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In 1834 Guillermo Schulz produced the first geological map in Spain, a 1:400 000 scale map of the area of Galicia. [49] the first geological map of Spain drawn by Joaquín Ezquerra del Bayo. Charles Lyell visited Spain in the summer of 1830 and also in the winter of 1853. Lyell's visit to the Pyrenees led him to study the orogeny that produced ...
An orthographic projection map detailing the present-day location and territorial extent of Mexico in North America.. This is a list of conflicts in Mexico arranged chronologically starting from the Pre-Columbian era (Lithic, Archaic, Formative, Classic, and Post-Classic periods/stages of North America; c. 18000 BCE – c. 1521 CE) up to the colonial and postcolonial periods (c. 1521 CE ...
This image is in the public domain in the United States because it only contains materials that originally came from the United States Geological Survey, an agency of the United States Department of the Interior.
Because defining a GSSP depends on finding well-preserved geologic sections and identifying key events, this task becomes more difficult as one goes farther back in time. Before 630 million years ago, boundaries on the geologic timescale are defined simply by reference to fixed dates, known as "Global Standard Stratigraphic Ages" (GSSAs).
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks).
Mexican independence from Spain was not an inevitable outcome of the relationship between the Spanish Empire and its most valuable overseas possession, but events in Spain had a direct impact on the outbreak of the armed insurgency in 1810 and the course of warfare through the end of the conflict.
During the period of the Independence of Mexico, part of the territorial organization of New Spain was integrated into the new nation of the Mexican Empire. Added to this were the Captaincy General of Yucatán and the Captaincy General of Guatemala (whose annexation was a strategy to counteract the Spanish crown).
Each period is marked below the era bar on top of its subdivided epochs and stages. Each stage is assigned an age in mya , an acronym for million years ago, which is the age at which it began. Most of these ages are derived from astronomical cycles in sediments, magnetic data, biostratigraphic data, and radiometric dating methods.