DOI: 10.1007/s00531-014-1085-7
Scopus记录号: 2-s2.0-84925504944
论文题名: Geometry of laccolith margins: 2D and 3D models of the Late Paleozoic Halle Volcanic Complex (Germany)
作者: Schmiedel T. ; Breitkreuz C. ; Görz I. ; Ehling B.-C.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2014
卷: 104, 期: 2 起始页码: 323
结束页码: 333
语种: 英语
英文关键词: GOCAD©
; Magma sheet emplacement
; Porphyritic rhyolite
; Well data
英文摘要: Well data and core samples from the Late Paleozoic Halle Volcanic Complex (HVC) have been used to describe the geometry of the rhyolitic porphyritic laccoliths and their margins. The HVC formed between 301 and 292 Ma in the intramontane Saale basin, and it comprises mainly rhyolitic subvolcanic bodies (~300 km3) as well as minor lava flows and volcaniclastic deposits. The major HVC laccolith units display aspect ratios ranging between 0.04 and 0.07, and they are separated by tilted and deformed Carboniferous–Permian host sediments. For the margin of the Landsberg laccolith, a major coarsely porphyritic unit of the HVC, an exceptional data set of 63 wells concentrated in an area of 10 km2 reaching to depth of 710 m exists. It was used to explore the 3D geometry and textures, and to deduce an intrusion model. For a 3D visualization of the Landsberg laccolith margin, Geological Object Computer Aided Design; Paradigm® software (GOCAD) was used. Curve objects have been derived from the intrusion–host contacts. Automated GOCAD® methods for 3D modelling failed. As a result, manual refinement was essential. A major finding of the 3D modelling is the presence of prolate sediment rafts, up to 1,400 m in length and up to 500 m in thickness, surrounded by Landsberg rhyolite. The sedimentary rafts dip away from the laccolith centre. The engulfing laccolith sheets reach thickness of 100–300 m. For other HVC laccolith units (Löbejün, Petersberg, Brachstedt), well data reveal vertical rhyolite/sediment contacts or magma lobes fingering into the host sediments. HVC laccolith contact textures include small-scale shearing of the intruding magma and of the host sediment. In addition, internal shear zones have been detected inside the rhyolite bodies. The present study suggests that the emplacement of successive magma sheets was an important process during laccolith growth in the HVC. © 2014, Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84925504944&doi=10.1007%2fs00531-014-1085-7&partnerID=40&md5=c6a35f7044afb6b02e5e8e9943d94b91
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70387
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Geology Department, TU Bergakademie Freiberg, Freiberg, Germany; Geophysics and Geoinformatics Department, TU Bergakademie Freiberg, Freiberg, Germany; Sachsen-Anhalt State Survey for Geology and Mining, Halle, Germany
Recommended Citation:
Schmiedel T.,Breitkreuz C.,Görz I.,et al. Geometry of laccolith margins: 2D and 3D models of the Late Paleozoic Halle Volcanic Complex (Germany)[J]. International Journal of Earth Sciences,2014-01-01,104(2)