Thermal Structure of the Northern Outer Albanides and Adjacent Adriatic Crustal Sector, and Implications for Geothermal Energy Systems

Abstract

Using an analytical methodology taking into account heat flow density data, frictional heating, temperature variations due to the re-equilibrated conductive state after thrusting and geological constrains, we calculated surface heat flow, geotherms and isotherms along a balanced and restored regional geological cross-section. Our results highlight the impact of frictional heating produced by thrusts on the thermal structure of the study area, leading to a raising of the isotherms both in the inner Albanides to the E and in the Adriatic sector offshore. Minimum values of Qs in the surroundings of Tirana and the reconstructed 2D thermal structure suggest less favorable conditions for exploitation of geothermal energy, besides the direct use (Borehole Heat Exchanger-Geothermal Heat Pump systems). Nevertheless, the occurrence of the “Kruja geothermal zone”, partially overlapping this area and including hot spring manifestations, emphasize the structural control in driving hot fluids to the surface with respect to the regional thermal structure.

Space and Time Variability of Detachment‐ Versus Ramp‐Dominated Thrusting: Insights From the Outer Albanides

“…Balanced and restored sections are shown in Figures 10 and 11, together with a strike section in Figure 11. Section A-A′ across the northern outer Albanides shows a ramp-dominated, basement-involved deformation style (Figure 1a) in the Sazani and Ionian units, consistent with previous work by Roure et al (2004), Santini et al (2020) and Teloni et al (2021). According to these authors, here the evaporites did not act as a décollement level, most probably due to their limited thickness.…”

“…The backthrust at the top of the intercutaneous wedge offsets the pre-Messinian unconformity, indicating that youngest thrust activity reached the early Pliocene (Nieuwland et al, 2001;Roure et al, 2004). Part of the thrust slip is also shown in section A-A′ to be passed to a pop-up involving the Neogene clastic succession (penetrated by a hydrocarbon exploration well; Santini et al, 2020) farther west. In the footwall of the Kruja thrust, a relatively low-displacement, basement-rooted reverse fault offsets the Mesozoic platform-to-basin transition (Kruja paleoslope) based on seismic interpretation by Roure et al (2004).…”

“…This deep foreland basin, known as Peri‐Adriatic Depression, includes shallow‐water deposits in its eastern and southern portions, and deeper water (mainly turbiditic) sediments in the northern and western (offshore) sectors (Lacombe et al., 2009; and references therein). In this northern structural province, available seismic lines show no major basement‐cover decoupling along the Triassic evaporites, and the Ionian basin succession is interpreted as essentially attached to the basement (Roure et al., 2004; Santini et al., 2020; Teloni et al., 2021). The overlying Cenozoic foredeep succession is deformed by thrust imbrication and minor duplexing in the eastern part of the Peri‐Adriatic Depression (Roure et al., 2004).…”

Controls of Radiogenic Heat and Moho Geometry on the Thermal Setting of the Marche Region (Central Italy): An Analytical 3D Geothermal Model

“…We considered a basement thermal conductivity of [8] and a heat production rate of the basement of H B = 3.15 µWm −3 with a range of 3.0 − 3.3 µWm −3 [76,77], exponentially decreasing with depth. The radiogenic sources' intensity, for any thickness h B , diminished downward with a logarithmic decrement D, which had the dimension of depth and a characteristic value of 8 km in the region [76,78]; 5…”

“…The entire thermal structure is affected by two sources of heat: (i) the heat flowing upward from the Moho, coming from the mantle (Q m ), and (ii) the heat production rates of the cover (H CS and H CC ) and the basement (H B ), due to the presence of radioactive elements in the crust. To obtain the surface heat flux, we used the analytical procedure by Dragoni et al [76] and further applied by Santini et al [9,78] and Basilici et al [74,81], modified specifically for the area of study. In the computation of the surface heat flow, in addition to contributions of Q m , we added radiogenic heat, obtaining the following equation used to calculate the surface heat flow (Q s ):…”