**4.3 Results hydrogeochemical hot springs centre Northen of Algeria (2013–2015)**

The Jurassic limestones of the Algerian North, which constitute important geothermal.

reservoirs, give rise to more than five hot springs located mostly in the northeast and northwest regions of the country [7]. These sources have temperatures above 40° C. That of Hammam Bouira (b) (80° C) is the most important. These natural emergences are generally the losses of existing reservoirs, with a flow rate of the order of 2 m3 /s. The temperature of the hot springs in the study area varies from 38° C to 80° C which corresponds to a low energy enthalpy. The pH of the thermal waters ranges from 6.4 to 7.53 and generally neutral rate is between 3 and 20 l/s (**Table 1**). The conductivity of the largest thermal water is the source of Hammam-Melouane with a value of 20000 μmhoS/cm and the lowest is that of Hammam-Righa with 4000 μmhoS/cm. The highest-dry residue is that of Hammam-Bouira-b source with 5.8 g/l.Sources H.Melouane and H; Bouira-b have the same chemical profile of a chloride-sodium kind while that the source of H.Righa has a sulfated lime facies and source H.Médéa a sodium bicarbonate-facies (**Figures 6** and **7**).
