黑龙江东部“新元古代”黄松群杨木组沉积时限和物源组成:来自锆石U-Pb年代学的制约

以出露于黑龙江东部地区前人原定为新元古代的黄松群底部杨木组为研究对象，对其中的二云母石英片岩和晚期片麻状二长花岗岩分别进行LA-ICP-MS锆石 U-Pb 年代学研究，旨在准确限定杨木组的沉积时限并揭示其物源组成。结果表明：采自黑龙江东宁地区黄松群杨木组标准剖面的二云母石英片岩中锆石多为岩浆成因，同位素年龄集中在古生代—早中生代，并且呈现出248、263、270、290、318、326、约360、426 Ma等多个显著的年龄峰值，而侵入到其中的晚期片麻状二长花岗岩的形成时代为（221±3）Ma；黄松群杨木组沉积于早—中三叠世（221-248 Ma），并非前人所厘定的新元古代。基于杨木组碎屑锆石年龄频数和区域地质年代学资料的对比分析，杨木组沉积物主要来源于周边的晚古生代—早中生代地质体以及次要的早古生代地质体。此外，新元古代岩浆锆石的出现证明研究区可能存在新元古代岩浆事件，而中—古元古代碎屑锆石的存在同时暗示早中生代期间该区地表或地表浅部应存在更为古老的前寒武纪残片。

鸡东县金场沟铜钼矿区筒状构造特征及控矿探讨

金场沟铜钼矿区位于兴凯湖--布列亚地块区、太平岭隆起带的北东端，敦密深大断裂在矿区西侧穿过。该区自古生代以来一直处于剥蚀、夷平环境，到晚三迭纪开始局部裂陷，伴随火山活动、岩浆侵入，形成了金、钼、铜为主的多金属矿床。

Isolation and characterization of wood components with aqueous acetic acid

A study was conducted on the isolation of poplar （Populusxeurarnaricana （Dode） Guineir cv. I -72/58） wood components with aqueous acetic acid （AcOH） containing small amounts of sulfuric acid. The reaction time, concentration of acetic acid, ratio of liquor to wood, and concentration of acid catalyst were investigated to examine their effects on the fractionation of wood components. The three main separated components were characterized. The results showed that the optimum conditions for fractionation of poplar wood components were： 0.3% H2SO4 in reaction solution, ratio of liquor to wood 6, reflux time 3 h, and 90% AcOH. The residues were mainly composed of a-Cellulose and hemicellulose, The water insoluble precipitate （acetic acid lignin, AcL） had a low weight-average molecular weight range from 341 to 253 （Mw） and a narrow molecular weight distribution from 1.1 to 1.2. The sugar analysis revealed the solubilized products resulted mainly from hemicellulose and exited as monosaccharides.