Age and origin of carlsbad cavern and related caves from 40Ar/39Ar of alunite

40Ar/39Ar dating of fine-grained alunite that formed during cave genesis provides ages of formation for the Big Room level of Carlsbad Cavern [4.0 to 3.9 million years ago (Ma)], the upper level of Lechuguilla Cave (6.0 to 5.7 Ma), and three other hypogene caves (11.3 to 6.0 Ma) in the Guadalupe Mountains of New Mexico. Alunite ages increase and are strongly correlative with cave elevations, which indicates an 1100-meter decline in the water table, apparently related to tectonic uplift and tilting, from 11.3 Ma to the present. 40Ar/39Ar dating studies of the hypogene caves have the potential to help resolve late Cenozoic climatic, speleologic, and tectonic questions.     

Ages of prehistoric earthquakes revealed by cosmogenic chlorine-36 in a bedrock fault scarp at hebgen lake

Cosmogenic chlorine-36 reveals dates of the multiple prehistoric earthquakes that have produced a scarp on the Hebgen Lake fault. Apparent chlorine-36 ages are stratigraphically correct, follow a predicted theoretical pattern, and produce geologically reasonable model ages of 24, 20, 7.0, 2.6, 1.7, and 0.4 thousand years ago. This result demonstrates the feasibility of using cosmogenic chlorine-36 to extract paleoearthquake records from bedrock fault scarps.     

Prehistoric rock avalanches in the olympic mountains, washington

Rock avalanches blocked streams in the Olympic Mountains southwest of Puget Sound during the past few thousand years. Limiting radiocarbon ages indicated that three or four of six avalanches occurred from 1000 to 1300 years ago or shortly thereafter. Most of the dates were from the outer preserved rings of trees drowned behind avalanche dams. These three or four avalanches may be coeval not only with one another but also with abrupt tectonic deformation in western Washington. No rock avalanches in the Olympic Mountains are known to have resulted from storms or earthquakes during the past century. The avalanches strengthen the case that a large prehistoric earthquake occurred in the Puget Sound region.     

贵州冷热洞、白龙洞和龙井洞环境质量及生态风险初步评价

为了解贵州喀斯特洞穴环境的污染状况,对贵州省3个洞穴冷热洞、白龙洞和龙井洞部分环境因子——土壤和水中重金属(Cu、Cr、Ni、Zn、Hg和As)含量进行测定,并对3洞穴土壤中重金属的污染指数及生态风险进行评价。结果表明:Zn在土样和水样中含量均最高,最低的是Hg;冷热洞土样的重金属含量均超过中国土壤背景值,白龙洞和龙井洞土样中的重金属含量除Cr外,均超过中国土壤背景值。洞穴土壤重金属综合潜在危害程度,龙井洞处于较高生态危害水平,冷热洞处于中等生态危害水平,白龙洞处于高生态危害水平;Hg是3洞穴最主要的生态风险因子。     

岩溶洞穴旅游开发影响因素综合分析

我国岩溶洞穴众多,每个岩溶洞穴都是自然景观资源中独特的一部分,如何开发岩溶洞穴资源来发展旅游活动,这关系到岩溶洞穴资源的有效开发利用问题。笔者就影响岩溶洞穴旅游开发的主要因素进行了系统分析,得出影响旅游开发的因素是岩溶洞穴资源特色、交通条件、建设施工条件、区域经济发展水平、客源市场、风景区（点）的地域组合、空间竞争、投资者决策行为、政府决策行为、当地居民态度等,其通过综合作用共同决定岩溶洞穴旅游开发的成功与否,只有充分认识岩溶洞穴旅游开发中各影响因素的地位和作用,才能扬长避短,合理的进行岩溶洞穴旅游开发。     

海拉尔东山达乌尔黄鼠洞穴结构与利用

2011 年5耀10 月在内蒙古呼伦贝尔市海拉尔东山,对达乌尔黄鼠的12 个未哺乳达乌尔黄鼠洞穴进行挖 掘和测量结果显示,达乌尔黄鼠洞穴有临时洞夏季洞”和居住洞冬眠洞两种洞穴的洞口朝向一般为西北或东 北方向临时洞的结构较简单多数只有一个洞口曰冬眠洞的结构较复杂冬眠洞的洞口光滑洞口宽度一般为6,9 cm洞口近处的洞道斜向下方,然后急转向下近乎垂直接着斜行一段入巢洞穴深度多为90,100 cm洞穴总长为 110,126 cm分叉较少洞道中部的巢穴形状扁平。巢穴中絮有碎草,塑料,泡沫等。巢穴附近有厕所,大多数达乌尔 黄鼠洞穴有盲洞,盲洞位于离洞口30,60 cm 处     

Deep-Sea coral evidence for rapid change in ventilation of the deep north atlantic 15,400 years Ago

Coupled radiocarbon and thorium-230 dates from benthic coral species reveal that the ventilation rate of the North Atlantic upper deep water varied greatly during the last deglaciation. Radiocarbon ages in several corals of the same age, 15.41 +/- 0.17 thousand years, and nearly the same depth, 1800 meters, in the western North Atlantic Ocean increased by as much as 670 years during the 30- to 160-year life spans of the samples. Cadmium/calcium ratios in one coral imply that the nutrient content of these deep waters also increased. Our data show that the deep ocean changed on decadal-centennial time scales during rapid changes in the surface ocean and the atmosphere.     

洞穴的农业综合利用研究进展

洞穴是非常珍贵的地下空间资源,合理利用洞穴资源对于提高资源利用率和增加经济收入非常重要.从洞穴的概况出发,重点综述洞穴在农业上的综合利用研究现状,分析当前洞穴作为农业利用存在的问题,为更好开展洞穴的综合利用和提高农民的收入奠定基础.     

贵州荔波干细洞和拉梭洞陆生动物群落结构与环境因子的关系

贵州省荔波县岩溶洞穴多,洞穴动物丰富,具有重要的科研价值。在洞穴生态系统中,洞穴动物是重要的生物类群,为探讨洞穴动物群落结构及其与环境的关系。本研究对荔波的干细洞（未受人类干扰）和拉梭洞（已受人类干扰）的洞穴动物进行了调查,并比较了两个洞穴的动物群落结构特征,应用主成分（PCA）法分析了动物群落结构与环境因子的关系。结果表明：干细洞共获动物536号,计56种,拉梭洞共获动物363号,计23种。多样性指数、丰富度指数、均匀度指数、优势度指数最高的分别是干细洞有光带群落（2.748 6）、干细洞有光带群落（6.733 8）、干细洞黑暗带群落（0.841 9）、拉梭洞黑暗带群落（0.395 5）;群落多样性指数和丰富度指数均沿有光带、弱光带、黑暗带呈递减趋势。群落间相似性指数偏低,除了群落E-F（0.428 5）、群落C-F（0.272 7）处于中等不相似水平,其余群落之间均处于极不相似水平。PCA分析表明,影响干细洞动物群落结构的主导因子为土壤营养元素（Na、K）、土壤有机质、气温、空气湿度和土壤湿度,影响拉梭洞动物群落结构的主导因子为土壤营养元素（Na、K）、土壤有机质、空气湿度、CO₂含量和滴水pH。研究可为洞穴动物的保护、生态资源可持续发展提供科学依据。     

“人防”山洞栽培蘑菇试验

[目的]为了研究"人防"山洞蘑菇栽培技术。[方法]采用荷兰技术,利用"人防"山洞种植双孢蘑菇,对六化建前洞菇房、后洞菇房的生产过程进行总结和分析。[结果]在5 417.6 m2菇床上,采收蘑菇131 105.9 kg,单位面积产量24.2 kg/m2。后洞采菇期自3月11日至5月3日,共54 d,全生产周期123 d,采收鲜菇59 567.0 kg,单位面积产量为23.5 kg/m2。前洞采菇期3月21日至5月4日,共45 d,采收鲜菇71 538.9 kg,单位面积产量24.8 kg/m2。两洞平均采菇期达47.5 d,前洞产量比后洞高出约44%。[结论]利用"人防"山洞种植双孢蘑菇是可行的。     

Radiocarbon Dating: Fictitious Results with Mollusk Shells

Evidence is presented to show that modern mollusk shells from rivers can have anomalous radiocarbon ages, owing mainly to incorporation of inactive (carbon-14-deficient) carbon from humus, probably through the food web, as well as by the pathway of carbon dioxide from humus decay. The resultant effect, in addition to the variable contributions of atmospheric carbon dioxide, fermentative carbon dioxide from bottom muds, and, locally, of carbonate carbon from dissolving limestones, makes the initial carbon-14-activity of ancient fresh-water shell indeterminate, but within limits. Consequent errors of shell radiocarbon dates may be as large as several thousand years for river shells.     

黄土高原地下窑洞开发思路探究

通过实地考察和应用统计分析等方法,对陕北地区具有代表性的窑洞进行探讨分析,结合地下窑洞的发展实际,系统分析地下窑洞的历史渊源、优缺点、现状成因和发展方式,论证了保留地下窑洞的必要性,并将其与第三产业捆绑,创新性地提出地下窑洞未来发展的新方案。     

Midwestern holocene paleoenvironments revealed by floodplain deposits in northeastern iowa

Pollen analysis of pond deposits in the upper reaches of a stream from northeastern Iowa, an area beyond the last glacial margin, provides a nearly complete record of vegetational changes during the last 12.5 thousand years. Sixty-one radiocarbon dates provide good chronological control. Spruce forest was replaced by deciduous forest before 9.1 thousand years ago, followed by prairie from 5.4 to 3.5 thousand years ago, and oak savanna from 3.5 thousand years ago until presettlement times. The prairie invasion was nearly 3 thousand years later here than at other sites in Iowa and Minnesota, documenting a late Holocene, rather than an early-middle Holocene, period of maximum warmth and dryness for the southern part of the upper Midwest.     

Lower Pliocene hominid remains from Sterkfontein

Cosmogenic aluminum-26 and beryllium-10 burial dates of low-lying fossiliferous breccia in the caves at Sterkfontein, South Africa, show that associated hominid fossils accumulated in the Lower Pliocene. These dates indicate that the skeleton StW 573 and newly discovered specimens from Jacovec Cavern have much the same age: approximately 4 million years. These specimens are thus of an age similar to Australopithecus anamensis from East Africa.     

浅谈灯光植物对旅游洞穴的影响及其防治措施——以湖南梅山龙宫为力

洞穴次生碳酸钙（CUCO3）沉积物是旅游洞穴最主要的观赏景观，由于洞们的不合理开发和缺乏必要的保护措施，导致许多旅游洞穴环境发生了变异如系列出大量灯光植物，景观风化剥蚀，景观褪色等，直接影响了该洞穴旅游的可持续性发展。以湖南省新化县梅山龙宫旅游洞穴系统为例，从温度变化，灯光系统和人类活动方面对龙宫洞穴发生碳酸钙（CaCO3）沉积物滋生灯光植物的原因和机理进行阐述，并对防治灯光植物提出了一些措施和建议。     

Flood basalt volcanism during the past 250 million years

A chronology of the initiation dates of major continental flood basalt volcanism is established from published potassium-argon (K-Ar) and argon-argon (Ar-Ar) ages of basaltic rocks and related basic intrusions. The dating is therefore independent of the biostratigraphic and paleomagnetic time scales. Estimated errors of the initation dates of the volcanic episodes determined from the distributions of the radiometric ages are, approximately, plus or minus 4 percent. There were 11 distinct episodes during the past 250 million years. Sometimes appearing in pairs, the episodes have occurred quasi-periodically with a mean cycle time of 32 +/- 1 (estimated, error of the mean) million years. The initiation dates of the episodes are close to the estimated dates of mass extinctions of marine organisms. Showers of impacting comets may be the cause.     

穴居狼蛛生活习性之初步观察

穴居狼蛛(Lycosa singoriensis)雌蛛平均体长31.9 mm,头胸长15.1 mm,腹长17.2 mm,体重4.2 g.头胸部梨形,前部隆起,中间有黑、褐、白相间的辐射状斑,两侧被灰黄色毛,腹部椭圆形,背面密布黑色小斑点,中间有黑褐色心斑,并有6对黄白色肌斑,胸板和腹部腹面密生黑色毛.雄蛛平均体长26.8 mm,头胸长14.6 mm,腹长12.9 mm,体重2.6 g,形状与雌蛛相似,但体色较浅,腹部明显较小.新疆已知分布于32个县市.生活在草原、森林、荒漠、农田、果园、山坡等地,筑穴而居,洞口圆形或椭圆形,平均直径2.65 cm,洞深31.6 cm.白天多在洞中隐伏,傍晚或夜间在洞口附近猎食,用直接袭击法捕食各类昆虫.雄成蛛一般不筑洞穴,游猎生活,主动寻找洞穴中雌蛛在洞内或将其引出洞外交配.交配可分3个阶段,即:雄蛛求婚、雌雄交配、雄蛛离开,历时1～1.5 h,但实际交配时间仅10～30 min.未发现雌蛛在交配后残杀雄蛛的事例.雌蛛于4～7月织卵袋产卵,卵袋椭圆形,灰白色,由两片组成,平均体积20.0×16.8×14.3(mm)3,每袋平均含卵466.3粒.卵自产出之日起至发育成若蛛并走出卵袋,平均需21 d.若蛛出袋后,先群聚于雌蛛腹背上,随雌蛛出外活动,有时下到地面吸水或采食雌蛛食剩的虫体或残屑,平均经11.8 d离开母体独立生活.雌若蛛经6～7次蜕皮成熟,10月下旬至次年3月上旬为越冬期,若蛛或成蛛将洞口用丝网封闭蛰伏在洞内越冬.雌蛛平均寿命2年,雄蛛1年左右.     

Thirty thousand years of human colonization in tasmania: new pleistocene dates

Basal dates of 30,420 years before present (BP) from a limestone cave in the Florentine River valley and 30,840 BP from a sandstone rockshelter in the Shannon River valley on the edge of the central Tasmanian highlands indicate colonization of Tasmania 8,000 years earlier than previously thought. These data indicate that people arrived before the Bassian Bridge was exposed about 23,000 years ago and support evidence that Tasmania and Australia may have been connected intermittently during the past 50,000 years. The dates support earlier suggestions that the Tasmanian inland was an important focus for systematic occupation and exploitation by human groups and dispel a belief that the Aboriginal economy 30,000 years ago was based on littoral, lacustral, and riverine resources. The absence of megafauna at both sites points to their extinction by 30,000 years ago in Tasmania. The people inhabiting Tasmania at this time, together with those at Monte Verde in Chile, were the most southerly humans on Earth.     

窑洞破坏的原因及其防治措施

详细划分了窑洞的类型,分析了窑洞常见的破坏形式和最常见的用土坯砌筑的半明半暗式窑洞的 受力情况,并根据窑洞的破坏原因,提出了比较可靠而且简单易行的防治措施。     

The Buttermilk Creek complex and the origins of Clovis at the Debra L. Friedkin site, Texas

Compelling archaeological evidence of an occupation older than Clovis (~12.8 to 13.1 thousand years ago) in North America is present at only a few sites, and the stone tool assemblages from these sites are small and varied. The Debra L. Friedkin site, Texas, contains an assemblage of 15,528 artifacts that define the Buttermilk Creek Complex, which stratigraphically underlies a Clovis assemblage and dates between ~13.2 and 15.5 thousand years ago. The Buttermilk Creek Complex confirms the emerging view that people occupied the Americas before Clovis and provides a large artifact assemblage to explore Clovis origins.