Eric joined the GSB after graduating as a geologist from Université Catholique de Louvain in 1970 and became statutory geologist, after getting his PhD at the same university in 1975. He pursued his career as a survey geologist, only interrupted by a brief stint at the cabinet of the Minister-President of the Walloon Region during 1984-1986, until his retirement in 2009, however maintaining an office at GSB. This was combined with a charge at Université Catholique de Louvain on field geology and geological mapping (1989-2009), including coordination of the UCL team of map geologists on the Geological map of Wallonia (2004-2009). He was a scientific collaborator at the Polytechnical Faculty of Mons (1988-2009) and industrial collaborator at the Mines and Mineral Processing department of Université libre de Bruxelles (1989-1999).
His research interests first of al concerned the conodont stratigraphy of the type Tournaisian and the Tournaisian – Visean boundary in Belgium, subject of his PhD thesis, quickly extended to stratigraphical studies of the Dinantian at large. His principal research interest became limestones and their polished varieties, the marbles, studied from quarry to their application in the building industry. Eric was for many decennia the principal expert and promoter on Belgian limestones and marbles, also on those of northern France.

His cultural and historical interests brought him to study the birth and development of the geological sciences, especially of Belgium, publishing with his spouse Marie-Claire Groessens-Van Dyck as co-author.

Eric has profound knowledge on the domains of his interest and has never failed to assist others with information and insight. His network was very extensive, covering the entire geoscience community and building stone industry in Belgium and beyond, not to forget the citizen scientists, often becoming the first contact person. This resulted in many ‘distinctions’ and fossils named after him.

GROESSENS, E., CONIL, R. & HENNEBERT, M., 1979. Le Dinantien du Sondage de Saint Ghislain., Stratigraphie et Paléontologie. Memoirs of the Geological Survey of Belgium, t. 22, 137 p.

GROESSENS, E., 1981. L’industrie du marbre en Belgique. Mém. Inst. Géol. Univ. Louvain, t. 31, pp. 219 253.

CONIL, R., GROESSENS, E. & VANDENVEN, G., 1981. Le Sondage de Denée. Geological Survey of Belgium Professional Paper 1981/4, pp. 1 56.

GROESSENS, E.,1987. Belgian stone, a review. Soc. belge de Géologie, Centenaire 1987, Volume hors série, pp. 75 87.

GROESSENS, E., 1989. A History of the Subdivision of the Dinantian Subsystem. Bull. Soc. belge de Géologie, t. 98, pp. 183 195.

CORDY, J.M., GROESSENS-VAN DYCK, M.Cl., GROESSENS, E. & TOURNEUR, F. (réd.), 1994. De la Bactérie à Lucy.- 4 Milliards d’années de Vie sur Terre. Catalogue d’Exposition, éd. Abbaye de Saint-Gérard de Brogne, 163 p.

DE JONGHE, S., GEHOT, H., GENICOT, L.-Fr., WEBER, Ph., TOURNEUR, F., DUCARME, P., GOHY, Fr. & GROESSENS, E., 1996. Pierres à bâtir traditionnelles de la Wallonie. Manuel de Terrain. Min. Rég. Wallonne.- D. G. Ress. Nat. & Envir. et Centre d’Hist. Archit. & du Bat.(CHAB/UCL), 261 p.

GROESSENS, E. & GROESSENS-VAN DYCK, M.- Cl., 2001. Histoire des Sciences en Belgique, 1815-2000. Ed. La Renaissance du Livre (Tournai) – Dexia. La Géologie, 1ère partie, chap.19. pp.269-288; Les Sciences de la Terre, 2ème partie, chap. 13, pp. 219-234.

GROESSENS, E., 2006. Dinantian. in Dejonghe, L., ed., Current status of chronostratigraphic units named from Belgium and adjacent areas. Geologica Belgica, t. 9, pp. 157-162.

GROESSENS, E. & GROESSENS-VAN DYCK, M.Cl., 2007. From d’Omalius d’Halloy to the Belgian Federal state, two hundred years of Geological mapping in Belgium, Earth Sciences History, Vol. 26, N°1, 2007, pp 75-84.

GROESSENS, E. & TOURNEUR, F., 2007. Les marbres wallons à Versailles. In “Les Wallons à Versailles” Ed. Luc Pire (Renaissance du Livre) et Commission royale des Monuments, sites et fouilles, Vol. spécial., pp 357-376.

GROESSENS, E., 2009. De Doornikse steen, bouwmateriaal sinds de Romeinse periode en een parel tussen de Belgische marmers. Geological Survey of Belgium Professional Paper 2009/1, N°305, pp. 25-46.

GROESSENS, E., 2009. Quelques pionniers de la Géologie officielle et la création d’un Service géologique en Belgique. Travaux du Comité français d’Histoire de la Géologie (COFRHIGEO) 3e série, t. XXII, 2008, n°1, pp.1-25.

GROESSENS, E. & TOURNEUR, F., 2014. Le Rouge et le Noir… Ou le roman passionant des beaux marbres wallons! In: Rouges en Noirs, rubis, grenat, onyx, obsidienne et autres minéraux rouges et noirs dans l’art et l’archéologie Monographies du Musée provincial des Arts anciens du Namurois, 67, pp. 35-57.

DE CEUKELAIRE M., DOPERÉ F., DREESEN R., DUSAR M., GROESSENS E., 2014. Belgisch marmer . Academia Press, 292 p.

GROESSENS, E. & GROESSENS-VAN DYCK, M.-C., 2015. De geologie. In: Robert Halleux, Geert Vanpaemel, Jan Vandersmissen en Andrée Despy-Meyer, Geschiedenis van de wetenschappen in België. 1815 – 2000. dbnl · digitale bibliotheek voor de Nederlandse letteren, 19, pp. 269-288.

TOURNEUR, F. & GROESSENS, E., 2018. Le matériau, d’ici et d’ailleurs. In: La sculpture gothique à Tournai. Splendeur, ruine, vestiges (eds. L. Nys & L. D. Casterman). Fonds Mercator, pp. 46-55.

GROESSENS, E., 2020. Le Marbre Lunel. In: La Pierre et les Carrières du Moyen Âge à nos jours. Journée d’étude au Musée de la Pierre de Maffle à l’occasion de son trentième anniversaire. 27-28.9.2019. Cercle royal d’Histoire et d’Archéologie d’Ath et de la région. Etudes et Documents, 31, pp. 175-189.

GROESSENS, E., 2021. Une console qui ne laisse pas de marbre. Le Courrier du Musée L et de ses amis, 58 septembre-novembre 2021, pp. 22-23.