Sol de Mañana is an area with geothermal manifestations in southern Bolivia, including fumaroles, hot springs and mud pools. It lies at about elevation, south of Laguna Colorada and east of El Tatio geothermal field. The field is located within the Eduardo Avaroa Andean Fauna National Reserve and is an important tourism attraction on the road between Uyuni and Antofagasta. The field has been prospected as a possible geothermal power production site, with research beginning in the 1970s and after a pause recommencing in 2010. Development is ongoing .
Description
Sol de Mañana lies in the San Pablo de Lipez municipality (Sud Lipez Province), in a remote and uninhabited region of Bolivia. In an area of there are steam vents, mud pools, hot springs, geysers and fumaroles. Apart from Sol de Mañana proper there are additional geothermal manifestations dispersed a few kilometres south-southwest at Apacheta and from Sol de Mañana; north-northwest at Huayllajara; The first two feature hydrothermally altered rocks and sometimes they are considered to be separate geothermal fields.
Steam/water emissions can under exceptional circumstances reach heights of . Gas vents release sulfur-containing gases. The temperatures of the springs reach and the fumaroles , hot enough to be visible from space in ASTER images. Seismic swarms and earthquakes have been recorded in the field. Sol de Mañana lies at about elevation, making it among the highest geothermal fields in the world.
The nearest major communities are Quetena Grande and Quetena Chico in Bolivia, northeast from Sol de Mañana, and the field can be accessed through unpaved roads from Uyuni, away. across the frontier, in Chile, lies El Tatio, the best-known geothermal manifestation in the Central Andes. There are numerous volcanoes in the area, including Tocorpuri west-southwest and Putana and Escalante southwest of Sol de Mañana, and the Pastos Grandes and Cerro Guacha caldera systems. The field lies - south of Laguna Colorada, which can be reached from Sol de Mañana. There are mines at Cerro Aguita Blanca, a few kilometres south of Sol de Mañana, and at Cerro Apacheta about five kilometres west-southwest; the latter can be reached through another road from Sol de Mañana.
Geology
Off the western coast of South America, the Nazca Plate subducts beneath the South American Plate. The subduction is responsible for the volcanism of the Andes. The growth of the Altiplano high plateau commenced 25 million years ago before shifting eastward 12-6 million years ago.
The Andean Central Volcanic Zone is one of four belts of volcanoes in the Andes. Volcanic activity began 23 million years ago and involved the emplacement of a series of ignimbrites, which form one of the largest ignimbrite plateaus of the world. Numerous younger stratovolcanoes grew on top of the ignimbrites; there are about 150 separate volcanic centres. The Altiplano volcanoes form the Altiplano-Puna volcanic complex, which is underpinned by the Altiplano-Puna Magma body. The dry climate leads to an exceptional preservation of the volcanic landforms. About 50 volcanoes in the Central Andes (Bolivia, northern Chile, northern Argentina) were active during the Holocene.
Local
Sol de Mañana is part of the Laguna Colorada geothermal area/caldera complex (the names are sometimes used interchangeably). The area features Miocene-Pleistocene volcanic rocks (dacite forming ignimbrites, lavas and tuffs) emplaced on top of Cenozoic marine sediments. Alluvial deposits and moraines occur in the area. There are various north-south and northwest–southeast trending tectonic lineaments in the region, associated with rock deformation. At Sol de Mañana there are a number of faults, including normal faults active during the Holocene, which constitute pathways for the ascent of hot water. The most important faults at the field trend north-northwest-south-southeast. Glacial erosion has taken place in the area during the past, which has left moraines east and north-northwest of Sol de Mañana.
Drill cores have identified several rock units under Sol de Mañana, including several layers of dacitic ignimbrites with ages of about 5-1.2 million years and andesitic lavas. Hydrothermal alteration has taken place throughout the layers, forming from top to bottom layers rich clays, silica and epidote; each of these layers is several hundred metres thick. Basement rocks were not encountered. This stratigraphy is similar to that at El Tatio, across the border in Chile. The geothermal heat reservoir appears to be located within the ignimbrites and andesites.