Hydrochemistry of Patagonian Wet Meadows (Mallines) Under Different Geological Frames

Abstract

Surface water resources of Extra-Andean Patagonia are scarce, being the large rivers that cross the entire territory from the Andean cordillera to the Atlantic coast the main water supply for human activities. However, the large part of the area without permanent watercourses has small springs that give rise to wetlands known as mallines (wet meadows), of great environmental relevance due to the ecosystem services they provide. These wet meadows are sustained by groundwater, which gives them great variations in hydrochemical characteristics. These variations result from groundwater interaction with rocks and sediments through which it flows. To reflect this variability, four areas with wet meadows in different geological frames are described within Extra-Andean Patagonia, distributed according to the major geo-geomorphological regions: one sector in northern Patagonia, within the Mountain Sector of the Neuquén Embayment (Domuyo area); another in the coastal sector, associated with the Patagonian Tableland (Península Valdés), one on the center associated with the Somún Curá Massif (Carri Laufquen sector); and the fourth in southern sector, associated with the Deseado Massif.