Answer to Question #211952 in Civil and Environmental Engineering for Panda

Question

• Define permineralization as a process in the preservation of fossils. Give a classical example of this mode of preservation that you have encountered as an Earth Science student

Answer 1

Permineralization is a process of fossilization in which mineral deposits form internal casts of organisms. There are various minerals present in water that fill the spaces inside organic tissue. The process gives a record of soft tissue as well as hard tissues. Fossils with permineralization are useful in studying internal structures, especially of plants.

Process of permineralization:

Generally, the groundwater does not contain pure water molecules alone.  The different minerals are found in the ground and dissolved by water until saturation, at which point water will not hold any additional mineral matter. The acidification of the water enhances it because acidic water dissolves more minerals.  Organic tissues such as bone, wood, and shell contain pores and spaces. The pores of the organic tissues are filled by mineralized water and move through the cellular spaces. During this process, the saturated water evaporates, and the excess minerals are deposited on the cells and tissues. This process creates many layers of mineral deposits, creating hard fossilized records.

Types:

Silicification: Silicification is the most common type of permineralization.

Carbonate mineralization: Carbonate mineralization occurs as coal balls.

Pyritization: Organisms are pyritized when they are in marine sediments saturated with iron sulfides.

Petrified wood is a classic example of Permineralization where the original, organic wood material has been replaced by silica and other minerals.

Lower Carboniferous (Mississippian) marine fossils are present near Takoradi in Ghana.