In situ EMPA and SIMS investigation of mineral geochemistry of mantle xenoliths from Cerro Nemby (25°24' S, 57°32' W), Paraguay

Description: Mantle xenoliths are hosted in lavas localized in the Nemby area (25°24' S, 57°32' W; Asunciòn-Sapucai-Villarrica graben, ASV, central Paraguay: Fig.1), where a small melanephelinitite plug (Cerro Nemby), with elliptical topography (800 x 500 m, about 100 m above the plain), contains very abundant mantle xenoliths (10-15% by volume of the plug) together with crustal xenoliths (Comin-Chiaramonti et al., 2001). According to Le Bas (1987), lavas consist of nephelinite and subordinately of ankaratrite (CIPW Ab < 5 wt% e Ne > 20 wt%). The average size of the mantle xenoliths (10-12 cm, max 45 cm, i.e. the largest observed in ASV) and the compositional range (lherzolite to dunite to pyroxenite) make these xenoliths particularly suitable for a study regarding metasomatic processe(s) affecting the Sub-Continental Lithospheric Mantle of central Paraguay. The dunite results to be the most abundant xenolith type in such lavas. In-situ geochemical characterization was performed on silicates and glasses from very fresh xenoliths, which document a large variety of rock types. Five samples were investigated, namely: i) dunite 3209; ii) spinel harzburgite 3284; iii) spinel lherzolite 3293; iv) olivine websterite 3253 and v) olivine clinopyroxenite 3270. The analyses were directly carried out on thin petrographic sections (30 µm thick) of the selected samples.

Global identifier:

Doi(
    "10.5880/fidgeo.2022.038",
)

Origins: /Wissenschaft/Helmholtz-Gemeinschaft/GFZ

Tags: Silikat ? Topographie ? Studie ? EPOS ? In Situ/Laboratory Instruments > Probes > ELECTRON MICROPROBES ? In Situ/Laboratory Instruments > Probes > ION MICROPROBES ? In Situ/Laboratory Instruments > Spectrometers/Radiometers > SIMS ? Mantle xenoliths ? compound material > igneous material > igneous rock > ultramafic igneous rock > peridotite ? compound material > igneous material > igneous rock > ultramafic igneous rock > pyroxenite ? multi-scale laboratories ?

License: cc-by/4.0

Language: Englisch/English

Organisations

• GFZ Data Services (Herausgeber*in)

Issued: 2023-01-01

Time ranges: 2023-01-01 - 2023-01-01

Status

Aktiv

Quality score

• Overall: 0.52
• Findability: 0.50

  • Title: 0.41
  • Description: 0.32
  • Identifier: true
  • Keywords: 0.27
  • Spatial: NoRegion (0.00)
  • Temporal: true
• Accessibility: 0.67

  • Landing page: Specific (1.00)
  • Direct access: false
  • Publicly accessible: true
• Interoperability: 0.25

  • Open file format: false
  • Media type: false
  • Machine-readable metadata: true
  • Machine-readable data: false
• Reusability: 0.67

  • License: ClearlySpecifiedAndFree (1.00)
  • Contact info: false
  • Publisher info: true

Accessed 1 times.