淮南煤田地下水类型及其特征

淮南煤田为全隐蔽煤田,松散层厚度大,主要含煤地层为二叠系。通过大量的勘探资料及生产矿井的开采成果,对影响煤层开采的地下水进行了分类,并对其水文地质特征进行了阐述,为新区的建井与开采提供了参考资料和决策依据。     

冲击地压煤层大直径卸压孔快速成孔关键技术

为了提高冲击地压矿井大直径卸压钻孔的成孔率和施工效率,通过对冲击地压矿井煤岩体应力特征、卸压孔孔壁扰动动力失稳特性及施工特点的分析,探讨了大直径卸压孔快速施工的关键点在于高效排渣、快速成孔提钻。采用具有1.25 m行程轨道、大通孔动力头的ZDY4000LR型钻机,优化了大直径卸压钻孔施工操作流程,形成了水介质螺旋宽翼片双动力排渣高效成孔工艺方法,并在河南义马矿区和陕西彬长矿区进行了现场试验。结果表明：该工艺技术能够安全、高效地施工大直径卸压钻孔,施工效率较大螺旋钻进技术提高了48.9%,成孔率可达到100%。研究成果对类似冲击地压矿区施工煤层卸压孔提供借鉴。     

四川九寨沟地貌与第四纪地质

九寨沟地处青藏高原向四川盆地陡跌的两在地貌单元的过渡地带,经笔者等调查可划分出高山地地貌、高山坡地地貌和高山河谷地貌等三种地貌类型及十种成因类型的第四纪堆积物,并对其分布规律、特征者描述。首次划分了区内第四纪地层,探讨其演化过程。为研究九寨沟自然资源的演化发展以及合理利用和保护提供了基础资料。     

汶川县南沟滑坡与防治

滑坡位于汶川县城关镇南沟,属深层牵引式土质滑坡。该滑坡正处于活动期,一旦大规模活动,将危及县政府等几十个机关、学校和居民的安全,给数千人的生命、财产带来极大的损失。本文提出了筑坝、排水、封山育林等具体防治方案和措施。     

40Ar-39Ar age of carbonatite-alkaline magmatism in Sung valley, Meghalaya, India

⁴⁰Ar-³⁹Ar analyses of one alkali pyroxenite whole rock and two phlogopite separates of calcite carbonatites from the Sung Valley carbonatite-alkaline complex, which is believed to be a part of the Rajmahal-Bengal-Sylhet (RBS) flood basalt province, yielded indistinguishable plateau ages of 108.8 ± 2.0Ma, 106.4 ± 1.3Ma and 107.5 ± 1.4Ma, respectively. The weighted mean of these ages, 107.2 ± 0.8 Ma, is the time of emplacement of this complex. This implies that Sung Valley complex and probably other such complexes in the Assam-Meghalaya Plateau postdate the main flood basalt event (i.e., the eruption of tholeiites) in the RBS province by ∼10Ma.     

Electrical Resistivity Imaging technique to delineate coal seam barrier thickness and demarcate water filled voids

Exploration and exploitation of coal seams is one of the major resources for the energy sector in any country but at the same time water filled voids/water logged areas in the old workings of these seams are very critical problems for the coal mining industry. In such situations, disasters like inundation, landslides, collapsing of the old seams may occur. In this regard, it is necessary to find out the water saturated/water filled voids and zones in the mining areas. Since no established technique is available to find such zones, an experimental study using Electrical Resistivity Imaging (ERI) has been carried out in one of the coal mining areas near Dhanbad, to find out the feasibility of finding the barrier thickness and the water logged area in underground coal mines. The area under study forms part of Jharia coalfield in Dhanbad district, Jharkhand state. The coal bearing rocks of Barakar Formation of Lower Permian age (Gondwana period) occur in the area under a thin cover (10 m to15 m) of soil and or alluvium. Coal bearing Barakar Formations consist mainly of sandstone of varying grain size, intercalation of shale and sandstone, grey and carbonaceous-shale and coal seams. Since the water saturation reduces the resistivity of a formation to a large extent, water filled voids and old coal workings are expected to have significant resistivity contrast with the surrounding host rock. Hence, ERI technique was applied in such an environment as this technique uses high-density data acquisition both laterally and vertically by using multiple number of electrodes. Along with ERI, mise-à-la-masse (also called charged body) technique was also employed at one of the promising sites to find out the connectivity of water logged areas and also detection of these old workings from the surface measurements was analyzed. The interpreted 2D resistivity sections have clearly indicated the water bearing zone(s) along the profile which was well confirmed with the existing water level in the nearby borewells. On the other hand, this technique did not identify the size of the coal pillar and gallery (air filled voids), which might be due to the small size of the voids (i.e. about 2 m × 2 m) below a depth of 15m and more but have indicated altogether as a high resistive zone ranging from 600–1000 Ohm-m.     

Sedimentary and drainage evolution of the Condamine Valley Transition Zone (eastern Australia)

The basal succession of the Condamine Valley, which overlays the boundary between the Surat and Clarence-Moreton basins (eastern Australia), contains a clay-rich horizon ‘the Transition Zone’ that marks a pronounced unconformity between the Jurassic Walloon Coal Measures and the Quaternary Condamine Alluvium. This paper provides insights into the tectonic and drainage evolution of the Condamine Valley through integrated analysis of U–Pb ages of detrital zircon from three samples (494 concordant analyses), stable oxygen isotope analysis on eight authigenic clay samples, X-ray fluorescence of primary and trace elements, and hyperspectral mineral analysis from two drill cores (Lone Pine 17 and Daandine 164). The Transition Zone is interpreted to consist of both weathered Jurassic sediments and Cenozoic clay deposits. Two sequential cycles of erosion, deposition and pedogenesis, related to geomorphological and climatic conditions are recognised. Distinctive oxygen isotope signatures of the two weathering fronts demonstrated an initial Early Cretaceous phase (δ¹⁸O?=?11.9–15.7‰ VSMOW) associated with laterisation and possible uplift, followed by Paleogene (δ¹⁸O?=?16.4–17.3‰ VSMOW) silcretisation of reworked Jurassic sediments. Detrital zircon geochronology yielded Jurassic maximum constraints for the age of deposition of three samples that are indistinguishable within error, the oldest of which (163?±?8?Ma from the lateritic profile) corresponds to the age of the underlying Walloon Coal Measures. The two overlaying samples from a silcrete profile and granular alluvium yielded overlapping yet younger ages of 150?±?6?Ma and 156?±?9?Ma, respectively. Vitrinite reflectance used as a proxy for the thermal condition of the coal strata enabled an estimated 2–3?km of burial and subsequent (likely Early Cretaceous) uplift. Geochemical insights from the Condamine Valley correspond to broad-scale climatic and tectonic conditions, suggesting that ‘transition zone equivalents’ and corresponding groundwater dynamics may occur in similar sedimentary settings throughout eastern Australia.     

煤田火区碳排放量计算模型和关键参数研究

完善碳排放清单,是进行减排工作的基础,为了查明煤田火区对大气碳排放的贡献量,以煤氧复合作用学说为理论基础,从不同的研究思路出发,提出了烧失煤量法和排放通量法两种火区碳排放量计算模型。在明确模型中关键参数“释放因子”“排放系数α”“排放通量”“排放系数β”的具体含义的基础上,重点对各参数所对应的获取途径进行了研究论述：(1)释放因子通过在室内进行煤自燃模拟实验得出;(2)排放系数α通过煤岩吸附实验结合火区实地勘测得出;(3)排放通量通过对火区现场煤自燃气体排放及环境因素的实时监测得出;(4)排放系数β通过对遥感图像裂隙信息的提取得到。上述两种计算模型在我国乌达实验区进行了实际应用,并对其可实现性进行了检验。     

福建煤田深孔钻探施工技术探讨

福建煤田地质构造复杂,断层发育,岩层极其破碎且较松软,泥岩受挤压破碎为薄片状或烂泥状,给钻探施工造成许多困难,比如泥页岩水化膨胀,孔壁失稳导致孔内坍塌严重等。采用绳索取心技术,优选金刚石钻头,科学确定泥浆配比和钻进参数,成功解决了这些孔内技术难题,提高了钻探效率,降低了生产成本,取得的施工经验可供该矿区或该类地层的钻探施工借鉴。     

The Valley and Ridge Province of eastern Pennsylvania—stratigraphic and sedimentologic contributions and problems

Many contributions that have led to a better understanding of Appalachian geology have resulted directly from work in the folded Appalachian Mountain and Great Valley sections of the Valley and Ridge physiographic province of eastern Pennsylvania. Disagreements have been common since H.D. Rogers first described the geology of the area in 1858. Many differing opinions still exist regarding the stratigraphy, structural geology, geomorphology, and glacial geology. The rocks in the area, which range from Middle Ordovician to Late Devonian in age, are more than 25000 feet (7620 m) thick. This diversified group of sedimentary rocks was deposited in many different environments, ranging from deep sea, through neritic and tidal, to alluvial. In general, the Middle Ordovician through Lower Devonian strata are a sedimentary cycle related to the waxing and waning of Taconic tectonism. The sequence began with a greywacke-argillite suite (Martinsburg Formation) representing synorogenic basin deepening. This was followed by basin filling and pro-gradation of a sandstone-shale clastic wedge (Shawangunk Formation and Bloomsburg Red Beds) derived from the erosion of the mountains that were uplifted during the Taconic orogeny. The sequence ended with deposition of many thin units of carbonate, sandstone, and shale on a shelf marginal to a land area of low relief. Another tectonic-sedimentary cycle, related to the Acadian orogeny, began with deposition of Middle Devonian rocks. Deep-water shales (Marcellus Shale) preceded shoaling (Mahantango Formation) and turbidite sedimentation (Trimmers Rock Formation) followed by another molasse (Catskill Formation).