2021/09/20 by Morten Lunde Nielsen, Mirinae Lee, Hong Chin Ng +7 · 1 citation
Earth and Planetary Sciences · #Biology #Biota #Diagenesis #Ecology #Geochemistry #Geological and Geochemical Analysis #Geology #Geology and Paleoclimatology Research #Lagerstätte #Metamorphism #Muscovite #Paleontology #Paleontology and Stratigraphy of Fossils #Quartz #Taphonomy
paper · pdf · doi:10.1130/g48906.1
openalex publication_date 2021/09/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Abstract Correct interpretation of soft-bodied fossils relies on a thorough understanding of their taphonomy. While the focus has often been on the primary roles of decay and early diagenesis, the impacts of deeper burial and metamorphism on fossil preservation are less well understood. We document a sequence of late-stage mineral replacements in panarthropod fossils from the Sirius Passet Lagerstätte (North Greenland), an important early Cambrian Burgess Shale–type (BST) biota. Muscle and gut diverticula were initially stabilized by early diagenetic apatite, prior to being pervasively replaced by quartz and then subordinate chlorite, muscovite, and chloritoid during very low- to low-grade metamorphism. Each new mineral replicates the soft tissues with different precision and occurs in particular anatomical regions, imposing strong biases on the biological information retained. Muscovite and chloritoid largely obliterate the tissues’ original detail, suggesting that aluminum-rich protoliths may have least potential for conserving mineralized soft tissues in metamorphism. Overall, the fossils exhibit a marked shift toward mineralogical equilibration with the matrix, obscuring primary taphonomic modes. Sequential replacement of the phosphatized soft tissues released phosphorus to form new accessory monazite (and apatite and xenotime), whose presence in other BST biotas might signal the prior, more widespread, occurrence of this primary mode of preservation. Our results provide critical context for interpreting the Sirius Passet biota and for identifying late-stage overprints in other biotas.