Research Article
Regression Proccess of Marine Hardground in Nanggulan FM., Kulon Progo Mountain, Yogyakarta
@INPROCEEDINGS{10.4108/eai.30-8-2021.2311536, author={Siti Nuraini and Lukmanul Hakim}, title={Regression Proccess of Marine Hardground in Nanggulan FM., Kulon Progo Mountain, Yogyakarta}, proceedings={Proceedings of the 2nd International Conference on Industrial and Technology and Information Design, ICITID 2021, 30 August 2021, Yogyakarta, Indonesia}, publisher={EAI}, proceedings_a={ICITID}, year={2021}, month={10}, keywords={hardground nanggulan beds coquina watupuru songgo clumprit regression}, doi={10.4108/eai.30-8-2021.2311536} }- Siti Nuraini
Lukmanul Hakim
Year: 2021
Regression Proccess of Marine Hardground in Nanggulan FM., Kulon Progo Mountain, Yogyakarta
ICITID
EAI
DOI: 10.4108/eai.30-8-2021.2311536
Abstract
A prominent of hardground layer was observed through the Nanggulan beds especially to Watupuru, Songgo and Clumprit Rive, Kulon Progo Montain. The hardground is characterized by a lithified of sea-floor due to sea surface exposure (Wilson and Palmer, 1992; James & Choquette, 1983). Basically, the hardground layer indicates a coarsening upward succession of calcareous claystone where the coarser carbonate material or grains concentrated to the uppermost of layer meanwhile the lower part tends to be decrease in grain-size. This research will study the character/ behavior of marine hardground whithin Nanggulan Formation during Middle Eocene time, which is reflecting a regression process. By using internal bedding character includes sedimentary texture (colourness, grain size, sorting, fabric, roundess, grain type) and sedimentary structures of Nanggulan beds in Watupuru, Songgo and Clumprit Rivers. Hardground layers in Watupuru exhibited bioclast or grain supported of conglomerate limestone. An intenssively ferroan oxide cement occurred among conglomeratic’s carbonate grains and or washed biosparite beds. Burrowing or ichnofossil still preserved as well to the coarser part of hardground layers. It indicates a shallowing depositional environment or regression process occurred during basin sedimentation. Another example of marine hardground related to shell debris layer or coquina.