Hydrolithology of the area between Tuscany, Latium and Umbria regions (Italy)

Figures & data

Figure 1. (a) Simplified geological map of the central Apennines showing the distribution of the main paleogeographic domains (modified and adapted from Bigi et al., 1990); (b) schematic relationship between palaeographic domains, lithological composition and permeability attitude. Note the width of boxes illustrating the permeability is expressed in chronostratigraphic terms and does not reflect the thickness of the lithological complexes. Stratigraphy of paleogeographic domains are obtained and adapted from Carmignani et al. (1994), Jolivet et al. (1998), Brogi and Fabbrini (2009), Mastrorillo and Petitta (2010).

Figure 2. Examples of available geological cartography for three different administrative regions, showing heterogeneous mapping criteria. CTR: Regional technical cartography. The extracted frames are from: Regione Toscana (2006; http://www.regione.toscana.it), for Tuscany region; Regione Umbria (1999; http://www.territorio.regione.umbria.it/), for Umbria region; Cosentino and Pasquali (2012), for Latium.

Figure 3. Flow chart illustrating the methodology adopted for hydrolithological complex mapping in the study area.

Figure 4. Hierarchical classification used for the redistribution of the geological units. The qualitative permeability attributed are also shown.

Table 1. The hydrolithological complexes obtained for the study area.

Class	Macro-complex	Hydrolithological complex (abbr.)	Lithological description	Hydrological description
Sedimentary rocks	Continental Quaternary deposits	1	Alluvial and debris flow deposits, seldom cemented.	The complex contains unconfined aquifers, whose importance depends on the extremely variable permeability and irregular geometry of water bearing deposits.
				MEDIUM-HIGH PERMEABILITY
		2	Embankment of perennial streams, quarry dumps, landfills.	It does not take significant role at regional scale, but it assumes the hydrogeological features of the hosting complex.
				VARIABLE PERMEABILITY
		3	Lacustrine and palustrine deposits, loam soils with peat.	No significant groundwater flow. The sporadically occurrence of interbedded gravels and sand beds can cause limited local perched aquifer.
				LOW PERMEABILITY
		4	Actual and recent terrace deposits, colluvial and eluvial deposits, products of slope decomposition, intercalation of actual and recent lacustrine soils, silts, sands and gravels.	The lithological heterogeneity favours the formation of small perched aquifers. The alluvial deposits may contain large multistrata aquifers recharged by rives or contiguous aquifers.
				VARIABLE PERMEABILITY
		5	Ancient, recent and actual travertines, travertine concretions, calcareous silts, crusting travertines.	Wider travertine plateau can host important groundwater flowpath. Travertine lenses have high permeability and storage capacity, but generally contain modest aquifer due to their limited extension.
				MEDIUM-HIGH PERMEABILITY
		6	Compact clays and marls with sandy lenses, clayey silts with gravels.	Absence of a significant groundwater flow.
				VERY LOW PERMEABILITY
		7	Sands, dominant siliceous pebbles, sands with lenses of clays, sands with lacustrine clays.	Absence of a significant groundwater flow.
				The lithological heterogeneity may promote the formation of small seasonal perched aquifers.
				LOW PERMEABILITY
		8	Gravels and sands with lacustrine clays, tufites with pumice layers, weakly cemented conglomerates, terraced conglomerates.	Absence of a significant groundwater flow. The conglomerate component, where more extensive, may favour the formation of small local aquifer.
				MEDIUM-LOW PERMEABILITY
	Marine and transitional Quaternary deposits	9	Fossiliferous clays and sands, grey clays interbedded with gravel layers, marine to brackish clays with brownish lignite.	Absence of a significant groundwater flow.
				VERY LOW PERMEABILITY
		10	Sands with poorly cemented conglomerates, sands and marls with volcanic material, sandy shelly limestones (bench).	Absence of a significant groundwater flow.
				The lithological heterogeneity may promote the formation of small seasonal perched aquifers.
				LOW PERMEABILITY
		11	Polygenic pebbles and coarse red sands.	Absence of a significant groundwater flow. The conglomerate component, where more extensive, may favour the formation of small local aquifer.
				MEDIUM-LOW PERMEABILITY
	Continental Neogene deposits	12	Sands, sandy red clays, blue-grey marls and clays, pebbly lenses with gypsum.	Absence of a significant groundwater flow.
				The lithological heterogeneity may promote the formation of small seasonal perched aquifers.
				LOW PERMEABILITY
	Marine Neogene deposits	13	Clays and sandy clays with blocks of Mesozoic limestone olistoliths, clays and sandy clays with olistoliths flysch, marls and grey clays with gypsum, fossiliferous clays.	Absence of a significant groundwater flow.
				VERY LOW PERMEABILITY
		14	Sandstone layers with interbedded clays, quartz-micaceous sandstones, clays and sands with lenses of conglomerates, seldom including blocks of Mesozoic limestone olistoliths.	Absence of a significant groundwater flow. The interbedded clays can support small seasonal perched aquifers
				MEDIUM-LOW PERMEABILITY
		15	Conglomerates with sandy cement, polygenic conglomerates alternating with marls, conglomerates with pebbles of basement units and Mesozoic covers.	It can host local important groundwater flow.
				MEDIUM PERMEABILITY
		16	Calcarenites and weakly massive sandy limestones including interbedded conglomerates, yellow sandstones and sandy mudstones containing abundant fossils.	Wider outcrops can host important groundwater flow.
				MEDIUM PERMEABILITY
	Flysch deposits	17	Mudstones, marls and marly limestone interbedded with grey marls, shales, marls with Cretaceous, Eocene and Oligo-Miocene microfaunas; limestones type ‘Palombino’, calcarenites and breccias with intercalations of ophiolites and molasses; locally include the marly limestones like ‘Pietraforte.’	Absence of a significant groundwater flow.
				VERY LOW PERMEABILITY
		18	Quartz- and calcareous-sandstones alternating with silty marls containing Eocene and Miocene microfaunas; sandstones with calcareous cement like ‘Pietraforte’, including lenses of conglomerates.	Modest groundwater flow in sandstone lithologies, locally sustained by clayey lithologies.
				LOW PERMEABILITY
		19	Quartz-feldspathic-micaceous sandstones like ‘Macigno’ with calcareous breccias and shales containing Cretaceous and Eocene microfaunas.	It can host local important groundwater flow confined within the sandstone bodies.
				MEDIUM-LOW PERMEABILITY
	Mesozoic-Tertiary deposits	20	Grey-greenish marls and marly limestones showing red-purple colour towards the base.	The occurrence of frequent intercalations between marls and limestones determines small seasonal perched aquifers.
				LOW PERMEABILITY
		21	Reddish marly limestones and calcareous marls with red chert, pinkish limestones and marly limestones, white limestones and marly limestones with blackish or whitish chert nodules and bituminous layers; calcarenites, fine detrital limestones and calcareous marls.	It can be the site of significant groundwater flow in domains characterized by intensely fracturation and reduced occurrence of marls.
				MEDIUM-HIGH PERMEABILITY
		22	Yellowish marly limestones alternating with clay marls, grey-black calcareous marls with thin layered cherts; varicolours shales with fucoids; intercalations of whitish limestone debris.	Absence of significant groundwater flow. This complex defines the aquiclude between the hydrolithological complexes at the top and at the bottom.
				LOW PERMEABILITY
		23	Whitish to grey massive limestones and laminated limestones with nodules of chert in different colours.	The intense fracturation promotes an important groundwater flow within this complex, which feeds perennial regional aquifers.
				HIGH PERMEABILITY
		24	Laminated marly limestones with abundant chert and interbedded marly limestones with Haptic; siliceous shales, radiolarites, red and green marls; red marly limestones with typical nodular facies, marls with ammonites, bivalves and ostracods.	Absence of significant groundwater flow. Where unfaulted or unfractured, it defines the local aquiclude between the hydrolithological complexes at the top and at the bottom.
				MEDIUM-LOW PERMEABILITY
		25	Marly limestones, massive grey-brown limestones with conchoidal fracture, well layered limestones containing grey chert in nodules or lenses; oolitic and pisolitic greyish limestones with corals and algae.	The intense fracturation promotes high infiltration that feeds massive aquifers hosted at bottom of the carbonate strata. The outcrops of this complex are the recharge area of the most important regional depth aquifers in carbonate environments.
				HIGH PERMEABILITY
		26	Limestones and dolostones, seldom with vacuolar appearance, containing gypsum.	It is characterized by significant groundwater flow, but of secondary importance compared to the circulation in the overlying complex. Regionally, it constitutes the basal aquitard of the complex 25.
				MEDIUM-LOW PERMEABILITY
		27	Whitish dolostones, whitish or dark grey dolomitic limestones, poorly stratified dark dolostones, evaporites.	The hydrogeological role of this complex is not yet fully known. The densely jointed dolomitic horizons are supposed to host a deep groundwater, whereas the evaporitic horizons may be regarded as aquicludes without significant groundwater flow. As a whole, this complex may be interpreted as an aquitard located at the base of the regional basal aquifer, in hydraulic continuity with the overlying complex.
				MEDIUM PERMEABILITY
Igneous rocks	Volcanic units	28	Scoria and welded lapilli beds, pumices, ballistic lava blocks; tephritic-leucititic and leucititic cinder cones, reddish layers and laminated lenses of scoria, laminated ash and lapilli tuffs variably compact.	It can be the site of an active groundwater flow with limited extension.
				MEDIUM-HIGH PERMEABILITY
		29	Rhyolitic and quartz-latitic lava domes with vitrophiric or ipocrystalline structure and phenocrysts of sanidine, plagioclase, biotite and pyroxene; leucitites, leucititic basalts, phonolites, trachybasalts, leucititic tephrites, olivintrachytes; reoignimbrites.	At local scale, it hosts a significant groundwater flow favoured by the occurrence of fracturing systems in more competent rock types.
				HIGH PERMEABILITY
		30	Massive and chaotic pyroclastic flow deposits; trachytic or leucititic-tephrytic ignimbrites showing cineritic matrix.	It is characterized by an extensive and articulated groundwater flow that feeds the most important regional aquifers in volcanic environments.
				PERMEABILITY MEDIA
		31	Alternations of: brownish tuffs, yellow tuffs with pumice, greyish volcanic silts and sands, granular tuffs, massive tuffs, travertine intercalations, paleosols, pyroclastic breccias, trachytic-phonolitic bedded tuffs related to the phreatic-magmatic eruptions, laminated lacustrine deposits.	Reduced groundwater flow. Locally, it can sustain perched aquifers and define local aquicludes in the flowpath.
				LOW PERMEABILITY
Metamorphic rocks	Basement units	32	Quartz-mica schists with interbedded graphitic shales; talc-shales with intercalations of whitish or yellow limestones; reddish quartz-sandstones with silty matrix, quartzschists; anagenites.	Absence of a significant groundwater flow.
				VERY LOW PERMEABILITY

Figure 5. (a) An extract of the official geological cartography at a scale of 1:100,000 (Italian Geological Survey), including the administrative boundaries. Note the dissimilarity between legends of each sheet; (b) extract of the hydrolithological map of the study area and (c) the derivative permeability distribution map.

Bigi, G. et al. (1990). Structural model of Italy, in Progetto Finalizzato Geodinamica, SELCA, Florence.

 Google Scholar

Carmignani, L., Decandia, F. A., Fantozzi, P. L., Lazzarotto, A., Liotta, D., & Meccheri, M. (1994). Tertiary extensional tectonics in Tuscany (Northern Apennines, Italy). Tectonophysics, 238, 295–315. doi: 10.1016/0040-1951(94)90061-2

 Web of Science ®Google Scholar

Jolivet, L., Faccenna, C., Goffé, B., Mattei, M., Rossetti, F., Brunet, C., … Parra, T. (1998). Midcrustal shear zones in postorogenic extension: Example from the northern Tyrrhenian Sea. Journal of Geophysical Research-Solid Earth, 103, 12123–12160. doi: 10.1029/97JB03616

 Web of Science ®Google Scholar

Brogi, A., & Fabbrini, L. (2009). Extensional and strike-slip tectonics across the Monte Amiata–Monte Cetona transect (Northern Apennines, Italy) and seismotectonic implications. Tectonophysics, 476, 195–209. doi: 10.1016/j.tecto.2009.02.020

 Web of Science ®Google Scholar

Mastrorillo, L., & Petitta, M. (2010). Effective infiltration variability in the Umbria-Marche carbonate aquifers of central Italy. Journal of Mediterranean Earth Sciences, 2, 9–18.

 Google Scholar

Regione Toscana. (2006). Carta Litologica della Toscana finalizzata alla pedologia, scala 1:250.000. http://www.regione.toscana.it/

 Google Scholar

Regione Umbria. (1999). Carta Geologica numerica in scala 1:200.000. http://www.territorio.regione.umbria.it/

 Google Scholar

Cosentino, D. and Pasquali, V. (2012). Carta geologica informatizzata della Regione Lazio Scala 1:25.000. Regione Lazio Agenzia Regionale Parchi Area Difesa del Suolo, http://www.arplazio.it/

 Google Scholar