MEXICAN URBAN COLONIAS IN THE SALT RIVER VALLEY OF ARIZONA

The history of the Salt River Valley is often characterized as a boomtown narrative that highlights the exploding Anglo population and rapid suburban sprawl that followed World War II. Frequently overlooked is the fundamental role that Mexicans played in the early suburbanization process through the formation of urban colonias, or suburban Mexican settlements. Early Mexican suburbs, despite their rural atmosphere, were connected to the pre–World War II urbanization process in the Salt River Valley. Our research seeks to amend and clarify the urban historical record by documenting the diverse and dispersed array of Mexican suburban settlements, a process generated by industrial agriculture, decentralization, and residential segregation.     

河北蔚县煤田构造沉降与构造演化分析

利用综合柱状图提取属性数据,弥补了煤田勘探资料的不足。通过尝试将盆地沉降史模拟技术应用于含煤盆地分析之中,反演了河北蔚县含煤盆地演化历程。根据沉降史、埋藏史、沉降量和沉降速率分析,将该盆地构造演化划分为三个阶段：早中生代（J）为盆地形成期,以快速沉降为特征;晚中生代（K）为稳定发展期,以抬升剥蚀为主;新生代（E—Q）为盆地反转期,蔚县煤田伸展断块格局定型。     

大渡河中游泸定-石棉段阶地特征及河谷发育史探讨

基于大渡河中游泸定一石棉河段野外观察和阶地沉积物研究,分析河流的发育特征,影响及其发育演化史。研究表明,该区存在多级构造裂点或岩性裂点,发育有三级夷平面和4～6级阶地,并对阶地沉积物的ESR年代测定,结合前人的阶地测年的数据,阐述了大渡河河谷第四纪的形成过程和青藏高原形成的响应。     

海拉尔盆地乌尔逊凹陷北部构造层及演化史研究

以地震剖面解释为基础,认识纵向上不同时期发育的断裂体系组合规律和构造特征;在分析构造特征的基础上,将乌尔逊凹陷北部划分为上部、中部和下部构造层,并阐述各构造层的构造特征。通过制作乌尔逊凹陷北部构造演化史剖面,认为盆地的演化分为三个构造旋回、五个演化阶段,并认为乌尔逊凹陷是由三期盆地叠合而成,即早期裂陷盆地、中期断陷盆地、晚期凹陷盆地。     

Thermal history, geodynamics, and current thermal activity of lithosphere in China

The tectonic framework of China includes major and smaller-scale units that differ in age and in style of tectonomagmatic activity, the latter being related to the thermal history of the lithosphere. Heat flow in the area varies from 25 to 150 mW/m² or higher, with an average of 58±11 mW/m². It is high in active faults, rifts, and other structures of extension (or sometimes compression) subject to heating from rising lithospheric and mantle plumes. The current thermal activity in the region is controlled by the Pacific subduction beneath Eurasia in eastern China and mainly by the lateral strain and rotation of the Ordos block associated with the India–Eurasia interaction in central and western China.     

利用生烃动力学研究鄂尔多斯盆地抬升后上古生界源岩生气作用结束时间

鄂尔多斯盆地上古生界气藏的研究已有较多的报道,但盆地抬升过程中源岩是否生气以及生气作用结束的时间等问题还存在争论或认识不清.本研究通过封闭体系的模拟实验,利用生烃动力学软件,对盆地不同区域代表钻孔的生烃史进行了计算.结果显示,在盆地的南部气体的转化率最高,可达70%以上,向北逐渐降低;在盆地抬升的过程中,源岩仍然有气体生成,不同地区的生气量随源岩的成熟度和降温幅度的不同而有所差别,总体来说盆地南部生气量低,西部高;生气作用在除天环坳陷外的广大地区,一般结束于老第三纪,并具有东早西晚的特点.天环坳陷到晚第三纪甚至现在仍有少量天然气生成.     

钢筋混凝土框排架结构在多维地震作用下的空间性能分析

针对钢筋混凝土横向框排架、纵向框架-剪力墙结构的某火力发电厂主厂房,建立此类不规则结构在双向水平地震作用下的振型分解反应谱方法。建立不同形式地震波作用下的结构空间整体计算模型,通过弹塑性时程分析,分别进行结构单向及水平双向地震反应分析,统计单双向地震作用效应比值,对抗震规范中的地震效应组合公式进行修正,获得了具有实用价值和理论意义的成果。     

Surge deposit misidentification at Spor Mountain,Utah and elsewhere: A cautionary message for Mars

Before base surges were described in association with nuclear blasts and explosive volcanic eruptions (especially, the 1980 eruption of Mount St. Helens, Washington), laminar and cross-bedded volcanogenic surge deposits were commonly misinterpreted as being of fluvial or aeolian origin. One well-documented example involves the “water-laid tuffs” in and near the Spor Mountain beryllium mine, Utah; other examples abound. In light of how frequently volcanogenic surge deposits have been misinterpreted on Earth, extreme caution is urged for Mars studies. Contrary to what has been claimed, the markedly cross-bedded, salty deposits at Meridiani Planum on Mars need not have been formed by a combination of aeolian and aqueous processes, and their contained hematitic spherules need not have formed as aqueous concretions. Given the lack of indications of volcanism in the vicinity, and the planet-wide abundance of impact craters, deposition by surges associated with distant impact targets consisting of brine-soaked, locally sulfidic regolith is a reasonable explanation for all features observed, especially if diagenesis and weathering are considered. The uniformly sized and shaped, Ni-enriched blue-gray hematitic spherules would then be some type of vapor condensation spherules (including accretionary lapilli). A similar interpretation is possible for deposits in the Home Plate area, Gusev Crater. Unlike on the dry and atmosphereless Moon, salty impact surge deposits containing spherules should be common, and well-preserved, on Mars.     

Meteoritic and bedrock constraints on the glacial history of Frontier Mountain in northern Victoria Land, Antarctica

In 2001, a small H4 chondrite, Frontier Mountain (FRO) 01149, was found on a glacially eroded surface near the top of Frontier Mountain, Antarctica, about 600 m above the present ice level. The metal and sulphides are almost completely oxidized due to terrestrial weathering. We used a chemical leaching procedure to remove weathering products, which contained atmospheric ¹⁰Be and ³⁶Cl in a ratio similar to that found in Antarctic ice. The FRO 01149 meteorite has a terrestrial age of 3.0 ± 0.3 Myr based on the concentrations of the cosmogenic radionuclides ¹⁰Be, ²⁶Al and ³⁶Cl. This age implies that FRO 01149 is the oldest stony meteorite (fossil meteorites excluded) discovered on Earth. The noble gas cosmic ray exposure age of FRO 01149 is ~ 30 Myr. The meteorite thus belongs to the 33 Myr exposure age peak of H-chondrites.The bedrock surface on which FRO 01149 was found has wet-based glacial erosional features recording a former high-stand of the East Antarctic ice sheet. This ice sheet evidently overrode the highest peaks (> 2800 m a.s.l.) of the inland sector of the Transantarctic Mountains in northern Victoria Land. We argue that FRO 01149 was a local fall and that its survival on a glacially eroded bedrock surface constrains the age of the last overriding event to be older than ~ 3 Myr. The concentrations of in-situ produced cosmogenic ¹⁰Be, ²⁶Al and ²¹Ne in a glacially eroded bedrock sample taken from near the summit of Frontier Mountain yield a surface exposure age of 4.4 Myr and indicate that the bedrock was covered by several meters of snow. The exposure age is also consistent with bedrock exposure ages of other summit plateaus in northern Victoria Land.     

Characteristics,genesis and accumulation history of natural gas in Hetianhe gasfield,Tarim Basin,China

Hetianhe gasfield in Bachu region of the Tarim Basin is mainly composed of three reservoir-caprock assembly,namely regional caprock of upper mudstone,middle mudstone and lower mudstone of the Carboniferous and reservoir of Bachu bioclastic limestone,glutenite and the Ordovician carbonate buried hill.Natural gas in Hetianhe gasfield sourced from the Cambrian source rock.It is thought that gases in Ma4 well block in the east of Hetianhe gasfield are mainly crude-oil cracked gases,while those in Ma3 and Ma8 well blocks in the west are the mixture gases of kerogen cracked gases and crude-oil cracked gases.Natural gas is rich in H2S and accumulated in multiply stages as the result of TSR.The accumulation history is divided into three stages,namely accumulation and breakage in the late Caledonian-early Hercynian,migration and dissipation in the late Hercynian and accumulation in Himalayan. The main accumulation of reformed gas reservoir is in Himalayan.