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| 潮水盆地侏罗系沉积特征及找煤潜力 | |
| 引用本文： | 王贞,邓亚婷,任玉梅,张忠喜.潮水盆地侏罗系沉积特征及找煤潜力[J].陕西地质,2007,35(1):28-37. |
| 作者姓名： | 王贞 邓亚婷 任玉梅 张忠喜 |
| 作者单位： | 1. 甘肃煤田地质勘查院,兰州,700000 2. 陕西国土资源信息中心,西安,710082 3. 甘肃煤田地质局,兰州,700000 |
| 摘 要： | 潮水盆地侏罗系为完整的断陷湖泊充填沉积序列,沉积环境属多种沉积体系,具有低位体系域—湖侵体系域—高位体系域的多层序旋回的特点。下侏罗统为断陷初始形成期的湖泊沉积,具有断陷盆地形成初期“填平补齐”的沉积特点。地层厚度变化大,沉积相变快。在层序中可识别出低位体系域与湖侵早期体系域。低位体系域主要发育了冲积扇、辫状河道、滨浅湖砂砾、洪积物等;中侏罗统为裂陷发展期湖泊沉积,为盆地内主要含煤岩组。层序中粒度旋回较发育,通常在每一旋回的上部含煤层或炭质泥岩,层序底部常发育砾岩。在该层序中可识别出局部低位体系域与高位体系域。低位体系域发育河流砂砾沉积和滨浅湖砂砾,常表现出垂向加积或退积序列。而湖侵体系域则以较深水的湖相沉积为特征,常表现出向上泥岩厚度加大的退积式准层序组;同时,亦发育诸多三角洲相沉积;上侏罗统为断陷消亡期沉积,形成低位体系域浅湖、扇三角洲和冲积扇沉积体系。潮水盆地下侏罗统芨芨沟群上岩组和中侏罗统青土井群下岩组均具有成煤的构造、成煤的环境和成煤的物质来源,而找煤的关键是寻找目前技术、经济水平可以达到的赋煤构造。 |
| 关 键 词： | 潮水盆地 侏罗系 沉积演化 找煤潜力 |
| 文章编号： | 1001-6996(2007)01-0028-10 |
| 修稿时间： | 2006年5月9日 |
SEDIMENTARY FEATURES OF THE JURASSIC SYSTEM IN TIDEWATER BASIN AND THE COAL-PROSPECTING POTENTIALS |
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| Wang Zhen,Deng Ya-ting,Ren Yu-mei,Zhang Zhong-xi.SEDIMENTARY FEATURES OF THE JURASSIC SYSTEM IN TIDEWATER BASIN AND THE COAL-PROSPECTING POTENTIALS[J].Geology of Shaanxi,2007,35(1):28-37. | |
| Authors: | Wang Zhen Deng Ya-ting Ren Yu-mei Zhang Zhong-xi |
| Abstract: | The Jurassic system in tidewater basin is an intact filling sedimentary sequence in a rift lake,the sedimentary environment of which pertained to various sedimentary systems with characteristics of multilayered cycles of low-level,lake system and high-level systems.The lower Jurassic series is lacustrine sediments formed in the beginning of rift formation,which is characterized by "filling and leveling up" sedimentation.The stratigraphic thickness changes a lot and the sedimentary facies change fast.The low-level system and the early-phase system of lake emplacement can be distinguished in stratigraphic sequence.In the low-level system mainly developed alluvial fan,braided river course,shoreline granule gravel and proluvium.The middle Jurassic series is lacustrine sediments formed in the period of rift development,which is the major coal-bearing formation in the basin.In stratigraphic sequence,granular cycle developed well,in which coal-bearing beds or carbargilite is distributed in the top of each cycle and breccias in the bottom.In the stratigraphic sequence,the local low-level and high-level systems can be distinguished.In the low-level system,alluvial sandy gravel sediments and shoreline lake sandy gravel developed well,showing vertical aggradations and retreatal sedimentation sequences.The lake replacement system is characterized by lacustrine sediments in deeper water,often showing a retreatal para-sequence formation with the thickness of argillite thickening upwards.Meanwhile,delta phase developed well.The upper Jurassic series was rift consumption sediments,forming a low-level system of shallow lake,fan-like delta and alluvial fan sedimentary system.The upper rock formation of the lower Jurassic Jijigou group in tidewater basin and the lower rock formation of the middle Jurassic Qingtujing group contain coal-forming structures,environment and sources of materials.The coal-hosted structures that can be approached by current technology and economic level are the key for coal prospecting. |
| Keywords: | tidewater basin the Jurassic system sedimentary evolution coal prospecting potential |
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