Holocene shell beds along the Brazilian coast provide critical records of sea level variations influenced by climatic changes. This study examines the taphonomic implications of bioerosional traces in bioclastic accumulations from coastal sites in Rio de Janeiro State, Brazil. By integrating sedimentological, taphonomic, and taxonomic data, the relationship between bioerosion and shell damage signatures was explored, focusing on three Quaternary localities rich in mollusk shell remains. Detailed analyses using thin sections, X-ray microtomography, and compaction tests identified four distinct bioerosion incipient- traces: Entobia, Caulostrepsis, Meandropolydora, and Oichnus. The results show that the one active depositional site has a higher proportion of bioclasts with bioerosion but fewer shells with taphonomic damage compared to two Holocene sites. The higher fragmentation rates at Holocene sites are linked to longer exposure times of bioeroded shells before final burial. These differences suggest that shorter exposure times lead to lower fragmentation rates despite higher bioerosion levels. Mechanical tests confirmed that bioeroded shells are more fragile, breaking into angular fragments, thereby contributing significantly to shell damage. Thus, bioerosion coupled with moderate surface residence times, plays a crucial role in shell fragmentation, with hydrodynamic conditions being a secondary agent of shell damage in high-energy environments.

The Indo-Pacific gastropod Terebralia palustris is particularly suitable for comparing natural and anthropogenic induced taphonomic pathways due to its wide geographic distribution and common presence within archeological context. The present study aims to (1) correlate shell architecture and morphology with fragmentation pattern and preservation, (2) quantify taphonomic changes to differentiate between natural vs. anthropogenic preservation features, (3) provide a guideline for analyzing fragmented shell remains in archeological material. Shells and taphonomic features were studied from both recent mangrove environments from the Emirate of Sharjah, United Arab Emirates as well as archeological material within the Iron age II site (1000–600 BC) of Muweilah near the City of Sharjah. Techniques utilized include morphometry, thin sectioning, scanning electron microscopy (SEM) of recent specimens and a semi—quantitative taphonomic analysis of anthropogenic material. Thin sectioning shows a complex internal shell morphology with a tripartite subdivision of shell layers. The recent material shows better preserved features on both the exterior and internal shell surfaces than the highly fragmented material recovered from the archeological context, which shows a distinct size distribution as well as showing higher levels of surface abrasion, surface cracks and color alterations. These features are correlated to extraction techniques, cooking methods and waste disposal handling.

Five types of reefs are described from the northern and southern parts of the Azrou-Khenifra Basin generated by the interactions of microbes and coral communities. The type 1 microbial reefs grew in both shallow- and deep-water settings, with a strong control by glacioeustasy. Type 2 microbial reefs developed in more tranquil periods, associated with common intermounds, and where only a single major regressive-transgressive sequence is recognised. Type 3 microbial reefs developed in constant deeper water conditions, generated by higher rates of subsidence in the basin, and creating an overall deepening-upward sequence. Type 4 microbial reefs recognised in the northern part of the basin have no clear counterparts in southern outcrops, but they are likely the capping strata observed in the latter area. Rugose corals allow to define a Type 5 reef, unrelated to microbial facies, and are recorded in oolitic-bioclastic backshoals or quiet inner platform settings. The presence of similar reefs in both the northern and southern parts of the basin demonstrates that conditions were not as different as previously proposed, and a lithostratigraphical, environmental uniformity occurs, which permits the analysis of different subsidence rates and glacioeustastic influence. In the Azrou-Khenifra Basin, the reefs, as well as other regional features, suggest that the basin, overall, evolved from an extensional tectonic regime during the early Brigantian into a complex extensional or compressional regime during the early Serpukhovian, passing into a predominantly compressional phase during the late Serpukhovian in a polyphase tectonic inversion during the onset of the Variscan Orogeny in the region.

The main goal of the paper is the reconstruction of a Middle Triassic buildup cropping out in the central part of the Southern Apennines. Middle Triassic reefs of the western Tethys realm are well known in the Northern and Southern Alps. In contrast, few studies of the Anisian–Ladinian carbonate platforms of the southern Apennines are available, due to the diagenetic alteration and tectonic disruption that hinder their paleoenvironmental and stratigraphic reconstruction. In an attempt to fill this gap, and to improve the knowledge on the Anisian–Ladinian carbonates of central Mediterranean area, this research is focused on a carbonate buildup cropping out in the “La Cerchiara” area, Sasso di Castalda (Basilicata, Southern Italy). The buildup, affected by intense tectonic deformation associated with the development of the Apennine thrust and fold belt, was studied using a statistical evaluation of the quantitative microfacies data. The research enabled a reconstruction of the original stratigraphic relationships of the various buildup fragments. A positive linear regression between the sample positions vs the percentage of autochthonous carbonates indicates an increase of the autochthons carbonate toward the top of the succession. The allochthonous fabrics (packstone/wackestone) at the base of the section (Unit IIIa) pass gradually upward into autochthonous (boundstones) facies (Units IIIb, I), consisting of microbialites (clotted peloidal micrite, microbial-derived laminae, and aphanitic micrite), microproblematica and cyanobacterial crusts, with few encrusting skeletal organisms. Statistical data suggest that units IIIa, IIIb, and I are in stratigraphic order while unit II appears to have been moved by tectonic dislocation from its original position at the base of the succession. The absence of metazoan reef framework, and the richness of micro-encrusters, autochthonous micrite and synsedimentary cements, suggest a mud-mound style of growth for the carbonate bodies of the Southern Apennine during the Anisian.