DOCSLIB.ORG

Where the Meghalayan Meets the Anthropocene: Stratigraphic Signals of Human-Environmental Interactions on the Periphery of Indian Civilisation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Where the Meghalayan Meets the Anthropocene: Stratigraphic Signals of Human-Environmental Interactions on the Periphery of Indian Civilisation Geographia Polonica 2020, Volume 93, Issue 4, pp. 505-523 https://doi.org/10.7163/GPol.0185 INSTITUTE OF GEOGRAPHY AND SPATIAL ORGANIZATION POLISH ACADEMY OF SCIENCES www.igipz.pan.pl www.geographiapolonica.pl WHERE THE MEGHALAYAN MEETS THE ANTHROPOCENE: STRATIGRAPHIC SIGNALS OF HUMAN-ENVIRONMENTAL INTERACTIONS ON THE PERIPHERY OF INDIAN CIVILISATION Paweł Prokop Institute of Geography and Spatial Organization Polish Academy of Sciences Jana 22, 31-018 Kraków: Poland e-mail: [email protected] Abstract The aims of this study were to review human-environment interactions during the Meghalayan and to search for the stratigraphic boundary of a new epoch, informally termed the Anthropocene, as well as to determine whether the stratigraphic signals of human activity on the Meghalaya Plateau in Northeast India can be cor- related globally. This plateau is the base of the Meghalayan Age that was determined from a speleothem in a cave located on it. Review indicates that study region developed on the periphery of ancient Indian civi- lisation, with stratigraphic signals of human activity being apparent in only the last few thousand years; that is, substantially later than the neighbouring ancient Indian civilisation. The stratigraphic signals are heteroge- neous and diachronous, not only as a result of various human activities, but also in the effect of the diverse sensitivities of the environment to anthropogenic disturbances. A discrete and visible cultural layer that relates to the development of settlements and the production of new materials is still being formed and reworked. The only synchronous stratigraphic signal with a global range seems to be associated with the artificial radio- nuclide fallout from nuclear weapons testing, which covers a topsoil layer of up to tens of centimetres thick. Key words stratigraphy • Holocene • Anthropocene • Meghalaya • human impact Introduction The effects of such interactions can be pre- served in accumulating strata as lithostrati- Human-environment interactions exhibit great graphic (environmental and human-induced diversity, with many feedbacks and nonlinear sediment transport and deposition, modifica- processes, thresholds and time lags (An, 2012; tion of terrain, deposition related to construc- Ruddiman, Ellis, Kaplan & Fuller, 2015; Waters tions, etc.), biostratigraphic (pollen grains & Zalasiewicz, 2018; Zalasiewicz et al., 2019b). spectra, extinctions and invasions of species) 506 Paweł Prokop and chemostratigraphic (heavy metal trac- Since then, ‘Anthropocene’, as an informal ers, isotopes, artificial radionuclides) signals term, has become popular, being used (Zalasiewicz et al., 2019). Such markers pro- among different scientific communities, vide a record of Earth’s history, and can form including scholars in the humanities, as well the basis for its subdivision within the Geologi- as in the scientific literature, discussions and cal Time Scale (GTS; Gradstein, Ogg, Schmitz, the public media (Fig. 1). Three scientific jour- & Ogg, 2012). nals listed in the Journal Citation Report have The units of geological time are defined the word ‘Anthropocene’ in their titles –, The with reference to their lower boundaries Anthropocene (Elsevier), The Anthropocene – their beginnings or ‘bases’ (Gradstein Review (SAGE) and Elementa: Science of the et al., 2012). Such boundaries are drawn Anthropocene (University of California Press). using a Global Stratigraphic Section and Simultaneously, since 2009 an Anthropocene Point (GSSP) or, before GSSP, can be defined Working Group (AWG) has been looking by an agreed date, termed a Global Strati- for scientific evidence for the basal Anthro- graphic Standard Age (GSSA). For a GSSP, pocene boundary to support its ratification ‘stratigraphic section’ refers to a deposit by the IUGS as an epoch in the GTS (Zala- (rock, sediment, glacier ice, speleothem) that siewicz et al., 2019). The problem of bound- developed an adequate thickness over time ary demarcation was slightly complicated that is chosen as the representative (i.e. type) when, in 2018, the IUGS accepted a subdivi- section, known as the ‘stratotype’, while sion of the Holocene Epoch, the new units ‘point’ refers to the location of the marker being the Greenlandian, the Northgrippian used to define the boundary within the strato- (both named after GSSPs located in Green- type. GSSP markers should ideally be comple- land) and the Meghalayan (the GSSP located mented by a series of auxiliary stratigraphic in Meghalaya state in Northeast India) Ages, sections that are globally synchronous. GSSPs which correspond to the Early, Middle and must also have an exact location and height Late Holocene, respectively (Walker et al., or depth, and must be accessible and have 2018). In effect, officially, we live in the Megh- provisions for conservation and protection. alayan Age of the Holocene Epoch, while the Proposals for new GSSPs must be formally rat- Anthropocene is used as an informal (i.e. not ified by the International Union of Geological yet officially defined) geological unit. Sciences (IUGS). The ratification of the Meghalayan Age The same criteria had to be met in the drew attention to the small state that covers defining and subdivision of the Holocene the hilly plateau located in Northeast India. Epoch, which is the epoch in which we live. This region lies at the junction of South Asia, The term ‘Holocene’ (meaning ‘entirely East Asia and Southeast Asia, and has been recent’) has been used for almost 150 years throughout the ages one of the most diverse (Walker et al., 2009); however, it was only areas in Asia, in terms of human-environmen- formally ratified by the IUGS in 2008. tal interactions (Ramakrishnan, 1992; Migoń While the Holocene refers to the current & Prokop, 2013; Prokop, 2014; Hazarika, interglacial, it is also known for the expan- 2017). The Meghalaya Plateau is the first bar- sion of humans, the development of agricul- rier to northward-moving air masses from the ture, and the growing use of metals. Thus, Bay of Bengal to the Himalayas, and as such even before the formal ratification of the receives the highest amount of orographic Holocene as an epoch, it was being sug- rainfall in the world, concentrated in the sum- gested that that epoch was over and that mer monsoon season (Prokop & Walanus, a new epoch, called the Anthropocene, 2015). In contrast, the low retention capacity had begun, its beginning distinguished of its soils, due to the geological conditions by the start of significant human activity in the area, results in water shortages dur- (Crutzen & Stroemer, 2000; Crutzen, 2002). ing the dry season (Starkel & Singh, 2004). Geographia Polonica 2020, 93, 4, pp. 505-523 Where the Meghalayan meets the Anthropocene: Stratigraphic signals… 507 1000 Holocene Anthropocene Meghalayan 800 Holocene Epoch ratification 600 400 Publications [number] Anthropocene Working Group Meghalayan Age 200 establishment ratification 0 2000 2005 2010 2015 2020 Figure 1. Publications in Web of Science with the topics Holocene, Anthropocene and Meghalayan from 2000 to 2019 The strong seasonality of the rainfall causes • (iii) to determine whether the effects this region to be equally vulnerable to floods of human-environmental interactions, and droughts, representing a significant bar- in the form of biogeochemical stratigraph- rier to human activity. At the same time, the ic signals on the Meghalaya Plateau, can neighbouring lowlands, incorporating the be correlated globally. Brahmaputra Valley and Bengal Plain, were corridors for early human dispersal between The Meghalayan Age versus South and East Asia, which may explain the the background of the Holocene cultural diversity of the Austro-Asiatic and Epoch in the context of human- Sino-Tibetan populations that inhabit this -environmental interactions area (Hazarika, 2017). The main aim of the present study is to The Holocene is the shortest epoch in the GTS review the role of natural and human-induced and, representing an interglacial, is relatively factors in the transformation of the environ- uniform in terms of climatic conditions. Thus, ment of the region where the Meghalayan its formal subdivision was based on a natural, GSSP is located. Assuming that, in the Anthro- short-lived episode that has left traces in the pocene, humans impact on the Earth system proxy climatic record (i.e. changes in the sta- at a global scale but their activities are het- ble oxygen isotope content in ice and speleo- erogeneous in space and time, it is important thems). Two such proxy events were used for to recognize the stratigraphic signals of this the global correlation of the Greenlandian/ impact in areas that have been developing Northgrippian and Northgrippian/Megha- on the periphery of ancient civilisations. layan boundaries (Walker et al., 2018). More specifically, the objectives of the The GSSP for the Greenlandian is the study are: same used for the previously ratified basal • (i) to review records of human-environ- Holocene in the NorthGRIP2 ice core, drilled ment interactions during the Meghalayan, in the central Greenland ice sheet (75.10°N, in contrast to the background Holocene; 42.32°W). This boundary corresponds to the • (ii) to investigate search for a definitive first signs of climatic warming at the end base for the Anthropocene as a potential of the Younger Dryas at 11,703±99 years b2k geological unit; and (before 2000 AD) (Walker et al., 2009). Geographia Polonica 2020, 93, 4, pp. 505-523 508 Paweł Prokop The basal Northgrippian was defined in the Mesopotamia (Weiss, 2017) and India (Staub- NorthGRIP1 Greenland ice core (75.10°N, wasser, Sirocko, Grootes, & Segl, 2003; Dixit, 42.32°W), in which there was a clear signal Hodell, & Petrie, 2014), as well as disrupting of climate cooling at 8,236±47 years b2k the Chinese civilisation (Liu & Feng, 2012; that reflects an outburst of water from gla- Li et al., 2018). cial lakes pouring into the North Atlantic Despite a growing human impact on the Ocean during the recession of the Laurentide Earth system during the Holocene, none Ice Sheet (Alley & Ágústdóttir, 2005; Kleiv- of its subdivisions were defined on the basis en et al., 2008).
Load more

Recommended publications
  • Circum-Indian Ocean Hydroclimate at the Mid to Late Holocene Transition: the Double Drought Hypothesis and Consequences for the Harappan” by Nick Scroxton Et Al
    Clim. Past Discuss., https://doi.org/10.5194/cp-2020-138-RC2, 2021 CPD © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Interactive comment Interactive comment on “Circum-Indian ocean hydroclimate at the mid to late Holocene transition: The Double Drought hypothesis and consequences for the Harappan” by Nick Scroxton et al. Harvey Weiss (Referee) [email protected] Received and published: 4 January 2021 Global KM-A Congruence and the Indus Collapse Harvey Weiss Printer-friendly version Department of Near Eastern Languages and Civilizations, Environmental Studies Pro- gram, and School of Environment, Yale University Discussion paper The IUGS-recognized global boundary stratotype for the 4.2 - 3.9 ka BP event, marking C1 the middle to late Holocene transition to the Meghalayan stage, is the KM-A speleothem δ18O record from Mawmluh Cave, Meghalaya, NW India, that is an Indian Summer CPD Monsoon (ISM) drought record (Berkelhammer et al 2012; Walker et al 2019). The recent analysis of the Indus delta foraminifera record at core 63KA has identified, as well, the Indian Winter Monsoon drought synchronous with the 4.2 ka BP ISM drought Interactive (Giesche et al 2019). The global boundary sub-stratotype is the Mt. Logan Yukon comment glacial core’s δ18O moisture event (Fisher et al 2008). Scroxton et al present a principal components analysis of seven recent δ18O speleothem records from the Indian Ocean region and the Giesche et al 2019 delta foraminifera analyses (line 110) “to investigate the impacts of the 4.2 kyr event on trop- ical Indian Ocean basin monsoonal rainfall” and the late third millennium BC Indus urban collapses.
    [Show full text]
  • Formal Ratification of the Subdivision of the Holocene Series/ Epoch
    Article 1 by Mike Walker1*, Martin J. Head 2, Max Berkelhammer3, Svante Björck4, Hai Cheng5, Les Cwynar6, David Fisher7, Vasilios Gkinis8, Antony Long9, John Lowe10, Rewi Newnham11, Sune Olander Rasmussen8, and Harvey Weiss12 Formal ratification of the subdivision of the Holocene Series/ Epoch (Quaternary System/Period): two new Global Boundary Stratotype Sections and Points (GSSPs) and three new stages/ subseries 1 School of Archaeology, History and Anthropology, Trinity Saint David, University of Wales, Lampeter, Wales SA48 7EJ, UK; Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, Wales SY23 3DB, UK; *Corresponding author, E-mail: [email protected] 2 Department of Earth Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario LS2 3A1, Canada 3 Department of Earth and Environmental Sciences, University of Illinois, Chicago, Illinois 60607, USA 4 GeoBiosphere Science Centre, Quaternary Sciences, Lund University, Sölveg 12, SE-22362, Lund, Sweden 5 Institute of Global Change, Xi’an Jiaotong University, Xian, Shaanxi 710049, China; Department of Earth Sciences, University of Minne- sota, Minneapolis, MN 55455, USA 6 Department of Biology, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada 7 Department of Earth Sciences, University of Ottawa, Ottawa K1N 615, Canada 8 Centre for Ice and Climate, The Niels Bohr Institute, University of Copenhagen, Julian Maries Vej 30, DK-2100, Copenhagen, Denmark 9 Department of Geography, Durham University, Durham DH1 3LE, UK 10
    [Show full text]
  • Regional Disparity in Summer Monsoon Precipitation in the Indian Subcontinent During Northgrippian to Meghalayan Transition
    REVIEW ARTICLES Regional disparity in summer monsoon precipitation in the Indian subcontinent during Northgrippian to Meghalayan transition Som Dutt1,*, Anil K. Gupta2, Rahul Devrani1, Ram R. Yadav1 and Raj K. Singh3 1Wadia Institute of Himalayan Geology, 33, General Mahadeo Singh Road, Dehradun 248 001, India 2Department of Geology and Geophysics, Indian Institute of Technology, Kharagpur 721 302, India 3School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Argul 752 050, India soon domain1–6,8–15. Detailed reviews on ISM variability The present study reveals distinct spatial variability of 1,2 summer monsoon precipitation in Indian subcontinent during Holocene are available , but regional precipita- during Northgrippian to Meghalayan transition. Pro- tion disparity in Indian subcontinent during the 4.2 ka tracted dry phase lasting ~1000 yrs was observed event is not much discussed. Here, we examined availa- ~4.2 ka BP in southern and northwestern India whereas ble marine and terrestrial proxy records of ISM variabi- 200–300 yrs event occurred in northeastern parts. lity from different regions in Indian subcontinent and Strong El Niño conditions beginning ~4.3 kyr BP were northern Indian Ocean (IO) for better understandings of associated with the millennial long dryness in western precipitation variability during Northgrippian to Megha- parts but its influence was limited in the eastern layan transition. region. Cross-verified, high-resolution records from different geographic regions of India are still required to ascertain if regional differences occurred in span Domain of ISM and magnitude during Northgrippian to Meghalayan transition. ISM precipitation is pivotal for socio-economic wellbeing of 1/3rd of human population living in Indian subconti- Keywords: Indian summer monsoon, Indus civilization, nent.
    [Show full text]
  • Sedimentological-Geochemical Data Based Reconstruction of Climate
    quaternary Article Sedimentological-Geochemical Data Based Reconstruction of Climate Changes and Human Impacts from the Peat Sequence of Round Lake in the Western Foothill Area of the Eastern Carpathians, Romania Réka Orsolya Tapody 1,Pál Sümegi 1,*, Dávid Molnár 1 ,Máté Karlik 2,3, Tünde Tör˝ocsik 1,Péter Cseh 1 and László Makó 1 1 Department of Geology and Palaeontology, University of Szeged, Egyetem Str. 2-6, H-6722 Szeged, Hungary; [email protected] (R.O.T.); [email protected] (D.M.); [email protected] (T.T.); [email protected] (P.C.); [email protected] (L.M.) 2 Isotope Climatology and Environmental Research Centre, Institute for Nuclear Research, Bem Square 18/c, H-4026 Debrecen, Hungary; [email protected] 3 Institute for Geological and Geochemical Research, RCAES, Budaörsi Str. 45, H-1112 Budapest, Hungary * Correspondence: [email protected] Abstract: This paper presents the results of comparative sedimentological and geochemical analysis of the mire at Sânpaul, Round Lake (Kerek-tó). The palaeoecological site is situated in the western Citation: Tapody, R.O.; Sümegi, P.; foothill area of the Eastern Carpathians in Romania. The primary objective of this study was to Molnár, D.; Karlik, M.; Tör˝ocsik,T.; analyse the accumulation of major and trace elements in a 7500 year-long peat and lake deposition. Cseh, P.; Makó, L. The concentrations of 13 elements were determined by using handheld XRF. This paper presents Sedimentological-Geochemical Data the results of a multidisciplinary study, for which the principal aims were to examine the long- Based Reconstruction of Climate term relationship between land degradation in the Homoród Hills using various palaeoecological Changes and Human Impacts from techniques, primarily comparative geochemical analyses.
    [Show full text]
  • Class 3 Social Science Chapter- 5 Our Beautiful Country Content-1 Landforms of India
    CLASS 3 SOCIAL SCIENCE CHAPTER- 5 OUR BEAUTIFUL COUNTRY CONTENT-1 LANDFORMS OF INDIA LANDFORMS OF INDIA HILLS AND PLAINS PLATEAUS DESERTS ISLANDS MOUNTAINS MAJOR LANDFORMS AND RIVERS OF INDIA HILLS AND MOUNTAINS • A high land with a round top is called a hill . The Vindhya Ranges in central India and the Nilgiri Hills in south India are examples of hills. • Very high hills with sharp tops (peaks) are called mountains . The Himalayan Mountain Ranges in the north is a example of mountains. • The Himalayan Mountain Ranges lie in the north. There are many peaks in these mountains. In mountain regions, it is cold throughout the year. • Mount Everest, on the Nepal-China border, is the highest peak in the Himalayan mountain ranges as well as in the world. Many rivers such as the Ganga, Yamuna, Satluj and Brahmaputra originate in these mountains and flow down to the plains. These rivers are formed by the melting snow. THE HIMALAYAS ARE THE HIGHEST MOUNTAIN RANGE IN THE WORLD PLAINS • Flat and level land is called a plain . To the south of Himalayas lie the Great Plains of India. In the plains, summers are hot and winters are cold. Rivers such as the Ganga and the Yamuna flow through these plains. These rivers have made the sofiel rtile . As a result, many crops are grown here. • There is a narrow strip of flat land along the eastern and the western coasts of India. It is known as the Eastern Coastal Plain and the Western Coastal Plain. These plains meet at Kanniyakumari. Rivers such as the Narmada, Tapi, Mahanadi, Godavari, Krishna and Kaveri flow through these plains and fall into the sea.
    [Show full text]
  • International Chronostratigraphic Chart
    INTERNATIONAL CHRONOSTRATIGRAPHIC CHART www.stratigraphy.org International Commission on Stratigraphy v 2018/08 numerical numerical numerical Eonothem numerical Series / Epoch Stage / Age Series / Epoch Stage / Age Series / Epoch Stage / Age GSSP GSSP GSSP GSSP EonothemErathem / Eon System / Era / Period age (Ma) EonothemErathem / Eon System/ Era / Period age (Ma) EonothemErathem / Eon System/ Era / Period age (Ma) / Eon Erathem / Era System / Period GSSA age (Ma) present ~ 145.0 358.9 ± 0.4 541.0 ±1.0 U/L Meghalayan 0.0042 Holocene M Northgrippian 0.0082 Tithonian Ediacaran L/E Greenlandian 152.1 ±0.9 ~ 635 Upper 0.0117 Famennian Neo- 0.126 Upper Kimmeridgian Cryogenian Middle 157.3 ±1.0 Upper proterozoic ~ 720 Pleistocene 0.781 372.2 ±1.6 Calabrian Oxfordian Tonian 1.80 163.5 ±1.0 Frasnian Callovian 1000 Quaternary Gelasian 166.1 ±1.2 2.58 Bathonian 382.7 ±1.6 Stenian Middle 168.3 ±1.3 Piacenzian Bajocian 170.3 ±1.4 Givetian 1200 Pliocene 3.600 Middle 387.7 ±0.8 Meso- Zanclean Aalenian proterozoic Ectasian 5.333 174.1 ±1.0 Eifelian 1400 Messinian Jurassic 393.3 ±1.2 7.246 Toarcian Devonian Calymmian Tortonian 182.7 ±0.7 Emsian 1600 11.63 Pliensbachian Statherian Lower 407.6 ±2.6 Serravallian 13.82 190.8 ±1.0 Lower 1800 Miocene Pragian 410.8 ±2.8 Proterozoic Neogene Sinemurian Langhian 15.97 Orosirian 199.3 ±0.3 Lochkovian Paleo- 2050 Burdigalian Hettangian 201.3 ±0.2 419.2 ±3.2 proterozoic 20.44 Mesozoic Rhaetian Pridoli Rhyacian Aquitanian 423.0 ±2.3 23.03 ~ 208.5 Ludfordian 2300 Cenozoic Chattian Ludlow 425.6 ±0.9 Siderian 27.82 Gorstian
    [Show full text]
  • UNIT – I PHYSIOGRAPHIC DIVISIONS of INDIA Geological Structure
    UNIT – I PHYSIOGRAPHIC DIVISIONS OF INDIA Geological Structure 1. THE ARCHAEAN FORMATIONS (PRE-CAMBRIAN) The Archaean Era is also known as the Precambrian Period. The division of geologic time scale from the formation of the Earth (about 4.6 billion years ago) to the beginning of the Cambrian Period of the Paleozoic Era (about 570 million years ago}. The Precambrian time constitutes about 86.7% of the Earth's history. The term 'Archaean', introduced by J.D. Dana in 1782, refers to the oldest rocks of the Earth's crust. The oldest known rocks of the Earth, the evolutionary atmosphere, the first chemosynthesis, the first photosynthesis, the life-supporting atmosphere and the Earth's modem atmosphere, were developed during the Precambrian Era (Archaean and Protozoic). Rocks of the Archaean System are devoid of any form of life. The Archaean rocks are all azoic or non fossiliferous. They are thoroughly crystalline, extremely contorted and faulted, and practically devoid of any sediment. They are largely intruded by plutonic intrusions and generally have a well-defined foliated structure. These rocks are known as the basement complex or fundamental gneisses. Cover two-thirds of Peninsular India. In the Peninsular region, the Archaean rocks are known to be of three well-defined types: a) The Bengal Gneiss occurs in the Eastern Ghats, Orissa (known as Khodoliles after Khond tribes in Koraput and Bolangir districts), stretching over Manbhum and Hazaribagh districts of Jharkhand, Nellore district of Andhra Pradesh and Salem district of Tamil Nadu. Occur in the Son Valley, Meghalaya Plateau and Mikir HiUs. Thinly foliated.
    [Show full text]
  • INTERNATIONAL CHRONOSTRATIGRAPHIC CHART International Commission on Stratigraphy V 2020/03
    INTERNATIONAL CHRONOSTRATIGRAPHIC CHART www.stratigraphy.org International Commission on Stratigraphy v 2020/03 numerical numerical numerical numerical Series / Epoch Stage / Age Series / Epoch Stage / Age Series / Epoch Stage / Age GSSP GSSP GSSP GSSP EonothemErathem / Eon System / Era / Period age (Ma) EonothemErathem / Eon System/ Era / Period age (Ma) EonothemErathem / Eon System/ Era / Period age (Ma) Eonothem / EonErathem / Era System / Period GSSA age (Ma) present ~ 145.0 358.9 ±0.4 541.0 ±1.0 U/L Meghalayan 0.0042 Holocene M Northgrippian 0.0082 Tithonian Ediacaran L/E Greenlandian 0.0117 152.1 ±0.9 ~ 635 U/L Upper Famennian Neo- 0.129 Upper Kimmeridgian Cryogenian M Chibanian 157.3 ±1.0 Upper proterozoic ~ 720 0.774 372.2 ±1.6 Pleistocene Calabrian Oxfordian Tonian 1.80 163.5 ±1.0 Frasnian 1000 L/E Callovian Quaternary 166.1 ±1.2 Gelasian 2.58 382.7 ±1.6 Stenian Bathonian 168.3 ±1.3 Piacenzian Middle Bajocian Givetian 1200 Pliocene 3.600 170.3 ±1.4 387.7 ±0.8 Meso- Zanclean Aalenian Middle proterozoic Ectasian 5.333 174.1 ±1.0 Eifelian 1400 Messinian Jurassic 393.3 ±1.2 Calymmian 7.246 Toarcian Devonian Tortonian 182.7 ±0.7 Emsian 1600 11.63 Pliensbachian Statherian Lower 407.6 ±2.6 Serravallian 13.82 190.8 ±1.0 Lower 1800 Miocene Pragian 410.8 ±2.8 Proterozoic Neogene Sinemurian Langhian 15.97 Orosirian 199.3 ±0.3 Lochkovian Paleo- Burdigalian Hettangian proterozoic 2050 20.44 201.3 ±0.2 419.2 ±3.2 Rhyacian Aquitanian Rhaetian Pridoli 23.03 ~ 208.5 423.0 ±2.3 2300 Ludfordian 425.6 ±0.9 Siderian Mesozoic Cenozoic Chattian Ludlow
    [Show full text]
  • Circum-Indian Ocean Hydroclimate at the Mid to Late Holocene Transition: the Double Drought Hypothesis and Consequences for the Harappan Nick Scroxton1,2,3, Stephen J
    https://doi.org/10.5194/cp-2020-138 Preprint. Discussion started: 4 November 2020 c Author(s) 2020. CC BY 4.0 License. Circum-Indian ocean hydroclimate at the mid to late Holocene transition: The Double Drought hypothesis and consequences for the Harappan Nick Scroxton1,2,3, Stephen J. Burns1, David McGee2, Laurie R. Godfrey4, Lovasoa Ranivoharimanana5, 5 Peterson Faina5 1Department of Geosciences, 611 North Pleasant Street, University of Massachusetts Amherst, MA 01030, USA 2Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA 3School of Earth Sciences, University College Dublin, Bellfield, Dublin 4, Ireland 10 4Department of Anthropology, 240 Hicks Way, University of Massachusetts, Amherst, MA 01003, USA 5Mention Bassins sédimentaires, Evolution, Conservation (BEC) – BP 906 – Faculté des Sciences, Université d’Antananarivo – 101 Antananarivo, Madagascar Correspondence to: Nick Scroxton ([email protected]) Abstract 15 The decline of the Mature Harappan period of the Harappan civilization in and around the Indus Valley between 4.3 and 3.9 kyr BP, its transition to the Late Harappan and subsequent abandonment by 3.0 kyr BP are frequently attributed to a reduction in summer monsoon rainfall associated with the 4.2 kyr event (4.26-3.97 kyr BP). Yet while the 4.2 kyr event is well documented in the Mediterranean and Middle East, its global footprint is undetermined, and its impact on monsoon rainfall largely unexplored. In this study we investigate the spatial and temporal variability of the tropical circum-Indian ocean 20 hydroclimate in the mid to late Holocene. We conducted Monte-Carlo principal component analysis, taking into account full age uncertainty, on ten high-resolution, precisely dated paleohydroclimate records from the circum-Indian Ocean basin, all growing continuously or almost continuously between 5 and 3kyr BP.
    [Show full text]
  • Meghalayan Age
    Meghalayan Age drishtiias.com/printpdf/meghalayan-age Why in news? Geologists have decided to classify the past 4,200 years as the Meghalayan Age. It is the most recent unit of the Geologic Time Scale in the 4.6 billion-year history of the Earth. Following this, the International Chronostratigraphic Chart, which depicts the timeline for Earth's history will be updated. What is Meghalayan Age? The “Meghalayan Age” began 4,200 years ago and experienced an abrupt mega- drought and cooling around the globe. The drought and the cooling lasted two centuries and severely impacted agricultural- based societies that developed in several regions after the end of the last Ice Age. It resulted in the collapse of civilisations in Egypt, Greece, Syria, Palestine, Mesopotamia, the Indus Valley, and the Yangtze River Valley. Evidence of the 4,200-year climatic event has been found on all seven continents. This age is considered unique as this was the only age which began with a global cultural event produced by a global climatic event. Geologists have also introduced two other age classifications: 1. Greenlandian Age (11,700 - 8,326 years ago) - began when the last ice age ended and the world began to warm up. 2. Northgrippian Age (8,326 – 4,200 years ago) – began after an abrupt global cooling started following the Greenlandian Age. Together, these three stages stretch across the Holocene Epoch, which is the current geological time unit - having started 11,700 years ago. The Holocene epoch falls under Cenozoic Era and is the time after Ice Age. Methods of Classification 1/3 Each subdivision of the Holocene Epoch is marked out by sediments accumulated on sea floors, lake bottoms, glacial ice and in stalactites and stalagmites across the world.
    [Show full text]
  • Download Download
    Revista Brasileira de Paleontologia, 23(4):234–250, Outubro/Dezembro 2020 A Journal of the Brazilian Society of Paleontology doi: 10.4072/rbp.2020.4.02 FIREFIRE EVENTS EVENTS AND AND VEGETATION VEGETATION DYNAMICS DYNAMICS DURING DURING THE LATETHE LATE PLEISTOCENE-MEGHALAYAN PLEISTOCENE-MEGHALAYAN INTERVAL INTERVAL IN THE IN THESOUTHERNMOST SOUTHERNMOST BRAZILIAN BRAZILIAN COASTAL COASTAL PLAIN PLAIN VERIDIANA RIBEIRO Programa de Pós-Graduação em Geografia, Centro Polar e Climático, Instituto de Geociências, Universidade Federal do Rio Grande do Sul/UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, Rio Grande do Sul, Brazil. [email protected] MARGOT GUERRA-SOMMER Programa de Pós-Graduação em Geociências, Instituto de Geociências, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS, Brazil. [email protected] RUALDO MENEGAT Departamento de Paleontologia e Estratigrafia, Instituto de Geociências, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS, Brazil. [email protected] LIDIA AUMOND KUHN Programa de Pós-Graduação em Geociências, Instituto de Geociências, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS, Brazil. [email protected] JEFFERSON CARDIA SIMÕES Programa de Pós-Graduação em Geografia, Centro Polar e Climático, Instituto de Geociências, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS, Brazil. [email protected] RICARDO BURGO BRAGA Laboratório de Gerenciamento Costeiro, Centro de Estudos de Geologia Costeira e Oceânica, Instituto de Geociências, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS, Brazil. [email protected] SORAIA GIRARDI BAUERMANN Laboratório de Palinologia, Universidade Luterana do Brasil, Av. Farroupilha, 8001, 92425-900, Canoas, Rio Grande do Sul, Brasil.
    [Show full text]
  • International Chronostratigraphic Chart
    INTERNATIONAL CHRONOSTRATIGRAPHIC CHART www.stratigraphy.org International Commission on Stratigraphy v 2018/07 numerical numerical numerical Eonothem numerical Series / Epoch Stage / Age Series / Epoch Stage / Age Series / Epoch Stage / Age GSSP GSSP GSSP GSSP EonothemErathem / Eon System / Era / Period age (Ma) EonothemErathem / Eon System/ Era / Period age (Ma) EonothemErathem / Eon System/ Era / Period age (Ma) / Eon Erathem / Era System / Period GSSA age (Ma) present ~ 145.0 358.9 ± 0.4 541.0 ±1.0 U/L Meghalayan 0.0042 Holocene M Northgrippian 0.0082 Tithonian Ediacaran L/E Greenlandian 152.1 ±0.9 ~ 635 Upper 0.0117 Famennian Neo- 0.126 Upper Kimmeridgian Cryogenian Middle 157.3 ±1.0 Upper proterozoic ~ 720 Pleistocene 0.781 372.2 ±1.6 Calabrian Oxfordian Tonian 1.80 163.5 ±1.0 Frasnian Callovian 1000 Quaternary Gelasian 166.1 ±1.2 2.58 Bathonian 382.7 ±1.6 Stenian Middle 168.3 ±1.3 Piacenzian Bajocian 170.3 ±1.4 Givetian 1200 Pliocene 3.600 Middle 387.7 ±0.8 Meso- Zanclean Aalenian proterozoic Ectasian 5.333 174.1 ±1.0 Eifelian 1400 Messinian Jurassic 393.3 ±1.2 7.246 Toarcian Devonian Calymmian Tortonian 182.7 ±0.7 Emsian 1600 11.63 Pliensbachian Statherian Lower 407.6 ±2.6 Serravallian 13.82 190.8 ±1.0 Lower 1800 Miocene Pragian 410.8 ±2.8 Proterozoic Neogene Sinemurian Langhian 15.97 Orosirian 199.3 ±0.3 Lochkovian Paleo- 2050 Burdigalian Hettangian 201.3 ±0.2 419.2 ±3.2 proterozoic 20.44 Mesozoic Rhaetian Pridoli Rhyacian Aquitanian 423.0 ±2.3 23.03 ~ 208.5 Ludfordian 2300 Cenozoic Chattian Ludlow 425.6 ±0.9 Siderian 27.82 Gorstian
    [Show full text]