MOLLUSCS TAPHONOMIC STUDY ON KALIWANGU FORMATION AT CIKANDUNG RIVER AND CIPEDES RIVER IN TANJUNGKERTA AREA SUMEDANG DISTRICT WEST JAVA

• Main Author: RIJANI, SONIA
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/13845
• Institution: Institut Teknologi Bandung

Kaliwangu Formation are consist of claystone, sandy clay and sandstone, and also consists of molluscs fossils dominated by gastropods and pelecypods. According to the taphonomical characteristics differentiation caused by sedimentary cycles, the molluscs shells concentration could be divided into four main classes: a. Early TST (Transgressive System Tract), which start on the top of erotional boundary (ravinement surface) or sequence boundary is characterized by disarticulation, bioturbation, gravel mix, high fragmentation without orientation from taksa, and concretion. b. Late TST (Transgressive System Tract) is charactarized by articulation (conjoined) in life position, where specimens are mature, low fragmentation, barren layers are sometimes founded. c. Early HST (Highstand System Tract) is characterized by mature taksa found locally random with life position and individual articulation, juvenille dominated, shell are broken a part and not complete, carbon layer and coal sometimes founded. d. Late HST (Highstand System Tract) is characterized by multiple-event concentrations, shell orientation parallel with layer without content fossils, disarticulation dominated, carbon thin layer or amber sometimes could be found. Clay mineral analysis show comprehensive result about molluscs sedimentary environment. The existence of Zaria angulata species of sample no 08 SRi 02, which associated with nontronite could be interpreted as the nearshore while its association with nacrite on sample no 08 SRi 76 could be interpreted as beach (intertidal) environtment. The existence of Paphia vandermeermohri on sampel 08 SRi 07, which associated with kaolinite could be interpreted as the beach (intertidal) environtment, while its association with montmorillonite (bentonite) is interpreted as nearshore. c. the existance of Placuna placenta species on sampel 08 SRi 10 and 08 SRi 03 that associated with montmorillonite, could be interpreted as the nearshore environtment. And the existance of Murex (M) lebacouldus MARTIN, on sample no 08 SRi 12 and its association with kaolinite could be interpreted as beach (intertidal) environtment.