Geological Age of the Lehner Mammoth Site

1959 ◽  
Vol 25 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Ernst Antevs
Keyword(s):  
Northern Europe ◽  
High Plains ◽  
Late Pliocene ◽  
Arid Conditions ◽  
Geological Age ◽  
Perennial Stream ◽  
Fluted Points ◽  
Sulphur Spring ◽  
Channel Deposits ◽  
Semi Arid

AbstractThe late Pliocene basal clay of the region and remnants of later deposits are cut by a perennial stream of pluvial age. Bones and artifacts, including Clovis- fluted points, occur in gravel and other channel deposits in a meander bow of this stream. The bone bed is overlain by a black swamp deposit indicating a subhumid climate and by calichified silts indicating arid conditions, both cut by an Altithermal channel. The hunt, stratigraphically pre- Altithermal, is dated by the equation of the relatively warm and dry 14-to-12 foot level in the San Augustin Plains profile with the Allerod of northern Europe (12,500-10,800 B.P.). This semi-arid period, called the Datil Interval or Datil Drought, is believed to have caused the extinction of the mammoth in both the Southwest and the High Plains by 11,500 B.P. The Sulphur Spring stage Cochise deposit at Double Adobe, which is overlain by a bed containing a mammoth skull, is dated at more than 12,500 B.P. The mammoth hunts of the Lehner and Naco sites are assigned an age of 13,000 or more years.

The Lehner Mammoth Site, Southeastern Arizona

1959 ◽  
Vol 25 (1) ◽  
pp. 2-30 ◽  
Author(s):  
Emil W. Haury ◽  
E. B. Sayles ◽  
William W. Wasley
Keyword(s):  
San Pedro ◽  
Geological Age ◽  
Perennial Stream ◽  
Short Period ◽  
Kill Site ◽  
Both Bones ◽  
Game Hunting ◽  
Fluted Points ◽  
Sulphur Spring ◽  
Big Game Hunting

AbstractIn 1955-56 the Arizona State Museum excavated an elephant-kill site on the Lehner ranch in the San Pedro valley, near Hereford, Arizona, and found 13 projectiles, mainly Clovis fluted points, eight butchering tools, and charcoal from two fires among the remains of nine immature mammoths and elements of horse, bison, and tapir. Bones and artifacts occurred on and in gravels of a former perennial stream exposed in the modern arroyo bank. Most or all of the animals were probably killed over a comparatively short period by hunters identified with the Llano complex by the Clovis points. The Lehner site and the nearby Naco site represent the southwesternmost extent of the presently known range of the Llano complex. The post-kill sequence of alluviation and erosion supports a geological age of 13,000 or more years for both bones and artifacts. Arizona, Michigan, and Copenhagen radiocarbon measurements of hearth charcoal indicate a date of 11,000 to 12,000 B.P. Since these dates are substantially older than the oldest radiocarbon assays for the Sulphur Spring stage of the Cochise culture, it is probable that the transition from big-game hunting to collecting is reflected in the change from Llano complex to Cochise culture, and that this shift in economic emphasis took place before the complete extinction of the late Pleistocene megafauna.

Triazine carryover in semi-arid conditions

1990 ◽  
Vol 9 (6) ◽  
pp. 429-432 ◽  
Author(s):  
O.A. Chivinge ◽  
B. Mpofu
Keyword(s):  
Arid Conditions ◽  
Semi Arid

Genetic parameters of Barki sheep raised under semi-arid conditions

1969 ◽  
Vol 11 (3) ◽  
pp. 361-367 ◽  
Author(s):  
M. H. Fahmy ◽  
E. Salah E. Galal ◽  
Y. S. Ghanem ◽  
S. S. Khishin
Keyword(s):  
Genetic Parameters ◽  
Genetic Correlations ◽  
Research Station ◽  
Phenotypic Correlations ◽  
Arid Conditions ◽  
Body Weights ◽  
Genetic And Phenotypic Correlations ◽  
Fleece Weight ◽  
Semi Arid ◽  
Desert Research

SUMMARYRecords on 695 lambs were collected over a period of 5 years from 1961/62 to 1965/66, at Ras El-Hekma Desert Research Station, 230 km west of Alexandria. The characters studied were birth, weaning and yearling body weights, pre- and post-weaning daily gains and greasy fleece weight.Birth, 120-day and 365-day body weights were 3·4, 18·2 and 33·4 kg respectively. Greasy fleece weight at 16 months of age was 3·29 kg. Heritability estimates of birth, weaning, yearling weights, pre- and post-weaning daily gains and greasy fleece weight were 0·22, 0·45, 0·41,0·45 and 0·29 respectively. Genetic and phenotypic correlations between birth, weaning and yearling weights were all positive and significant. Genetic correlations between fleece weight and body characteristics were negative and low.

Competition between maize andDatura stramoniumin an irrigated field under semi‐arid conditions

Weed Research ◽  
1999 ◽  
Vol 39 (3) ◽  
pp. 225-240 ◽  
Author(s):  
Cavero ◽  
Zaragoza ◽  
Suso ◽  
Pardo
Keyword(s):  
Arid Conditions ◽  
Semi Arid

Quantifying risk for water harvesting under semi-arid conditions

2005 ◽  
Vol 76 (2) ◽  
pp. 77-93 ◽  
Author(s):  
M. Tsubo ◽  
S. Walker ◽  
M. Hensley
Keyword(s):  
Water Harvesting ◽  
Arid Conditions ◽  
Semi Arid ◽  
Quantifying Risk

scholarly journals AGRONOMIC EFFICIENCY OF THE INTERCROPPING OF ARUGULA WITH CARROT UNDER DIFFERENT POPULATION COMBINATIONS

2016 ◽  
Vol 29 (1) ◽  
pp. 76-84 ◽  
Author(s):  
THAÍZA MABELLE DE VASCONCELOS BATISTA ◽  
FRANCISCO BEZERRA NETO ◽  
ÍTALO NUNES SILVA ◽  
MAIELE LEANDRO DA SILVA ◽  
ELIANE QUEIROGA DE OLIVEIRA ◽  
...  
Keyword(s):  
Experimental Design ◽  
Maximum Yield ◽  
Population Densities ◽  
Agronomic Efficiency ◽  
Green Mass ◽  
Sole Crop ◽  
Arid Conditions ◽  
Caatinga Biome ◽  
Brazilian Northeast ◽  
Semi Arid

ABSTRACT: The objective of this study was to evaluate the agronomic efficiency of intercropping combinations of carrot and arugula at different population densities in bicropping in the semi-arid conditions of the Brazilian Northeast. The study was conducted at the "Rafael Fernandes" Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA) during the period September 2011 to February 2012. The experimental design was of randomized complete blocks with treatments arranged in a 4 x 4 factorial scheme with four replications. The combinations were four population densities of carrot (40, 60, 80 and 100% of the recommended population in sole crop - RPSC) with four population densities of arugula (40, 60, 80 and 100% of the RPSC). The recommended population densities for sole crops of carrot and arugula are 500,000 and 1,000,000 plants per hectare, respectively. All treatments were fertilized with hairy woodrose (Merremia aegyptia L.), a spontaneous species of the Caatinga biome. The highest agronomic efficiency of carrot intercropped with arugula in bicropping was achieved in the combination of 40% of RPSC for the carrot and 100% of RPSC for the arugula. The commercial maximum yield (33.74 t ha-1) of carrot roots and the maximum yields of arugula green mass (8.06 and 2.67 t ha-1) in both cultivations were also obtained in the combination of population densities of 40% of RPSC for carrot and 100% of RPSC for arugula.

scholarly journals Growth and production of irrigated vitória pineapple grown in semi-arid conditions

2014 ◽  
Vol 36 (3) ◽  
pp. 693-703 ◽  
Author(s):  
Rodinei Facco Pegoraro ◽  
Bruna Aparecida Madureira de Souza ◽  
Victor Martins Maia ◽  
Uirá do Amaral ◽  
Marlon Cristian Toledo Pereira
Keyword(s):  
Plant Height ◽  
Biomass Production ◽  
Plant Traits ◽  
Block Design ◽  
Leaf Length ◽  
Stem Diameter ◽  
Plant Residue ◽  
Arid Conditions ◽  
Vegetative Biomass ◽  
Semi Arid

This study aimed to evaluate the growth characteristics of irrigated Vitória pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: < 20% biomass production (V1); 21-40% (V2); 41-60% (V3); 61-80% (V4); and > 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.

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