I dont need a complete explanation a short answer descriptio

1. Discuss the origin of the oxygen minimum zone and why it is important in preservation of organicS 2. If CaSO4 is one of the least common salts then how do we get thick CaS04 deposits in basins? 3. What are sabhkas? How do they connect with carbonate sediment deposition?

Solution

1.The places in the world ocean where lowest oxygen saturation column exits that is Oxygen Minimum Zones (OMZ). Typically occurs at depths of about 200 to 1,000 meters. This zone is more efficient to preservation of avalible organic matter. Because in the absence of oxygen, nitrate represents the ‘next best’ electron acceptor. The nitrogen cycle producing ammonium and nitrate, respectively. The importance of OMZ as an environment associated with source rock deposition. Ex: Gulf of Mexico

2. We get thick CaSO4 deposits by complete evoporation of sea water in a closed basin. Normally deposition of 1m thickness of CaSO4 take some 1700m of the sea water. For this,barred-basin theory of evaporaite deposition with its various modifications has been proposed.  

3. A flat area lying between ocean and a desert subject to periodic flooding and evaporation. Due to this aeolian clays, evaporites, and salts are accumulating. Ex: North Africa and Arabia.