Tampering of the geological map of Malta

I refer to the article ‘Bedrock under collapsed residence “remains unchanged’ in latest survey’ based on comments from the Continental Shelf Department about its geological map of Malta and Clyde Caruana as the minister responsible for the map in his reply to a parliamentary question tabled by opposition deputy Darren Carabott. 

The minister emphatically pointed out that the 1993 geological map has a scale of 1:25,000 whereas the 2022 ‘updated’ map is at a scale of 1:10,000. This confirms that the 2022 ‘updated’ map is of a much higher resolution than the previous one but, instead of showing more detail, as would be expected, it has more omissions. 

It is a fact that the southern entrance to the Santa Venera tunnel, excavated in 1992, indisputably exposes the several metres of the middle globigerina, visible at the surface along the road cut leading to the tunnel. The 1993 geological map shows this area as middle globigerina limestone but the ‘updated’ 2022 geological map shows the same area as lower globigerina limestone, proving that the map must have been tampered with. 

Malta’s geological map was updated in 2022.

The Continental Shelf Department failed to give a valid reason for this change or provide new evidence to support the erasing of a much larger adjoining area of middle globigerina extending from the limits of Fleur-de-Lys to Ħamrun in the 2022 map, shown as middle globigerina limestone in the low-resolution map of 1993. 

The Malta Chamber of Geologists had already warned the public about errors and omissions in the ‘updated’ 2022 geological map in its press release issued in December 2022, which also advised users of this map to consult a professional geologist. 

The Continental Shelf Department tries to deflect attention from the tampering of the geological map by claiming that the 2020 excavation site next to the collapsed house of Miriam Pace (located only 200 metres away from the Santa Venera tunnel entrance) was always shown as lower globigerina limestone in geological maps.

It is remarkable that no geological investigation was carried out before or after the collapse to verify what type of rock was excavated and how this could have contributed to the collapse. In the absence of a geological investigation, there is no direct geological evidence to support the claim for lower globigerina in the 2020 excavation site as shown in the map.

Rather than shrink the extent of the middle globigerina, the 2022 ‘updated’ map should have extended the area of the middle globigerina in the map. However, the 2022 map did the opposite by ignoring definitive geological evidence from the tunnel area and proceeding to erase from the map a large area of middle globigerina, a rock known to be weaker than lower globigerina limestone and problematic. 

The tampering has a long-term effect on public safety. The law obliges the consultation of the geological map prior to excavation. Undoubtedly, method statements on rock excavation will exploit the tampered map to save on costs of proper geological investigations, to the detriment of public safety and third-party property. 

The irresponsible tampering of the geological map raises questions on who stands to benefit from this irresponsible act in a densely populated area ripe for redevelopment. 

Peter Gatt – president, Malta Chamber of Geologists, Attard