I am afraid the REE profile of a single gabbro sample is not going to be of any use to explain magma emplacement and tectonic setting. You need to go back to basics and look at the field relationships between this gabbro and the surrounding rocks. You need to take thin sections of multiple samples from the field area and look at them down an optical microscope to determine their mineralogy and textures. Only once you have some basic observations will whole rock geochemistry be of any use to you.

The enriched LREE patterns show that gabbros might be related with OIB or EMORB nature, further you can draw the NMORB multile-element patterns for understanding the Nb-Ta-Ti enrichment or depletion, then you can easily draw any conclusions. Further use HFSE tectonic related diagrams for your understanding.

Cheers

I would urge you to specify if these enriched pattern is shown by the whole suite or a single sample. If it is the characteristic of the suite then try to understand if it is the source characteristics or imparted from the existing continental crust via contamination. If its source characteristic then the suite is possibly related to an enriched mantle source like E-MORB or a source similar to OIB composition. Also do consider the role of fractionation in the LREE enrichment.

Gabbros are coarse grained rocks, and as such their whole-rock geochemistry is unlikely to completely represent a liquid composition. Clinopyroxene and minor phases such as apatite can fractionate the REE during crystallization, as Aniruddha Mitra eluded too. So, if the rocks are cpx-cumulative for example, this alone may produce unusual REE profiles that are nothing to do with the rocks tectono-magmatic origin. I also couldn't agree more concerning the possibility of crustal contamination as, depending on the extent, this is likely to completely overprint any source characteristics are far as the REE are concerned. I find the rush to geochemical analysis and plotting source discrimination diagrams BEFORE fully understanding the mineralogy, petrography and petrology of your samples quite alarming.

Jeremy Preston Elaborated it very well, indeed petrography is the first step to understanding the nature of the rock, secondly either your geochemistry supports your petrographic evidence.