Scientists map the borders of a hidden microcontinent beneath the Indian Ocean

The recent discovery of an undersea fragment of continental crust, which is part of the ancient Indian Ocean, has attracted great interest from scientists. This discovery relates to the identification of the likely boundaries of an underwater landform referred to as Mauritia. The Mauritian microcontinent is not part of any lost continent of Atlantis; instead, it is a proposed microcontinent located below the Indian Ocean.It should be noted that the scientific importance of Mauritia does not stem from any fantasies of a lost civilisation, but rather from its role in understanding the process of continental rifting and drift.A 2013 study in the journal Nature Geoscience suggested Mauritius and nearby parts of the Mascarene Plateau may rest on fragments of ancient continental crust rather than entirely on young volcanic rock. The researchers used zircon dating, gravity data inversion, and plate tectonic reconstructions to argue that remnants of a much older landmass survive beneath the region.What scientists mean by a ‘lost continent’Regardless of the strong phrasing posed in the headlines, Mauritia can be categorised as a microcontinent and not a continent itself. From a geological perspective, a microcontinent is an isolated piece of continental crust that has been detached from a larger landmass due to tectonic activity. Scientists say that Mauritia could have once been part of the supercontinent Gondwana but was later stretched, broken apart, and submerged.The Nature Geoscience study explains that the proposed borders of Mauritia were reconstructed using indirect evidence such as crustal thickness and gravity anomalies beneath the ocean floor. Scientists were therefore not mapping visible land, but modelling what lies deep below the seabed.This classification is crucial because, on the surface, the area seems primarily volcanic. Mauritius Island itself is a fairly new volcanic island; however, some of the geological evidence indicates that the material may be much older than the visible rocks.Ancient zircons provided a major clueOne of the strongest pieces of evidence that has been found for the Mauritia hypothesis was the discovery of zircon particles in volcanic rocks of Mauritius. According to reports, young hotspot volcanic rocks found in Mauritius have ancient Archaean zircons, some of which were estimated to be billions of years old. According to the scientists, these ancient zircons could have come from continental rock deposits under Mauritius that had been uplifted through volcanic activity.Zircons play an important role for geologists since these minerals retain information about their age despite undergoing several processes of melting and metamorphism. The fact that such old zircons exist implies that there is some connection between these volcanic rocks and some continental rock deposits underneath.However, scientists caution that the evidence does not point to an intact continent sitting beneath the Indian Ocean. Instead, it suggests the survival of fragmented continental crust hidden beneath younger volcanic layers.Why the Indian Ocean can conceal ancient crustStudies show that the western Indian Ocean is a geographically complicated area, with a combination of volcanic islands, oceanic plateaus, tectonic ridges, and continental fragments. According to researchers, the Mascarene Plateau contains continental fragments. At the same time, the area close to the Mascarene Plateau contains the Seychelles, which was identified as a recognised microcontinent in the larger system.Additionally, it has been stated that volcanism and later sea-floor processes could cover old crust material with new rock. It means that continental fragments could be under a layer of younger rock for millions of years but still remain in existence tectonically.Such a geological environment increases the likelihood of the existence of the Mauritia fragment theory, as other similar examples are already present in the Indian Ocean. Mapping what can no longer be seenThe most recent interest in Mauritia involves geophysical efforts to more accurately define the limits of the concealed microcontinent using geophysical analysis. Based on findings, the scientists utilised gravity inversion to calculate crustal thickness variations at the seafloor in the Indian Ocean. This kind of approach helps scientists determine regions wherein the continental crust might be thicker than the average oceanic crust.Instead of exposing the hidden landmass, the scientists essentially build upon a concealed geological entity using numerous layers of information such as zircon age, crustal modelling, ridge geomorphology, and tectonic evolution.Recent scientific debate also confirms the notion that parts of a continent could still remain intact even after many millions of years following a break-up event.Why Mauritia matters?Scientists consider that Mauritia offers an important lesson on continental breakup and evolution.The underground layer in Mauritius can help us learn about plate tectonics, hotspot volcanic activity, and the development of sea basins. In addition, it shows that traces of ancient continents can be found in areas without visible geological evidence.It is evident that the discovery in Mauritius does not reveal any mystical past. On the contrary, it brings to light something much more realistic and scientific.