The spatial distribution of the dominant matrix minerals present in the middle-Proterozoic Athabasca Group sandstone (kaolin, illite, sudoite, dravite, hematite) was studied at a regional scale in the Shea Creek region (Saskatchewan, Canada), in which two epigenetic unconformity-type uranium deposits have been discovered. 3D models of matrix mineral distribution were derived from normative mineral calculations and 3D interpolation using whole-rock geochemical analyses of sandstone samples collected from both mineralized and barren areas. The calculations were constrained by information obtained from petrographic and crystal-chemical clay mineralogical studies on representative samples. The 3D mineral distribution models were compared to the lithostratigraphy and structural features of the Athabasca Group sandstone to ascertain the source and mobility of the main elements involved in the sandstone host-rock alteration processes related to the U mineralization. The distribution of Al is conformable with the lithostratigraphy throughout the studied area, regardless of proximity to basement-rooted structures and U ore bodies. The distribution of illite displays similar features, but the intensity of the illitization of kaolin decreases with increasing distance from the structures and U ore bodies. Hematite bleaching and neoformation of sudoite and dravite were restricted to the vicinity of the fault zones above the U ore bodies. The spatial configurations of the mineral anomalies show that syn-ore fluids flowed from the basement towards the sandstone cover via the fault zones, as described in current metallogenic models. Although Al remained immobile (mass transfer), the anomalous K, B and Mg present in the host-rock alteration haloes were probably imported from the basement rocks (mass transport). Unlike B and Mg, K migrated laterally at least several kilometers from the basement-rooted faults. The mineral distribution models were used to quantify the volume of altered sandstone (10−2−10−1 km3) and the amounts of K, Mg and B which were imported to the alteration haloes above the Shea Creek U ore bodies: 186,000 t of K, 66,000 t of Mg, and 11,000 t of B above the Anne ore body, and 24,000 t of K, 185,000 t of Mg, and a similar 11,000 t of B above the Colette ore body.

We present a photogrammetric model and new line drawing of Sacul Stela 3 at the ancient Maya site of Sacul 1, Guatemala. Although virtually illegible in person and from photographs, the inscription on the eroded stela can largely be read or reconstructed in the 3D model. Our reading confirms a previous argument that the kingdom based at Sacul 1 was attacked in A.D. 779 by forces from the site of Ucanal. Traveling by night, warriors from Sacul retaliated with a raid at dawn next day on an unidentified site and, months later, followed up with an attack on Ucanal itself. The same narrative appears substantially on a well-known monument, Ixkun Stela 2, but there are differences between the two texts which suggest that Sacul and Ixkun had their own sculptors and record-keepers and which offer insights into the implications of verbs (pul, “to burn” and ch'ak, “to chop”) commonly attested in Classic Maya accounts of war. We then present the results of GIS analysis which suggests that the site area of El Rosario (between Sacul 1 and Ucanal) is an appealing candidate for the unidentified site mentioned in the stela text.

Coastal shell midden deposits are a quintessential component of the archaeological record on the Pacific Northwest Coast. Despite their importance in informing the cultural and environmental histories of Indigenous peoples, research on shell middens has largely not sought to address the physical extent of these cultural deposits, which requires estimating shape, depth, and volume. Here, we present a new scalable geospatial model, designed to work with legacy survey data, for estimating midden volumes based on applying a regular geometric solid to sites with known extent and depth. We evaluate the accuracy of this technique using percussion core, total station, and lidar data from eight sites in Tseshaht territory on western Vancouver Island and three sites on the north coast of British Columbia (Canada). As part of the evaluation process of our results, we calculate uncertainty using subsurface core depth data and then compare generalized and modeled midden volume estimates. We demonstrate an accurate general model applied at the regional scale across a systematically surveyed landscape. This work presents the first landscape-scale measure of midden extents and volume within our study area, with relevance to historical ecology and settlement patterns.

Daily data collection during archaeological fieldwork forms the basis for later interpretation and analysis. Across the world, we observe a wide variety of digital data collection methods and tools employed during fieldwork. Here, we detail the daily practices at four recent survey and excavation projects in the South Caucasian country of Armenia. As archaeology continues to become ever more digital, it is useful to consider these day-to-day recording processes at a typical field project. We provide details on both the types of data collected and the ways they are collected so as to foreground these topics. Finally, we reflect on how our work is currently impacted by digital changes and how it may continue to change in the future.

In the past decade, archaeologists have increasingly made use of photogrammetry, the process of creating 3D models from photographs, in a variety of field and lab settings. We argue that we must, as a discipline, develop a consistent methodology to ensure that 3D models are held to a consistent standard, including not only photographic protocol but also the documentation of model accuracy using an agreed-upon measure. To help develop this discussion, we present our system for incorporating photogrammetry into the documentation of architecture. This technique was developed at the site of Nim Li Punit, Belize, in 2018. Excavating architecture involves documenting the pre-excavated building, liberating overburden, documenting all in situ construction (including wall fall, fill stones, and standing architecture), drawing consolidated architecture, and documenting the final state of the post-excavated buildings. The generation of 3D models greatly assisted in all facets of the excavation, documentation, analysis, and consolidation processes. To ensure that our models were accurate, we documented the reprojection error and final model horizontal distortion to assess the quality of the model. We suggest that documenting both forms of error should become standard practice in any discussion of archaeological applications of photogrammetry.

In this study a novel approach for 3D modeling of cylindrical sample of hot mix asphalt (HMA) is presented. To this end, the cylindrical sample was divided into several slices and using a developed algorithm the processed images were extended to 3D volumetric objects to reconstruct the 3D microstructure of HMA. To evaluate the efficiency of the presented 3D model for prediction of mechanical behavior, HMA was regarded as a two-phase mixture; mastic phase and aggregate phase. The asphalt binder, filler, air voids and fine aggregates were considered as mastic with viscoelastic behavior and the aggregate was considered as an elastic material. Two models (Burger and generalized Kelvin) were studied for determining viscoelastic behavior of mastic. Finally, to verify the model using Finite Element Method (FEM) the behavior of the 3D model was simulated under different uniaxial compressive loads. A good agreement was observed between the simulated results and corresponding experimental data which indicates the efficiency of the proposed model to simulate three-dimensional asphalt.