A novel actinomycete, designated strain Sco-B14(T), was isolated from volcanic ash collected near Darangshi Oreum (a parasitic or satellite volcano) in Jeju, Republic of Korea. The organism formed well-developed, branched substrate mycelium, on which short chains of non-motile spores were arranged singly or in clusters. Aerial mycelium was not produced. Globose bodies were observed. The reverse colour of colonies was light brown to brown. Diffusible pigments were produced on ISP medium 3 and oatmeal-nitrate agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain Sco-B14(T) formed a lineage within the family Micromonosporaceae and was distinct from established genera. The 16S rRNA gene sequence similarity of strain Sco-B14(T) to members of related genera of the family was 95.0-95.7 % to type strains of Catellatospora species, 94.7 % to Hamadaea tsunoensis IMSNU 22005(T), 94.7 % to Longispora albida K97-0003(T) and 94.0 % to Catelliglobosispora koreensis LM 042(T). 3-Hydroxydiaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. Whole-cell sugars were glucose, rhamnose, ribose, xylose, arabinose, galactose and mannose. The polar lipids included diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol. The menaquinone profile contained MK-10(H(4)) (49 %), MK-9(H(4)) (24 %), MK-10(H(6)) (18 %) and MK-9(H(6)) (9 %). The predominant fatty acids were iso-C(15 : 0) and C(17 : 0). The DNA G+C content was 70.1 mol%. The combination of chemotaxonomic and phylogenetic data clearly separated the isolate from the type strains of all genera in the family Micromonosporaceae. On the basis of the phylogenetic and chemotaxonomic data presented in this paper, strain Sco-B14(T) is considered to represent a novel species of a new genus in the family Micromonosporaceae, for which the name Allocatelliglobosispora scoriae gen. nov., sp. nov. is proposed. The type strain of Allocatelliglobosispora scoriae is Sco-B14(T) (=KCTC 19661(T) =DSM 45362(T)).