Siwalik synopsis: A long stratigraphic sequence for the Later Cenozoic of South Asia

Abstract

The Tertiary sediments of northern Pakistan are an exceptional record of terrestrial sedimentation and represent most of Neogene time. Foremost is the Siwalik Group of the Potwar Plateau, for which multiple, superposed fossil levels span ~18 -6 Ma. Welldeveloped magnetostratigraphic control provides secure dating so that Siwalik fossil horizons may be interpolated into a time scale with resolution to 100,000 years. We describe the geographic setting of the Potwar, give an overview of the temporal distribution of faunas, and discuss changes in paleohabitat and paleoecology with latter deposits are Oligocene in age (Welcomme et al., 2001). Together they produce a rich record of successive faunas that can be studied for questions on lineage evolution, community structure, and faunal change.The Siwaliks and related formations have been the subject of field exploration for almost 200 years. Early collecting was sporadic, with little attention paid to provenance, but it provided impetus for later expeditions. Two of these were collecting campaigns under the direction of Barnum Brown of the American Museum of Natural History in the 1920s and G. Edward Lewis of Yale University in the 1930s. Their collecting (Lewis, 1937) was geographically controlled and today we can reconstruct in general where many of their collections were made. Richard Dehm (Dehm et al., 1958), Universität München expeditions of 1939 and 1955-56, and G.H.R. von Koenigswald, Rijksuniversiteit, Universiteit Utrecht (1966, also recorded data for fossils recovered by their groups.However, the potential for biostratigraphic study of long sections in defined areas was still largely unrealized.It is now feasible to record precisely the level of occurrence of superposed stratigraphic horizons that produce fossils. The sequence of sites records the local histories of organisms during much of the Miocene Epoch, both changes among members in associated faunas as well as evolution within lineages. The fossil horizons of the Potwar Plateau can be dated relative to one another, and ages can generally be resolved on the scale of 100,000 years for the interval of approximately 18 to 6 Ma . The Siwaliks present a special geobiological case in which many successive and dated levels can be sampled for their often abundant vertebrate fossils and ecological proxies, affording an excellent opportunity to document changes in landscapes, habitats, and faunas through time. The dimensions of information that can be retrieved from the Siwaliks are considerable compared to other sequences of comparable age.In the following, we discuss the geological and geographic setting for the major fossil-producing regions of the Indian Subcontinent. We sketch the history of exploration by early workers in the Indian Subcontinent. We touch on major features of the terrestrial deposits and age determination, and then turn to our current assessments of faunas and paleohabitats of the Miocene. Major Fossil-Producing Sequences and History of ExplorationEarly fossil collecting invo...

The taxonomic content of the genus Gavialis from the Siwalik Hills of India and Pakistan

“…However, recent biostratigraphical calibrations reveal that the Chinji Formation spans between about 14 and 11 Ma, corresponding to the middle Miocene (Flynn et al . ).…”

Understanding Soanian occurrences at Bam locality of Siwalik frontal range, north-western India

“…These are recovered at different points of times. It is important to mention that few archaic lineages continued much later here, at times when such continuity is found nowhere else in the Old World (Flynn et al, 2016). There is plentiful evidence of hominin occupation in the Siwalik area of the Indian subcontinent since at least the Middle Pleistocene.…”

Fluvial deposits as an archive of early human activity: Progress during the 20 years of the Fluvial Archives Group

“…central and peninsular India). The most recent claim is 2.6 Ma evidence of pre-Acheulian hominin activity, again from the Siwalik Hills, which preserve a continuous sequence of fluviolacustrine sediments from about 18 Ma onwards and extend from Pakistan to NE India (Flynn et al, 2016). This new claim from Masol (near Chandigarh, northern India) has been made by an Indo-French team which has published a series of 10 multidisciplinary papers in Comptes Rendus Palevol.…”