LAGO YOLNAJAB
Laguna Brava is unique among other natural lakes in Guatemala. It's located in Yuxquen Nenton, Huehuetenángo, standing at an elevation of 1142 m. above sea level. It is positioned at a latitude of 16°03'30'' and at a longitude of 91°33'50'' and it has an area of 3.8 sq. kilometers. It has a longitude of 6 kilometers and a maximum width of 1200 meters across. The transparency and clarity of its turquoise waters in its presently pristine conditions, is a valuable and rare environment that needs immediate protection.
The geological origin of the entire region including the Yucatan peninsula dates back to the Cretacic geologic era hundred million years ago, when it was part of the ocean floor made of a limestone cover about a kilometer deep.
At some point in geologic time, the southern part of Guatemala, currently attached to the Caribbean tectonic plate, rammed obliquely into the edge of the North American plate. As a result of this slow-motion collision, the plate was uplifted way above sea level. Additionally, the edge of the plate became folded, wrinkled at places. Just north of the suture zone between the two plates, the uplift and folding of the terrain was dramatic, the ancient sea floor was slowly raised to about 4000 m (13,000 ft) creating the Cuchumatanes, the highest and most dramatic mountain range in Central America. 100 Km behind the oblique collision front, the terrain uplifted to a modest 1200 m (4000 ft), this being the zone where
Laguna Brava is.
The lake was formed as a natural dam. The site, still needs to be geologically surveyed in detail to confirm his theory. But if true, the amazing fact is that the lake has managed to remain stable in the limestone environment in which it is located. It appears to him that the body of water was impounded behind the debris fan of a large landslide that blocked a fine V-shaped ravine, that created a long, narrow lake that forks into two fingers upstream, as the ravine itself branches. The lake is surrounded by wet and dry cenotes (small adjacent lagoons) that in the rainy season, receive water from the main lake as it spills into the lower basins in beautiful streams and waterfalls.
In any case, weather, Laguna Brava formed as a natural dam or not, its system must be in a fine-tuned equilibrium, probably very fragile, because there are no other bodies of water with these characteristics in the region. True, there are many spectacular "cenotes", dry and wet, in the immediate vicinity, but those are created by different geological mechanism.
Yolnajab is different and possibly fragile geological feature.
Limestone dissolves as water seeps through its cracks creating an ever growing network of pipes and conduits that eventually breaches the mass of rock creating a cave or a trench. The piping effect should be facilitated by the very nature of the purported dam, which would be a conglomerate of randomly placed limestone boulders embedded in a matrix of very fine material. On the other hand, if seepage is slow enough, fine limestone particles and sediments may become "welded" together creating an impervious limestone liner that prevents the breaching of the dam.
Therefore, it is of utmost importance to preserve the entire basin of the lake, as it has been untouched by man up to this time, due to its location in a remote and inaccessible area. In the past ten years, the lake surroundings have been reached by a rapidly advancing human and agricultural frontier. We have here a unique resource that we must protect promptly and which should be studied not only for its rainforest and wildlife, but for its geological uniqueness
