Retrieving "Precambrian Biota" from the archives

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1. Geological Strata

   Linked via "Precambrian biota"

   Biostratigraphy
   Biostratigraphy utilizes the fossil content within the strata to establish relative age relationships. Index fossils, which are easily recognizable, abundant, short-lived in geologic time, and geographically widespread, are used to define biozones. A notable difficulty arises in assessing deep, anoxic strata where the presence of Cryptobiotic Microforms ($\text{CMF}$)/) leads to [spectral signature…