## 5 Conclusions  
Isolated strains of native bacteria belonging to _Pseudoalteromonas tetradonis_, _Oceanobacillus profundus_, and _Vibrio maritimus_ were identified and cultured. These are moderately alkalo-tolerant bacteria, showing maximum growth and urease activity at an ambient temperature of 37 \({}^{\circ}\)C, which is compatible with the tropical climate prevailing in the target region. Microbial carbonate overriding environmental control is seen in the present day by localization of microbial carbonates in calcareous streams and springs and in shallow tropical seas, and in the past by temporal variation in the abundance of marine microbial carbonates. Only \(\sim\)4.7% of ureolytic bacteria and algae precipitation, respectively, were assumed to be catalytic factors in beachrock precipitation. The beachrock of Krakal-Sadranan beach in the studied area can be categorized into non-beachrock, unconsolidated beachrock (similar to limestone sands), and well-consolidated beachrock consisting of mostly rock-mineral. Beachrock has a fairly consolidated feature and consists of a mixture of gravel-sized deposits of sand in the form of limestone fragments, calcite, and fossil minerals, and almost 50% CaO content (carbonaceous). The interpretation of the cesium anomaly can be used to determine the source of the REEs in this formation, indicating that the beachrock deposition processes originated from the precipitation of seawater under oxidative conditions. This can be interpreted as the beachrock derived from microbial process involving terrigenous materials under oxidative conditions. Thus, the most favorable condition is to have the presence of oxygenated material contamination. Beachrock occurrence in an area depends on highly geological factors that contribute the matrix interior. Indonesian geological settings seem to be dominated by marine activities of the Pacific Ocean and may be labeled as oxidative conditions. **Supplementary Materials:** The following are available online at [[http://www.mdpi.com/2076-3417/10/2/520/s1](http://www.mdpi.com/2076-3417/10/2/520/s1)]([http://www.mdpi.com/2076-3417/10/2/520/s1](http://www.mdpi.com/2076-3417/10/2/520/s1)), S1-S3 Regional geology of research study; Figure S1. Beachrock occurrences in Krakal-Sadranan, Yogyakarta, Indonesia; Figure S2. Geological settling of Yogyakarta south coast, Indonesia. (a) Krakal-Sadranan beach consists of limestone formation between Wonosari formation interfering with Pununung formation (b) Parampatrisity beach consist of alluvial Merapi volcano deposit. ; Figure S3: Map of the esearch area; Figure S4: Syringe cementation test scheme; Figure S5: Stratigraphic of the Trench CD: (A) Petrographic on cross polarized nicol (XPL, A1) and plane polarized nicol (PPL, A2) with sf = skeletal fragment; mc = micrite; sp = sparitic; ca = calcite, ar = arcagnite. (B) Degree of cementation based on composition of beachrock; Figure S6: Stratigraphic of the Trench EF: (A) Petrographic on cross polarized nicol (XPL, A1) and plane polarized nicol (PPL, A2) with sf = skeletal fragment; mc = micrite; sp = sparitic; ca = calcite, ar = arcagnite. (B) Degree of cementation based on composition of beachrock; Figure S7: Beachrock elements analysis based on (a) PAAS (Post-Archean Australian Shale from [PERSON] et al. [20]) normalized major oxide diagram for limestone samples of beachrock, (b) Trace element normalizing based on Average Phanerozoic Limestone from [PERSON] et al. [19]; Figure S8: Cell growth and urase activity of (a) _Pseudoalteromonas tetradonis_, (b) _Oceanobacillus profundus_, and (c) _Vibrio maritimus_; Table S1: Standart normalization rare earth element (REE) results concentration for sediment. The major element of beachrock (ppm), trace element result (in ppm), and REE of beachrock (in ppm). **Author Contributions:** L.R.D., and S.K. performed the measurements, S.K., K.N., and L.R.D. were involved in planning and supervised the work, L.R.D., processed the experimental data, performed the analysis, drafted the manuscript and designed the figures.