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Geophysical survey and excavations from 2010–2016 at Lawrenz Gun Club (11CS4), a late pre-Columbian village located in the central Illinois River valley in Illinois, identified 10 mounds, a central plaza, and dozens of structures enclosed within a stout 10 hectare bastioned palisade. Nineteen radiocarbon (14C) measurements were taken from single entities of wood charcoal, short-lived plants, and animal bones. A site chronology has been constructed using a Bayesian approach that considers the stratigraphic contexts and feature formation processes. The village was host to hundreds of years of continuous human activity during the Mississippi Period. Mississippian activity at the site is estimated to have begun in cal AD 990–1165 (95% probability), ended in cal AD 1295–1450 (95% probability), and lasted 150–420 yr (95% probability) in the primary Bayesian model with similar results obtained in two alternative models. The palisade is estimated to have been constructed in cal AD 1150–1230 (95% probability) and was continuously repaired and rebuilt for 15–125 yr (95% probability), probably for 40–85 yr (68% probability). Comparison to other studies demonstrates that the bastioned palisade at Lawrenz was one of the earliest constructed in the midcontinental United States.
The building blocks of planets in planet-forming (“protoplanetary”) disks are assembled early in the lifetime of a young star. The gas disks are relatively short-lived, with a half-life of about 3 million years, as chemical reactions modify the reservoir of material from the natal molecular cloud. Spitzer Space Telescope Infrared Spectrograph (IRS) spectra of protoplanetary disks around T Tauri stars show emission from H2O and absorption from other gases, sometimes consistent with formaldehyde, H2CO , and other times consistent with formic acid, HCOOH, in the 5-7.5 μm region. SOFIA-EXES spectra of YSOs that follow up on these Spitzer-IRS studies are presented. How the gaseous features observed between 5-7.5 μm relate to those at other wavelengths is discussed. This work suggests that water and organic molecules, which are crucial for life as we know it, are present in the habitable zones of stars at a very early age [of 1-3 million years].
The Neotoma Paleoecology Database is a community-curated data resource that supports interdisciplinary global change research by enabling broad-scale studies of taxon and community diversity, distributions, and dynamics during the large environmental changes of the past. By consolidating many kinds of data into a common repository, Neotoma lowers costs of paleodata management, makes paleoecological data openly available, and offers a high-quality, curated resource. Neotoma’s distributed scientific governance model is flexible and scalable, with many open pathways for participation by new members, data contributors, stewards, and research communities. The Neotoma data model supports, or can be extended to support, any kind of paleoecological or paleoenvironmental data from sedimentary archives. Data additions to Neotoma are growing and now include >3.8 million observations, >17,000 datasets, and >9200 sites. Dataset types currently include fossil pollen, vertebrates, diatoms, ostracodes, macroinvertebrates, plant macrofossils, insects, testate amoebae, geochronological data, and the recently added organic biomarkers, stable isotopes, and specimen-level data. Multiple avenues exist to obtain Neotoma data, including the Explorer map-based interface, an application programming interface, the neotoma R package, and digital object identifiers. As the volume and variety of scientific data grow, community-curated data resources such as Neotoma have become foundational infrastructure for big data science.
Investigations of ancient political economies frequently focus on craft production. How manufacturing is organized can provide critical insights on more than the economy because social interactions and political processes are also involved. Here we consider how the acquisition, fabrication, and distribution of obsidian blades figured in the political strategies of craftworkers and elites within the Late Classic (AD 600–800) lower Cacaulapa Valley, northwestern Honduras. This evidence provides insights into the organization of craft manufacture across southeastern Mesoamerica and suggests that current models do not capture the varied production strategies that may be pursued within the same polity.
Silver Lake is the modern terminal playa of the Mojave River in southern California (USA). As a result, it is well located to record both influences from the winter precipitation dominated San Bernardino Mountains – the source of the Mojave River – and from the late summer to early fall North American monsoon at Silver Lake. Here, we present various physical, chemical and biological data from a new radiocarbon-dated, 8.2 m sediment core taken from Silver Lake that spans modern through 14.8 cal ka BP. Texturally, the core varies between sandy clay, clayey sand, and sand-silt-clay, often with abrupt sedimentological transitions. These grain-size changes are used to divide the core into six lake status intervals over the past 14.8 cal ka BP. Notable intervals include a dry Younger Dryas chronozone, a wet early Holocene terminating 7.8 – 7.4 cal ka BP, a distinct mid-Holocene arid interval, and a late Holocene return to ephemeral lake conditions. A comparison to potential climatic forcings implicates a combination of changing summer – winter insolation and tropical and N Pacific sea-surface temperature dynamics as the primary drivers of Holocene climate in the central Mojave Desert.
Archaeological data and research results are essential to addressing such fundamental questions as the origins of human culture; the origin, waxing, and waning of civilizations and cities; the response of societies to long-term climate changes; and the systemic relationships implicated in human-induced changes in the environment. However, we lack the capacity for acquiring, managing, analyzing, and synthesizing the data sets needed to address important questions such as these. We propose investments in computational infrastructure that would transform archaeology’s ability to advance research on the field’s most compelling questions with an evidential base and inferential rigor that have heretofore been impossible. At the same time, new infrastructure would make archaeological data accessible to researchers in other disciplines. We offer recommendations regarding data management and availability, cyberinfrastructure tool building, and social and cultural changes in the discipline. We propose funding synthetic case studies that would demonstrate archaeology’s ability to contribute to transdisciplinary research on long-term social dynamics and serve as a context for developing computational tools and analytical workflows that will be necessary to attack these questions. The case studies would explore how emerging research in computer science could empower this research and would simultaneously provide productive challenges for computer science research.
We present the results of an approximately 6 100 deg2 104–196 MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the MWACS. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 h < RA < 8.5 h, − 58° < Dec < −14°over three frequency bands centred on 119, 150 and 180 MHz, with image resolutions of 6–3 arcmin. The catalogue has 3 arcmin angular resolution and a typical noise level of 40 mJy beam− 1, with reduced sensitivity near the field boundaries and bright sources. We describe the data reduction strategy, based upon mosaicked snapshots, flux density calibration, and source-finding method. We present a catalogue of flux density and spectral index measurements for 14 110 sources, extracted from the mosaic, 1 247 of which are sub-components of complexes of sources.