The Monitoring Well, Reflections on Geology & Society

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February 26, 2024

News and notes

Before going on to discuss the geology and geopolitics of Chile, here are some news items I thought were interesting.



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February 26, 2024

Geology and the Fate of Societies – Chile

Figure 1 – Republic of Chile
Credit: CIA World Factbook – Chile, public domain

The Republic of Chile is located on the west side of the Andes Mountains in South America. According to the Central Intelligence Agency (CIA) World Factbook on Chile the country has a total area of 756,102 square kilometres (km2) of which 743,812 km2 is land and 12,290 km2 is water. In addition to the territory on mainland South America, Chile rules several Pacific islands, including the Juan Fernández Archipelago, Isla Salas y Gómez, the Desventuradas Islands, and Easter Island. Chile also claims about 1,250,000 km2 of Antarctica as the Chilean Antarctic Territory. To the west of Chile is a long coastline on the Pacific Ocean and to the south, Chile’s coastline extends to the Drake Passage. East of Chile is Argentina; northeast is Bolivia; and to the north is Peru. (Last year we looked at Argentina and Bolivia in this blog).

Also according to the CIA World Factbook, the current population of Chile is about 18,549,457. 88.9% of the population is considered white and non-Indigenous. The remaining 10.1% are various indigenous peoples including Mapuche 9.1%, Aymara 0.7%, together with small numbers of Rapa Nui (Easter Islanders), Likan Antai, Quechua, Colla, Diaguita, Kawesqar, and Yagan peoples. The official language of Chile is Spanish. Most people, 60% in Chile are Roman Catholic. Of the remainder, 18% are Evangelical Protestants, 4% call themselves atheist or agnostic and 17% have no professed religion.

Figure 2 – Demographic Profile of Chile
Credit: United States Census Bureau, International Database, public domain

The demographic profile for Chile shows an aging population with a declining population of people under 25. The total fertility rate is 1.75 births per woman, which is below replacement rate. The median age in Chile is 36.6 years and the average life expectancy is 80 years for both male and female.

Figure 3 – Palacio de la Moneda in Santiago de Chile
Credit: Miguel hernandez, Creative Commons
 Attribution-Share Alike 2.0 Generic license

Under the current constitution, adopted in 1980, the government of Chile is presidential republic; the current President is Gabriel Boric (the Palacio de la Moneda is his residence). The government structure includes: a Senate, with Juan Antonio Coloma as President of the Senate; a Chamber of Deputies, with Ricardo Cifuentes as President of the Chamber; and a Supreme Court, with Juan Fuentes Belmar as President of the Supreme Court.

The Capital City and largest city in Chile is Santiago de Chile (pop. 6,269,384). The legislature is based in Valparaíso (pop. 284,630).


Figure 4 – Chilean Ridge and the Formation of the Andes
Credit: Candyyeung168, Creative Commons
 Attribution-Share Alike 4.0 International license

The geology of Chile is very much the geology of the Andes Mountains. The Andean Orogeny that formed the Andes began during the Jurassicand Early Cretaceous and was characterized by the expansion of the Nazca Plate and its subduction under the South American Plate. At the south end of the Nazca plate, the Chilean Ridge marks a divergent plate boundary between the Nazca Plate, the Antarctic Plate and the Scotia Plate.

Figure 5 – Subduction Zone
Credit: K. D. Schroeder KDS4444, Creative Commons
 Attribution-Share Alike 4.0 International license

A consequence of the subduction of the Nazca Plate is the melting of the buried oceanic crust, the rising of magmatic melt, and the consequent creation of a volcanic arc, i.e. the Andes Mountains. Overall, the Andes Mountains in Chile are divided into three main units:

The oldest rocks in Chile are Paleozoic aged micaceousschist, phyllite, gneissand quartzitemany of which are found in the Coast Range. The schist rocks of southern Chile originated in the sediment of the proto-Pacific Ocean metamorphosed in the forearcwedge of the Peru–Chile Trench.

Many of the volcanic rocks of the Andes began to be deposited following the breakup of Gondwana and the beginning of the Andean Orogeny in the Jurassic. The Altiplano Plateau formed during the Cenozoic. In the latest period of the Cenozoic, the Quaternary, extensive glaciations began during the Pleistocene and many glaciers persist into the current Holocene Epoch.



Figure 6 – Flock of sheep and farm, Laguna Blanca, Magallanes, Chile
Credit: LBM1948, Creative Commons
 Attribution-Share Alike 4.0 International license

According to the CIA World Factbook on Chile, agricultural land makes up 21.1% of the total land area. Of this 1.7% is arable land, 0.6% is covered in permanent crops, and 18.8% is permanent pasture. Agriculture makes up 4.2% of the national economy. The wide range of climate and geography in Chile allows for a large range of agricultural production in the country. Major agricultural products of Chile include grapes, apples, onions, wheat, corn, oats, peaches, garlic, asparagus, beans, beef, poultry, wool, and farmed fish such as salmon. Chilean wine has a high reputation as do many of their other fruit products. We frequently see Chilean fruit products on our store shelves here in Canada. Statistics on agriculture in Chile are found here.

Figure 7 – Chilean Salmon Farms
Credit: Sam Beebe/Ecotrust, Creative Commons
 Attribution-Share Alike 3.0 Unported license

In general, hunger is rare in Chile. However, economic dislocations, such as the 2020 – 2022 Covid-19 Pandemic, seriously disrupted food distribution systems and food insecurity happened in Chile.


Figure 8 – Southern Chile Forest
Credit: Luis Enrique Pérez López, Creative Commons
 Attribution-Share Alike 4.0 International license

Forestry is a major industry in Chile, making up 14% of the country’s exports. Major wood species harvested include Pinus radiata, Eucalyptus globulus and Eucalyptus nitens. About 112,200 people are employed in the industry.

In contrast to some countries where deforestation is a problem, Chile's total forest area has been increasing since the turn of the 21stcentury. Production statistics are here.

Mineral Resources

Figure 9 – Copper Mine in Chile
Credit: Sebastian Kawa &Tomasz Kawa, Creative Commons
 Attribution-Share Alike 3.0 Unported license

Chile is a major mining producer. Metallic minerals produced include copper (from about 32 mines), gold, iron, lead, mercury, molybdenum, rhenium, silver and zinc. Industrial minerals produced include: boron, iodine, lithium, phosphates (including guano), potash, salt, and sulphur. Mineral fuels produced include coal, natural gas and petroleum. At one time Chilean nitrates were considered a major strategic mineral for the production of fertilizer, ammonia, nitric acid and explosives; the development of the Haber-Bosch Process meant that they were less important.

Mineral production statistics from the USGS Minerals Yearbook is here; other statistics can be found here.


Given the north to south extent of Chile, it is not surprising that it has a wide range of climates. In the north are dry deserts, including the world’s driest desert, the Atacama. The central portion of the country is more temperate and the extreme south there is polar tundra. If you want to visit Chile, check out these sites here, and here. Travel advisories for the worried are here.

Figure 10 – Köppen Climate Types of Chile
Credit: Bdm121, Creative Commons
 Attribution-Share Alike 4.0 International license

You can find a key to description of the climate types shown in Figure 10, here.

History and Geopolitics


Figure 11 – The Inca Army on the March
Credit: Miguel Vera León, Creative Commons
 Attribution 2.0 Generic license

In the history of Chile, the earliest evidence of human settlement was from the Monte Verde site, dated at approximately 14,500 years ago. This finding really threw a wrench into the archaeological community’s assessment of human settlement in the Americas, but the hard science evidence has withstood the scrutiny.

Various tribes of hunter/gathers inhabited Chile for the next 14,000 years. The earliest state-level culture to exist in Chile was the Inca Empire, who occupied part of northern Chile after they fought against the Mapuche between 1460 and 1491. The three-day Battle of the Mauleset the limit to the Inca territories in Chile at the Maule river.

The arrival of the Spaniards in 1528 lead to the Spanish conquest of the Inca territories and beyond into Chile. It was not a peaceful take over. Following the extermination of indigenous tribes, mostly Spanish settlers moved into the most fertile lands in the centre of Chile. Wars with indigenous peoples in the Chile, the so called Arauco War, lasted until 1656.

By 1810, the descendants of the Spanish settlers were ready for independence from their Spanish masters. The result was the Chilean War of Independence from 1810 to 1827. Independence was followed by a civil warthat was in turn settled in the Constitution of 1833. A relatively peaceful time followed from 1833 to 1861 in the so-called Conservative Republic followed by Liberal Republic of 1861 to 1891. These republics were followed by the Parliamentary Era (1891 to 1925) and the Presidential Era (1925 to 1973). Border disputes with Argentina lead to a naval arms race and the eventual resolution of the border dispute in the 1902 General Treaty of Arbitration.

In 1970, the election of a doctrinaire socialist, Salvador Allende, led to an openly Marxist regime that lasted from 1970 to 1973. With the generous aid by the CIA and other American organizations, the Chilean military, under General Augusto Pinochet, overthrew the Allende government in a coup d’etatin September 1973.

The Pinochet regime lasted from 1973 to 1990 and was marked by harsh suppression of their political opponents – approximately 30,000 people were killed and countless others illegally detained. Thousands others fled the country, in fear of their lives. It should be pointed out that the Pinochet regime enjoyed widespread support from middle-class Chileans. The people supporting the overthrow of the Allende regime feared a repeat in Chile of measures enacted by other socialist regimes. As well, the Pinochet regime faced an armed insurrection by people opposed to the military government, so many of the people executed by Pinochet’s regime were people at war with the government.

The Pinochet regime reformed the economy of Chile under the guidance of the Chicago School of economists who followed the direction of Nobel Laureate Milton Friedman. Friedman’s advice – reduce excessive regulation and free up economic activity – had overall positive results.

The 1980 constitution allowed General Pinochet to remain in office until he retired in 1990. Since then, Chile has been ruled by a variety of governments, some socialist and some conservative. Overall, there seems to be no wish to return to the bad old days of the Pinochet regime. However, the generaleconomic and political upheavalof our times has led to thecurrent troubles in Chile as well. The current troubles in Chile seems to be exacerbating the rivalry between right-wing and left-wing political parties that is a feature of Chilean history.Recently,in 2023, a right-wing party came to power, to the distress of the left-wingers. Some of this is just democratic churn and some of it reflects deep divisions within Chilean society. These strains in the body politic persist to this day, as shown in a recent failed attempt to reform the 1980 constitution. It is hard to see where this will lead, but it may not be good.


Figure 12 – Quirihue, Biobío, Chile
Credit: CARLOS SALGADO MELLA, Creative Commons
 Attribution-Share Alike 3.0 Unported license

Leaving aside the internal issues in Chile, let’s take a look at the relationships that Chile has with its neighbours. For now these relations are peaceful, it hasn’t always been so. Looking at each of the three neighbouring states, here is how their relations with them seem to be in 2024:

Argentina and Chile share a long border and have similar cultures and histories. Relations between the two countries have varied from tense to cooperative. Right now, there doesn’t seem to be any existential issues dividing the two countries, in fact there has been a fair amount of cooperation. I don’t expect their disagreements to get out of hand anytime soon; although that all depends upon wise or foolish leadership.

Bolivia and Chile: the Bolivians have not forgotten that Chile took the land connecting Bolivia to the Pacific Ocean in the War of the Pacific, 1879 to 1884. Since then, attempts to secure access Bolivian to the sea with Chilean agreements have failed. This dispute will not likely go away anytime soon.

Peru and Chile: in another case of long memories, Peru was also a loser in the 1879-1884 war. As well, there have been many other conflicts between the two countries, often in disputes over resources. It is hard to see where this will lead; again it will depend on the leadership in the two countries.

In the wider world, the United States(USA) maintains a strong interest in Chile, involving a wide range of bilateral agreements and relationships. We can expect that the USA will continue to take a keen interest in Chilean affairs, if only because Chile is a major producer of critical minerals vital to the American economy.

Another world actor, China, is also taking an interest in South American affairs. China’s main interest in Chile seems to be trade and investment, although we shouldn’t discount its great power rivalry with the United States as a motive for playing in America’s backyard. It could become a theatre of operations in a conflict.

That kind of wraps it up for this very brief look at Chile. I am optimistic for the country. Provided their leaders remember the lessons of their harsh past (still in living memory) they should be able to accommodate the contrasting ambitions of the left and right wings in their body politic. All they need is good people.

Check out the links in this post if any of this interests you.

Standard Caveat

The purpose of my weblog postings is to spark people's curiosity in geology. Don't entirely believe me until you've done your own research and checked the evidence. If I have sparked your curiosity in the subject of this posting, follow up with some of the links provided here. If you want to, go out into the field and examine some rocks on your own with the help of a good field guide. Follow the evidence and make up your own mind.

In science, the only authority is the evidence.