Water chemistry of lakes related to active and inactive Mexican volcanoes

Hydrochemistry and microbialites of the alkaline crater lake Alchichica, Mexico

“…Mg is the most important cation in the seepage water, while Ca is the only ion that is indisputably higher in the seepage water compared to the lake water bodies. The water of Atexcac has a composition of Cl ) Alk ) SO 4 and Na [ Mg ) K [ Ca, and that of Alchichica Cl ) Alk [ SO 4 and Na ) Mg ) K ) Ca while the seepage water is characterized by Alk [ Cl [ SO 4 and Mg [ Na [ Ca ) K. These main ion results compare well with those published by Armienta et al (2008) who analyzed four water samples: two from Lake Alchichica (0 m and 61 m depth) and two from Lake Atexcac (0 and 31 m depth).…”

“…Volumes and areas obtained from integrating our new map are given for 10-m intervals in Table 1. The area is significantly larger than reported before (i.e., 2.26 km 2 compared to 1.8 km 2 reported by Armienta et al 2008). The volume amounts to just over 0.1 km 3 .…”

“…Besides Alchichica, five other neighboring crater lakes belong to this system: Quechulac, La Preciosa, Atexcac, Tecuitlapa, and Aljojuca. More details concerning the location, bathymetry, and limnobotanic characteristics of these lakes can be found in Alcocer and Hammer (1998); Vilaclara et al (1993); Caballero et al (2003); Armienta et al (2008). Four of these lakes are located in the region Los Llanos de San Juan, and the other two in the region Los Llanos de San Andrés.…”

Hydrochemistry, ostracods and diatoms in a deep, tropical, crater lake in Western Mexico

“…Lake Alchichica, lying in a drier climate than SMO (399 vs 1214 mm annual precipitation), is at a more advanced stage of brine evolution, for it is already a saline lake (~9 g L Vilaclara et al 1993). An even more extreme case in the TMVB is Rincón de Parangueo, a crater lake in the state of Guanajuato that has undergone severe desiccation due to a marked drop in phreatic level (Alcocer et al, 2000a) ]-depleted brine with very high salinity (EC>140 mS cm -1 ) and alkalinity (>1500 meq L -1 ; Armienta et al, 2008).…”

“…As a consequence of this recent volcanism, the TMVB has several crater lakes; these cluster in two main areas, at Los Tuxtlas, Veracruz (Vazquez et al, 2004), and in the Oriental basin, Puebla (Vilaclara et al, 1993) (Fig. 1), but there are several others along the TMVB (Armienta et al, 2008). Most are small (<1 km 2 ), with depths ranging from a few metres (2 to 4 m) up to about 60 m. Santa María del Oro (SMO), Nayarit, in the western sector of the TMVB, is one of the largest and deepest of these lakes, with a ~2 km diameter and 65.5 m maximum depth (Serrano et al, 2002).…”