What is a Sabkha area?
What is a Sabkha area?
The sabkhas (Arabic for area of low-lying salty ground) are broad intertidal areas and coastal plains (Figs. 8 and 9) that may be flooded by lagoon waters when storm winds blow landward. From: Encyclopedia of Geology (Second Edition), 2021.
What is a Sabkha geology?
A term typically used by Earth scientists, a sabkha (Arabic: سبخة) is a coastal, supratidal mudflat or sandflat in which evaporite-saline minerals accumulate as the result of semiarid to arid climate.
What is sabkha deposit?
1. n. [Geology] An environment of coastal sedimentation characterized by arid or semiarid conditions above the level of high tide and by the absence of vegetation. Evaporites, eolian deposits and tidal-flood deposits are common in sabkhas.
Where are evaporites found?
Modern evaporites are limited to arid regions (those of high temperature and low rates of precipitation), for example, on the floors of semidry ephemeral playa lakes in the Great Basin of Nevada and California, across the coastal salt flats (sabkhas) of the Middle East, and in salt pans, estuaries, and lagoons around …
What are evaporite minerals commonly used for?
Evaporite minerals, especially nitrate minerals, are economically important in Peru and Chile. Nitrate minerals are often mined for use in the production on fertilizer and explosives.
Where are evaporites deposited?
Typically, evaporite deposits occur in closed marine basins where evaporation exceeds inflow. The deposits often show a repeated sequence of minerals, indicating cyclic conditions with a mineralogy determined by solubility.
How do evaporites occur?
Evaporites are layered crystalline sedimentary rocks that form from brines generated in areas where the amount of water lost by evaporation exceeds the total amount of water from rainfall and influx via rivers and streams.
Where do evaporites most commonly form?
Evaporites. Evaporite minerals are deposited from saline lakes, where they form as a result of the evaporative concentration of lake water (see SEDIMENTARY ROCKS | Evaporites).
What is the definition of evaporites?
Definition of evaporite : a sedimentary rock (such as gypsum) that originates by evaporation of seawater in an enclosed basin.
What is the most common evaporite deposit?
The most common minerals that are generally considered to be the most representative of marine evaporites are calcite, gypsum and anhydrite, halite, sylvite, carnallite, langbeinite, polyhalite, and kainite.
What is a sabkha surface?
These surfaces are created by the deflation of the sabkha surface that is related to the level of the groundwater table acting as a local base level. Sabkha deposits are believed to form some of the major subsurface hydrocarbon reservoirs in the Middle East (and elsewhere).
What causes a sabkha to form?
The lagoons continue to fill until the lagoon floor is exposed at low tide, and the sabkha begins to form. A sabkha may be inundated during higher than normal spring tides, after rainstorms, or when driving winds push seawater onshore to a depth of a few centimeters.
Why are sabkhas so important?
Modern sabkhas were an important part of this trend as a worthy and convenient analogue for many ancient marine evaporite deposits, convenient in the sense that the analogue model was sometimes applied to evaporites even when evidence for “shallow marine conditions” were lacking.
What is a Sabkha lake?
The large family of dry lakes includes a variety of morphologies, types of surfaces, facies, and sedimentary structures where the evaporation of water plays a major role. To describe them, the term sabkha is largely used in the literature.
