Sand Shale Ratio as Holocene Sea Level Change Indicator on The Gresik Plain, East Java

Sea Level Change Phenomenon is interest to be researched. Since Geological Quantitative approach needs to be required to solve the facing problem. Sand Shale Ratio as Holocene Sea Level Change Indicator on The Gresik Plain, East Java as the topic of the thesis research, wish could be implemented in the future. Analytical data were obtained by the shallow wells drilled on the surrounding area. Statistical probabilistic approach has been utilized to verify, whether there is a difference between fluviatile sediments product and marine environment on the adjacent research area. The interpretation result of the Super Impose Map, Isopach Map, and Sand Shale Ratio, was indicated that probably, there are two kind of different genetic associated with the process of sedimentation occurring in the North and The South Blocks of the research area. Lilliefors method has been tasted on the Sidayu Block resulting as a normal distribution where L0 = 0, 2658, L (=0, 05) = 0, 271. However, on the Bungah Block resulting opposite, where L0 = 0, 824, L (=0, 05) = 0, 190. The result of Mann Withney Test which given Zcalc greater than Ztab (6, 5288 greater than 1, 96). indicated that there is a difference in the process of sedimentation between in Sidayu and Bungah Blocks. And also both population are tend to be different, as well as in the North and South Blocks. Geologically, it could be interpreted that the population data on Sidayu Block has been controlled by the external factor during the sedimentation process. Probably, due to the involvement of tectonic activity.