Structural controls on polyphase hydrothermal dolomitization in the Kinta Valley, Malaysia: Paragenesis and regional tectono-magmatism

Abstract

In the eastern side of the Malay Peninsula, thick successions of limestone formations preserve important records of the Mesozoic and Cenozoic tectonic events. Here we investigate the strata-and fracture-bound hydrothermal dolomites in the Palaeozoic carbonates of the Kinta Valley, western Peninsular Malaysia. Based on their textural and morphologic characteristics, structural relationships with the host rock, different facies types, and associations with hydrothermal calcite and low-grade metamorphic marble, we attempt to trace their polyphase origin and relationship with thermo-tectonic events of the region. A detailed evaluation of the nature of brecciation and crystallization of polyphase dolomites, dolomitic limestones, limestones and marble, under the influences of episodic faulting, is associated with the regional structural geology with emphasis on pre-existing fault reactivations, granitic emplacement and progressive thermal influence. Supply of Mg 2+ from the host rock for dolomitization, limited and episodic influx of circulating fluids and cessation of thermotectonic evolution with progressive cooling are also inferred. Correlating the geological events in western Peninsular Malaysia with regional structural dynamics reveals that the major deformation episodes exerted first order controls on the loci of dolomite occurrences.The occurrence, geometry and structural relationships of the dolomites were controlled by successive magmatic events, whereas, the intensity of replacement dolomitization was controlled by host rock texture and varied bulk chemistry, together with the nature of circulating fluids.

Geochemical evolution of structure-bedding controlled hydrothermal dolomites of the Kinta Valley, Western Malaysia

“…K The brecciated dolomites in P6 facies are cut through by calcite veins. L Dolomite crystals being severely sheared and tectonized again reflects the recurrence of tectonic events (adapted from Ramkumar et al 2019) statistical analyses examined 33 geochemical constituents for their quantitative measurements using SPSS software, utilizing a standardized dataset with uniform measurement units and PAAS-normalized REE data. Statistical techniques such as correlation and factor analysis were also performed within the same facies and among various facies, grouping according to elemental compositions, the variance of data and dominance of respective elements over total variance (Ramkumar et al 2006(Ramkumar et al , 2013(Ramkumar et al , 2014.…”

“…Fig. 1 A-D Regional geological setting, structural trends and location of the study area (modified after Ramkumar et al 2019). A Simplified regional topographic map showing the regional setting and location of the Kinta Valley in western Malaysia.…”

“…The Kinta Valley roughly exhibits a "V" shaped morphology. Ramkumar et al (2019) documented the structural characteristics of the quarry and from the study of the petrographic characteristics of Kinta-Valley carbonates, classified them into seven facies using textural and morphological classification in which six are dolomitic facies and the other is HCM facies and the same are considered for the present study. Textural descriptions adopted terminologies proposed by Friedman (1965), Gregg and Sibley (1984), Gregg (1987), andMazzullo (1992), while that of size description adopted Folk's (1962) size scale (< 30 µm -finecrystalline, 30-150 µm -medium-crystalline and > 150 µm -coarse-crystalline dolomite).…”

“…It is herein inferred that the extensive recrystallization and dolomitization affecting the Kinta host calcareous mudstones (HCMs) were also the result of these thermal events (Fontaine and Ibrahim 1995;Lee 2009). The chronological sequence of these major tectono-magmatic events and subsequent structural deformations (Ramkumar et al 2019) are presented in Fig. 1E and F.…”

Hydrothermal Dolomitization on Devonian to Carboniferous Carbonates in Kinta Valley, Perak, Malaysia: A Petrographic Study

“…Ali et al, 2016;François et al, 2017;Sautter et al, 2017). They likewise suggested that moving liquids in the Late Cretaceous brought a significant remagnetiz ation of Palaeozoic and Triassic rocks (Metcalfe, 1993(Metcalfe, , 2013Richter et al, 1999;Ramkumar et al, 2019). In the Main Range granitoids, during Late Cretaceous, thermal episodes may be presented by huge acidic or felsic fluids stopping up existing structure sets (Sautter et al, 2017).…”