On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics
The mid-Proterozoic (ca. 1850–850 Ma) is a peculiar period of Earth history in many respects: ophiolites and passive margins of this age are rare, whereas anorthosite and A-type granite suites are abundant; metamorphic rocks typically record high thermobaric (temperature/pressure) ratios, whereas ul...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Sprog: | English |
| Udgivet: |
Elsevier
2022
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| _version_ | 1826308249222119424 |
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| author | Roberts, NMW Salminen, J Johansson, Å Mitchell, RN Palin, RM Condie, KC Spencer, CJ |
| author_facet | Roberts, NMW Salminen, J Johansson, Å Mitchell, RN Palin, RM Condie, KC Spencer, CJ |
| author_sort | Roberts, NMW |
| collection | OXFORD |
| description | The mid-Proterozoic (ca. 1850–850 Ma) is a peculiar period of Earth history in many respects: ophiolites and passive margins of this age are rare, whereas anorthosite and A-type granite suites are abundant; metamorphic rocks typically record high thermobaric (temperature/pressure) ratios, whereas ultrahigh pressure (UHP) rocks are rare; and the abundance of economic mineral deposits features rare porphyry Cu-Au and abundant Ni-Cu and Fe-oxide Cu-Ag (IOCG) deposit types. These collective observations have been used to propose that a stagnant-lid, or single-lid, tectonic regime operated at this time, between periods of plate tectonics in the Paleoproterozoic and Neoproterozoic. In our reappraisal of the mid-Proterozoic geological record, we not only assess the viability of the single-lid hypothesis for each line of evidence, but also that of the plate tectonic alternative. We find that evidence for the single-lid hypothesis is equivocal in all cases, whereas for plate tectonics the evidence is equivocal or supporting. We therefore find no reason to abandon a plate tectonic model for the mid-Proterozoic time period. Instead, we propose that the peculiarities of this enigmatic interval can be reconciled through the combination of two processes working in tandem: secular mantle cooling and the exceptionally long tenure and incomplete breakup of Earth's first supercontinent, where both of these phenomena had a dramatic effect on lithospheric behaviour and its resulting imprint in the geological record.
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| first_indexed | 2024-03-07T07:16:45Z |
| format | Journal article |
| id | oxford-uuid:5eee4811-a1fa-47c1-ac29-f0b471d48331 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:16:45Z |
| publishDate | 2022 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | oxford-uuid:5eee4811-a1fa-47c1-ac29-f0b471d483312022-08-22T09:29:23ZOn the enigmatic mid-Proterozoic: Single-lid versus plate tectonicsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5eee4811-a1fa-47c1-ac29-f0b471d48331EnglishSymplectic ElementsElsevier2022Roberts, NMWSalminen, JJohansson, ÅMitchell, RNPalin, RMCondie, KCSpencer, CJThe mid-Proterozoic (ca. 1850–850 Ma) is a peculiar period of Earth history in many respects: ophiolites and passive margins of this age are rare, whereas anorthosite and A-type granite suites are abundant; metamorphic rocks typically record high thermobaric (temperature/pressure) ratios, whereas ultrahigh pressure (UHP) rocks are rare; and the abundance of economic mineral deposits features rare porphyry Cu-Au and abundant Ni-Cu and Fe-oxide Cu-Ag (IOCG) deposit types. These collective observations have been used to propose that a stagnant-lid, or single-lid, tectonic regime operated at this time, between periods of plate tectonics in the Paleoproterozoic and Neoproterozoic. In our reappraisal of the mid-Proterozoic geological record, we not only assess the viability of the single-lid hypothesis for each line of evidence, but also that of the plate tectonic alternative. We find that evidence for the single-lid hypothesis is equivocal in all cases, whereas for plate tectonics the evidence is equivocal or supporting. We therefore find no reason to abandon a plate tectonic model for the mid-Proterozoic time period. Instead, we propose that the peculiarities of this enigmatic interval can be reconciled through the combination of two processes working in tandem: secular mantle cooling and the exceptionally long tenure and incomplete breakup of Earth's first supercontinent, where both of these phenomena had a dramatic effect on lithospheric behaviour and its resulting imprint in the geological record. |
| spellingShingle | Roberts, NMW Salminen, J Johansson, Å Mitchell, RN Palin, RM Condie, KC Spencer, CJ On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics |
| title | On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics |
| title_full | On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics |
| title_fullStr | On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics |
| title_full_unstemmed | On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics |
| title_short | On the enigmatic mid-Proterozoic: Single-lid versus plate tectonics |
| title_sort | on the enigmatic mid proterozoic single lid versus plate tectonics |
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