currently has two offices,
one located in Ciudad Universitaria in Mexico City, which houses the National Geochemical and
Mineralogy Laboratory, among other buildings, and the Northwest Regional Station (ERNO)
located in Hermosillo, Sonora.
The IGl also has the Geology Museum in Colonia Santa María la Ribera in Mexico City and the
Tlayúa Site Museum in Tepexi de Rodríguez, Puebla. As of 2015, our community is made up of
59 researchers and 43 academic technicians, an oscillating population of scholarship holders who
carry out bachelor’s, master’s and doctoral thesis work, and 117 people from the administrative
area.
www.geologia.unam.mx
ABOUT UNAM GEOLOGY MUSEUM
The UNAM Geology Museum, located in the heart of the Santa María La Ribera neighborhood,
concentrates the most important geological collections in Mexico. It is a space that, in addition to
safeguarding this important heritage, disseminates scientific knowledge of Earth sciences.
www.geologia.unam.mx/igl/museo/
