永平花岗岩成因类型探讨

永平花岗岩属陆壳改造型,是继海西一印支期混合岩的基础上进一步重熔、交代而成的具明显侵位特征的异地一半原地花岗岩,具有物质来源浅,形成温度较高,侵位浅,受改造时间长等特点。经历了地槽沉积-加里东期变质-海西-印支期混合岩化-燕山期的进一步重熔、交代这样漫长复杂的历史。     

无尾两栖类宿主与多盘科吸虫关系的初步探讨

文章调查研究了云南14种无尾两栖类体内寄生多盘吸虫的自然感染情况。滇中、滇东地区滇蛙和昭觉林蛙、滇南杜氏泛树蛙为多盘吸虫宿主。分析影响多盘吸虫宿主分布的原因可能有:地质构造、无尾两栖类宿主对多盘吸虫的免疫力和多盘吸虫侵入宿主产生的致病力对抗的不同。两栖类宿主和多盘吸虫的协同进化,导致同一种无尾两栖类宿主体内寄生的多盘吸虫有交叉感染情况存在。     

西藏地壳模型及其化学成分初探

西藏地壳是指西藏高原内中-新生代造山带的地壳。其面积210万km~2,地壳平均厚度63.5km,地壳体积1.32亿km~3,地壳内的岩石平均密度2.775g/cm~3,地壳质量3663地克(=3.663×10~(17)吨)。西藏地壳由五个槽壳构成。它们是松潘甘孜槽壳、三江槽壳,喀拉昆仑唐古拉槽壳,冈底斯念青唐古拉槽壳和喜马拉雅槽壳。根据现有的地质学、地球物理学、地球化学和地理学资料,本文概略地给出了西藏地壳模型及其化学成分。     

鄂尔多斯北部塔巴庙地区奥陶系风化壳储渗体特征及分布

在古岩溶作用、同生成岩作用下,鄂尔多斯北部塔巴庙地区马五5以上地层发育为典型的古岩溶储层.储层岩石特征及电性、物性特征表明研究区为低孔、低渗致密风化壳储层.根据测井地质及储层地质特征将该区储层划分为孔隙型、溶蚀孔(洞)型、裂缝型及裂缝-(溶)孔隙型.其中以孔隙型储渗体为主,溶蚀孔(洞)型及裂缝-(溶)孔隙型储渗体次之,裂缝型少量.查明并论述了风化壳储渗体在岩溶地貌与岩溶剖面中的分布与规模.储渗体的特征和分布将为确定有利的勘探目标提供可靠的依据.     

四川南桐风化煤硝酸氧化降解的研究

研究了四川南桐风化煤硝酸氧化降解制取硝基腐植酸的可行性。用正交试验方法找出适宜的反应条件为：硝酸的质量分数３５％；煤酸比３．５；反应时间１５分钟；反应温度３６９Ｋ。所制得硝基腐植酸质量指标为：Ｗ＾ｆ２．９１％；Ａ＾ｇ１４．０６％；ＨＡ＾ｇ７８．２８％；Ｎ＾ｇ１．６２％。     

Variation of the FeMn ratio of ferromanganese crusts from the Central North Pacific: implication for paleoclimate changes

Contents of Fe, Mn and other elements in four ferromanganese crusts recovered from the central North Pacific are analyzed at high depth-resolution by electron microprobe for reconstructing factors controlling their deposition. Manganese (IV) in hydrogenetic ferromanganese crusts is mainly supplied as colloidal precipitates from the Oxygen Minimum Zone (OMZ), which concentrates high amounts of dissolved Mn (II). The iron is derived from carbonate dissolution and silicate particles of eolian dust. An increase in paleoproductivity during cooler climate would potentially lead to a decrease in Mn deposition due to enlargement of the OMZ which has a “temporary storage” effect for Mn. On the other hand, not affected by the OMZ, the iron entering the Fe-Mn crust would likely increase with the eolian dust input and surface productivity at glacial stages. As a result, the increasing FeMn ratio should indicate a cooling climate. This is supported by the following observations. In the profile of the past 1 Ma, the variations of FeMn ratio coincide with benthic oxygen isotope fluctuation in glacial-interglacial cycles. Three episodes with high FeMn ratios, approximately at 2.6, 1.8 and 0.8 Ma, are detected within the past 3 Ma and coincide with major climate transitions and cooling events. The secular evolution pattern of FeMn ratio in the Cenozoic is similar to the Pb isotope evolution which is mainly controlled by eolian dust and related to climate. The FeMn evolution pattern is also broadly consistent with the global deep-sea oxygen isotope records. Therefore, FeMn ratio recorded in the ferromanganese crusts may be a new proxy for climate change.     

Os isotopic compositions of a cobalt-rich ferromanganese crust profile in Central Pacific

Cobalt-rich ferromanganese crusts occur throughout the global ocean on seamounts, ridges, and plateaus where currents have kept the rocks swept clean of sediments for millions of years. Crusts are important as a potential re-source for primarily cobalt, but also for titanium, nickel, REE, PGE, and other elements. Most Co-rich crusts pre-cipitate at water depths of about 1000-3000 m, and are easy to be exploited. Besides the high cobalt contents compared to abyssal Fe-Mn nodules, exploitati…     

漳浦沿海新生代玄武岩的风化成矿作用

玄武岩红土壳具帝状结构。本文叙述了红土壳各带的岩石、矿物特征,风化过程中元素的迁移和聚散,硅铝分离、铁铝分离在铝土矿形成上的重要意义;用扫描电镜和能谱仪对各带样品作了系统观测;探讨了矿物的风化和演变;认为三水铝石可通过多种方式形成于风化作用的不同阶段。     

房山岩体的岩浆来源、形成机制及动力学意义

房山岩体是华北东部典型的燕山期中酸性侵入杂岩体,其地球化学特征为富Si、Na、Al、Sr,亏损高场强元素(Nb、Ta),轻重稀土分异强烈,Sr-Nd同位素具有类似EMI型富集地幔的特点,表明其岩浆来自于加厚下地壳的部分熔融,并且中生代华北东部下地壳已经被早先的富集岩石圈地幔置换.不同基性程度岩浆的不完全混合是形成微粒闪长质包体的原因.侵入杂岩的角闪石压力计显示下地壳部分熔融形成的中酸性岩浆先后在19~8 km里的深度范围内结晶就位.古太平洋板块在地幔过渡带深度于早白垩世水平俯冲至太行山一线,洋壳脱水导致上覆地幔部分熔融,后者成为加热下地壳部分熔融的热源.