Carbon and U-Pb evidence for a Palaeoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa

I. S. Buick; I. S. Williams; R. L. Gibson; I. Cartwright; J. A. Miller

doi:10.1144/0016-764902-059

Carbon and U-Pb evidence for a Palaeoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa

I. S. Buick^*, I. S. Williams, R. L. Gibson, I. Cartwright, J. A. Miller

^*Corresponding author for this work

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

48 Citations (Scopus)

Abstract

Supposedly mid-Archaean (c. 3.3 Ga) granulite-grade marbles from the Gumbu Group, Central Zone, Limpopo Belt (South Africa) have anomalously high δ¹³C values (+4.6 to +7‰) interpreted as minimum values for their limestone protoliths. Such elevated δ¹³C values are unknown in any Archaean carbonate worldwide, but occur in Palaeoproterozoic (c. 2.4-2.1 Ga) carbonates; for example, on the adjacent Zimbabwe and Kaapvaal cratons. This suggests that the Central Zone contains a previously unrecognized Palaeoproterozoic cover sequence, contrary to the prevailing view. This conclusion is supported by zircon U-Pb sensitive high-resolution ion microprobe ages from two metasediments, which, in addition to c. 2.02 Ga metamorphic zircon overgrowths, contain detrital zircons no older than c. 2.68 Ga, and some possibly as young as c. 2.2 Ga. The recognition of post-3.3 Ga metasedements in the Central Zone requires a major revision of models of the tectonic evolution of the Limpopo Belt.

Original language	English
Pages (from-to)	601-612
Number of pages	12
Journal	Journal of the Geological Society
Volume	160
Issue number	4
DOIs	https://doi.org/10.1144/0016-764902-059
Publication status	Published - Jul 2003

Access to Document

10.1144/0016-764902-059

Cite this

@article{58249a0e6f27430fa058fa3426a93c17,

title = "Carbon and U-Pb evidence for a Palaeoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa",

abstract = "Supposedly mid-Archaean (c. 3.3 Ga) granulite-grade marbles from the Gumbu Group, Central Zone, Limpopo Belt (South Africa) have anomalously high δ13C values (+4.6 to +7‰) interpreted as minimum values for their limestone protoliths. Such elevated δ13C values are unknown in any Archaean carbonate worldwide, but occur in Palaeoproterozoic (c. 2.4-2.1 Ga) carbonates; for example, on the adjacent Zimbabwe and Kaapvaal cratons. This suggests that the Central Zone contains a previously unrecognized Palaeoproterozoic cover sequence, contrary to the prevailing view. This conclusion is supported by zircon U-Pb sensitive high-resolution ion microprobe ages from two metasediments, which, in addition to c. 2.02 Ga metamorphic zircon overgrowths, contain detrital zircons no older than c. 2.68 Ga, and some possibly as young as c. 2.2 Ga. The recognition of post-3.3 Ga metasedements in the Central Zone requires a major revision of models of the tectonic evolution of the Limpopo Belt.",

keywords = "Age, Carbon isotopes, Limpopo Belt, Precambrian",

author = "Buick, {I. S.} and Williams, {I. S.} and Gibson, {R. L.} and I. Cartwright and Miller, {J. A.}",

year = "2003",

month = jul,

doi = "10.1144/0016-764902-059",

language = "English",

volume = "160",

pages = "601--612",

journal = "Journal of the Geological Society",

issn = "0016-7649",

publisher = "Geological Society of London",

number = "4",

}

TY - JOUR

T1 - Carbon and U-Pb evidence for a Palaeoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa

AU - Buick, I. S.

AU - Williams, I. S.

AU - Gibson, R. L.

AU - Cartwright, I.

AU - Miller, J. A.

PY - 2003/7

Y1 - 2003/7

N2 - Supposedly mid-Archaean (c. 3.3 Ga) granulite-grade marbles from the Gumbu Group, Central Zone, Limpopo Belt (South Africa) have anomalously high δ13C values (+4.6 to +7‰) interpreted as minimum values for their limestone protoliths. Such elevated δ13C values are unknown in any Archaean carbonate worldwide, but occur in Palaeoproterozoic (c. 2.4-2.1 Ga) carbonates; for example, on the adjacent Zimbabwe and Kaapvaal cratons. This suggests that the Central Zone contains a previously unrecognized Palaeoproterozoic cover sequence, contrary to the prevailing view. This conclusion is supported by zircon U-Pb sensitive high-resolution ion microprobe ages from two metasediments, which, in addition to c. 2.02 Ga metamorphic zircon overgrowths, contain detrital zircons no older than c. 2.68 Ga, and some possibly as young as c. 2.2 Ga. The recognition of post-3.3 Ga metasedements in the Central Zone requires a major revision of models of the tectonic evolution of the Limpopo Belt.

AB - Supposedly mid-Archaean (c. 3.3 Ga) granulite-grade marbles from the Gumbu Group, Central Zone, Limpopo Belt (South Africa) have anomalously high δ13C values (+4.6 to +7‰) interpreted as minimum values for their limestone protoliths. Such elevated δ13C values are unknown in any Archaean carbonate worldwide, but occur in Palaeoproterozoic (c. 2.4-2.1 Ga) carbonates; for example, on the adjacent Zimbabwe and Kaapvaal cratons. This suggests that the Central Zone contains a previously unrecognized Palaeoproterozoic cover sequence, contrary to the prevailing view. This conclusion is supported by zircon U-Pb sensitive high-resolution ion microprobe ages from two metasediments, which, in addition to c. 2.02 Ga metamorphic zircon overgrowths, contain detrital zircons no older than c. 2.68 Ga, and some possibly as young as c. 2.2 Ga. The recognition of post-3.3 Ga metasedements in the Central Zone requires a major revision of models of the tectonic evolution of the Limpopo Belt.

KW - Age

KW - Carbon isotopes

KW - Limpopo Belt

KW - Precambrian

UR - http://www.scopus.com/inward/record.url?scp=0042347711&partnerID=8YFLogxK

U2 - 10.1144/0016-764902-059

DO - 10.1144/0016-764902-059

M3 - Article

SN - 0016-7649

VL - 160

SP - 601

EP - 612

JO - Journal of the Geological Society

JF - Journal of the Geological Society

IS - 4

ER -

Carbon and U-Pb evidence for a Palaeoproterozoic crustal component in the Central Zone of the Limpopo Belt, South Africa

Abstract

Access to Document

Other files and links

Fingerprint

Cite this