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In Central Western Argentina (CWA), the incorporation of cultigens by hunter-gatherer populations has been much discussed. This paper explores the relationship between population dynamics, subsistence change, and burial patterns driven by the process of land use intensification and increasing reliance on maize. We hypothesize that territorial behavior emerged in the context of population growth and competition for resources with a high probability of failure, as expected in an arid environment. To evaluate this hypothesis, we explore four lines of inquiry in southern Mendoza (CWA): 1) the frequency of radiocarbon dates to estimate population dynamics; 2) the Juvenile Index as a fertility rate proxy; 3) the stable isotopes on human bone (δ 13C co , δ 15N, δ 13C ca) to reconstruct diet; and 4) burial patterns as an estimate of territorial control. Our results partially support our hypothesis: During an early stage, when maize started to appear in the diet, the population was increasing, and cemeteries emerged along with some signs of violence. The hypothesis is not supported in a second period, when maize consumption and population were highest, but large cemeteries disappeared. In light of this evidence, the effect of maize on human societies was not uniform and irrevocable, and the adoption of maize by human foragers contributed to a new and diverse set of human-environment relationships. [ABSTRACT FROM AUTHOR]

In this paper we describe for the first time the calcareous dinoflagellate cysts and calpionellid associations from upper Valanginian-Hauterivian orbital-driven rhythmic distal ramp deposits (Agrio Formation) in the Neuquén Basin, Argentina. Three stratigraphic sections from the northern Neuquén province (Loma La Torre and El Portón) and southern Mendoza province (Arroyo Loncoche) were studied. The Agrio Formation contains a low diverse association of these microfossils, among which ten calcareous dinoflagellate cyst species and five calpionellid species were recognized, all of them known from the Lower Cretaceous pelagic sediments of the Tethyan region. Two calcareous dinoflagellate cyst zones (Carpistomiosphaera valanginiana , and Stomiosphaera echinata), as well one calpionellid zone (Tintinnopsella), previously proposed for the Tethyan realm, are confirmed for the Agrio Formation. These zones are consistent to late Valanginian - Hauterivian age assignments previously established based on ammonites, nannofossils, and organic-walled dinoflagellate cysts. • First record of Valanginian-Hauterivian calpionellids and calcareous dinocyts in the Southern Hemisphere. • New data that support the presence of family Calpionellidae up to the late Hauterivian. • Calpionellids and calcareous dinocyts zones in the Andes show a similar distribution to those defined for the Tethyan realm. [ABSTRACT FROM AUTHOR]

Laccolith emplacement and growth are controlled by doming of overburden rocks. Understanding the mechanics and structural evolution of laccolith-induced doming is therefore essential for revealing the emplacement dynamics and growth of laccoliths. In this paper, we present a 3D reconstruction of a subsurface laccolithic intrusion through the structural reconstruction of a well-exposed dome at Pampa Amarilla, Neuquén Basin, southern Mendoza province, Argentina. The 3D reconstruction was made possible by the unique integration of surface geological data and subsurface 3D seismic and borehole data. We estimate that the Pampa Amarilla laccolith is ~400 m thick, ~3 km and 2 km long in the E -W and N-S directions, respectively. Along an E-W cross section, the laccolith exhibits a wedge shape with maximum thickness near its western edge and gradual thinning toward the east. The structure of the dome is typical of a trapdoor, with faulting along the western, northwestern and southwestern edges, and tilting of the overburden to the east. The trapdoor tilting of the laccolith's overburden was the main mechanism controlling the thickening and growth of the Pampa Amarilla laccolith, which exhibits a relatively high thickness-to-length ratio T / D ~ 0.13. Numerous laccolithic intrusions exhibit similar values of T / D , and our study suggests that faulting commonly controls emplacement of laccoliths with T/D > 0.1; conversely, our study suggests that the established mechanical models of laccolith emplacement based on elastic bending of the overburden applies only to thin laccoliths. Finally, our study highlights the necessity and value of integrating field geological measurements with subsurface 3D seismic and borehole data for structural reconstructions of subsurface laccolith intrusions. • 3D reconstruction of a subsurface Pampa Amarilla laccolith and overlaying dome • We integrated surface geological mapping and subsurface 3D seismic and borehole data. • Laccolith is a thick laccolith with a thickness-to-diameter ratio T/D ~ 0.13. • Dome exhibits a trapdoor structure with faulting on western edge. • Our study suggests that overburden faulting controls growth of thick laccoliths. [ABSTRACT FROM AUTHOR]