ALBERT

Description: Extract Perhaps the most important advance in our knowledge of the Precambrian Earth over the last three decades has been the general consensus on the episodic nature of the amalgamation and dispersal of supercontinents (e.g. Rogers 1996; Condie & Aster 2010; Nance et al. 2014). The Precambrian history of the Earth is thought to be punctuated by the assembly and breakdown of at least three supercontinents: Columbia (Nena), Rodinia and Gondwana (Fig. 1; e.g. McMenamin & McMenamin 1990; Rogers & Santosh 2002; Meert 2012). ... This 250-word extract was created in the absence of an abstract.

Description: Records of fluctuations of the East Antarctic Ice Sheet (EAIS) are best preserved in proximal marine sediments. The examined section is a part of a drillcore at Site U1359 of IODP (Integrated Oceanic Drilling Program) 318 located at the eastern levee of Jussieau submarine channel off the coast of Wilkes Land. Drillcore U1359 from 200 m below seafloor (mbsf) to 600 mbsf represents samples from Mid-Miocene to Late Miocene. Heavy media separation, characterization of heavy minerals and quantification of their population were carried out using scanning electron microscopy and electron microprobe analysis. Relative abundance of various minerals at different depths revealed that amphiboles and pyroxene show antipathic relationship at some depths. Multiple sources for supply of sediments at drillhole Site U1359 have been proposed with both magmatic and metamorphic minerals and rock fragments contributing clastic sediments. Factor analysis was carried out to test this inference. Six factors were obtained out of which the first three explain 76.6% of the variance. Relating variability of the factors to the provenance allows inference of four major ice advance phases during Mid to Late Micene which are largely positively correlatable with the global climate record. Supplementary material: Table showing the linear relationship between the rows and columns of the matrix of correlation coefficients of samples is available at https://doi.org/10.6084/m9.figshare.c.3805726

Description: The hydrological budget of the three major Asian rivers, namely the Indus, the Ganga and the Brahmaputra, is controlled by the Indian monsoon and Westerlies but their contribution in these basins are highly variable. Widely varying average annual precipitation has been reported within these basins. A poor network of in situ rain gauges, particularly in mountainous regions, inaccessible terrain, high variations in altitude and the significantly large size of basins forces adaption of satellite-based average annual precipitation. We investigate precipitation patterns for these three basins by using satellite-based Tropical Rainfall Measuring Mission (TRMM-3B42) data and compare and validate it with Asian Precipitation Highly Resolved Data Integration Towards Evaluation (APHRODITE) and India Meteorological Department (IMD) interpolated gridded precipitation data. The entire basins as well as basinal areas within the geographic limits of India have been considered. Our study shows that the precipitation broadly follows an east–west and north–south gradient control. The easternmost Brahmaputra Basin has the highest amount of precipitation followed by the Ganga Basin, and the westernmost Indus Basin has the least precipitation; precipitation is highest on the higher elevations than compared to lower elevations of the basins. A seasonal- and elevation-based approach is adapted to estimate snow precipitation and is discussed in terms of overall precipitation.

Description: Of the several types of Quaternary deposits formed by glacial, alluvial and mass-wasting processes, with vast climatic and tectonic significance lake deposits stand out prominently in the Indus valley around the town of Leh. We studied a number of palaeolake deposits between the Zinchan–Indus confluence and Shey village and carried out optically stimulated luminescence (OSL) quartz dating of samples from critical sections. Our results indicate that, during the late Quaternary, the Indus River was dammed at least twice in the narrow gorge downstream of Spituk Gompa, forming a reservoir up to 35 km long in which 20–68 m thick sediments were deposited under fluvial and lacustrine environments. During the older phase, the Indus was blocked by debris of moraines/landslides in the narrow zone near the Zinchan–Indus confluence. The resulting lake existed between c. 125 ± 11 and 87 ± 8 ka during marine isotopic stage (MIS) 5. No evidence of damming material is preserved. Present-day elevations of lake deposits suggest a possible extension of the lake up to Ranbirpura upstream. After the lake breach, the Indus River was again dammed near Phey village by the advancing alluvial fan of the Phyang River. This lake, extending up to Karu, formed at c. 79 ± ka. The lake existed in this phase during c. 72–49 ka, during cold-stage MIS-4. The lake was breached after c. 46 ± 3 ka, however.

Description: Extract The Tibetan Plateau and the Himalaya, which comprise a major portion of the region often referred to as the ‘third pole’, contain the largest surface area of the cryosphere outside the polar regions (Fig. 1). Unlike in other domains, glacier melting in this region is complex and highly variable. The glaciers in the western part of the region, dominated by the Karakoram and Western Himalaya, are either advancing or retreating relatively slowly, whereas the glaciers in the monsoon-dominated Eastern and Central Himalaya are retreating at a faster rate (Fig. 1). ... This 250-word extract was created in the absence of an abstract.

Description: The 600–660 Ma East African Orogen (EAO) granulites of the Mozambique Belt were correlated and extended into a coast marginal area of East Antarctica through the NNW–SSW-trending granulite-bearing Schirmacher Oasis. Tracing similarities in lithological association, granulite-facies metamorphism and geochronological data, the 640 Ma EAO was extended by another 110 km south of Schirmacher into the Humboldt Mountains in central Dronning Maud Land (cDML). Based on younger anorogenic magmatism east and west of the Humboldt Mountains, a 10–20 km-wide linear corridor of the EAO from the Schirmacher to the Humboldt Mountains was proposed. There are eight nunataks between Schirmacher and the Humboldt Mountains projected above the ice sheet. These nunataks are strategically placed because they represent the small (4–10 km 2 ), isolated rock exposures in approximately 5000 km 2 of ice-covered area. Baalsrudfjellet is one of these nunataks that is located at the easternmost margin of the proposed EAO corridor and represents a significant outcrop to validate the presence of the EAO between Schirmacher and the Humboldt Mountains. This study brings out a two-stage metamorphic evolution ( c. 660–680 Ma and c. 580 Ma) with melt generation associated with the younger event. Geochronological constraints by monazite chemical dating from metapelites confirm and validate the continuation of the EAO in-between the Schirmacher Oasis and the Humboldt Mountains. Supplementary material: Monazite analyses, computed ages and age errors of three grains from the high- and low-melt metapelite are available at https://doi.org/10.6084/m9.figshare.c.3738362