Prussian Formation


The Prussian Formation, previously known as the Amber Formation, is a geologic formation in Prussia, today mostly Kaliningrad Oblast that dates to the Eocene. It holds 90% of the world's amber supply and Baltic amber is found exclusively in the Prussian Formation.
The Prussian Formation is equivalent to the Obukhov Formation of Ukraine and Belarus.

Geological context

In situ Baltic amber is found within the Prussian Formation, with the main amber bearing horizon being referred to as "Blue Earth", so named due to its glauconite content. The formation is exposed in the northern part of the Sambia Peninsula in Kaliningrad.
Different authors have given estimates of 40-47 million years ago and 35-43 million years ago as the age of the Prussian Formation.

Paleobiology

Numerous extinct genera and species of plants and animals have been discovered and scientifically described from inclusions in the Prussian Formation. Inclusions of insects make up over 98% of the animals preserved in the amber, while all other arthropods, annelids, molluscs, nematodes, protozoans contribute less than 0.5% of the animals. Vertebrates are another 0.5% of the animals included and mostly are represented by mammal fur, feathers, and reptiles.

Flora

Fauna