scholarly journals Interactive comment on “SHORT COMMUMNICATION: Massive Erosion in Monsoonal Central India Linked to Late Holocene Landcover Degradation” by Liviu Giosan et al.

2017 ◽  
Author(s):  
Yogesh Kulkarni
Keyword(s):  
2021 ◽  
pp. SP515-2020-216
Author(s):  
Nupur Tiwari ◽  
P. Morthekai ◽  
K. Krishnan ◽  
Parth R. Chauhan

AbstractThe earliest occurrence of microliths in South Asia dates back to the Late Pleistocene at Mehtakheri (45 ka) and Dhaba (48 ka) in Central India, Jwalapuram 9 in Southern India (38 ka), Kana and Mahadebbara in Northeastern India (42-25 ka) and Batadomba-Lena (35-36 ka) and Fa Hien Lena (48 ka) in Sri Lanka. Microlithic technology is distributed across the entire Indian Subcontinent and chronologically continues up to the Iron Age and Early Historic periods. This paper discusses new data acquired from the first author's doctoral research in the two districts of Madhya Pradesh (Hoshangabad and Sehore), which fall within the central part of the Narmada Basin in central India. We present here the preliminary dates from key areas of distribution to understand the geo-chronological contexts of microliths at Pilikarar, Morpani, and Gurla-Sukkarwada. Initial dates from these respective occurrences range between 12.5 ka and 2.3 ka.


The Holocene ◽  
2017 ◽  
Vol 27 (12) ◽  
pp. 1976-1987 ◽  
Author(s):  
Meng Cui ◽  
Zhanghua Wang ◽  
Kakani Nageswara Rao ◽  
S J Sangode ◽  
Yoshiki Saito ◽  
...  

The mid- to late-Holocene monsoon decline led to aridification of the Indian Peninsula impacting the early agricultural practices in the region. Our analysis of organic carbon, mineral magnetic properties and AMS 14C dating of a 54.2-m-long sediment core (CY) from the Godavari Delta, India, showed changes in the organic carbon source and sediment provenance, which are linked to the changes in vegetation and soil/rock erosion caused by widespread aridification and associated human adaptation in central India. Our results show a decline in the concentration of ferrimagnetic minerals, indicating reduced input from the basalts of the Deccan Plateau after ~6.0 cal. ka BP in response to the weaker Indian monsoon. δ13C values show a distinct increase from ~4.9 cal. ka BP, indicating an increase in C4 plant sources under the continued weak monsoon phase, whereas a higher ferrimagnetic mineral concentration in the sediment suggested an increased Deccan basalt source. Abrupt increase in δ13C values and decrease in TOC content accompanied with a significant increase in ferrimagnetic mineral concentration from ~3.2 to 3.1 cal. ka BP reflected a shift of organic carbon and sediment source and a severe decline in vegetation coverage. Such phenomena indicate intensified deforestation and soil/rock erosion in the Deccan Plateau producing higher ferrimagnetic mineral inputs, which is in agreement with significant expansion of agricultural activities in the Deccan Chalcolithic cultural period. In addition, C3 plants recovered and magnetic concentration declined during the wet events (4.6 and 4.0 cal. ka BP) of Neolithic time, while both C3 plants and magnetic parameters increased during the wet events (3.1–2.8 and 2.1 cal. ka BP) of the Chalcolithic cultural period. This implies increased agricultural activity and the onset of human modification of the ecosystem.


2017 ◽  
Author(s):  
Liviu Giosan ◽  
Camilo Ponton ◽  
Muhammed Usman ◽  
Jerzy Blusztajn ◽  
Dorian Fuller ◽  
...  

Abstract. Soil erosion plays a crucial role in transferring sediment and carbon from land to sea, yet little is known about the rhythm and rates of soil erosion prior to the most recent few centuries. Here we reconstruct a Holocene erosional history from central India, as integrated by the Godavari River in a sediment core from the Bay of Bengal. We quantify terrigenous fluxes, fingerprint sources for the lithogenic fraction and assess the age of the exported terrigenous carbon. Taken together, our data show that the monsoon decline in the late Holocene, later exacerbated by the Neolithic adoption and Iron Age extensification of agriculture on the Deccan Plateau, significantly increased soil erosion and the age of exported organic carbon. Despite a constantly elevated sea level since the middle Holocene, this erosion acceleration led to rapid continental margin growth. We conclude that in monsoon conditions, aridity boosts rather than supresses sediment and carbon export acting as a veritable monsoon erosional pump modulated by landcover conditions.


The Holocene ◽  
2021 ◽  
pp. 095968362110031
Author(s):  
Mohammad Firoze Quamar ◽  
Ratan Kar ◽  
Biswajeet Thakur

Pollen analysis and radiocarbon dating of a 1.4 m deep lacustrine sediment profile from Chhattisgarh State, central India, in the core monsoon zone (CMZ), has revealed the vegetation history, associated climate change and the Indian Summer Monsoon (ISM) rainfall variability during the Late-Holocene. The pollen evidence suggests that between ca. 3000 and 2600 cal year BP, tree-savannah vegetation occurred in the region having a comparatively lesser monsoon rainfall. The forest expanded and culminated into an open-mixed tropical deciduous forest between ca. 2600 and 2200 cal year BP under a warm and moderately humid climate with an increase in monsoon rainfall. Subsequently, between ca. 2200 and 2000 cal year BP, the existing open-mixed tropical deciduous forest transformed into a mixed tropical deciduous forest under a warm and humid climate with further increase in monsoon rainfall. Finally, between ca. 2000 and 1800 cal year BP, a dense mixed tropical deciduous forest occupied the landscape under a regime of a warm and relatively more humid climate with further strengthening of the ISM. The gradual warming, and the climatic amelioration with the intensification of the ISM, during the Late-Holocene (ca. 2600–1800 cal year BP; ~650 BC to AD150) corresponds to the Roman Warm Period (RWP), recorded globally between 2500 and1600 cal year BP (~550 BC to AD ~350). Human activities were present around the study area, which varied according to the ISM variations. The present study provides insights into the gradual intensification of the monsoon since the last ca. 2600 cal year BP (between ca. 2600 and1800 cal year BP), and an increase in the ISM strength in the CMZ of India, against the generally weakening trend during the Late-Holocene.


2017 ◽  
Vol 5 (4) ◽  
pp. 781-789 ◽  
Author(s):  
Liviu Giosan ◽  
Camilo Ponton ◽  
Muhammed Usman ◽  
Jerzy Blusztajn ◽  
Dorian Q. Fuller ◽  
...  

Abstract. Soil erosion plays a crucial role in transferring sediment and carbon from land to sea, yet little is known about the rhythm and rates of soil erosion prior to the most recent few centuries. Here we reconstruct a Holocene erosional history from central India, as integrated by the Godavari River in a sediment core from the Bay of Bengal. We quantify terrigenous fluxes, fingerprint sources for the lithogenic fraction and assess the age of the exported terrigenous carbon. Taken together, our data show that the monsoon decline in the late Holocene significantly increased soil erosion and the age of exported organic carbon. This acceleration of natural erosion was later exacerbated by the Neolithic adoption and Iron Age extensification of agriculture on the Deccan Plateau. Despite a constantly elevated sea level since the middle Holocene, this erosion acceleration led to a rapid growth of the continental margin. We conclude that in monsoon conditions aridity boosts rather than suppresses sediment and carbon export, acting as a monsoon erosional pump modulated by land cover conditions.


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