Trzeciorzdowy

Trzeciorzdowy is a nonstandard variant spelling of the Polish geological term trzeciorzędowy. In Polish geology, trzeciorzędowy describes anything related to the Tertiary period of the geologic time scale. The Tertiary is the traditional name for the interval of the Cenozoic Era that extends roughly from 66 million to 2.6 million years ago. In modern stratigraphic practice, the Tertiary is subdivided into the Paleogene and Neogene, and many sources now prefer these terms; however, trzeciorzędowy remains common in older literature and in contexts where a broader or nonformal reference to the period is sufficient.

The adjective is used to describe rocks, formations, fossils, and biological groups dating to the Tertiary. Examples include phrases such as skały trzeciorzędowe (tertiary rocks) or fauna trzeciorzędowa (tertiary fauna). In field descriptions, a designation of the trzeciorzędowy character typically signals sediments deposited during the early to middle part of the Cenozoic.

Etymology and usage notes: the form derives from Polish roots meaning “third” (trzeci) and a suffix indicating a relation to a period or stage (–rzędowy), reflecting the historical designation of the Tertiary. The term serves as a bridge to non-specialist texts or older catalogs.

Contemporary usage: since geochronology shifted toward Paleogene and Neogene in the late 20th century, trzeciorzędowy is often considered archaic or regional. It may still appear in textbooks, translations from older sources, or in contexts that require a broad, informal reference to Tertiary geology.