التفاصيل البيبلوغرافية
| العنوان: |
Sheared peridotites from the cratonic mantle beneath Lesotho (Kaapvaal craton): Investigating deformation and related metasomatic processes from mid-lithospheric depth to the LAB |
| المؤلفون: |
Heckel, Catharina, Woodland, Alan B., Linckens, Jolien, Gibson, Sally A., Seitz, Hans-Michael |
| بيانات النشر: |
Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV), 2022. |
| سنة النشر: |
2022 |
| الوصف: |
Sheared peridotites give direct evidence for deformation processes in the subcratonic mantle shortly before their transport to the surface by kimberlites. We studied 12 sheared peridotites (11 garnet-peridotites, one spinel-bearing) from three localities in Lesotho, which were entrained in the Late Cretaceous (90Ma). The peridotites exhibit different degrees of depletion from more fertile (XFo =91) to depleted (XFo =93). Typical for sheared peridotites, textures reveal a bimodal grain size with mm-size porphyroclasts, which are surrounded by 10s – 100s µm neoblasts. Our suite can be split into two groups: (i) low-T ( Crystallographic preferred orientations of olivine verify the presence of metasomatic agents during deformation in both groups and reveal various types: B-, C-, E-, AG- and bimodal CPOs. Increasing Ti-contents in olivine and orthopyroxene neoblasts, accompanied with an increase in temperature in the low-T group, reveal a connection between metasomatism and deformation during interaction with (failed) kimberlites. In contrast, the porphyroclasts and neoblasts of all phases in the high-T peridotites have homogeneous major and trace element contents, implying (re-)equilibration (during deformation?). Trace element signatures in garnet, clinopyroxene and orthopyroxene indicate that metasomatism at the LAB caused either enrichments or depletions in the high-T sheared peridotites. |
| اللغة: |
English |
| DOI: |
10.48380/f5tj-bk92 |
| URL الوصول: |
https://explore.openaire.eu/search/publication?articleId=doi_________::3b963bf46dd01da684439d618a311c2f |
| رقم الانضمام: |
edsair.doi...........3b963bf46dd01da684439d618a311c2f |
| قاعدة البيانات: |
OpenAIRE |