What term describes the preservation of an organism in substances like amber or ice with minimal chemical change?

The term that describes the preservation of an organism in substances like amber or ice with minimal chemical change is unaltered preservation. This process allows the original organic materials of the organisms, such as soft tissues and other delicate features, to remain intact and relatively unchanged from their original state. This preservation can occur in environments where conditions inhibit decay, such as in frozen areas or in resin that hardens into amber.

In contrast, processes like petrification involve the gradual replacement of organic materials with minerals, leading to significant changes in the structure of the original organism. Frozen fossilization is not a widely recognized term in the scientific community, and trace fossilization refers to fossilized evidence of an organism's activity rather than the preservation of the organism itself. Thus, unaltered preservation accurately captures the concept of minimal chemical change in the preservation process.