Geochronological problems related to polymetamorphism in the Limpopo Complex, South Africa

D. D. Van Reenen; R. Boshoff; C. A. Smit; L. L. Perchuk; J. D. Kramers; S. McCourt; R. A. Armstrong

doi:10.1016/j.gr.2008.01.013

Geochronological problems related to polymetamorphism in the Limpopo Complex, South Africa

D. D. Van Reenen, R. Boshoff^*, C. A. Smit, L. L. Perchuk, J. D. Kramers, S. McCourt, R. A. Armstrong

^*Corresponding author for this work

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

72 Citations (Scopus)

Abstract

The integration of new and published geochronologic data with structural, magmatic/anatectic and pressure-temperature (P-T) process information allow the recognition of high-grade polymetamorphic granulites and associated high-grade shear zones in the Central Zone (CZ) of the Limpopo high-grade terrain in South Africa. Together, these two important features reflect a major high-grade D₃/M₃ event at ~ 2.02 Ga that overprinted the > 2.63 Ga high-grade Neoarchaean D₂/M₂ event, characterized by SW-plunging sheath folds. These major D₂/M₂ folds developed before ~ 2.63 Ga based on U-Pb zircon age data for precursors to leucocratic anatectic gneisses that cut the high-grade gneissic fabric. The D₃/M₃ shear event is accurately dated by U-Pb monazite (2017.1 ± 2.8 Ma) and PbSL garnet (2023 ± 11 Ma) age data obtained from syntectonic anatectic material, and from sheared metapelitic gneisses that were completely reworked during the high-grade shear event. The shear event was preceded by isobaric heating (P = ~ 6 kbar and T = ~ 670-780 °C), which resulted in the widespread formation of polymetamorphic granulites. Many efforts to date high-grade gneisses from the CZ using PbSL garnet dating resulted in a large spread of ages (~ 2.0-2.6 Ga) that reflect the polymetamorphic nature of these complexly deformed high-grade rocks.

Original language	English
Pages (from-to)	644-662
Number of pages	19
Journal	Gondwana Research
Volume	14
Issue number	4
DOIs	https://doi.org/10.1016/j.gr.2008.01.013
Publication status	Published - Dec 2008

Access to Document

10.1016/j.gr.2008.01.013

Cite this

@article{8d68dd2a462942a5b08674b0e94a8dbd,

title = "Geochronological problems related to polymetamorphism in the Limpopo Complex, South Africa",

abstract = "The integration of new and published geochronologic data with structural, magmatic/anatectic and pressure-temperature (P-T) process information allow the recognition of high-grade polymetamorphic granulites and associated high-grade shear zones in the Central Zone (CZ) of the Limpopo high-grade terrain in South Africa. Together, these two important features reflect a major high-grade D3/M3 event at ~ 2.02 Ga that overprinted the > 2.63 Ga high-grade Neoarchaean D2/M2 event, characterized by SW-plunging sheath folds. These major D2/M2 folds developed before ~ 2.63 Ga based on U-Pb zircon age data for precursors to leucocratic anatectic gneisses that cut the high-grade gneissic fabric. The D3/M3 shear event is accurately dated by U-Pb monazite (2017.1 ± 2.8 Ma) and PbSL garnet (2023 ± 11 Ma) age data obtained from syntectonic anatectic material, and from sheared metapelitic gneisses that were completely reworked during the high-grade shear event. The shear event was preceded by isobaric heating (P = ~ 6 kbar and T = ~ 670-780 °C), which resulted in the widespread formation of polymetamorphic granulites. Many efforts to date high-grade gneisses from the CZ using PbSL garnet dating resulted in a large spread of ages (~ 2.0-2.6 Ga) that reflect the polymetamorphic nature of these complexly deformed high-grade rocks.",

keywords = "High-temperature shear zones, Limpopo high-grade terrain, PbSL and U-Pb age dating, Polymetamorphic granulites, Southern Africa",

author = "{Van Reenen}, {D. D.} and R. Boshoff and Smit, {C. A.} and Perchuk, {L. L.} and Kramers, {J. D.} and S. McCourt and Armstrong, {R. A.}",

year = "2008",

month = dec,

doi = "10.1016/j.gr.2008.01.013",

language = "English",

volume = "14",

pages = "644--662",

journal = "Gondwana Research",

issn = "1342-937X",

publisher = "Elsevier Inc.",

number = "4",

}

TY - JOUR

T1 - Geochronological problems related to polymetamorphism in the Limpopo Complex, South Africa

AU - Van Reenen, D. D.

AU - Boshoff, R.

AU - Smit, C. A.

AU - Perchuk, L. L.

AU - Kramers, J. D.

AU - McCourt, S.

AU - Armstrong, R. A.

PY - 2008/12

Y1 - 2008/12

N2 - The integration of new and published geochronologic data with structural, magmatic/anatectic and pressure-temperature (P-T) process information allow the recognition of high-grade polymetamorphic granulites and associated high-grade shear zones in the Central Zone (CZ) of the Limpopo high-grade terrain in South Africa. Together, these two important features reflect a major high-grade D3/M3 event at ~ 2.02 Ga that overprinted the > 2.63 Ga high-grade Neoarchaean D2/M2 event, characterized by SW-plunging sheath folds. These major D2/M2 folds developed before ~ 2.63 Ga based on U-Pb zircon age data for precursors to leucocratic anatectic gneisses that cut the high-grade gneissic fabric. The D3/M3 shear event is accurately dated by U-Pb monazite (2017.1 ± 2.8 Ma) and PbSL garnet (2023 ± 11 Ma) age data obtained from syntectonic anatectic material, and from sheared metapelitic gneisses that were completely reworked during the high-grade shear event. The shear event was preceded by isobaric heating (P = ~ 6 kbar and T = ~ 670-780 °C), which resulted in the widespread formation of polymetamorphic granulites. Many efforts to date high-grade gneisses from the CZ using PbSL garnet dating resulted in a large spread of ages (~ 2.0-2.6 Ga) that reflect the polymetamorphic nature of these complexly deformed high-grade rocks.

AB - The integration of new and published geochronologic data with structural, magmatic/anatectic and pressure-temperature (P-T) process information allow the recognition of high-grade polymetamorphic granulites and associated high-grade shear zones in the Central Zone (CZ) of the Limpopo high-grade terrain in South Africa. Together, these two important features reflect a major high-grade D3/M3 event at ~ 2.02 Ga that overprinted the > 2.63 Ga high-grade Neoarchaean D2/M2 event, characterized by SW-plunging sheath folds. These major D2/M2 folds developed before ~ 2.63 Ga based on U-Pb zircon age data for precursors to leucocratic anatectic gneisses that cut the high-grade gneissic fabric. The D3/M3 shear event is accurately dated by U-Pb monazite (2017.1 ± 2.8 Ma) and PbSL garnet (2023 ± 11 Ma) age data obtained from syntectonic anatectic material, and from sheared metapelitic gneisses that were completely reworked during the high-grade shear event. The shear event was preceded by isobaric heating (P = ~ 6 kbar and T = ~ 670-780 °C), which resulted in the widespread formation of polymetamorphic granulites. Many efforts to date high-grade gneisses from the CZ using PbSL garnet dating resulted in a large spread of ages (~ 2.0-2.6 Ga) that reflect the polymetamorphic nature of these complexly deformed high-grade rocks.

KW - High-temperature shear zones

KW - Limpopo high-grade terrain

KW - PbSL and U-Pb age dating

KW - Polymetamorphic granulites

KW - Southern Africa

UR - http://www.scopus.com/inward/record.url?scp=53849113419&partnerID=8YFLogxK

U2 - 10.1016/j.gr.2008.01.013

DO - 10.1016/j.gr.2008.01.013

M3 - Article

SN - 1342-937X

VL - 14

SP - 644

EP - 662

JO - Gondwana Research

JF - Gondwana Research

IS - 4

ER -

Geochronological problems related to polymetamorphism in the Limpopo Complex, South Africa

Abstract

Access to Document

Other files and links

Fingerprint

Cite this