Pemelajaran Sedimentology dari Singkapan Batuan Miosen di Cekungan Kutai, Kalimantan Timur

Rp200,000.00

SARI

Singkapan batuan Miosen Delta Mahakam yang dipelajari karakterisitik sedimentnya secara detail sebanyak 49 singkapan. Singkapan tersebut terdiri dari sekuen endapan pasir dan lempung delta. Pemelajaran singkapan ini didukung oleh pengukuran paleo-current, analisa paleontology dan surface gamma-ray logging dari singkapan. Singkapan-singkapan yang memperlihatkan perubahan genesa akan dipelajari secara detail dengan menggunakan kolom deskripsi batuan, yang bertujuan untuk memperlihatkan pengukuran paleo-current yang akan dianalisa secara detail sepesii dalam satu lapisan, satu tubuh pasir dan perulangan dari beberapa tubuh pasir. Pemelajaran ini memperlihatkan perkembangan dari paleo-current selama Miosen yang bekembang kearah Timur, meskipun terdapat beberapa penyimpangan hasil pengukuran pada bagian Selatan Delta Mahakam Pemelajaran singkapan Miosen Delta Mahakam ini memberikan masukan bahwa proses fluvial merupakan proses sedimentologi yang paling dominan, dan proses kedua yang berpengaruh adalah proses arus pasang dan proses gelombang hanya dapat ditemukan dibeberapa tempat.

ABSTRACT

A total of 49 Miocene outcrops in eastern Kutai Basin have been studied for their sedimentology characteristics. They mostly consist of sandstone and shale of deltaic sequences. To complement the study, paleo-current measurements, paleontology analyses, and surface gamma-ray logging were also performed on the outcrops. Several outcrops, which show some degrees of heterogeneity, were specially described by using spatial lithology column description strategy. Likewise, the paled-current measurements cm these outcrops were specially analyzed, i.e.: on a bed-set, sand body, and stacked-sand scales. The study reveals that most of the paleo-current during Miocene is toward the easterly direction. Some anomalies were observed in southern part of Mahakam Delta area, where there is a component of a southerly paleo-current direction on the outcrops. The sedimentology study suggests that most of the time the fluvial processes were predominant in the Miocene deltaic environment interpreted from the outcrops. The tidal processes were ranked as the second most important factor, while the wave actions were only found as traces and scattered unsystematically.

Description

Authors : Hendarman, Edy Kurniawan, Yulie Purwanti, Andang Bachtiar & Dody Apriadi