Open AccessThe Palaeo-Kambaniru river mouth, Sumba, East Nusa Tenggara, Indonesia: A record of strongly seasonal catastrophic flow in a monsoon-controlled deltaic complex
Author(s) -
JohnPaul Zonneveld,
Yahdi Zaim,
Yan Rizal,
Aswan Aswan,
A.R. Fortuin,
Roy Larick,
Russell L. Ciochon
Publication year - 2021
Publication title -
berita sedimentologi
Language(s) - English
Resource type - Journals
eISSN - 2807-274X
pISSN - 0853-9413
DOI - 10.51835/bsed.2021.47.3.360
Subject(s) - geology , reef , fluvial , paleontology , coral reef , terrace (agriculture) , conglomerate , pleistocene , ecological succession , river terraces , delta , geomorphology , oceanography , sedimentary rock , archaeology , structural basin , geography , ecology , aerospace engineering , engineering , biology
The Kambaniru River valley near the city of Waingapu preserves a thick succession of coarse-grained fluvial-deltaic sediment deposited during the Late Pleistocene. This succession incises through a thick uplifted coral reef terrace succession and records intervals of highly episodic flow events during the last glacial interval. The occurrence of intraclastic, coarse sand/gravel matrix olistostromes in several areas attests to the occasionally catastrophic nature of flow in the ancestral Kambaniru River. Small to moderate-sized coral-rich reefs and laterally restricted reef terraces occur on delta-front conglomerate successions at multiple horizons through the study interval. These reefs record both intervals of low flow as well as periodic river-mouth avulsion episodes. Comparison of radiometric dates obtained from pelecypod and coral material from both deltaic successions and laterally adjacent coral reef terrace intervals indicates that uplift/subsidence history of the terraces differs from that of the valley and that correlation between the two should be taken with care.