『Abstract
　The Transdanubian Range (Hungary, ALCAPA Unit) preserves a series of black shale-hosted Mn-carbonate deposits and cherty, Fe-rich Mn-oxide mineralized rocks associated with varicolored metalliferous claystones. Coccoid clumps (spherules), oval, tubular, and filamentous morphologies were observed by petrography, SEM-EDS, and TEM studies and are interpreted to be mineralized cellular materials. Local selective enrichment of bioessential elements (Mn, Fe, S, As, P, Mg, Ba, Sr, Co, Ce) occurs, and together with low δ¹³C values of the Mn carbonates also supports microbial mediated reactions. The results strongly suggest that the formation of Mn-Fe and Si minerals was associated with microbial metabolic processes. The role of aerobic chemolithoautotroph bacteria was essential in sequestering metal ions (Mn²⁺, Fe²⁺) from solution, which were deposited in the sediment pile and serve as a paleoenvironmental indicator of oxic conditions. These deposits are examples of, and therefore provide important criteria for identifying, non-sulphidic, oxic, microbial mineral processes. We provide a new genetic model for giant black shale-hosted Mn-carbonate deposits that involves episodic aerobic microbial processes.
　Although a part, if not the whole of the black shale-hosted Mn-carbonate deposits is of biogenetic-bacterial sedimentary origin, a hydrothermal/exhalative source of metals may have contributed to the formation of the deposits. An Fe-Mn-oxide chimney system is proposed to be a proximal facies to geofluid vents that occurred along fracture systems, which may have provided metals from deep-seated sources.

Keywords: Geomicrobiology; Geochemistry; Hydrothermal; Manganese deposits; Black shale; Jurassic; Microbial genetic model; Paleoenvironmental indicators』

1. Introduction
2. Metallogeny of black shale-hosted manganese deposits with special reference to the Tethyan realm
　2.1. Manganese deposits in space and time
　2.2. Manganese deposits and indications in the Tethyan realm with special attention to Jurassic occurrences
3. Geological setting and characteristics of the Urkut（Uとuの頭に´） deposit
　3.1. Regional tectonic setting
　3.2. Characteristics of the Urkut（Uとuの頭に´） manganese ore deposit
4. Results and discussion
　4.1. Textural characteristics and mineral composition of ore types
　　4.1.1. Cherty Fe-Mn-oxide ore (Csarda（最初のaの頭に´）-hill)
　　4.1.2. Contact Fe-Mn-oxide ore
　　4.1.3. Mn-carbonate ore
　4.2. Whole-rock geochemistry
　　4.2.1. Cherty Fe-Mn oxide ore (Csarda（最初のaの頭に´）-hill)
　　4.2.2. Contact Mn-oxide ore
　　4.2.3. Black shale-hosted Mn-carbonate ore
　4.3. Element ratios
　4.4. Stable isotope data, Mn-carbonate ore
　4.5. Organic geochemistry of black shale
　4.6. Metal source and enrichment
　4.7. Biomineralization
　4.8. Aerobic chemolithoautotrophic microbial model
　4.9. Mass-balance calculations
　4.10. The black shale problem - microbial Mn (II) oxidation as the key
5. Summary and conclusions
　5.1. Sources and concentration of metals
Acknowledgment
Appendix 2. Estimated Mn accumulation data of different environments
Appendix 3. Calculations
　Calculation for Mn
　Calculation for Fe
References