No abstract

Bone River Estuary acts as a connecting lane between the three rivers (Bolango River, Bone River, and Tamalate River) with Tomini Bay. There is a port activity of goods located right on the river estuary, which is potentially disrupted due to the silting and can cause flood. This situation will undoubtedly disrupt port transportation routes and affect the economic condition of Gorontalo. The aim of this research is to identify the potential of sediment utilization at the downstream of the Bone River as an effort to prevent siltation at the estuary of river Bone, Gorontalo and to prevent flood. The method used in this research is field observation which includes observation of the morphological condition of research location and sampling. Samples will then be processed by means of sieving, separation, and classification of Sphericity sediment material by referring to zoning classification and Sneed and Folk classification. The result of histogram data showed that the sediment material was dominated by coarse sand size and grain size distribution dominated by coarse sand with size of phi is 0, on sediment data showed generally very leptokurtic with skewed skill or highly skewed.

Geology is an important aspect in the development of tourism in an area. One of the attractions in a natural tourism location is certainly highly controlled by the geological setting in the area. The purpose of this research is to assess tourism values of geological features in the Bongo and surrounding areas as a basis for developing geotourism on the southern coast of Gorontalo. The research location is at coordinates N 00029’42” - N 00029’51” and E 12301’26” - E 12303’32”. The method used in this study is a surface geological survey, which includes field data collection in the form of lithology, geological structure and geomorphology. The standard used for assessing tourism values is the technical guide for assessing geological heritage resources by the Geological Survey Center. The results showed that the lithology unit of the study area consists of granite, volcanic breccia and reef limestone. The geological structure in the research area is shear fracture with main stress that relatively directed to northwest-southeast. The geomorphic unit of the study area consisted of two units, namely volcanic hills, and marine units. The results of the assessment of tourism values on geological features explain that the Bongo and surrounding areas are included in the medium category. Improvements are needed on low value criteria, namely vulnerability, relationships with other values, and economic level.

The Dolokapa Formation is a sedimentary rock formation formed in a deep-sea depositional environment with a fairly complex level of deformation and tectonic arrangement. Analysis of the sedimentation mechanism is carried out to determine how much tectonic influence on the mechanisms that occur in a depositional environment and the variations in the sedimentation mechanism formed. Research on the sedimentation mechanism needs to be carried out to determine the history of the formation of Gorontalo sedimentary rocks, especially in the Dolokapa Formation which was formed during the Miocene. The purpose of this study is to know the mechanisms of deep-marine sedimentation based on the identification of lithological characteristics, layer stacking patterns, and sedimentary structures. The method used was measuring sections using a range of ropes divided into four measurement paths. After that, a correlation was performed based on the genesis of deep marine formation. Based on the results of processing and analysis of the data, obtained units of lithology that insertion silty-clay, and the sandstone graining insertion of silt. In vertical succession, the layering pattern formed generally thickens upwards which describes the energy of the depositional currents. The sedimentary structure consists of rip up-clast, parallel lamination, graded bedding, convolute, slump, and trace fossils of nereites trace fossils of nereites that characterize the sedimentation of traction currents and turbidite currents in the deep-sea environment. The sedimentation mechanism formed is the traction current mechanism which is a further development of turbidite current and high-low concentration turbidity current mechanism that occurs slowly on a suspension-controlled grain. The stratigraphic relationship of the rock units in the research area is aligned based on the genesis formation that is located in the setting of the deep marine.