Hybrid finite element–finite volume discretization of complex geologic structures and a new simulation workflow demonstrated on fractured rocks

The generation of computational meshes of complex geological objects is a challenge: their shape needs to be retained, resolution has to adapt to local detail, and variations of material properties in the objects have to be represented. Also mesh refinement and adaptation must be sufficient to resolve variations in the computed variable(s). Here, we present an unstructured hybrid finite element, node‐centred finite‐volume discretization suitable for solving fluid flow, reactive transport, and mechanical partial differential equations on a complex geometry with inhomogeneous material domains. We show that resulting meshes accurately capture free‐form material interfaces as defined by non‐uniform rational B‐spline curves and surfaces. The mesh discretization error is analysed for the elliptic pressure equation and an error metric is introduced to guide mesh refinement. Finite elements and finite volumes are represented in parametric space and integrations are conducted numerically. Subsequently, integral properties are mapped to physical space using Jacobian transformations. This method even retains its validity when the mesh is deformed. The resulting generic formulation is demonstrated for a transport calculation performed on a complex discrete fracture model.     

Are Teeth Better? Histological Characterization of Diagenesis in Archaeological Bone–Tooth Pairs and a Discussion of the Consequences for Archaeometric Sample Selection and Analyses

Teeth are often the preferred source material for isotopic and genetic assay involving ancient biomolecules. The assumption is that dental tissue preserves better due to its anatomically protected location, the enamel cap, and lower porosity compared to bone. However, this assumption has not been widely tested. Some similarities in diagenetic processes are to be expected due to similarities in structure and chemical composition of dentine and bone. This has led to the suggestion that bone can be used as an indicator of dental preservation, as a pre‐screening technique in the selection of suitable samples for biomolecular studies. Thus, direct testing of the correlation between bone and tooth preservation and diagenesis is needed. This paper reports the results of the histological characterization of diagenetic alterations within 25 human femur–tooth pairs, from a Medieval to modern (AD 1850) cemetery in Eindhoven, the Netherlands. The results showed that teeth do indeed preserve better overall, but not always, and that this was dependent on the main diagenetic factor(s) at the burial location. Furthermore, good correlations are found between the microstructural preservation of bone and teeth; similar processes of decay were observed within bone and teeth of the same individual. Overall, the study demonstrated that histological analysis of bone is useful for the identification of degradation processes that affect biomolecular preservation in skeletal material. In this way, sample selection and analytical strategies can be optimized. Copyright © 2013 John Wiley & Sons, Ltd.     

Assyrian Attitude Towards Captive Enemies: A 2700‐year‐old Paleo‐forensic Study

The Assyrians, who ruled at the height of their power between Egypt and the Persian Gulf (745–630 BC), are known from historical records to have been cruel and unrelenting towards their enemies. However, osteological evidence for this behavior is scarce. We herein present a case of an adult male skeleton, dated to the Iron Age IIB period (second half of the 8th century BC), who manifests traumatic injuries to the skull, left forearm, vertebrae, and ribs. Using modern forensic methods, the injuries were studied, and the consequences that led to these injuries reconstructed. Three possible scenarios are presented: (i) wounds inflicted during a chaotic battle; (ii) wounds caused by the chasing and capturing of a victim; and (iii) a commonly practiced violent attitude of Assyrian soldiers towards a captive combatant. Combining all the evidence at hand, the latter scenario appears more likely. This skeleton may therefore be one of the sole tangible physical evidence for the veracity of the Assyrians’ post‐battle behavior, as depicted in ancient texts and reliefs. Copyright © 2012 John Wiley & Sons, Ltd.