The　nature　of　Early　Paleozoic　Caledonian　orogeny　(Guangxi　movement),　as　one　of　the　key　geolocial　problems　of　tectonic　evolution　in　South　China,　has　been　controversial　for　a　long　time.　In　this　study　we　report　a　suite　of　deformed　and　metamorphosed　basic　rocks　in　tectonic　slices　that　are　exposed　in　epimetamorphic　Ordovician　strata,　located　at　the　Nuodong　in　the　Cenxi　area　of　the　Southeast　Guangxi,　South　China.　This　suite　of　rock　is　mainly　composed　of　metamorphic　basalt,　diabase　dike　and　minor　pyroxenite.　Petrogeochemical　data　of　the　metabasalt　and　metadiabase　dike　show　the　content　of　SiO2=49.20%-52.30%,　MgO=6.78%-9.11%,　Mg#=55-63,　TiO2=1.02%-1.34%,　indicating　the　low　potassium　tholeiitic　series　of　basic　rocks.　The　chondrite-normalized　REE　distribution　patterns　are　flat　type　with　light　rare　earths　depleted,　no　obvious　Eu　anomaly,　(La/Sm)N=0.72-1.05,　(La/Yb)N=0.7-1.0,　while　the　N-MORB　normalized　spider　diagrams　show　slightly　enrichment　of　LILEs　(e.　g.　Rb,　Ba,　Th,　U,　K,　Pb)　and　flat-slightly　depletion　of　HFSEs　(e.　g.　Nb,　Ta,　Zr,　Hf,　Ti),　Ti/V=21.30-25.12,　Nb/Th=2.1-4.2.　The　geological　and　petrogeochemical　features　imply　that　this　series　of　rocks　represent　a　dismembered　ophiolites　formed　in　supra-subduction　zone　(SSZ)　tectonic　environment.　The　LA-ICP-MS　zircon　U-Pb　age　of　the　metadiabase　is　437±5　Ma,　indicating　that　the　ophiolites　were　formed　at　the　Early　Silurian.　Based　on　the　above　comprehensive　study,　we　propose　that　the　Nuodong　metamorphic　basic　rock　series　are　Early　Paleozoic　ophiolite　fragments　formed　in　a　forearc　tectonic　environment　in　a　supra-subduction　zone　(SSZ).　The　document　of　the　Early　Paleozoic　Nuodong　ophiolite　provides　key　evidence　for　the　existence　of　an　Early　Paleozoic　oceanic　basin　and　subduction-accretionary　collisional　orogenesis　between　Yangtze　craton　and　Cathaysia　blocks　in　South　China.　©　2016,　Editorial　Department　of　Earth　Science.　All　right　reserved.