• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Bulletin of Volcanology: Journal of the International Association of Volcanology and Chemistry of the Earth s Interior >Reconstruction of the volcanic history of the Tacámbaro-Puruarán area (Michoacán, México) reveals high frequency of Holocene monogenetic eruptions
【24h】

Reconstruction of the volcanic history of the Tacámbaro-Puruarán area (Michoacán, México) reveals high frequency of Holocene monogenetic eruptions

机译：塔卡波洛-普鲁拉朗地区（墨西哥米却肯州）的火山历史的重建揭示了全新世单基因喷发的高频率

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The 690 km ~2 Tacámbaro-Puruarán area located at the arc-front part of the Michoácan-Guanajuato volcanic field in the Trans-Mexican Volcanic Belt (TMVB) records a protracted history of volcanism that culminated with intense monogenetic activity in the Holocene. Geologic mapping, ~(40)Ar/ ~(39)Ar and ~(14)C radiometric dating, and whole-rock chemical analyses of volcanic products provide insights to that history. Eocene volcanics (55-40 Ma) exposed at uplifted blocks are related to a magmatic arc that preceded the TMVB. Early TMVB products are represented by poorly exposed Pliocene silicic domes (5-2 Ma). Quaternary (<2 Ma) volcanoes (114 mapped) are mainly scoria cones with lavas (49 vol.%), viscous lava flows (22 vol.%), and lava shields (22 vol.%). Erupted products are dominantly either basaltic andesites (37 vol. %), or andesites (17 vol.%), or span across both compositions (28 vol.%). Basalts (9 vol.%), dacites (4 vol.%), shoshonites (2 vol.%), and other alkali-rich rocks (<3 vol.%) occur subordinately. Early-Pleistocene volcanism was bimodal (dacites and basalts) and voluminous while since 1 Ma small-volume eruptions of intermediate magmas have dominated. Higher rates of lithospheric extension in the Quaternary may have allowed a larger number of small, poorly evolved dikes to reach the surface during this period. Eruptive centers as old as 1.7 Ma are aligned in a NE direction parallel to both, basement faults and the direction of regional compressive stress, implying structural control on volcanic activity. Data suggest that volcanism was strongly pulsatory and fed by localized low-degree partial melting of mantle sources. In the Holocene, at least 13 eruptions occurred (average recurrence interval of 800 years). These produced ~3.8 km ~3 of basaltic andesitic to andesitic magma and included four eruptions dated at ~1,000; 4,000; 8,000; and 11,000 years bc (calibrated ~(14)C ages). To date, this is one of the highest monogenetic eruption frequencies detected within such a small area in a subduction-related arc-setting. These anomalous rates of monogenetic activity in an area with thick crust (>30 km) may be related to high rates of magma production at depth and a favorable tectonic setting.
机译：位于跨墨西哥火山带（TMVB）的米却肯-瓜纳华托火山场弧前部分的690 km〜2Tacámbaro-Puruarán地区记录了一段漫长的火山历史，并伴随着全新世强烈的单基因活动达到顶峰。地质制图，〜（40）Ar /〜（39）Ar和〜（14）C放射性测年以及火山产品的全岩化学分析为这一历史提供了见识。在隆起块处暴露的始新世火山岩（55-40 Ma）与TMVB之前的岩浆弧有关。早期的TMVB产品以上新世硅质穹顶（5-2 Ma）暴露不足为代表。第四纪（<2 Ma）火山（测绘出114个）主要是具有熔岩（49％（体积）），粘性熔岩流（22％（体积））和熔岩护层（22％（体积））的圆锥锥。喷出的产品主要是玄武质安山岩（37％（体积））或安山岩（17％（体积）），或横跨这两种成分（28％（体积））。玄武岩（9％（体积）），dacites（4％（体积）），shoshonites（2％（体积））和其他富含碱的岩石（<3％（体积））从属发生。早更新世的火山活动是双峰的（达科特岩和玄武岩），且数量众多，而自1 Ma以来，中等岩浆的小体积喷发占主导地位。在第四纪期间，较高的岩石圈扩张速率可能已允许大量小的，发育不良的堤防在此期间到达地面。早于1.7 Ma的喷发中心沿着与基底断层和区域压应力方向平行的NE方向排列，这意味着对火山活动进行结构控制。数据表明，火山作用强烈，由地幔源的局部低度局部融化引起。在全新世，至少发生了13次喷发（平均复发间隔为800年）。这些产生了约3.8 km〜3的玄武岩至安山岩浆，并包括4次约1000年的喷发。 4,000; 8,000;和公元前11,000年（已校准〜（14）C年龄）。迄今为止，这是在与俯冲有关的弧形环境中如此小的区域内检测到的最高单基因爆发频率之一。在地壳较厚（> 30 km）的区域中，这些单基因活动的异常速率可能与深部岩浆生成速率高和构造环境有利有关。

著录项

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号