A new perspective to model subsurface stratigraphy in alluvial hydrogeological basins, introducing geological hierarchy and relative chronology
Chiara Zuffetti, Alessandro Communian, Riccardo Bersezio & Philippe Renard
| Résumé |
This paper presents a novel perspective for modelling alluvial
stratigraphy. It integrates the spatial geological information,
geological maps and well log descriptions, with the rules
describing the hierarchy and relative chronology of the geological
entities. As geological modelling tools are moving fast forward,
the urgent need for expert geological input, codified as modelling
rules, persists. Concerning subsurface alluvial architectures, the
concepts of “stratigraphic hierarchy” and “relative chronology”
provide the most relevant rules which permit to link the modelling
procedure to the geo-history of a region. The paper shows how to
formalize this knowledge into modelling rules. This is illustrated
and implemented in a Python™ module named HIEGEO which is applied
on a 2-D cross-section from the Po Basin (N-Italy). The
stratigraphic correlation yields 2-D pictures of the hierarchic
stratigraphy and relative chronology of the units. The input are:
an attribute table of stratigraphic boundaries expressing their
hierarchy and chronology; contact points where these boundaries
cross the control logs. Since the aim of HIEGEO is to illustrate
the principle of the method but not to replace existing 3-D
geological modelling tools, it implements a linear interpolation
algorithm which creates joins between contact points. It plots
linear joins framing polygons based on their hierarchy, at any
user’s desired detail. HIEGEO highlights potential inconsistencies
of the input dataset, helping to re-evaluate the geological
interpretation. The proposed workflow allows to: i) translate
geological knowledge into modelling rules; ii) compute
stratigraphic models constrained by the hierarchy of stratigraphic
entities and the relative chronology of geological events; iii)
represent internal geometries of the stratigraphic units,
accounting for their composite nature; iv) reduce uncertainty in
modelling alluvial architectures. It represents a starting point
for multi-scale applications and could be easily integrated into
3-D modelling packages, to couple the hierarchical concept proposed
here with existing advanced interpolation methods. |
| Mots-clés |
Alluvial stratigraphy; Hierarchy; Modelling rules; Po basin; Python; Relative chronology |
| Citation | Zuffetti, C., Communian, A., Bersezio, R., & Renard, P. (2023). A new perspective to model subsurface stratigraphy in alluvial hydrogeological basins, introducing geological hierarchy and relative chronology. Computers & Geosciences, 140, 104506-104530. |
| Type | Article de périodique (Anglais) |
| Date de publication | 17-1-2023 |
| Nom du périodique | Computers & Geosciences |
| Volume | 140 |
| Pages | 104506-104530 |
| URL | https://doi.org/10.1016/j.cageo.2020.104506 |