Biostratigraphy and paleobiogeography of Middle and Late Ordovician conodonts from the Langkawi Islands, northwestern peninsular Malaysia

Abstract

The Middle and Upper Ordovician sequence of the Langkawi Islands, northwestern peninsular Malaysia, contains 20 species of conodonts belonging to 15 genera and four unidentified species, which are described and illustrated. The following four biostratigraphic zones are established for the study area: the Scolopodus striatus assemblage zone, the Periodon sp. A range zone, the Baltoniodus alobatus range zone, and the Hamarodus europaeus range zone, in ascending order. The Middle Ordovician fauna belongs to the low-latitude, warm-water Australian Province. Conodonts of the H. europaeus zone represent the HDS (Hamarodus europaeus-Dapsilodus mutatus-Scabbardella altipes) biofacies, which has been reported from the cool-water North Atlantic Faunal Region. The middle Arenigian limestones in the study area were deposited on a shallow-water shelf, whereas the late Arenigian to middle Darriwilian limestones formed in hemipelagic deeper-water conditions on an outer shelf or slope.

Global Upper Ordovician correlation by means of δ13C chemostratigraphy: implications of the discovery of the Guttenberg δ13C excursion (GICE) in Malaysia

“…faunas that show similarities to tropical zone faunas from Australia and China (Agematsu, Sashida & Ibrahim, 2008). and other taxa indicating a Tremadocian age.…”

“…This section, which is situated on an island off the northeastern corner of Langkawi Island (Fig. For this investigation, we used samples 27-30, 32-37, 39, 80 and 79 of Agematsu, Sashida & Ibrahim (2008), which provided suitable material for δ 13 C carb analysis. For this investigation, we used samples 27-30, 32-37, 39, 80 and 79 of Agematsu, Sashida & Ibrahim (2008), which provided suitable material for δ 13 C carb analysis.…”

“…The best biostratigraphic control of the study succession is provided by the conodonts as described by Agematsu, Sashida & Ibrahim (2008). The best biostratigraphic control of the study succession is provided by the conodonts as described by Agematsu, Sashida & Ibrahim (2008).…”

“…Pioneer work on the conodonts was published by Igo & Koike (1967), based on a very small number of samples. Agematsu, Sashida & Ibrahim (2008) showed that the late Sandbian and Katian conodont species successions exhibit a striking similarity to those in the interval of the globally distributed Guttenberg δ 13 C excursion (GICE) in the Pagoda Formation of the Yangtze Platform in southern China as recorded by Bergström et al (2009b). Recently, using 40 systematically collected samples from the top 150 m of the Kaki Bukit Formation, Agematsu, Sashida & Ibrahim (2008) provided a modern reappraisal of the conodont biostratigraphy of this interval.…”

“…In this region, a succession of mainly carbonate rocks, which is estimated to have a thickness of more than 1 km, is now classified as the Kaki Bukit Formation. Recently, using 40 systematically collected samples from the top 150 m of the Kaki Bukit Formation, Agematsu, Sashida & Ibrahim (2008) provided a modern reappraisal of the conodont biostratigraphy of this interval. Pioneer work on the conodonts was published by Igo & Koike (1967), based on a very small number of samples.…”