Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1130/B31378.1 |
Dike propagation and magma flow in a glassy rhyolite dike: A structural and kinematic analysis | |
Walker, R. J.; Branney, M. J.; Norry, M. J. | |
2017-05-01 | |
发表期刊 | GEOLOGICAL SOCIETY OF AMERICA BULLETIN |
ISSN | 0016-7606 |
EISSN | 1943-2674 |
出版年 | 2017 |
卷号 | 129 |
文章类型 | Article |
语种 | 英语 |
国家 | England |
英文摘要 | Exhumed magma conduits provide important evidence of the development and evolution of subvolcanic plumbing systems. We use a 5-14-m-thick flow-banded rhyolite dike in Arran (Scotland) to present the first reconstruction of the directions and styles of initial propagation and subsequent magma flow, based on mesoscale kinematic indicators. The dike has concave-inward dike-margin segments with plumose-like structures that record vertical and horizontal propagation of lobes, which inflated and linked to form a through-going sheet. Devitrified rhyolite zones at the dike margins show gentle to open folds. In contrast, glassy central parts of the dike are flow laminated and preserve folded and refolded isoclinal, curvilinear folds and sheath folds that record sustained progressive deformation. The inner interface between the glassy and devitrified facies is abrupt and marked by elongation lineations and mullions. In the dike center, fold axes plunge 27 degrees NE along the dike, and parallel to elongation lineations. Combined with shear sense indicators (sigma-and delta-objects, sheared vesicles, and asymmetric folds), these features indicate that magma flow was obliquely upward, to the southwest, and locally <= 60 degrees to the propagation direction of the dike. The distribution of structures within the rhyolite indicates local accretion of the (now) devitrified material to the margins, with localization of flow into the center of the dike. We find that the initial magma flow direction was controlled by fracture propagation and interaction, with the subsequent flow record controlled by accretion and flow localization in the conduit. This study demonstrates that analysis of mesoscopic structural and kinematic features (several of which have not previously been reported from dikes) is a power-ful tool that can be used to reconstruct the complex evolution of conduit initiation and magma flow processes. |
领域 | 地球科学 |
收录类别 | SCI-E |
WOS记录号 | WOS:000403309300006 |
WOS关键词 | EAST GREENLAND ; EMPLACEMENT ; PATTERNS ; SCOTLAND ; DYKES ; ISLE ; AMS ; DEFORMATION ; ORIENTATION ; IGNIMBRITE |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/25093 |
专题 | 地球科学 |
作者单位 | Univ Leicester, Dept Geol, Univ Rd, Leicester LE1 7RH, Leics, England |
推荐引用方式 GB/T 7714 | Walker, R. J.,Branney, M. J.,Norry, M. J.. Dike propagation and magma flow in a glassy rhyolite dike: A structural and kinematic analysis[J]. GEOLOGICAL SOCIETY OF AMERICA BULLETIN,2017,129. |
APA | Walker, R. J.,Branney, M. J.,&Norry, M. J..(2017).Dike propagation and magma flow in a glassy rhyolite dike: A structural and kinematic analysis.GEOLOGICAL SOCIETY OF AMERICA BULLETIN,129. |
MLA | Walker, R. J.,et al."Dike propagation and magma flow in a glassy rhyolite dike: A structural and kinematic analysis".GEOLOGICAL SOCIETY OF AMERICA BULLETIN 129(2017). |
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