Evidence for late tertiary volcanic activity in the northern black hills, South dakota

Rhyolitic volcanic rock in the northern Black Hills has a potassium-argon isotopic age of 10.5 +/- 1.5 million years. This is considerably younger than any previously reported igneous activity in this or adjacent areas and indicates that the renewed uplift of the Black Hills, which occurred after the Oligocene epoch, was also accompanied by some volcanism.     

Holocene stratigraphy and archeology in the middle missouri river trench, South dakota

Shoreline erosion along man-made lakes in North Dakota and South Dakota has led to the discovery of stratified preceramic cultural remains in an area where previously few such materials have been found. One important exposure, the Walth Bay site, contains a 7000-year sequence of alluvial and eolian deposition capping an abandoned Missouri River terrace. Three distinct soil profiles are associated with successive Late Paleo-Indian, Plains Archaic, and Plains Village Tradition occupations.     

Paleolimnology of late quaternary deposits: seibold site, north dakota

A unique late Quaternary lacustrine deposit has been discovered recently on the Missouri Coteau of North Dakota. A diverse, extremely well-preserved biota of more than 160 species has been recovered primarily from an organic mud deposited about 9500 years before the present. The lacustrine body shallowed gradually as the climate became drier.     

Stone age prehistory of northern Spain

The Vasco-Cantabrian region of Spain is one of the few areas of the world where a large sample of archeological sites has yielded a detailed record of the changes in the human condition in the period spanning Neanderthal times from about 125,000 years ago until the adoption of food production, less than 6000 years ago in this area. During this time, human adaptations underwent a series of crucial transformations involving profound changes in cultural systems and perthaps also in aspects of the biological basis for culture.     

U-Pb isotopic age of the StW 573 hominid from Sterkfontein, South Africa

Sterkfontein cave, South Africa, has yielded an australopith skeleton, StW 573, whose completeness has excited great interest in paleoanthropology. StW 573, or "Little Foot," was found 25 meters below the surface in the Silberberg Grotto. 238U-206Pb measurements on speleothems immediately above and below the fossil remains, corrected for initial 234U disequilibrium, yield ages of 2.17 +/- 0.17 million years ago (Ma) and 2.24(-0.07)(+0.09) Ma, respectively, indicating an age for StW 573 of close to 2.2 Ma. This age is in contrast to an age of approximately 3.3 Ma suggested by magnetochronology and ages of approximately 4 Ma based on 10Be and 26Al, but it is compatible with a faunal age range of 4 to 2 Ma.     

Dynamics of liquefaction during the 1987 superstition hills, california, earthquake

Simultaneous measurements of seismically induced pore-water pressure changes and surface and subsurface accelerations at a site undergoing liquefaction caused by the Superstition Hills, California, earthquake (24 November 1987; M = 6.6) reveal that total pore pressures approached lithostatic conditions, but, unexpectedly, after most of the strong motion ceased. Excess pore pressures were generated once horizontal acceleration exceeded a threshold value.     

Cristobalite in volcanic ash of the soufriere hills volcano, montserrat, british west indies

Crystalline silica (mostly cristobalite) was produced by vapor-phase crystallization and devitrification in the andesite lava dome of the Soufriere Hills volcano, Montserrat. The sub-10-micrometer fraction of ash generated by pyroclastic flows formed by lava dome collapse contains 10 to 24 weight percent crystalline silica, an enrichment of 2 to 5 relative to the magma caused by selective crushing of the groundmass. The sub-10-micrometer fraction of ash generated by explosive eruptions has much lower contents (3 to 6 percent) of crystalline silica. High levels of cristobalite in respirable ash raise concerns about adverse health effects of long-term human exposure to ash from lava dome eruptions.     

南海北部金线鱼延绳钓渔获分析

根据2007年8—9月的海上生产调查数据,对南海北部母子式金线鱼延绳钓渔获情况进行了初步分析。结果显示,金线鱼、深水金线鱼和长尾大眼鲷为渔获优势种,其相对重要性指标（IRI）分别为7518．10、3446．33和2052．65;渔获平均体长分别为203mm、129mm和264mm;平均体重分别为190g,57g和426g：渔获物的优势体长组分别为160～240mm、100～160mm和230～270mm;平均上钩率分别为0．96％、0．96％和0．19％;方差分析未显示此3种鱼在早晨、中午和傍晚不同时段的上钩率有显著差异。     

Early human cultural and skeletal remains from guitarrero cave, northern peru

An early man site in highland Peru yielded a rich cultural assemblage in stratigraphic association with faunal remains, botanical remains, and campfire remnants that furnished secure radiocarbon dates. A human mandible and teeth, showing interesting patterns of occlusal wear, were found in a stratum dated by a charcoal sample to 10,610 B.C., the oldest such date in South America.     

南海北部金线鱼延绳钓渔获分析

根据2007年8—9月的海上生产调查数据,对南海北部母子式金线鱼延绳钓渔获情况进行了初步分析。结果显示,金线鱼、深水金线鱼和长尾大眼鲷为渔获优势种,其相对重要性指标（IRI）分别为7518．10、3446．33和2052．65;渔获平均体长分别为203mm、129mm和264mm;平均体重分别为190g,57g和426g：渔获物的优势体长组分别为160～240mm、100～160mm和230～270mm;平均上钩率分别为0．96％、0．96％和0．19％;方差分析未显示此3种鱼在早晨、中午和傍晚不同时段的上钩率有显著差异。     

我国南方优势产区梨品种主要品质性状评价

对我国南方梨优势产区主栽33个品种88份样品进行了采样调查.结果显示:南方梨果集中成熟期为7月下旬,占45.57％;砧木选择以豆梨为主,占52.56％;果皮分为绿皮和褐皮两大类,早美酥、初夏绿、5-18等品种果锈极少、果点小;果形指数0.78 ～1.04,平均值0.90;平均单果重128.0～660.0 g,平均值264.5 g,湖北宣恩椒园镇黄坪村的秋黄单果重最大.果肉硬度1.72 ～ 5.09 kg/cm2,平均值2.80 kg/cm2;每百克果肉石细胞含量0.055～0.965 g,平均值0.259 g,湖北砂梨圃德胜香石细胞含量最低;可溶性固形物含量8.46％～13.61％,平均值11.54％,国家果树资源武昌砂梨圃丰水含量最高;可溶性糖含量变化范围为5.86％～10.06％,平均值7.6％,湖北宣恩县椒园黄坪村秋黄含量最高;可滴定酸含量变化范围为0.09％～0.27％,平均值0.14％,湖北应城市松林岗林果基地金水2号含量最高;糖酸比变化范围为26.7 ～100.6,平均值为58.14,湖北宣恩县椒园黄坪村的秋黄糖酸比最高,风味甜.     

南海北部陆架区海域科鱼类的分布

1997年12月至1999年6月对南海北部陆架区海域进行了底拖网渔业资源调查。调查分春(4-6月)、夏(7-9月)、秋(10-12月)、冬(12-2月)4个季节,每个季节都进行全海域的大面积定点调查,共采获科鱼类31种,分隶属于11属。通过对渔获种类组成和渔获率在不同区域、不同季节、不同水深以及昼夜变化等的分析,结果表明,北部湾海区的渔获率最高,粤东海区最低,并由西往东呈逐渐递减的趋势;夏、冬季科鱼类的渔获率较高,而春、秋季较低;渔获率沿水深梯度的变化为≤100m水深海域沿水深的增加而增加,>100m水深海域随水深的增加而下降,以80～100m海域的渔获率相对较高;午夜的渔获率最低,14时最高。     

南海北部陆架区海域鯵科鱼类的分布

1997年12月至1999年6月对南海北部陆架区海域进行了底拖网渔业资源调查。调查分春(4-6月)、夏(7-9月)、秋(10-12月)、冬(12-2月)4个季节,每个季节都进行全海域的大面积定点调查,共采获科鱼类31种,分隶属于11属。通过对渔获种类组成和渔获率在不同区域、不同季节、不同水深以及昼夜变化等的分析,结果表明,北部湾海区的渔获率最高,粤东海区最低,并由西往东呈逐渐递减的趋势;夏、冬季科鱼类的渔获率较高,而春、秋季较低;渔获率沿水深梯度的变化为≤100m水深海域沿水深的增加而增加,>100m水深海域随水深的增加而下降,以80～100m海域的渔获率相对较高;午夜的渔获率最低,14时最高。     

南海北部陆坡水域尾明角灯鱼生物学特征的初步研究

尾明角灯鱼Ceratoscopelus warmingii是南海北部陆坡水域中层鱼类的重要种类之一,本试验中根据2015年6月南海北部陆坡水域综合调查中的中层拖网数据,对尾明角灯鱼生物学特征及分布进行了初步研究。结果表明:夏季南海北部陆坡水域尾明角灯鱼的体长范围为30~64 mm,体长由3个股群组成,其体长平均值分别为(37.52±2.39)、(44.62±2.84)、(49.80±3.17)mm,其体长与体质量关系式为W=8.418×10~(-6)L~(3.0985);性腺成熟度以Ⅱ期、Ⅲ期居多,50%性腺发育为Ⅱ期及以上的尾明角灯鱼体长为42.54mm,雌、雄比为1∶0.7,较大个体中雌性居多;夜间其平均摄食等级随时间的延长逐渐增加,20:00、22:00、4:00时尾明角灯鱼的平均摄食等级分别为0.82、1.58、2.53;本次调查白天在600 m以浅水层多未捕获尾明角灯鱼,傍晚开始捕获少量样品,夜间在上层捕获的量较大,该现象反映了南海北部陆坡水域尾明角灯鱼昼夜垂直移动的习性,同时佐证了该鱼白天多分布于700 m以深水域的相关研究结果。本研究结果可为南海北部陆坡水域尾明角灯鱼的进一步研究提供基础参数及资料。     

南海北部陆坡水域尾明角灯鱼生物学特征的初步研究

尾明角灯鱼Ceratoscopelus warmingii是南海北部陆坡水域中层鱼类的重要种类之一,本试验中根据2015年6月南海北部陆坡水域综合调查中的中层拖网数据,对尾明角灯鱼生物学特征及分布进行了初步研究。结果表明:夏季南海北部陆坡水域尾明角灯鱼的体长范围为30⁶4 mm,体长由3个股群组成,其体长平均值分别为(37.52±2.39)、(44.62±2.84)、(49.80±3.17)mm,其体长与体质量关系式为W=8.418×1064 mm,体长由3个股群组成,其体长平均值分别为(37.52±2.39)、(44.62±2.84)、(49.80±3.17)mm,其体长与体质量关系式为W=8.418×10^(-6)L(-6)L^(3.0985);性腺成熟度以Ⅱ期、Ⅲ期居多,50%性腺发育为Ⅱ期及以上的尾明角灯鱼体长为42.54mm,雌、雄比为1∶0.7,较大个体中雌性居多;夜间其平均摄食等级随时间的延长逐渐增加,20:00、22:00、4:00时尾明角灯鱼的平均摄食等级分别为0.82、1.58、2.53;本次调查白天在600 m以浅水层多未捕获尾明角灯鱼,傍晚开始捕获少量样品,夜间在上层捕获的量较大,该现象反映了南海北部陆坡水域尾明角灯鱼昼夜垂直移动的习性,同时佐证了该鱼白天多分布于700 m以深水域的相关研究结果。本研究结果可为南海北部陆坡水域尾明角灯鱼的进一步研究提供基础参数及资料。