Late Pleistocene landscape evolution in south-central Chile constrained by luminescence and stable cosmogenic nuclide dating

2010 ◽  
Vol 122 (7-8) ◽  
pp. 1235-1247 ◽  
Author(s):  
Katrin Rehak ◽  
Samuel Niedermann ◽  
Frank Preusser ◽  
Manfred R. Strecker ◽  
Helmut P. Echtler
Keyword(s):  
Late Pleistocene ◽  
Landscape Evolution ◽  
Central Chile ◽  
Cosmogenic Nuclide ◽  
South Central ◽  
Cosmogenic Nuclide Dating

Patchy bedrock explained: Tectonic fracture control on landscape evolution patterns in south-Central Chile 

2021 ◽  
Author(s):  
Emma Lodes ◽  
Dirk Scherler ◽  
Hella Wittmann ◽  
Renee Van Dongen
Keyword(s):  
Chemical Weathering ◽  
Landscape Evolution ◽  
Tectonic Deformation ◽  
Fracture Density ◽  
Rock Fracturing ◽  
Central Chile ◽  
Erosion Rates ◽  
Denudation Rates ◽  
South Central

<p>Rock fracturing induced by tectonic deformation is thought to promote faster denudation in more highly fractured areas by lowering grain size and directing the flow of water. That the density and pattern of fractures in a landscape play a role in controlling erosion and landscape evolution has been known for over a century, but not until recently do we have tools, like cosmogenic nuclides, to quantify erosion rates in places with varying fracture densities. In the Nahuelbuta Range in south-central Chile, we observed that >30-m thick regolith exists next to patches of unweathered bedrock. We hypothesize that the density of fractures dictates the pace and patterns of chemical weathering, regolith conversion, and erosion in the Nahuelbuta Range. To test this, we used in situ cosmogenic <sup>10</sup>Be to obtain denudation rates from amalgamated samples of bedrock, corestones and soils, and measured fracture density and orientation, as well as hillslope boulder size in several sites in the Nahuelbuta Range. We found that more highly fractured areas indeed have higher denudation rates than less fractured areas, and that bedrock denudation rates are ~10 m/Myr while soil denudation rates are ~30 m/Myr, suggesting that soil-covered areas may be sites of higher fracture density at depth. Fractures have orientations that match mapped faults across the Nahuelbuta range, and thus are considered to be tectonically-induced. In addition, both fracture and fault orientations match the orientation of streams incising the range, suggesting that fractures control stream channel orientation by weakening bedrock and thus directing flow.</p>

New excavations at the late Pleistocene site of Chinchihuapi I, Chile

2019 ◽  
Vol 92 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Tom D. Dillehay ◽  
Carlos Ocampo ◽  
Jose Saavedra ◽  
Mario Pino ◽  
Linda Scott-Cummings ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Early Holocene ◽  
Occupied Site ◽  
Radiocarbon Dates ◽  
Central Chile ◽  
South Central ◽  
Cool Temperate ◽  
Human Use ◽  
Monte Verde ◽  
Point Type

AbstractThis paper presents new excavation data on the Chinchihuapi I (CH-I) locality within the Monte Verde site complex, located along Chinchihuapi Creek in the cool, temperate Valdivian rain forest of south-central Chile. The 2017 and 2018 archaeological excavations carried out in this open-air locality reveal further that CH-I is an intermittently occupied site dating from the Early Holocene (~10,000 cal yr BP) to the late Pleistocene (at least ~14,500 cal yr BP) and probably earlier. A new series of radiocarbon dates refines the chronology of human use of the site during this period. In this paper, we describe the archaeological and stratigraphic contexts of the recent excavations and analyze the recovered artifact assemblages. A fragmented Monte Verde II point type on an exotic quartz newly recovered from excavations at CH-I indicates that this biface design existed in at least two areas of the wider site complex ~14,500 cal yr BP. In addition, associated with the early Holocene component at CH-I are later Paijan-like points recovered with lithic tools and debris and other materials. We discuss the geographic distribution of diagnostic artifacts from the site and their probable relationship to other early sites in South America.

The late Pleistocene Pilauco site, Osorno, south-central Chile

2013 ◽  
Vol 299 ◽  
pp. 3-12 ◽  
Author(s):  
Mario Pino ◽  
Martín Chávez-Hoffmeister ◽  
Ximena Navarro-Harris ◽  
Rafael Labarca
Keyword(s):  
Late Pleistocene ◽  
Central Chile ◽  
South Central

scholarly journals Cardiorespiratory Fitness: Reference on the Six-Minute Walk Test and Oxygen Consumption in Adolescents from South-Central Chile

2021 ◽  
Vol 18 (5) ◽  
pp. 2474
Author(s):  
Jaime Vásquez-Gómez ◽  
Nelson Gatica Salas ◽  
Pedro Jiménez Villarroel ◽  
Luis Rojas-Araya ◽  
Cesar Faundez-Casanova ◽  
...  
Keyword(s):  
Cardiorespiratory Fitness ◽  
Reference Values ◽  
Estimation Error ◽  
Walk Test ◽  
Central Chile ◽  
Six Minute Walk Test ◽  
Body Adiposity ◽  
South Central ◽  
Males And Females ◽  
Minute Walk

Cardiorespiratory fitness (CRF) provides oxygen to the exercising muscles and is related to body adiposity, with cardiometabolic variables. The aim was to develop reference values and a predictive model of CRF in Chilean adolescents. A total of 741 adolescents of both genders (15.7 years old) participated in a basic anthropometry, performance in the six-minute walk test (SMWT), and in Course Navette was measured. Percentiles were determined for the SMWT, for the V̇O2max, and an equation was developed to estimate it. The validity of the equation was checked using distribution assumptions and the Bland–Altman diagram. The STATA v.14 program was used (p < 0.05). The 50th percentile values for males and females in the SMWT and in the V̇O2max of Course Navette were, respectively, from 607 to 690 and from 630 to 641 m, and from 43.9 to 45 and from 37.5 to 31.5 mlO2·kg·min−1, for the range of 13 to 17 years. For its part, the model to predict V̇O2max incorporated gender, heart rate, height, waist-to-height ratio (WHR), and distance in the SMWT (R2 = 0.62; estimation error = 0.38 LO2·min−1; p <0.001). Reference values can guide physical fitness in Chilean adolescents, and V̇O2max was possible to predict from morphofunctional variables.

Sign in / Sign up

Export Citation Format

Share Document