Intermittent upwelling of asthenosphere beneath the Gregory Rift, Kenya

Journal Article · Sat Jun 01 00:00:00 EDT 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL01348· OSTI ID:5558823

Tatsumi, Yoshiyuki ^[1]; Kimura, Nobukazu ^[2]; Itaya, Tetsumaru ^[3]; Koyaguchi, Takehiro ^[4]; Suwa, Kanenori ^[5]

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1. Univ. of Tasmania (Australia) Kyoto Univ. (Japan)
2. Kyoto Univ. (Japan)
3. Okayama Univ. of Science (Japan)
4. Kumamoto Univ. (Japan)
5. Nagoya Univ. (Japan)

K-Ar dates and chemical compositions of basalts in the Gregory Rift, Kenya, demonstrate marked secular variation of lava chemistry. Two magmatic cycles characterized by incompatible element relative depletion are recognized; both occurring immediately after the peak of basaltic volcanism and coeval with both trachyte/phonolite volcanism and domal uplift of the region. These cycles may be attributed to increasing degree of partial melting of mantle source material in association with thinning of the lithosphere by thermal erosion through contact with hot upwelling asthenospheric mantle. Cyclic variation in asthenosphere upwelling may be considered an important controlling process in the evolution of the Gregory Rift.

• OSTI ID: 5558823
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 18:6; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AFRICA
AGE ESTIMATION
ALKALI METAL ISOTOPES
ARGON ISOTOPES
BASALT
CHEMICAL COMPOSITION
DEVELOPING COUNTRIES
EARTH MANTLE
GEOLOGIC STRUCTURES
IGNEOUS ROCKS
ISOTOPE RATIO
ISOTOPES
KENYA
LAVA
MAGMATISM
POTASSIUM ISOTOPES
RIFT ZONES
ROCKS
SAMPLING
VOLCANIC ROCKS
VOLCANISM