The Sidon River: Where it Was and Where it Wasn’t – Part I

Map of the Land of Promise overlaid onto a map of Peru; note that prior to the destruction in 3 Nephi, the East Sea covered the area that is now east of the Andes Mountains before the Andean Uplift occurred

We are continually being asked by readers where the Sidon River was and is located within the South America Peruvian area of the Land of Promise. Over the years we have repeatedly maintained in numerous articles and in answering previous questions on this blog issue, that rivers, cities, even shorelines, were most likely affected during the cataclysmic events of the crucifixion that saw “the whole face of the land was changed” (3 Nephi 8:12), and “thus the face of the whole earth became deformed” (3 Nephi 8:17), and “the rocks were rent in twain; they were broken up upon the face of the whole earth, insomuch that they were found in broken fragments, and in seams and in cracks, upon all the face of the land” (3 Nephi 8:18).
    In addition, Nephi saw in a vision the Land of Promise at this time: “I saw the earth and the rocks, that they rent; and I saw mountains tumbling into pieces; and I saw the plains of the earth, that they were broken up; and I saw many cities that they were sunk” (1 Nephi 12:4); and Samuel the Lamanite describing these events, that there were “many mountains laid low, like unto a valley, and there shall be many places which are now called valleys which shall become mountains, whose height is great” (Helaman 14:23), and describing this change, “The earth shall shake and tremble; and the rocks which are upon the face of this earth, which are both above the earth and beneath, which ye know at this time are solid, or the more part of it is one solid mass, shall be broken up; they shall be rent in twain, and shall ever after be found in seams and in cracks, and in broken fragments upon the face of the whole earth, yea, both above the earth and beneath” (Helaman 14:21-22).
    Consequently, given all this, it is safe to say that any single river running through this land, no matter its size, would have drastically been affected in its course, as mountains ceased to exist and other mountains rose to majestic heights, obviously changing the course of rivers, and with the ripping apart the rock base beneath the earth of the Land of Promise, drastically change the aquifer below which often forms rivers and lakes.
    Today, of course, there are ten long rivers in Peru that eventually flow into the Amazon River, either directly or via one of the amazon’s many large tributaries. To believe that all these rivers are the same as in the days of the Nephites and were not affected by the rise of the Andes is without merit.
    Consequently, in answer to these inquiries, we have merely suggested that the drastic changes in the topography of the Andean land form that occurred during the Andean Uplift when the Andes Mountains rose to such a great height (many peaks over 20,000 to 22,000 feet), that such orogeny change would have altered the flow of rivers, the existence or size of lakes, and even altered shorelines of the sea, making any determination about the Sidon merely speculative.

Left: the Mantaro River; Right: the Apurimac River. Note how these rivers (and most rivers in Andean Peru) are deeply imbedded in canyons, with high mountains on either side—obviously, one can easily imagine that if the mountain was changed around the river, the flow of the river would be altered

However, recent geological information has been learned, accomplished by two Peruvian geologists working in concert with a commission from the National Geological Charter to study the specific area south of Junin Lake in Andean Peru. Their findings show an interesting fact regarding the area of the Junin-Huancayo-Haunta Depression that alters the previous thinking about the area known as the Pampas Quadrangle, which includes the present area of the Tayacaja Peninsula, and area south of there toward Ayacucho. Thus, the previous beliefs held about the Mantaro River thought by many are now in doubt, and the interest in the Apurimac River increases.

The Apurimac River flowing northward, from below Cuzco all the way to the join the Urubamba and flow into the Amazon River

Obviously, despite all this change that took place, water sources continued to exist, though their flow would likely have been altered and changed; but there is now a “possible” answer to the location of the Sidon River, and that is the rivers now known as the Apurimac which flows into the Ene, which flows into the confluence of the Perene and Tambo, becoming the Tambo, which curves southward then northward to the confluence of the Urubamba and the Ucayali, and past the confluence of the Marañón and into the Amazon River. This is all basically one river, but it has several different names today, and numerous tributaries, which basically flows northward from what would be the Land of Nephi through the eastern part of the Land of Zarahemla (along the eastern border) and eventually winds toward the east and down through Amazonia and into the lowland Amazonian Basin.
    The problem with this overall choice is that presently, the Apurimac River runs too far south (beginning far south of Cuzco or the city of Nephi); however, if there were mountains that became valleys at its northern end, it may at one time have been formed there (which would have been within the narrow strip of wilderness)—but that is merely speculation. Still, rivers were affected by the destruction in 3 Nephi.

Red: Course of the present Mantaro River; Blue: the present course of the two main rivers, Apurimac (west) and the Urubamba (east) that form a single river northward called the Ucayali, now known by numerous names along their length that eventually empties into the Amazon River

Another example of this is the Mantaro River, which flows into the confluence of the Apurimac and Ene, is considered by some to be the Sidon River, however, that river today flows out of Lake Junin, which is too far north, and then flows 185 miles southeast (not according to scriptural record) through the area of Zarahemla, including Huancayo to Mayoc and Puente Allccomachay at the confluence of the Warpa River (but not as far south as Ayacucho; making it north of the narrow strip of wilderness) where it curves around a mountain range known as the Tayacaja Peninsula, to flow across the Pampas quad, where its second curve turns to the northward for 56 miles, then southward again to where it joins the confluence of the Apurimac and Ene rivers.
    To better understand this area, and why this Mantaro River as seen today is not the same as it was before the rise of the Andes to become “mountains whose height is great” (Helaman 14:23), it needs to be understood that it is part of the Pampas de La Joya, a broad geomorphic unit characterized by an uplifted plain mainly floored by so-called Precambrian gneisses and granites limited on the northeast and southwest by the Andean foothills and the Cordillera de La Costa, which is divided into several sectors by the spectacular gorges of the Sihuas and Vitor rivers carved across the volcanic and sedimentary cover into the crystalline basement.
    As geologist Jorge Guizado Jol and geologist Cesar Landa Tovar, authors of Geology of the Pampas Quadrangle, state that after the rise of the Andes in this area and the change in flow of the Mantaro River, there was a general deepening of the valley until its current state had been produced mainly by fluvial erosion in accordance with the Andean uplift, originating the enchained profile that characterizes all its route, especially waters below Huancayo.
    Several sections of this impressive valley remain within the Pampas leaf or Plain, and together with the numerous subsidiary valleys, originated a very broken topography with a strong relief, especially in the northern and eastern portions.
    It might be noted that this bottom curve of the Mantaro is a longitudinal inter-Andean valley whose formation is related to faulting processes that occurred in the final stages of the Andean uplift, and cut distinctly in igneous, sedimentary and metamorphic rocks, presenting numerous inflections, many of which are controlled by faults, fractures contacts, confining the deep valley in a very narrow bottom, only a few places where there are small beaches and remnants of terraces. For most of its journey the river is encased in a deep valley, limited by interandean mountain ranges.
    As geologists familiar with the area claim, all of this suggests that this mountain area did not exist before the rise of the Andes and, therefore, any river at this point would not have flowed back to the north again as it presently does, but continued on south through the valley. However, as the Andes came up at this point, forming the range known as the Tayacaja Peninsula, it gave rise to depressions, zones of weakness and high massifs, which exerted control in the direction of watercourses and the formation of lake basins.

Left: A zone of geological weakness resulted in the Junin, Huancayo and Hunta depressions through which the Mantaro River would have naturally (Right) flowed to the south had the Andes uplift not occurred, raising the Andes Mountains to their great height

Thus, it is probable that the primitive course of the Mantaro (before the rise of the Andes at this point) was delineated in a southerly direction, along a zone of weakness that connected the depressions of Junin, Huancayo and Huanta. In these depressions there would have been wide lagoons located at different levels. Subsequently, the backward erosion smoothed the unevenness, drained the lagoons and established a general course of drainage, causing the Mantaro River, after the depression of Huanta, to head southeast through the Mantaro Canyon, and empty into the Apurimac River in the south (Jorge Guizado Jol and César Landa Tovar, Geología del cuadrángulo de Pampas, edited by the commission of the National Geological Charter).   
(See the next post, “The Sidon River: Where it Was and Where it Wasn’t – Part II,” for more on what changed the Mantaro River course)