东秦岭丹凤地区黄龙庙二长花岗岩LA-ICP-MS锆石 U-Pb年龄、岩石地球化学特征及其地质意义

东秦岭丹凤地区黄龙庙含榴二长花岗岩是典型的浅色含铀花岗岩体之一。它具有高硅(73.65%~76.60%)、过铝(13.01%~13.80%,A/CNK1.0)、富钾(4.89%~6.14%)的特点,其轻重稀土元素强烈分馏,铕负异常十分发育,微量元素具有典型上地壳的含量特征。所获得LA-ICP-MS锆石U-Pb年龄为415.2±2.0Ma,是志留纪末期花岗岩。该花岗岩是在后碰撞环境下,由秦岭岩群郭庄岩组的含榴黑云斜长片麻岩部分熔融所形成的钙碱性S型花岗岩。与巴罗型区域变质作用的年龄(426Ma)一起,限定了东秦岭早古生代碰撞作用415~426Ma之间进入后碰撞构造环境,也表明早泥盆世以后的东秦岭地区并未经历大规模区域性变质变形,进入了相对稳定的地质演化阶段。     

基于高分辨率DEM的裂点序列提取和古地震序列的识别——以霍山山前断裂为实验区

以霍山山前断裂为实验区,基于高分辨率IRS-P5 DEM数据提取了横穿断裂的冲沟,在23条冲沟纵剖面上识别出断裂活动诱发裂点.在其中5条冲沟上识别出1级裂点,裂点几乎位于断裂上;在2条冲沟上识别出2级裂点,最新裂点也位于断裂上.这些位于断裂上的裂点,高度达4～9m,推测它们形成之后并未向上游明显迁移,并可能接受了多次事...     

金雕巢期行为谱及时间分配

2010年7～9月、2011年4～9月、2012年7月,采用焦点动物取样法,累计对新疆西北部别珍套山和阿拉套山巢期的5对金雕（Aquila chrysaetos）及其雏鸟观测89 d,行为记录911 h。制成金雕的行为谱,将各行为分为12类46种,并进行了相关描述。依据巢期的不同阶段（孵化期和育雏期）统计出各行为的时间分配：孵化期,亲鸟行为以孵卵为主（95.28%）;育雏期,亲鸟的各行为时间分配依次为,离巢（77.81%）、护幼（18.5%）、喂食（2.64%）、警戒（1.05%）,在育雏期的前（0～3周）、中（3～6周）、后（6-雏鸟离巢）阶段,护幼、喂食、离巢的时间分配差异极其显著（p<0.01）。雏鸟各行为时间分配依次为,休息（68.73%）、警戒（21.41%）、取食（5.56%）、运动（4.28%）、保养（1.02%）。育雏期的前、中、后阶段,雏鸟的休息、警戒和运动行为的时间分配差异极其显著（p<0.01）。行为时间分配的差异,主要受不同阶段金雕能量需求、身体发育状况的影响。     

Chemical and isotopic variations in the Wiśniówka Mała mine pit water,Holy Cross Mountains (south-central Poland)

In 2005 and 2006, hydrogeochemical study was carried out in the bipartite Wiśniówka Mała pit lake of the Holy Cross Mountains (south-central Poland). This is the largest acidic water body in Poland. This report presents the element concentrations in the water and sediment, stable sulfur and oxygen isotope ratios in the soluble sulfates, and stable oxygen isotope ratio in the water. The scope of the investigation also encompassed mineralogical examinations (scanning electron microscope, X-ray diffraction) of the sediment. The results of this study show that there is a spatial and temporal variability in concentrations of most elements and sulfur isotope ratios in the examined pit lake. The water of the western pond displayed a lower pH with a mean of 3.73 and higher conductivity (390 μS cm⁻¹) as well as higher concentrations of sulfates (156 mg L⁻¹) and most of the cations and anions. The concentrations of Fe²⁺ and Fe³⁺ averaged 0.8 and 0.4 mg·L⁻¹. In contrast, the eastern pond water revealed a higher pH (mean of 4.36), lower conductivity (293 μS cm⁻¹) and lower sulfate (90 mg L⁻¹) and trace metal levels. Similar variations were recorded in the stable sulfur isotope ratios. The δ³⁴S_V-CDT(SO₄ ²⁻) values in the water of the western pit pond were in the range of −6.7 to −4.6‰ (mean of −5.6‰), whereas that in the eastern pit pond ranged from −2.2 to −0.9‰ (−1.6‰). The alkalinity of the entire lake water was below 0.1 mg·L⁻¹ CaCO₃. No distinct difference in the δ¹⁸O_V-SMOW(SO₄ ²⁻) was noted between the western and eastern pit ponds. Compared to the Purple Pond in the Sudetes (Poland) and similar sites throughout the world, the examined pit lake is highlighted by distinctly low concentrations of sulfates, iron and other trace metals. Based on this and other studies performed in the Holy Cross Mountains, a conclusion can be drawn that the SO₄ ²⁻ in the Wiśniówka Mała pit lake water is a mixture of SO₄ ²⁻ derived from the following sources: (1) pyrite oxidation (especially in the western pond water), (2) leaching of soluble sulfates from soils and waste material, as well as (3) subordinate deposition of airborne sulfate precipitation.     

天沃煤矿聚煤特征及对恢复横断山古环境意义

从聚煤沉积环境与聚煤规律判断,矿床形成于古特提斯海消亡、金沙江板块碰撞结合带西侧的晚三叠世（T3）,古地理环境应为滨海海陆交互相。     

秦岭东部李官桥盆地玉皇顶组生物地层划分

长期以来,李官桥盆地始新统玉皇顶组的时代一直被认为是属早始新世。笔者通过野外追索,使盆地中原来分散的化石地点有了层位归属,并于玉皇顶组上部发现了新的哺乳动物化石群。本文将玉皇顶组分为上、中、下三段,并根据各层位哺乳动物化石性质,提出玉皇顶组的时代范围应为早始新世至中始新世早期。     

西天目山南坡垂直自然带分异规律

西天目山为国家自然保护区,生物物种丰富,其南坡垂直自然带谱明显,本文论述西天目山南坡垂直自然带分异规律。     

长白山雪蚀地貌发育特征

在中国东北长白山广泛发育着雪蚀地貌，尤其以雪蚀洼和高夷高阶地最为多见。与世界其它地区相比，长白山发育的雪蚀地貌具有规模小，形成年代久，成因复杂等特点，此外，通过野外半定位观测发现，雪蚀洼地年下蚀作用存在着不均一性，本着重对上述方面进行论述。     

天山北麓工业带城市工业经济结构分析

本文选择新疆区域工业发展为参照系，用Ｓｈｉｆｔ－ｓｈａｒｅ方法对天山北麓工业带６城市工业增长与工业经济结构进行分析，从动态角度判别各城市工业结构的优劣及存在问题并揭示其原因，提出发展方向。     

阴山东段先寒武变质岩的Rb-Sr年代

采自阴山东段先寒武变质岩的全岩样品给出四个等时线年龄。下部集宁群为2497±124Ma;上部乌拉山群为2367±127Ma;上部二道洼群给出两个年龄:2067±39Ma和325±16Ma。据此认为,2.5Ga前发生了麻粒岩化;2.35Ga前发生混合岩化;2.0Ga和0.33Ga前有变质事件叠加。