Sierra la Primavera is a
Late Pleistocene
The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division of ...
volcanic centre in
Jalisco
Jalisco (, , ; Nahuatl: Xalixco), officially the Free and Sovereign State of Jalisco ( es, Estado Libre y Soberano de Jalisco ; Nahuatl: Tlahtohcayotl Xalixco), is one of the 31 states which, along with Mexico City, comprise the 32 Federal En ...
of central-western
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
, located immediately west of
Guadalajara
Guadalajara ( , ) is a metropolis in western Mexico and the capital of the list of states of Mexico, state of Jalisco. According to the 2020 census, the city has a population of 1,385,629 people, making it the 7th largest city by population in Me ...
in
La Primavera Biosphere Reserve
La Primavera Biosphere Reserve, also known as La Primavera Flora and Fauna Protection Area, is a protected natural areas of Mexico, protected natural area in western Mexico. It is located in the state of Jalisco, immediately west of the city of Gu ...
. It consists of a
caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
,
lava dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on ...
s and lava flows that have formed in the last 200,000 years, with the latest known volcanic eruption having occurred about 30,000 years ago.
Geology
The formation of Sierra la Primavera commenced about 120,000 years ago with the eruption of
rhyolitic
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
flows and domes. This was followed by a
VEI-6 eruption about 95,000 years ago that deposited of
tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism.
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they rem ...
with the creation of an wide caldera.
The tephra forms a volcanic deposit known as the Tala Tuff and consists of voluminous
pumice
Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular vol ...
flows.
Subsequent filling of the caldera with water resulted in the formation of a lake through which several lava domes were created. Several lava domes were emplaced along the caldera about 95,000 years ago, which was followed by the eruption of a younger series of ring domes about 75,000 years ago.
After uplift and sedimentation filled the lake, a final series of lava domes were erupted along the southern margin of the caldera about 60,000 to 30,000 years ago. Although volcanic eruptions are not known to have occurred from Sierra la Primavera in
recorded history
Recorded history or written history describes the historical events that have been recorded in a written form or other documented communication which are subsequently evaluated by historians using the historical method. For broader world hist ...
, it is still potentially active, containing a series of
fumaroles and
hot spring
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...
s.
Subfeatures
Sierra la Primavera contains 29 named subfeatures:
See also
*
List of volcanoes in Mexico
Types of volcanoes
There are multiple types of volcanoes in Mexico. Volcanoes can be of different types such as cinder cone volcanoes, composite volcanoes, shield volcanoes, and lava domes. Each of these variations of volcanos forms in its ...
References
{{reflist
Calderas of Mexico
VEI-6 volcanoes
Pleistocene calderas
Potentially active volcanoes
Trans-Mexican Volcanic Belt
Volcanoes of Jalisco