Premium
The Olenekian (Early Triassic) Red Ammonoid Limestone, A Time‐Specific Facies on the Gondwana Margin: Timor – Roof of the World – Oman Connection
Author(s) -
BAUD Aymon
Publication year - 2013
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/1755-6724.12150_2
Subject(s) - extinction event , geology , margin (machine learning) , gondwana , baud , connection (principal bundle) , facies , cover (algebra) , paleontology , tectonics , computer science , geometry , mathematics , telecommunications , sociology , mechanical engineering , biological dispersal , population , demography , structural basin , transmission (telecommunications) , machine learning , engineering
biological crises (Brett et al., 2012). The lower Triassic red ammonoid limestone is one of them deposited during a recovery phase following the end of Permian great dying. This Olenekian TSF is similar to strongly condensed younger Triassic cephalopod limestone known as the Hallstatt limestone in the Austrian Alps (Marcoux & Baud, 1996). We will introduce here three areas with localities on the former Gondwana margin, from Timor to Oman through the roof of the World (Plate, Fig. 1). The first locality occurs near Basleo, in West Timor (Plate, Fig. 5 and 7) where a red ammonoid limestone Exotic block, Smithian (Lower Olenekian) in age according to H. Bucher, (oral communication), crops out within the Neogene Bobonaro melange. This exotic is originating from a detached Triassic seamount incorporated in the North Australian accretion prism, some blocks has been subsequently reworked during Neogene time and transported on West Timor Island. Oman Exotic isolated blocks of same size and same age (Smithian) condensed red ammonoid limestone occur in Wadi Musjah (Plate, Fig. 4 and 6) about 100 km South of Muscat (Sultanate of Oman). The ammonoid faunas have been recently described by Bruehwiler et al. (2012). The Olenekian TSF also occurs within a Permian to Jurassic stratigraphic succession of a large block, the Ba'id Exotic in Wadi Alwa area (Plate, Fig. 4, Oman Mountains). The microbial input in the red ammonoid limestone has been described by Woods & Baud, (2008), and an early Olenekian (Smithian) age is given by Bruehwiler et al., (2012). The Ba'id Exotic is interpreted as a tilted block of the distal margin (Pillevuit et al., 1997; Baud et al., 2001). As other Exotics, these blocks have been transported on the Arabian margin during the upper Cretaceous obduction of oceanic crust. Between Timor and Oman, this Olenekian TSF is present in the Indus Suture zone within the Lamayuru Exotic block (Plate, Fig. 2 and 3) described by Bassoullet Aymon BAUD, 2013. The Olenekian (Early Triassic) Red Ammonoid Limestone, A Time-Specific Facies on the Gondwana Margin: Timor Roof of the World Oman Connection. Acta Geologica Sinica (English Edition), 87(supp.): 894-895.