Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia
Silicification in New Caledonian pseudo-karsts developed on peridotite was assessed using δ<sup>18</sup>O and δ<sup>30</sup>Si pairs on quartz cements. The objective was to document the chronology of pseudo-karst development and cementation relative to geomorphic evolution. T...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-04-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/13/4/518 |
| _version_ | 1797604142559002624 |
|---|---|
| author | Michel Cathelineau Marie-Christine Boiron Jean-Louis Grimaud Sylvain Favier Yoram Teitler Fabrice Golfier |
| author_facet | Michel Cathelineau Marie-Christine Boiron Jean-Louis Grimaud Sylvain Favier Yoram Teitler Fabrice Golfier |
| author_sort | Michel Cathelineau |
| collection | DOAJ |
| description | Silicification in New Caledonian pseudo-karsts developed on peridotite was assessed using δ<sup>18</sup>O and δ<sup>30</sup>Si pairs on quartz cements. The objective was to document the chronology of pseudo-karst development and cementation relative to geomorphic evolution. The latter began at the end of the Eocene with the supergene alteration of peridotites and the subsequent formation of extended lateritic weathering profiles. Neogene uplift favoured the dismantling of these early lateritic profiles and valley deepening. The river incision resulted in (i) the stepping of a series of lateritic paleo-landforms and (ii) the development of a pseudo-karst system with subvertical dissolution pipes preferentially along pre-existing serpentine faults. The local collapse of the pipes formed breccias, which were then cemented by white quartz and Ni-rich talc-like (pimelite). The δ<sup>30</sup>Si of quartz, ranging between −5‰ and −7‰, are typical of silcretes and close to the minimum values recorded worldwide. The estimated δ<sup>18</sup>O of −6 to −12‰ for the fluids are lower than those of tropical rainfall typical of present-day and Eocene–Oligocene climates. Evaporation during drier climatic episodes is the main driving force for quartz and pimelite precipitation. The silicification presents similarities with silcretes from Australia, which are considered predominantly middle Miocene in age. |
| first_indexed | 2024-03-11T04:42:10Z |
| format | Article |
| id | doaj.art-0c4233221bdb4199ab94b4198d0f0d45 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-11T04:42:10Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-0c4233221bdb4199ab94b4198d0f0d452023-11-17T20:35:48ZengMDPI AGMinerals2075-163X2023-04-0113451810.3390/min13040518Pseudo-Karst Silicification Related to Late Ni Reworking in New CaledoniaMichel Cathelineau0Marie-Christine Boiron1Jean-Louis Grimaud2Sylvain Favier3Yoram Teitler4Fabrice Golfier5Université de Lorraine, CNRS, GeoRessources, F-54000 Nancy, FranceUniversité de Lorraine, CNRS, GeoRessources, F-54000 Nancy, FrancePSL University/MINES Paris/Centre de Géosciences, 35 rue St Honoré, 77305 Fontainebleau Cedex, FranceUniversité de Lorraine, CNRS, GeoRessources, F-54000 Nancy, FranceUniversité de Lorraine, CNRS, GeoRessources, F-54000 Nancy, FranceUniversité de Lorraine, CNRS, GeoRessources, F-54000 Nancy, FranceSilicification in New Caledonian pseudo-karsts developed on peridotite was assessed using δ<sup>18</sup>O and δ<sup>30</sup>Si pairs on quartz cements. The objective was to document the chronology of pseudo-karst development and cementation relative to geomorphic evolution. The latter began at the end of the Eocene with the supergene alteration of peridotites and the subsequent formation of extended lateritic weathering profiles. Neogene uplift favoured the dismantling of these early lateritic profiles and valley deepening. The river incision resulted in (i) the stepping of a series of lateritic paleo-landforms and (ii) the development of a pseudo-karst system with subvertical dissolution pipes preferentially along pre-existing serpentine faults. The local collapse of the pipes formed breccias, which were then cemented by white quartz and Ni-rich talc-like (pimelite). The δ<sup>30</sup>Si of quartz, ranging between −5‰ and −7‰, are typical of silcretes and close to the minimum values recorded worldwide. The estimated δ<sup>18</sup>O of −6 to −12‰ for the fluids are lower than those of tropical rainfall typical of present-day and Eocene–Oligocene climates. Evaporation during drier climatic episodes is the main driving force for quartz and pimelite precipitation. The silicification presents similarities with silcretes from Australia, which are considered predominantly middle Miocene in age.https://www.mdpi.com/2075-163X/13/4/518silcretepseudo-karstlateritenickeloxygen and silicon isotopesweathering |
| spellingShingle | Michel Cathelineau Marie-Christine Boiron Jean-Louis Grimaud Sylvain Favier Yoram Teitler Fabrice Golfier Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia Minerals silcrete pseudo-karst laterite nickel oxygen and silicon isotopes weathering |
| title | Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia |
| title_full | Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia |
| title_fullStr | Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia |
| title_full_unstemmed | Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia |
| title_short | Pseudo-Karst Silicification Related to Late Ni Reworking in New Caledonia |
| title_sort | pseudo karst silicification related to late ni reworking in new caledonia |
| topic | silcrete pseudo-karst laterite nickel oxygen and silicon isotopes weathering |
| url | https://www.mdpi.com/2075-163X/13/4/518 |
| work_keys_str_mv | AT michelcathelineau pseudokarstsilicificationrelatedtolatenireworkinginnewcaledonia AT mariechristineboiron pseudokarstsilicificationrelatedtolatenireworkinginnewcaledonia AT jeanlouisgrimaud pseudokarstsilicificationrelatedtolatenireworkinginnewcaledonia AT sylvainfavier pseudokarstsilicificationrelatedtolatenireworkinginnewcaledonia AT yoramteitler pseudokarstsilicificationrelatedtolatenireworkinginnewcaledonia AT fabricegolfier pseudokarstsilicificationrelatedtolatenireworkinginnewcaledonia |