大地构造与成矿学
大地構造與成礦學
대지구조여성광학
GETECTONICA ET METALLOGENIA
2014年
3期
670-685
,共16页
王章棋%江秀敏%郭晶%徐飞%邓欣%张倩%李解%牛启营%罗照华
王章棋%江秀敏%郭晶%徐飛%鄧訢%張倩%李解%牛啟營%囉照華
왕장기%강수민%곽정%서비%산흔%장천%리해%우계영%라조화
西准噶尔%谢米斯台%年代学%火山岩地层
西準噶爾%謝米斯檯%年代學%火山巖地層
서준갈이%사미사태%년대학%화산암지층
West Junggar%Xiemisitai%geochronological%volcanic rock strata
传统上,新疆西准噶尔谢米斯台地区的火山岩地层被归属为泥盆系-石炭系。这种归属主要依据区域地层对比,缺乏确定的科学依据。本文报道了该区火山岩地层的三条剖面,并对区内出露的主要火山岩类型进行了详细描述。根据火山岩地层中岩石的不整合接触关系、岩石组合及蚀变特征将其分为两套不同时代的火山岩,并提供了代表性火山岩的锆石U-Pb测年结果,提出谢米斯台火山岩的时代(423.6~394.1 Ma)属于晚志留世-早泥盆世而不是中晚泥盆世-石炭纪。晚志留世火山岩主要为安山岩和英安岩,夹少量火山凝灰岩和蚀变砂岩。下泥盆统主要为安山质-英安质火山碎屑岩,夹有大量砂砾岩。该区地层的产状总体南倾构成一个单斜。此外本文探讨了该区火山岩地层的大地构造归属及其时空联系性,认为谢米斯台火山岩是东哈萨克斯坦博什库尔-成吉斯早古生代岩浆弧向东的延伸,可与东西两侧的火山岩地层构成一个连续的晚志留世-早泥盆世火山岩带。
傳統上,新疆西準噶爾謝米斯檯地區的火山巖地層被歸屬為泥盆繫-石炭繫。這種歸屬主要依據區域地層對比,缺乏確定的科學依據。本文報道瞭該區火山巖地層的三條剖麵,併對區內齣露的主要火山巖類型進行瞭詳細描述。根據火山巖地層中巖石的不整閤接觸關繫、巖石組閤及蝕變特徵將其分為兩套不同時代的火山巖,併提供瞭代錶性火山巖的鋯石U-Pb測年結果,提齣謝米斯檯火山巖的時代(423.6~394.1 Ma)屬于晚誌留世-早泥盆世而不是中晚泥盆世-石炭紀。晚誌留世火山巖主要為安山巖和英安巖,夾少量火山凝灰巖和蝕變砂巖。下泥盆統主要為安山質-英安質火山碎屑巖,夾有大量砂礫巖。該區地層的產狀總體南傾構成一箇單斜。此外本文探討瞭該區火山巖地層的大地構造歸屬及其時空聯繫性,認為謝米斯檯火山巖是東哈薩剋斯坦博什庫爾-成吉斯早古生代巖漿弧嚮東的延伸,可與東西兩側的火山巖地層構成一箇連續的晚誌留世-早泥盆世火山巖帶。
전통상,신강서준갈이사미사태지구적화산암지층피귀속위니분계-석탄계。저충귀속주요의거구역지층대비,결핍학정적과학의거。본문보도료해구화산암지층적삼조부면,병대구내출로적주요화산암류형진행료상세묘술。근거화산암지층중암석적불정합접촉관계、암석조합급식변특정장기분위량투불동시대적화산암,병제공료대표성화산암적고석U-Pb측년결과,제출사미사태화산암적시대(423.6~394.1 Ma)속우만지류세-조니분세이불시중만니분세-석탄기。만지류세화산암주요위안산암화영안암,협소량화산응회암화식변사암。하니분통주요위안산질-영안질화산쇄설암,협유대량사력암。해구지층적산상총체남경구성일개단사。차외본문탐토료해구화산암지층적대지구조귀속급기시공련계성,인위사미사태화산암시동합살극사탄박십고이-성길사조고생대암장호향동적연신,가여동서량측적화산암지층구성일개련속적만지류세-조니분세화산암대。
The volcanic rocks in the Xiemisitai area of West Junggar was traditionally attributed to the Devonian to Carboniferous. The attribution is mainly based on the regional stratigraphic correlation, which lacks convincing scientific evidence. This paper reports the three profiles of the volcanic rocks and a detailed description of the main volcanic rock types exposed in this area. According to the unconformity contact, rock assemblage and alteration characteristics of the volcanic rocks, two sets of volcanic rocks of different eras were distinguished. Zircons U-Pb dating results show that the volcanic rocks in the Xiemisitai area were formed at (423.6~394.1 Ma), i.e., belonging to the late Silurian-early Devonian. The late Silurian strata mainly are composed of andesite, dacite and minor volcanic tuff and altered sandstone. The Middle Devonian strata consist of andesitic-dacitic volcanic clastic rocks and glutenite. The volcanic rock strata in the Xiemisitai area were likely the products of the late Silurian Boshchekul-Chingiz magmatic arc stretches eastward from East Kazakhstan into China, which constitute parts of a suit of continuous volcanic strata of late Silurian-middle Devonian.