Towards defining the transition in style and timing of Quaternary glaciation between the monsoon-influenced Greater Himalaya and the semi-arid Transhimalaya of Northern India

Abstract

To delineate the transition in pattern and timing of glaciation between two contrasting regions, Lahul to the south and Ladakh to the north, moraines in the Puga and Karzok valleys of Zanskar in the Transhimalaya of northern India were mapped and dated using cosmogenic 10 Be. In Lahul, Late Quaternary glaciation was extensive glaciers advanced > 100 km from the modern ice margin, whereas glaciation in Ladakh has been comparatively restricted, glaciers advanced only ~30 km from the contemporary glaciers during the last 200 ka. In the Puga valley, glaciers advanced > 10 km at ~115 ka and < 10km at ~40 ka, ~3.3 ka, and ~0.5 ka. In the Karzok valley glaciers advanced < 2 km at ~3.6 ka. Boulder exposure ages from a large moraine complex in Karzok indicate a glacial advance at ~80 ka of < 5 km. The oldest moraine in Karzok is ~310 ka, indicating that glaciers advanced > 10 km during MIS-9 or older. The glacial chronology of the two valleys shows a lack of early Holocene glaciation and generally asynchronous glaciation between them. Moraines in the Puga and Karzok valleys broadly correlate with previous studies in the Zanskar Range but the paucity of data for many of the glacial stages across the Zanskar region makes the correlations tentative. The lack of early Holocene glaciation in the Puga and Karzok valleys is in stark contrast to many regions of the Himalaya, including Lahul, and the restricted glacial extent in Zanskar is more similar to the style of glaciation in Ladakh. The similarity between the glacial records in the Puga and Karzok study areas suggests that the transition to Lahul style glaciation is to the south of the Karzok valley; this geographical transition is abrupt.iv v AcknowledgmentsThe author would like to thank her committee members Lewis A. Owen, Craig Dietsch, and Marc W. Caffee for their interest, support, and invaluable feedback and contributions towards this project. Additionally, she would like to thank Discover Ladakh Adventure for

Recycling of Pleistocene valley fills dominates 135 ka of sediment flux, upper Indus River

“…Denudation rates along the Indus drop from >1000 mm ka -1 near the syntaxis (Burbank et al, 1996) to ~10 mm ka -1 at the western Tibetan Plateau margin . Denudation rates estimated from cosmogenic 10 Be inventories are low despite the steep alpine topography (Dortch et al, 2011;Dietsch et al, 2014;Munack et al, 2014), so that the Transhimalayan ranges of Ladakh and Zanskar host some of the oldest glacial landforms in the Himalaya-Tibet orogen Hedrick et al, 2011). Massive staircases of river-derived fill terraces (Fort et al, 1989;Clift and Giosan, 2014) located up to 400 m above present river levels, together with stacks of lake sediments and local landslide and fan deposits (Hewitt, 2002;Phartiyal et al, 2005; 2013), testify to major alternating cut-and-fill cycles in the upper Indus catchment (Blöthe et al, 2014).…”

“…given that local glacial chronologies -particularly since MIS 5e -show only minor glacier advances that could have influenced 10 Be concentrations (Taylor and Mitchell, 2000;Owen et al, 2006;Hedrick et al, 2011); the high-altitude desert of Zanskar also rarely favours thick snow cover (Burbank and Fort, 1985).…”

The timing and extent of Quaternary glaciation of Stok, northern Zanskar Range, Transhimalaya, of northern India

“…Much of the Zanskar Range has remained unglaciated throughout the late Quaternary (Hedrick et al, 2011). Consequently, parts of the Ladakh region have preserved ancient preglacial landscapes where fluvial processes have primarily driven landscape evolution (Dietsch et al, 2015).…”

“…8). As an example, the Karzok valley of eastern Zanskar records a succession of glacial advances back to ~ 300 ka, a glacial chronostratigraphy that extends well into previous glacial cycles (Hedrick et al, 2011). Adjacent to Stok itself, the southern Ladakh…”

Studies on Quaternary Glaciations in India During 2010-2016

“…Given the style and timing of glaciation in the study area, they suggested that climate in the Nun-Kun region is linked to Northern Hemisphere climate oscillations with teleconnections via the mid-latitude westerlies. Moreover, Hedrick et al (2011) presented glacial chronology for the Puga and Karzok valleys along the south-eastern Zanskar Range. In the Puga valley, glaciers advanced >15 km at ~129 ka and ~10 km at ~46 ka,~4.2 ka and ~0.6 ka.…”