Early, intensive marine resource exploitation by Middle Stone Age humans at Ysterfontein 1 rockshelter, South Africa

Modern human behavioral innovations from the Middle Stone Age (MSA) include the earliest indicators of full coastal adaptation evidenced by shell middens, yet many MSA middens remain poorly dated. We apply ²³⁰Th/U burial dating to ostrich eggshells (OES) from Ysterfontein 1 (YFT1, Western Cape, South Africa), a stratified MSA shell midden. ²³⁰Th/U burial ages of YFT1 OES are relatively precise (median ± 2.7%), consistent with other age constraints, and preserve stratigraphic principles. Bayesian age–depth modeling indicates YFT1 was deposited between 119.9 to 113.1 thousand years ago (ka) (95% CI of model ages), and the entire 3.8 m thick midden may have accumulated within ∼2,300 y. Stable carbon, nitrogen, and oxygen isotopes of OES indicate that during occupation the local environment was dominated by C₃ vegetation and was initially significantly wetter than at present but became drier and cooler with time. Integrating archaeological evidence with OES ²³⁰Th/U ages and stable isotopes shows the following: 1) YFT1 is the oldest shell midden known, providing minimum constraints on full coastal adaptation by ∼120 ka; 2) despite rapid sea-level drop and other climatic changes during occupation, relative shellfish proportions and sizes remain similar, suggesting adaptive foraging along a changing coastline; 3) the YFT1 lithic technocomplex is similar to other west coast assemblages but distinct from potentially synchronous industries along the southern African coast, suggesting human populations were fragmented between seasonal rainfall zones; and 4) accumulation rates (up to 1.8 m/ka) are much higher than previously observed for dated, stratified MSA middens, implying more intense site occupation akin to Later Stone Age middens

Geoarchaeology and Heritage Management:Identifying and Quantifying Multi-Scalar Erosional Processes at Kisese II Rockshelter, Tanzania

Natural and anthropogenically induced soil erosion can cause serious loss of the archaeological record. Our work shows the value of multi-scalar geoarchaeological study when excavating and re-excavating rockshelters in a highly dynamic sedimentary environment where erosion is prominent. Here we present our work on Kisese II rockshelter, Tanzania, originally excavated in the 1950s and largely unpublished, that preserves an important Pleistocene-Holocene archaeological record integral to understanding the deep history of the Kondoa Rock-Art World Heritage Center. Unlike rockshelters in quiescent tectonic settings, like much of central Europe or South Africa, Kisese II exists in highly dynamic sedimentary environments associated with the active tectonics of the Great Rift Valley system exacerbated by human-induced environmental and climate change. We report on our 2017 and 2019 exploratory research that includes integrated regional-, landscape-, and site-scale geoarchaeological analyses of past and present sedimentary regimes and micromorphological analyses of the archaeological sediments. Historical records and aerial photographs document extensive changes in vegetation cover and erosional regimes since the 1920s, with drastic changes quantified between 1960 and 2019. Field survey points to an increased erosion rate between 2017 and 2019. To serve future archaeologists, heritage specialists, and local populations we combine our data in a geoarchaeological catena that includes soil, vegetation, fauna, and anthropogenic features on the landscape. At the site, micromorphological coupled with chronological analyses demonstrate the preservation of in situ Pleistocene deposits. Comparison of photographs from the 1956 and 2019 excavations show a maximum sediment loss of 68 cm in 63 years or >10% of >6-m-thick sedimentary deposit. In the studied area of the rockshelter we estimate ∼1 cm/yr of erosion, suggesting the ongoing removal of much of the higher archaeological sediments which, based on the coarse stratigraphic controls and chronology of the original Inskeep excavations, would suggest the loss of much of the archaeological record of the last ∼4000 years. These multi-scalar data are essential for the construction of appropriate mitigation strategies and further study of the remaining stratigraph

Fucino palaeo-lake: Towards the Palaeoenvironmental history of the last 430 Ka

© 2010 AIQUA - Associazione Italiana per lo Studio del Quaternario e EMMEVI - Servizio Congressi SPA. The sedimentary succession deposited in Fucino palaeo-lake potentially records the environmental history of the Central Mediterranean Region continuously since the early Pleistocene and up to recent historical times. Fucino palaeo-lake sediments are interbedded with numerous volcanic ash layers which allow the reconstruction a robust and independent chronological framework of past environment changes. This framework is a fundamental tool to synchronise different archives at a regional and extra-regional scale and to better understand the spatio-temporal climate variability in the Quaternary at the orbital and millennial-scales. Here we present new preliminary data for the last five glacial to interglacial cycles

Determining Timescales and Paleoenvironments of Quaternary Human Evolution Using Stable and Radiogenic Isotopes

Assessing the covariance of human biological and cultural evolution with major climate fluctuations requires independent, precise, and accurate chronologies documenting environmental change in association with rare fossils and archaeology. This thesis aims to improve and diversify geochronological tools and associated paleoenvironmental characterization of paleoanthropological sequences using two of the most precise and accurate chronometers applicable in the Quaternary Period, 40Ar/39Ar and U-Series (i.e., 230Th) geochronology, combined with light stable isotopes, to reconstruct timescales and terrestrial paleoenvironments at paleoanthropological sites.The first chapter refines the age of the Alder Creek sanidine (ACs) fluence monitor which is frequently utilized to determine 40Ar/39Ar ages of volcanic rocks in association with hominid fossil-bearing and archaeological deposits in eastern Africa. The age of ACs is significantly different if anchored by astronomical tuning (tACs = 1.1848 ± 0.0006 Ma, σ) than if anchored solely by constraints from radioactive decay (tACs = 1.1891 ± 0.0008 Ma), possibly due to 1) leads and lags in the deposition of astronomically tuned sequences, 2) inaccuracy of decay constants, and/or 3) assumptions inherent to each dating method. The second chapter outlines the use of C, N, and O stable isotopes of ostrich eggshells to reconstruct local paleoenvironments at African archaeological sites. Combined with novel 230Th burial dating of ostrich eggshells, these may provide precisely dated paleoenvironmental records for sites up to ~ 500 ka. The light stable isotope composition of ostrich eggshells from two eastern African archaeological sites ~50 – 4 ka, which include diachronous occurrences of the Middle to Later Stone Age transition, suggest a mosaic of local environments through time and space that is not apparent from global or regional paleoenvironmental records. In the third chapter, I apply 230Th dating to coral abrader artifacts from a stratified archaeological sequence at Tangatatau Rockshelter, Mangaia (Cook Islands). I compare the results with a recent Bayesian 14C chronology for the site and develop screening criteria to identify reliable 230Th dates from buried contexts at other sites in an effort to develop more precise ways of dating Polynesian expansion. Precise 230Th dates from coral abraders support early Polynesian arrival to Mangaia (1011.6 ± 5.8 CE) and the arrival of the sweet potato (Ipomoea batatas) to no later than 1361–1466 CE, indicating that trans-Pacific voyaging had introduced this South American native plant to the Cook Islands by that time. The techniques used in this thesis demonstrate the power of integrative research in isotope geochemistry to address questions about geological processes and human evolution

Determining Timescales and Paleoenvironments of Quaternary Human Evolution Using Stable and Radiogenic Isotopes

Assessing the covariance of human biological and cultural evolution with major climate fluctuations requires independent, precise, and accurate chronologies documenting environmental change in association with rare fossils and archaeology. This thesis aims to improve and diversify geochronological tools and associated paleoenvironmental characterization of paleoanthropological sequences using two of the most precise and accurate chronometers applicable in the Quaternary Period, 40Ar/39Ar and U-Series (i.e., 230Th) geochronology, combined with light stable isotopes, to reconstruct timescales and terrestrial paleoenvironments at paleoanthropological sites.The first chapter refines the age of the Alder Creek sanidine (ACs) fluence monitor which is frequently utilized to determine 40Ar/39Ar ages of volcanic rocks in association with hominid fossil-bearing and archaeological deposits in eastern Africa. The age of ACs is significantly different if anchored by astronomical tuning (tACs = 1.1848 ± 0.0006 Ma, σ) than if anchored solely by constraints from radioactive decay (tACs = 1.1891 ± 0.0008 Ma), possibly due to 1) leads and lags in the deposition of astronomically tuned sequences, 2) inaccuracy of decay constants, and/or 3) assumptions inherent to each dating method. The second chapter outlines the use of C, N, and O stable isotopes of ostrich eggshells to reconstruct local paleoenvironments at African archaeological sites. Combined with novel 230Th burial dating of ostrich eggshells, these may provide precisely dated paleoenvironmental records for sites up to ~ 500 ka. The light stable isotope composition of ostrich eggshells from two eastern African archaeological sites ~50 – 4 ka, which include diachronous occurrences of the Middle to Later Stone Age transition, suggest a mosaic of local environments through time and space that is not apparent from global or regional paleoenvironmental records. In the third chapter, I apply 230Th dating to coral abrader artifacts from a stratified archaeological sequence at Tangatatau Rockshelter, Mangaia (Cook Islands). I compare the results with a recent Bayesian 14C chronology for the site and develop screening criteria to identify reliable 230Th dates from buried contexts at other sites in an effort to develop more precise ways of dating Polynesian expansion. Precise 230Th dates from coral abraders support early Polynesian arrival to Mangaia (1011.6 ± 5.8 CE) and the arrival of the sweet potato (Ipomoea batatas) to no later than 1361–1466 CE, indicating that trans-Pacific voyaging had introduced this South American native plant to the Cook Islands by that time. The techniques used in this thesis demonstrate the power of integrative research in isotope geochemistry to address questions about geological processes and human evolution