The distribution of vesicular structures in Sukadana Basalt, East Lampung, Indonesia, and its significance for the geological structure interpretation

Abstract

The characteristics of the geological structures controlling the presence of Sukadana basalt on the Earth’s surface are still an enigma. Therefore, this study was conducted to determine the probable types of geological structures and their orientations that could control the occurrence of Sukadana Basalt lava on the Earth’s surface. To seek answers to this problem, this study utilized vesicular structure data from Sukadana Basalt based on 13 rock samples from 13 observation points. We measured the diameter of the vesicular and the sum of the megascopic vesicular per cm2 for every sample. We used a scale of 1-5, where 1-2 indicated as small-low intensity vesicular, 3 indicated as medium-middle intensity vesicular, and 4-5 indicated as large-high intensity vesicular. it was found that there are three groups of vesicular that were developed in Sukadana Basalts: small-low, medium-middle, and large-high groups. This study gives information that there are three fracturures including two normal faults at the northern and southern parts of Sukadana Basalt and one fisurre in the middle of Sukadana basalt. The normal fault at the southern part of Sukadana Basalt has the widest fault core spacing and the fissure at the middle of Sukadana Basalt has the narrowest fissure core spacing. All groups show northwest-southeast striking fractures. This study will provide a new point of view that in interpreting subsurface geological structures can use primary structure characteristics data, especially vesicular structures.