eprintid: 6875
rev_number: 2
eprint_status: archive
userid: 1
dir: disk0/00/00/68/75
datestamp: 2023-11-09 16:18:40
lastmod: 2023-11-09 16:18:40
status_changed: 2023-11-09 16:07:53
type: article
metadata_visibility: show
creators_name: Mathew, M.J.
creators_name: Menier, D.
creators_name: Siddiqui, N.
creators_name: Kumar, S.G.
creators_name: Authemayou, C.
title: Active tectonic deformation along rejuvenated faults in tropical Borneo: Inferences obtained from tectono-geomorphic evaluation
ispublished: pub
keywords: deformation; fold and thrust belt; geomorphology; landscape evolution; neotectonics; tectonic structure; uplift, Borneo
note: cited By 45
abstract: The island of Borneo is enveloped by tropical rainforests and hostile terrain characterized by high denudation rates. Owing to such conditions, studies pertaining to neotectonics and consequent geomorphic expressions with regard to surface processes and landscape evolution are inadequately constrained. Here we demonstrate the first systematic tectono-geomorphic evaluation of north Borneo through quantitative and qualitative morphotectonic analysis at sub-catchment scale, for two large drainage basins located in Sarawak: the Rajang and Baram basins. The extraction of morphometric parameters utilizing digital elevation models arranged within a GIS environment focuses on hypsometric curve analysis, distribution of hypsometric integrals through spatial autocorrelation statistics, relative uplift values, the asymmetry factor and the normalized channel steepness index. Hypsometric analysis suggests a young topography adjusting to changes in tectonic boundary conditions. Autocorrelation statistics show clusters of high values of hypsometric integrals as prominent hotspots that are associated with less eroded, young topography situated in the fold and thrust belts of the Interior Highlands of Borneo. High channel steepness and gradients (>200 m0.9) are observed in zones corresponding to the hotspots. Relative uplift values reveal the presence of tectonically uplifted blocks together with relatively subsided or lesser uplifted zones along known faults. Sub-catchments of both basins display asymmetry indicating tectonic tilting. Stream longitudinal profiles demonstrate the presence of anomalies in the form of knickzones without apparent lithological controls along their channel reaches. Surfaces represented by cold spots of low HI values and low channel gradients observed in the high elevation headwaters of both basins are linked to isolated erosional planation surfaces that could be remnants of piracy processes. The implication of our results is that Borneo experiences active folding of the Rajang Group fold-thrust belt to present and these events reactivated old major faults and minor related dislocations. From geomorphic analysis associated with sedimentary record, we posit that the terrain could have undergone high uplift rates since 5 Ma or multi-phased uplift with periodic intermittent pulses of high and low uplift rates. © 2016 Elsevier B.V.
date: 2016
publisher: Elsevier B.V.
official_url: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84969780200&doi=10.1016%2fj.geomorph.2016.05.016&partnerID=40&md5=c0fbcb170f50ef2cc5a6c7625a5778a3
id_number: 10.1016/j.geomorph.2016.05.016
full_text_status: none
publication: Geomorphology
volume: 267
pagerange: 1-15
refereed: TRUE
issn: 0169555X
citation:   Mathew, M.J. and Menier, D. and Siddiqui, N. and Kumar, S.G. and Authemayou, C.  (2016) Active tectonic deformation along rejuvenated faults in tropical Borneo: Inferences obtained from tectono-geomorphic evaluation.  Geomorphology, 267.  pp. 1-15.  ISSN 0169555X