The Uplift of the Longmenshan Thrust Belt and Subsidence of the West Sichuan Foreland Basin

Based on fission track dating of apatite, and measurement of vitrinite reflectance of rock samples from the Longmenshan (Longmen Mountain)area and the West Sichuan foreland basin and computer modelling it is concluded that (l)the Songpan-Garze fold belt has uplifted at least by 3-4 km with an uplift rate of no less than 0.3-0.4 mm/a since 10 Ma B.P.; (2) the Longmenshan thrust nappe belt has uplifted at least by 5-6 km with an uplift rate of more than 0.5- 0.6 mm /a since 10 Ma B.P.; (3) the Longmenshan detachment belt has uplifted by 1 - 2 km at a rate of 0.016-0.032 mm/a since 60 Ma B.P.; (4) the West Sichuan foreland basin has uplifted by 1.7-3 km at a rate of 0.028-0.05 mm/a since 60 Ma B.P.; (5) the uplift rate of the area on the west side of the Beichuan-Yingxiu-Xiaoguanzi fault for the last 10 Ma is 40 times as much as that on its east side; (6) the uplifting of the the Songpan - Garze fold belt and the subsidence of the West Sichuan foreland basin 60 Ma ago exhibit a mirro-image correlation, i.e     

都江堰ML4.4地震前兆异常特征及预报概况

介绍了１９９３年１２月３０日都江堰ＭＬ４．４地震的前兆异常特征及震前预报概况。震前异常主要有空区、ｂ值、波速比、电磁波等     

岩浆不混溶对岩石成分和结构的控制———川西乡城地区玻镁安山岩成岩特征探讨

川西乡城地区的球颗状玻镁安山岩是一种玻璃质、含辉石斑晶、具淬火结构的中性熔岩．它相对富硅富镁、贫钛贫磷，产于三叠纪川西义敦岛弧早期火山活动阶段．外观最醒目特征是具有球颗构造，从化学成分和岩浆性质分析，球颗构造是成岩过程中岩浆不混溶的直接产物．不混溶对岩石成分和结构起着控制作用；岩石中球颗相富硅碱，以玻璃质结构为主，而基质相富铁镁，以微晶结构为主．成岩时化学成分随岩浆不混溶发生相对分离，该岩浆属于一种低程度不混溶．结构差异是两相中矿物结晶能力不同的结果     

四川盆地碳酸盐岩油气勘探实践与认识

四川盆地烃源十分丰富。但油气演化程度高,大多已进入高成熟和过成熟阶段,至今只在侏罗系发现有油藏,三叠系及其更老地层皆为气藏。储层主要为碳酸盐岩,其特点是低孔低渗,平均孔隙度仅1.7%,平均渗透率小于1×10~(-3)μm~2,但其中的“孔洞发育层段”平均孔隙度可达3%～6%。根据四十年的勘探经验,加强预探并争取新发现是四川盆地油气勘探发展的关键。预探中,按构造带规划大中型气田勘探目标,将成藏条件相似、地域上相邻的局部圈闭群作为一个整体勘探对象,实行稀井广探,少井高效。“八五”以来,在高陡构造带勘探技术、储层横向预探技术等方面有长足的进步,勘探成效不断提高,实现了资源序列的良性循环。     

川陕丁家林金矿区探矿权的评估

为准确、客观估价丁家林金矿区探矿权价值，根据矿区地质报告中提交的储量级别、矿体控制程度和工程质量，确定了基础和可采储量、生产规模、矿山服务年限、贴现率、有关实物工作量等6项参数。综合运用贴现现金流量和重置成本法对探矿权进行评估，对达到详查程度的基础储量采用贴现现金流量法，控制程度低的资源量采用重置成本法，二者之和综合反映探矿权的价值。此方法适用于地质工作程度不均衡矿区的探矿权评估，贴现现金流量法要充分考虑储量的可信度和获利临界品位．重置成本法关键是准确确定有关的实物工作量。     

川西北倒三角形断块东部区域强震带形成机制与地震活动特征

川西北倒三角形断块东部区域地处青藏高原东部边缘地带,地跨川西北高原及其与四川盆地过渡带的高山峡谷区,属我国著名的南北向地震带的中段,因其特定的大地构造环境和强烈的现代地壳构造运动,导致其在强大的近东西向构造应力场的驱动和平卧“A”字型控震构造体系的控制下,沿两侧边界断裂向东强力楔入,于“构造急剧收口带”之西侧形成了一个近SN向地跨三大构造单元的强震带,强震沿该带有规律的往返迁移和重复发生,且地震活动强弱具有较明显的分形特征。     

开发旅游观光资源与四川西部之发展

川西甘孜州旅游观光资源丰富多彩，遍布的温泉、热泉与雪山、草地、森林相配置成的景点、景区比比皆是．加之悠久的人文、宗教建筑和文物，都具有很高的研究和观赏价值。开发这些资源以引导甘孜州经济的发展，将是大有可为的。     

Kinetic-simulating experiment combined with GC-IRMS analysis: application to identification and assessment of coal-derived methane from Zhongba Gas Field (Sichuan Basin, China)

The main purpose of this study is to model the δ¹³C values of methane derived from coal by combining kinetic-simulating experiment with the gas chromatography-isotope ratio mass spectrum (GC-IRMS) analysis. The stable carbon isotopic variation of methane in pyrolysates with heating temperature indicates that the assumptions for both a constant kinetic isotope effect (α) and a uniform initial isotopic composition (δ¹³C_o) are impractical for explaining the carbon isotopic fractionation during coalification. For purposes of simplification, two approaches are used in this paper to deal with the heterogeneity of terrestrial organic matter. One is that, assuming a uniform initial isotopic composition (i.e., δ¹³C_{i, o}=δ¹³C_o) for all methane-generating precursors in coal, the isotopic variation of methane is fitted by adjusting ΔE_{a, i} (E_{a¹³C, i}−E_{a¹²C, i}) for each hypothetical reaction. The other is that, assuming a constant kinetic isotope effect during the whole gas formation, that is all ΔE_{a, i} values are identical, the modeling of methane isotopic composition is achieved by changing the ¹³CH₄ generation potential of each reaction (f_{i, ¹³C}), namely, by adjusting the initial δ¹³C value (δ¹³C_{i, o}) for each methane-generating precursor. Results of the kinetic calculation shows that the two simulating methods can yield a similar result at a geological heating rate of 2 °C/My, which further demonstrates that those natural gases with methane δ¹³C value being approximately −36‰ are possibly sourced from the upper Triassic coal measure strata in the Northwestern Sichuan Basin.     

四川盆地潜在震源区的细致划分

四川盆地包括川中台拱和川东陷褶束的范围，具有相对稳定的大地构造环境.鉴于该地区地震活动水平相对较低、发震构造不甚明确的特点，在编制1990年版中国地震烈度区划图时，划分的潜在震源区面积也相对较大.本文在总结四川盆地中强地震（Ms=4.7-5.7）发震构造条件的基础上，用地震构造类比原则对四川盆地的潜在震源区进行了重新划分.确定潜在震源区边界时，充分考虑了背斜轴走向、背斜构造的影响带宽度、小震活动密集条带和余震的分布范围.得到了四川盆地更加细致的潜在震源区划分方案.这对于低地震活动水平地区的潜在震源区的细化研究具有一定参考意义。     

Isotopic evidence of TSR origin for natural gas bearing high H_2S contents within the Feixianguan Formation of the northeastern Sichuan Basin, southwestern China

Isotopic evidence of TSR origin for natural gas bearing high H2S contents 1961 As the hazardous component of natural gas, the ex-istence of H2S, due to its extremely strong toxicity and corrosivity, not only decreases the percentage of hy-drocarbon gas within natural gas and reduces its in-dustrial value, it also threatens each aspect of drilling and exploitation. It frequently causes serious safety accidents[1] and leads to the E&P cost and risk of natural gas with higher H2S contents be…