Abstract

From all the various types of natural features and wonders we have in the world, the White dune in the U.S.A can’t miss being one of them Located in the Chihuahua desert in the northern part of the United States, the feature is famous for its dramatic and dazzling landscape made up of rare white gypsum dunes.

The sand sprawls over 700 square kilometers of the southward central region of New Mexico. The sands of the White National Monument are formed from gypsum, a soft mineral often left behind after the evaporation of water bodies, though this mineral is rarely found as sand reason being it is readily soluble in water and rivers .

In this case, the water that was flowing into the basin carrying white sand monumental dunes would not find an outlet from the pool. Therefore this made the water to evaporate.

Fig.1.1. Location of White Monumental dunes in New Mexico

FORMATION PROCESS

The geology of the white sand monumental dunes dates back to more than 250 million years ago, when a large mass of water, occupied the southwestern part of the American State. It was this period when quite a good number of gypsum layers are believed to have deposited on the sea that covered this area. Due to the rising and falling of the sea level that was taking place during this time .

A lot of factors one of them being the late ice age period influenced the formation of this beautiful natural scenery. The exploration and explanation through time distinguish the various transformations and the multiple factors that gave room to this dazzling dune field to exist.

Fig.1.2 Ancient Sea that covered the southwestern part of the United States.

260 to 290 million years back

iTs was the period when the crust of the earth was a single supercontinent that i referred to as Pangaea. To the southwestern part of the planet where the United States located (now New Mexico) was covered by Permian which was a shallow sea. Other mineral particles together with gypsum were deposited and left over in terms of sediments on the floor of the water body as the sea was going through processes of rising as well

Fig 1.3 Gypsum and other mineral left behind in terms of layers

60 to 80 million years ago

It was a time when the globe’s landmass underwent shifting and collision between the plates. The forces that were due from this movement shifted the landmass upwards and eventually led to what we term currently to as ranges a good example being The Rocky Mountains and some of the fields within the region where the white dune monument is located.

This plate tectonic period led to the lifting of the gypsum-layer formed the seabed that was laid down by the Permian sea formation process, from the lowlands to the upper ranges whereby until now gypsum bands can be witnessed within the environment’s surrounding ranges. The gypsum bands in the surrounding mountain ranges are still the significant sources of gypsum product that led to dune formation that thrives till today.

Fig 1.4 Lifting of sea bed into ranges due to plate tectonics

25 to 30 million years ago

During this period, the crust was still pulling apart. Whsat led to the development of many fault zones. A good number of mountain ranges were separated from one another, a factor that led to some areas of the landmass in some areas to sink some meters within these faults. Thus, this led to the formation of lowlands within the regions that were within the ranges. Late down the line, about 2 million years ago, a significant crack developed. The portion led to the shutting off of the southern part of the Tularosa basin which led to the blocking of an outlet from the Tularosa Basin to any sea or ocean. ThisIt led to the creation of a closed-basin water system.

Fig. 1.5. Dropping of the crust due to development of faults forming basins.

25000 to 10000 years ago

il=t entails the period under which the last ice age also occurred. Took place in not more than 25000 years ago. This period experienced a much wetter climate. Melting snow and rainwater carried the white band gypsum from the eastern ranges to the western side as well as from the west of fields to the eastern lowlands. The runoff settled in about 1500-sq. Miles water body referred to as Lake Otero.

As the Ice Age ended during this period, the lake started to evaporate changing to a playa(dry lake bed). The matter that was left over was a concentration of a crystalline form of gypsum.

Fig.1.6 Melting snow and rainwater are carrying gypsum from the mountain ranges into the basin.

11000 years ago to present-dune field formation

As soon as the Ice Age was over, there was also a change of climate as it became warm and dry. With time, the climatic changes effects started to change the shift in the region. Soon, the Chihuahua desert developed, and Lake Otero disappeared. With time, other lakes developed and replaced. Other lakes such as Lucero and Alkali Flat formed in place of Otero. There was the formation of gypsum selenite crystals on the floor of the lake. Later on, the force of the wind sweeps the area. Dry. This brought into the surface the underlying sediments exposing the gypsum crystals to the surface. The processes of ice eventually took over thus reducing the size of the gypsum particles into smaller pieces which were later swept by air currents which bounces them along the dry basin land. Due to the constant motion of the grains by the wind blowing from the Northeast direction towards the Southwest, the movement was by small distances which ended up forming the dune monument.

Fig.1.7 Silt sweeping the area after a change of climate into warm and dry

Present/current day

Presently, precipitation from the regions that surround the region fills the basin with water laden with gypsum. The lake within the area is seasonal. Later on, the water evaporates due to the hot weather, leaving behind selenite crystals. With time, whether agents break down the gypsum crystals into fine particles which are picked up by the wind which pushes them across the dry basin. Lake Lucero is a Playa lake which rarely contains water. Finally, the full sediments pool was heated by the warm weather leaving behind selenite crystals. With time, whether agents facilitate the disintegration of these vast chunks into finite gems, which are later picked up by the wind which pushes them across the entire dry region. Thus, it is a mechanism that reduces the particles till they are fine-grained white gypsum dune grains

The formation of sand across the playa currently is the significant input of sand for the establishment of dunes.

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Fig.1.8 Present-day white monument dunes in New Mexico

Methods of conducting more extensive research in this field

Since dunes cover vast areas of the earth’s desert areas, they can be very sensitive indicators of the changing climate and environmental conditions. Hence landscape and features create can act as good sources of information on how these dunes were formed.

Studying and taking record of how the climate changes from time to time concernintog how the various features and landforms are we armed another method. Dunes were through a complicated interaction of different climatic conditions.

The study of the topology of the area is also very crucial as it’s formed as a result of the processes that take place as changing climatic conditions interact with the environment.

The meteorological study, pedology study, scientific study, and chemical analysis are some of the fieldwork methods that can be used to carry out extensive research in this area.

Water samples and soil samples are the significant samples that can be acquired from this area from time to time to help study how the formation of the white sand monumental dunes takes place.

Stratified or random sampling can be used to make sure that data is even when researching this field.

References

Bowler, J. M. (1973). Clay dunes: their occurrence, formation, and environmental significance. Earth-Science Reviews, 9(4), 315-338.

Hanna, S. R. (1969). The formation of longitudinal dunes by large helical eddies in the atmosphere. Journal of Applied Meteorology, 8(6), 874-883

Kennedy, J. F. (1969). The formation of sediment ripples, dunes, and antidunes. Annual review of fluid mechanics, 1(1), 147-168.

Nishimori, H., & Ouchi, N. (1993). Formation of ripple patterns and dunes by wind-blown sand. Physical Review Letters, 71(1), 197.