Age and geochemistry of Karoo dolerite dykes from northeast Botswana

M. Elburg; A. Goldberg

doi:10.1016/S0899-5362(00)80006-8

Age and geochemistry of Karoo dolerite dykes from northeast Botswana

M. Elburg, A. Goldberg

Research output: Contribution to journal › Article › peer-review

57 Citations (Scopus)

Abstract

The Botswana Dyke Swarm is a prominent 800 km long and 100 km wide feature on aeromagnetic maps of southern Africa, but little has been published on its exact age or geochemical composition. New age, trace element and isotope data for this dyke swarm show that its magmatism is indistinguishable from Karoo continental flood basalts. Ar/Ar dating gives an age of 178.9 ± 1.4 Ma. Both high Ti-Zr and low Ti-Zr dolerites occur, but the high Ti-Zr rocks appear to be the dominant type of magmatism. Low Ti-Zr mafic rocks have isotopic and trace element characteristics similar to a combination of a normal mid-ocean ridge basalt source with sedimentary and fluid-enriched components, which are thought to reside in the sub-continental lithospheric mantle. A lithospheric component seen in the high Ti-Zr mafic rocks is similar to that in nephelinites from Zimbabwe.

Original language	English
Pages (from-to)	539-554
Number of pages	16
Journal	Journal of African Earth Sciences
Volume	31
Issue number	3-4
DOIs	https://doi.org/10.1016/S0899-5362(00)80006-8
Publication status	Published - 2000
Externally published	Yes

ASJC Scopus subject areas

Geology
Earth-Surface Processes

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/S0899-5362(00)80006-8

Cite this

@article{6cb616b6e6b94236a189abb765082ec4,

title = "Age and geochemistry of Karoo dolerite dykes from northeast Botswana",

abstract = "The Botswana Dyke Swarm is a prominent 800 km long and 100 km wide feature on aeromagnetic maps of southern Africa, but little has been published on its exact age or geochemical composition. New age, trace element and isotope data for this dyke swarm show that its magmatism is indistinguishable from Karoo continental flood basalts. Ar/Ar dating gives an age of 178.9 ± 1.4 Ma. Both high Ti-Zr and low Ti-Zr dolerites occur, but the high Ti-Zr rocks appear to be the dominant type of magmatism. Low Ti-Zr mafic rocks have isotopic and trace element characteristics similar to a combination of a normal mid-ocean ridge basalt source with sedimentary and fluid-enriched components, which are thought to reside in the sub-continental lithospheric mantle. A lithospheric component seen in the high Ti-Zr mafic rocks is similar to that in nephelinites from Zimbabwe.",

author = "M. Elburg and A. Goldberg",

year = "2000",

doi = "10.1016/S0899-5362(00)80006-8",

language = "English",

volume = "31",

pages = "539--554",

journal = "Journal of African Earth Sciences",

issn = "0899-5362",

publisher = "Elsevier Ltd.",

number = "3-4",

}

TY - JOUR

T1 - Age and geochemistry of Karoo dolerite dykes from northeast Botswana

AU - Elburg, M.

AU - Goldberg, A.

PY - 2000

Y1 - 2000

N2 - The Botswana Dyke Swarm is a prominent 800 km long and 100 km wide feature on aeromagnetic maps of southern Africa, but little has been published on its exact age or geochemical composition. New age, trace element and isotope data for this dyke swarm show that its magmatism is indistinguishable from Karoo continental flood basalts. Ar/Ar dating gives an age of 178.9 ± 1.4 Ma. Both high Ti-Zr and low Ti-Zr dolerites occur, but the high Ti-Zr rocks appear to be the dominant type of magmatism. Low Ti-Zr mafic rocks have isotopic and trace element characteristics similar to a combination of a normal mid-ocean ridge basalt source with sedimentary and fluid-enriched components, which are thought to reside in the sub-continental lithospheric mantle. A lithospheric component seen in the high Ti-Zr mafic rocks is similar to that in nephelinites from Zimbabwe.

AB - The Botswana Dyke Swarm is a prominent 800 km long and 100 km wide feature on aeromagnetic maps of southern Africa, but little has been published on its exact age or geochemical composition. New age, trace element and isotope data for this dyke swarm show that its magmatism is indistinguishable from Karoo continental flood basalts. Ar/Ar dating gives an age of 178.9 ± 1.4 Ma. Both high Ti-Zr and low Ti-Zr dolerites occur, but the high Ti-Zr rocks appear to be the dominant type of magmatism. Low Ti-Zr mafic rocks have isotopic and trace element characteristics similar to a combination of a normal mid-ocean ridge basalt source with sedimentary and fluid-enriched components, which are thought to reside in the sub-continental lithospheric mantle. A lithospheric component seen in the high Ti-Zr mafic rocks is similar to that in nephelinites from Zimbabwe.

UR - http://www.scopus.com/inward/record.url?scp=0034453795&partnerID=8YFLogxK

U2 - 10.1016/S0899-5362(00)80006-8

DO - 10.1016/S0899-5362(00)80006-8

M3 - Article

AN - SCOPUS:0034453795

SN - 0899-5362

VL - 31

SP - 539

EP - 554

JO - Journal of African Earth Sciences

JF - Journal of African Earth Sciences

IS - 3-4

ER -

Age and geochemistry of Karoo dolerite dykes from northeast Botswana

Abstract

ASJC Scopus subject areas

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this