MOSCOW, June 2, Vladislav Strekopytov. The International Scientific Committee for Antarctic Research (SCAR) announced the completion of the GeoMAP project to create a complete interactive geological map of the Ice Continent. For the first time, it was possible to collect data on all the rocks that come to the surface in the ice-free regions of Antarctica.
The basis of the study of the territory
The Soviet naturalist academician Borisyak considered the construction of a detailed geological map, which serves as the basis for the search for minerals, to be the crowning achievement of scientific research in the region.
In Russia, the first overview maps with elements of the geological structure began to be compiled under Peter I. century, regional mapping at a scale of 1:1,000,000 was completed throughout the entire territory of the Soviet Union, and the most promising territories in terms of prospecting for minerals were covered with maps of a larger scale.
The situation is similar in other countries. But there is a whole continent on Earth, which, from the point of view of geological exploration, has long remained a blank spot — Antarctica.
The principle of constructing geological maps is that rocks emerging on the surface are applied to the topographic base. This is problematic in Antarctica. Of the 14 million square kilometers of the total area, only 50 thousand — less than one percent — is free of ice. Nevertheless, even for this small area, slightly larger than the Moscow region, until recently there was no single geological map. «photo» data-crop-ratio=»1″ data-crop-width=»600″ data-crop-height=»600″ data-source-sid=»cc_by_30″ class=»lazyload» width=»1920″ height =»1920″ decoding=»async» />
New life for old maps
At the open scientific conference SCAR in Auckland in 2014, New Zealand geologists presented a fundamentally new cartographic product — a digital map of New Zealand at a scale of 1:250,000, which combined all the disparate geological data available in the country. In fact, this is an electronic database, where materials for each rock outcrop, or, as geologists say, outcrop, are linked to a single coordinate grid.
The format was widely approved by scientists, and at the conference it was decided to implement a similar project on the Ice Continent. The Geological Mapping Update of Antarctica (Geological Mapping Update of Antarctica) initiative group included researchers from the USA, Norway, Italy, the United Kingdom, Australia, Russia and New Zealand. The project was led by Simon Cox from the New Zealand Royal Research Institute (GNS Science).
In total, specialists from 14 countries participated in the work. The task was to bind all geological observations and cartographic data to the GIS base, as well as provide access to them through web services.
The basis of the electronic database of sources was 589 published maps of different scales: local (1:250,000 and larger — 49 percent of data), regional (from 1:250,000 to 1:1,000,000 — 44 percent) and continental (more than 1:1,000 000 — seven percent). For areas not covered by official mapping, data from unpublished maps, scientific articles and dissertations were used. At the same time, only actually surveyed rock outcrops were included in the registry without interpretation of geophysical data and extrapolation of geological boundaries to subglacial areas. No new field work was done specifically for GeoMAP purposes. » data-crop-width=»600″ data-crop-height=»478″ data-source-sid=»cc_by_40″ class=»lazyload» width=»1920″ height=»1529″ decoding=»async» />
The scientists checked the descriptions of more than 99,000 polygons covered by the mapping. For convenience, all data were reduced to a single scale of 1:250,000. In most cases, the coordinates of the boundaries of the polygons had to be set anew — based on high-resolution satellite images of the LIMA (Landsat Image Mosaic of Antarctica) program, since the accuracy of referencing the original maps often did not meet the scale requirements .
The most difficult thing was to compose a single legend for the entire continent. Geological maps are usually based on a combined geochronological-lithostratigraphic method, in which the age of the rocks is shown by color, and their type and composition by letter indices. In a situation where rock outcrops are separated from each other by tens and hundreds of kilometers, and their age is sometimes determined very approximately, it was very difficult to do this.
Wikipedia of Antarctic Geology
A test version of the GeoMAP map (v.2019-07) was presented at the XIII International Symposium on Antarctic Geosciences, which was held in 2019 in South Korea. Its finalized and refined versionGeoMAP (v.2022-08) was recently posted to the PANGEA Digital Data Library and the description was published in Nature Scientific Data. An interactive geological map is available on the GNS Science website.GeoMAP is distributed under the Creative Commons Attribution 4.0 International License (CC BY for short) and is available for download with all metadata. This is the most free license in terms of what users can do with the work — redistribute, remake, correct and supplement, provided that the primary author is credited. .jpg» media-type=»photo» data-crop-ratio=»0.593207547169811″ data-crop-width=»600″ data-crop-height=»356″ data-source-sid=»cc_by_40″ class=»lazyload » width=»1920″ height=»1139″ decoding=»async» />
The developers believe that this approach makes it possible to make GeoMAP a living database that will be updated and improved with each new discovery.
«There are still many areas in Antarctica that no geologist has yet visited and where there is still more to be done. mapping,” lead project data architect Belinda Smith Little of GNS Science said in a press release, “New data is coming in all the time, so GeoMAP is designed to be edited and improved over time.”
“The new map as a database is very convenient,” says German Leychenkov, head of the Department of Geology and Mineral Resources of Antarctica VNIIOkeangeologia, Doctor of Geological and Mineralogical Sciences. “If you need to get information about the geology of a region, now it is easy and accessible. Antarctica, but on a smaller scale. Now this is the most detailed map of the entire continent, although there are more detailed ones for individual outcrops.»
Russian scientists took an active part in the creation of GeoMAP.
“In 2018, we published a geological map of one of the key regions — the Prince Charles Mountains in the area of the Lambert Glacier,” says Leichenkov. “We have been working there for thirty years, and our materials were used in the project. In addition, we handed over a number maps for other regions».
Hidden treasures of Antarctica
Without knowing the structure of the Ice Continent, it is impossible to imagine the geological history of the planet as a whole. In the east of Antarctica, scientists have discovered some of the most ancient rocks on Earth. Their age is about four billion years. The same breeds are in Australia, South Africa. All these territories were part of the very first continent that existed in the Archaean 3.6-2.8 billion years ago.
Later, about a billion years ago, the East Antarctic Plate was part of the Rodinia supercontinent. About 500 million years ago, one of its blocks participated in the formation of Gondwana, and then the last supercontinent — Pangea. After its collapse about 80 million years ago, the breakaway southern part took shape as the modern Antarctic continent.
Accurate dating and mapping of rocks makes it possible to understand how the climate and natural environment of our planet have changed over hundreds of millions of years. Scientists have already established that 100-65 million years ago it was very warm in Antarctica, there were no glaciers and tropical forests grew throughout the continent. In sedimentary deposits of this age, geologists everywhere find the remains of petrified trees and heat-loving animals, including dinosaurs. Approximately 40 million years ago, global cooling began, and 34 million years ago, the main part of Antarctica was covered with glaciers. Over the subsequent time, their volume has changed. crop-width=»600″ data-crop-height=»525″ data-source-sid=»cc_by_40″ class=»lazyload» width=»1920″ height=»1680″ decoding=»async» />
The ban expires in 2048. If it is not extended, interest in the mineral resources of the Ice Continent will flare up with renewed vigor, and a detailed geological map will become the basis for their search.