The role of fractional crystallization and late-stage peralkaline melt segregation in the mineralogical evolution of Cenozoic nephelinites/phonolites from Saghro (SE Morocco)
| dc.contributor.author | Berger, J | |
| dc.contributor.author | Ennih, N | |
| dc.contributor.author | Mercier, J.C.C | |
| dc.contributor.author | Liégeois, J.P. | |
| dc.contributor.author | Demaiffe, D | |
| dc.date | 2009 | |
| dc.date.accessioned | 2016-03-15T10:03:26Z | |
| dc.date.available | 2016-03-15T10:03:26Z | |
| dc.identifier.uri | https://orfeo.belnet.be/handle/internal/466 | |
| dc.description | The Saghro Cenozoic lavas form a bimodal suite of nephelinites (with carbonatite xenoliths) and phonolites emplaced in the Anti-Atlas belt of Morocco. Despite the paucity of samples with intermediate composition between the two main types of lava (only one phonotephrite flow is reported in this area), whole-rock major element modelling shows that the two main lithologies can be linked by fractional crystallization. The most primitive modelled cumulates are calcite-bearing olivine clinopyroxenites, whereas the final stages of differentiation are characterized by the formation of nepheline-syenite cumulates. This evolution trend is classically observed in plutonic alkaline massifs associated with carbonatites. Late-stage evolution is responsible for the crystallization of hainite- and delhayelite-bearing microdomains, for the transformation of aegirine-augite into aegirine (or augite into aegirine-augite), and for the crystallization of lorenzenite and a eudialyte-group mineral as replacement products of titanite. These phases were probably formed, either by crystallization from late residual peralkaline melts, or by reaction of pre-existing minerals with such melt, or hydrothermal peralkaline fluid. | |
| dc.language | eng | |
| dc.title | The role of fractional crystallization and late-stage peralkaline melt segregation in the mineralogical evolution of Cenozoic nephelinites/phonolites from Saghro (SE Morocco) | |
| dc.type | Article | |
| dc.subject.frascati | Earth and related Environmental sciences | |
| dc.audience | Scientific | |
| dc.subject.free | Geodynamics and mineral resources | |
| dc.source.title | Mineralogical Magazine | |
| dc.source.volume | 73 | |
| dc.source.page | 59-82 | |
| Orfeo.peerreviewed | Yes | |
| dc.identifier.doi | 10.1180/minmag.2009.073.1.59 | |
| dc.identifier.rmca | 84 |
