1. A new trace fossil assemblage from the Middle Permian Broughton Formation, southern Sydney Basin (southeastern Australia): Ichnology and palaeoenvironmental significance.
- Author
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Luo, Mao, Shi, G.R., Lee, Sangmin, and Yang, Bo
- Subjects
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FOSSILS , *GEOLOGICAL formations , *GEOLOGICAL basins , *SEDIMENTARY rocks , *ICHNOLOGY , *PALEOECOLOGY - Abstract
The Permian-Triassic sedimentary succession of the southern Sydney Basin in southeastern Australia contains a wealth of well-preserved trace fossils that are important for systematic ichnological, palaeoecological, and palaeoenvironmental interpretations. In this study, a new ichnofossil assemblage comprising Macaronichnus , Palaeophycus , Psammichnites , Protovirgularia , Rosselia , and Teichichnus is documented from the tide-influenced shoreface deposit of the Middle Permian Jamberoo Sandstone Member of the Broughton Formation. Two distinct ichnofabrics are recognized: i) the Psammichnites ichnofabric characteristic of the upper–middle shoreface deposit; and ii) the crowded Rosselia ichnofabric (CRI) representing the lower shoreface. The Psammichnites -dominated ichnofabric is interpreted to have resulted from opportunistic behaviours of unknown trace makers, whereas the CRI is interpreted to represent possible strategic behaviours of stress-tolerant polychaetes (e.g., terebellid, spionid, and cirratulid polychaetes) in a distal shoreface with high sedimentation rate. Thus, the Psammichnites –crowded Rosselia ichnofabric succession can be considered to represent a response to an environmental shift from proximal to distal shoreface. As such, this study highlights the utility of these two ichnofabrics as stressed environmental indicators. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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