The Early Paleolithic Go Da Site and the Bifacial Lithic Industries of Southeast Asia

The lithic industry of the stratified site Go Da in Central Vietnam is described, and its place among the contemporaneous Early Paleolithic sites of East and Southeast Asia is determined. Results of a morphological technotypological analysis of the Go Da assemblage are provided. Go Da is attributed to the An Khe-type sites situated in the eponymous area of Vietnam. Cores and tools were made from pebbles, less often from fl akes. Primary reduction focused on simple pebble cores with natural striking-platforms, whereas radial cores were less common. Predom inant among the tools are picks, scrapers of various modifi cations, choppers, and chopping tools, as well as denticulate and notched tools; also, bifaces occur. These tools belong to a single homogeneous industry, showing common features in primary reduction, preparation, and design of key artifacts. On the basis of analysis of the stratigraphic sequence of Go Da and the absolute date of 806 ± 22 ka BP, generated by the potassium-argon analysis of tektites, it is proposed that the site is older than other dated locations with the An Khe industry. Apparently, it resulted from a convergent evolution of the pebble-fl ake industry introduced by the fi rst wave of Homo erectus from Africa. Go Da and other An Khe sites likely belong to a vast habitation zone of Southeast Asian hominins with technologically and typologically similar industries dating to the boundary between the Lower and the Middle Pleistocene.

Study on the Construction of 3D Geological Model of Quaternary Loose Sedimentary Strata Based on the Global Stratigraphic Discrete Points

Accurately depicting the spatial structure characteristics of Quaternary loose sedimentary strata is not only of great significance for the research of Quaternary geological evolution, but also for the analysis of spatial variation characteristics of the inner hydrogeological and engineering geological attributes of the strata. In this study, an approach for constructing a 3D geological model of Quaternary loose sedimentary strata is proposed based on global stratigraphical discrete points. The approach obtains the discrete control point set of each stratum by using limited borehole data for interpolation and encryption, and the contact relationships and intersection modes of adjacent strata can be determined via the analysis of stratigraphic sequence; finally, taking these as the professional basis, the construction of the 3D geological model of Quaternary loose sedimentary strata can be carried out. This application can not only accurately describe the three-dimensional spatial distribution characteristics of the Quaternary loose sedimentary strata, it can also be used to perform a layered simulation of the spatial variation characteristics of the inner geological properties of the Quaternary loose sedimentary strata, such as lithology, porosity, and water content, by taking the three-dimensional spatial framework of each stratum as the simulation boundary. Finally, this study takes the citizen center of Xiong’an new area as an example in order to verify the reliability and advancement of the 3D geological modeling scheme.

Nazugum, a new 4000 year old rockshelter in the Ili Alatau, Tien Shan

The PALAEOSILKROAD project has been conducting field surveys in Kazakhstan to explore the regional Palaeolithic record by targeting primarily caves and rockshelters. However, the survey also discovered numerous sites that were occupied during the Holocene. In this paper, we present our preliminary findings from the Nazugum rockshelter, a new archaeological site located in south-eastern Kazakhstan (Almaty region). The stratigraphic sequence demonstrates the transition from fluvial channel deposits without artifacts to aeolian loess deposits with lithics, charcoal remnants, and fragments of animal bones. The lithics recovered from the sediment wall are dominated by bladelet technology, characteristic for Holocene assemblages. Radiocarbon dates from adjacent charcoal samples yielded an age of 2461-2347 cal. years BC attributing the human occupation to the transitional period of late Eneolithic and early Bronze Age. Our study provides new data for the use of rockshelters in Kazakhstan during the late Holocene and lays the groundwork for future salvage work in Nazugum rockshelter due to the active erosion of the archaeological record.

The Potential of Micromammals for the Stratigraphy and the Timing of Human Occupations at La Roche-à-Pierrot (Saint-Césaire, France)

As micromammals are highly sensitive to changes in their habitat, variations in species representation are often used to reconstruct local environmental conditions. However, taphonomic aspects of micromammals are often overlooked, despite the fact that they can provide important information for our understanding of archaeological sites. La Roche-à-Pierrot, Saint-Césaire, is a major archaeological site for our understanding of the Middle-to-Upper Palaeolithic transition in Western Europe. Clearly documenting site formation processes, the post-depositional reworking of deposits and the sequence of human occupations is fundamental for providing a secure archaeostratigraphic context of the site. The exceptionally large accumulation of micromammals from recently excavated stratigraphic units at the site makes it possible to track variations in the density of micromammals across the stratigraphic sequence. The taphonomic analysis of micromammals demonstrates these variations are not related to a change in the main accumulation agent or post-depositional phenomena. A negative correlation between small mammal remains and archaeological material suggests that peaks in micromammal densities can potentially be correlated with periods when the site was abandoned or when human occupation was less intense, and therefore provide new data for interpreting the Saint-Césaire stratigraphic sequence.

COMPLEX BIOSTRATIGRAPHIC SCHEME OF THE JURASSIC DEPOSITS OF THE PIENNINE ZONE OF THE UKRAINIAN CARPATHIANS

The article summarizes the results of the study of paleontology and biostratigraphy of the Jurassic of the Piennine Zone of the Ukrainian Carpathians by domestic and foreign researchers. For the first time, a summary paleontological description of these sediments is presented, taking into account numerous published data on identified macro- and mictofossils. A correlation biozonal scale has been created, as well as complex biostratigraphic schemes for each Jurassic series of its region in accordance with the International Stratigraphic Scale (2020). Because the stratigraphic sequence was disturbed by disjunctive dislocations, these schemes were developed by analysis of fragmentary sections. At present, three series of the Jurassic are determined by ammonites, belemnites, pelecypods, brachiopods, the Lower and Upper series are also dated by dinocysts, the Upper also by foraminifera and tintinnids. The stages and standard zones of the modern international scale are determined by ammonites: Liasicus of the Gettangian; Bucklandi, Obtusum, Raricostatum of the Sinemurian; Jamesoni, Emaciatum of the Pliensbachian; Tenuicostatum, Serpentinum, Bifrons, Thouarcense of the Toarcien; Opalinum, Murchisonae, Bradfordensis, Concavum of the Aalenian; Propinquans, Humpriesianum, Parkinsoni of the Bajocian; Zigzag, Aurigerus, Subcontractus, Bremeri, Retrocostatum of the Bathonian; Athletа of the Callovian; Plicatilis і Bifurcates of the Oxfordian; Divisum, Acanticum і Cavouri of the Kimmeridgian. Continuous dinocyst zonation is traced in the Upper Jurassic – Fibrata Аcme (Upper Oxfordian), Parvula Acme, Moluccana і Borzai (Kimmerigian), Pulla, Tithonica, Malmica, Semiradiata (Lower Tithonian) and all standard tintinnide zones of Tithonian — Chitinoidella (підзони Dobeni і Boneti), Praetintinnopsella, Crassicollaria. The boundaries of the stages from the Gettangiean to the Oxfordian are not determined. The boundaries between the Lower and Upper Oxfordian as well as between the Kimmeridgian substages are determined by ammonites as well as the boundary between the Kimmeridgian and Tithonian is determined by dinocysts, and the boundary between the Jurassic and Cretaceous is determined by tintinnids (corresponds to the boundary between the zones Crassicollaria of Tithonian and Calpionella of Berriassian). Stratigraphic unconformities were revealed by the macro- and mictofossils: the regional erosion on the boundary between the Aalenian and Bajocian as well as in Early Callovian, and short gap on the boundary between the Lower and Upper Bajocian.

Stratigraphy And Paleolithic Landscapes of the Beganchik Site at the Kama-Volga Confluence

The Beganchik locality is a stratigraphic sequence of loessic deposits, pedogenic horizons and Paleolithic occupations located at the Kama-Volga confluence. The sequence is exposed on a bluff formed on the west side of an erosional remnant between the Kuybyshev Reservoir and the former channel of the Aktay River. Although the site is known for its Terminal Paleolithic-Mesolithic occupations of the Pleistocene-Holocene transition, evidence of older occupations and remains of fauna has been identified. Our research team identified evidence of human presence associated with a pedogenic horizon of MIS 3 age. Two AMS radiocarbon ages from a hearth produced ages around 47 000 years BP. Pollen and phytoliths from two soils horizons, including the one associated with the hearths indicate a steppe environment coincident with the formation of correlative soils elsewhere in the Russian Plain.

The Orogenic Crixás Gold Deposit, Goiás, Brazil: A Review and New Constraints on the Structural Control of Ore Bodies

A review of the current knowledge of lithostratigraphy, geochronology, mineralogy, alteration, fluid chemistry and structural data is provided in order to discuss the main controls on mineralization in the Crixás gold deposit and the existing structural framework and evolution. Gold mineralization at Crixás represents orogenic upper mesothermal to lower hypothermal types developed within the overturned Paleoproterozoic (Rhyacian) stratigraphic sequence. The structural data indicates that upright folding of the stratigraphy and formation of a distinct S1 foliation characterizes D1 deformation. This controls the formation of laminated quartz veins, precipitation of Au-rich sulfides, and the development of NW trending orebodies. Localized F2 folding of D1 structures and strong L2 stretching lineations characterizes the D2 event. This localized F2 folding created oreshoots trending W-WNW within distinct orebodies. The D2 deformation is associated with the precipitation of native Au. The ‘bulk plunge’ of these orebodies is a combination of both plunges defined by D1 and D2 deformation events. A critical assessment of lithostratigraphic and structural data reveal two possible tectonic scenarios operating during the Paleoproterozoic. The first possible tectonic scenario considers sagduction and the development of a regional-scale synclinorium, followed by tilting and localized folding of D1 structures. The second scenario, which is similar to the current model, considers accretion producing a synclinorium, followed by thrusting. Based on the current knowledge, both models are considered to be permissible and a series of focused research studies are proposed to test both the current and the new tectonic models.

Upper Grand Coulee: New views of a channeled scabland megafloods enigma

ABSTRACT New findings about old puzzles occasion rethinking of the Grand Coulee, greatest of the scabland channels. Those puzzles begin with antecedents of current upper Grand Coulee. By a recent interpretation, the upper coulee exploited the former high-level valley of a preflood trunk stream that had drained to the southwest beside and across Coulee anticline or monocline. In any case, a constriction and sharp bend in nearby Columbia valley steered Missoula floods this direction. Completion of upper Grand Coulee by megaflood erosion captured flood drainage that would otherwise have continued to enlarge Moses Coulee. Upstream in the Sanpoil valley, deposits and shorelines of last-glacial Lake Columbia varied with the lake’s Grand Coulee outlet while also recording scores of Missoula floods. The Sanpoil evidence implies that upper Grand Coulee had approached its present intake depth early the last glaciation at latest, or more simply during a prior glaciation. An upper part of the Sanpoil section provides varve counts between the last tens of Missoula floods in a stratigraphic sequence that may now be linked to flood rhythmites of southern Washington by a set-S tephra from Mount St. Helens. On the floor of upper Grand Coulee itself, recently found striated rock and lodgement till confirm the long-held view, which Bretz and Flint had shared, that cutting of upper Grand Coulee preceded its last-glacial occupation by the Okanogan ice lobe. A dozen or more late Missoula floods registered as sand and silt in the lee of Steamboat Rock. Some of this field evidence about upper Grand Coulee may conflict with results of recent two-dimensional simulations for a maximum Lake Missoula. In these simulations only a barrier high above the present coulee intake enables floods to approach high-water marks near Wenatchee that predate stable blockage of Columbia valley by the Okanogan lobe. Above the walls of upper Grand Coulee, scabland limits provide high-water targets for two-dimensional simulations of watery floods. The recent models sharpen focus on water sources, prior coulee incision, and coulee’s occupation by the Okanogan ice lobe. Field reappraisal continues downstream from Grand Coulee on Ephrata fan. There, some of the floods exiting lower Grand Coulee had bulked up with fine sediment from glacial Lake Columbia, upper coulee till, and a lower coulee lake that the fan itself impounded. Floods thus of debris-flow consistency carried outsize boulders previously thought transported by watery floods. Below Ephrata fan, a backflooded reach of Columbia valley received Grand Coulee outflow of small, late Missoula floods. These late floods can—by varve counts in post-S-ash deposits of Sanpoil valley—be clocked now as a decade or less apart. Still farther downstream, Columbia River gorge choked the largest Missoula floods, passing peak discharge only one-third to one-half that released by the breached Lake Missoula ice dam.