J 2017

Micromorphological changes as an indicator of the transition from glacial to glaciofluvial quartz grains: Evidence from Svalbard

KŘÍŽEK, Marek, Klára KRBCOVÁ, Peter MIDA a Martin HANÁČEK

Základní údaje

Originální název

Micromorphological changes as an indicator of the transition from glacial to glaciofluvial quartz grains: Evidence from Svalbard

Autoři

KŘÍŽEK, Marek (203 Česká republika, garant), Klára KRBCOVÁ (203 Česká republika), Peter MIDA (703 Slovensko) a Martin HANÁČEK (203 Česká republika, domácí)

Vydání

Sedimentary Geology, Amsterdam, Elsevier Science, 2017, 0037-0738

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10500 1.5. Earth and related environmental sciences

Stát vydavatele

Nizozemské království

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 2.575

Kód RIV

RIV/00216224:14310/17:00097622

Organizační jednotka

Přírodovědecká fakulta

UT WoS

000410018500003

Klíčová slova anglicky

Micromorphology; Microtextures; Glaciofluvial environment; Fluvial transport; Svalbard

Štítky

Změněno: 9. 4. 2018 10:51, Ing. Nicole Zrilić

Anotace

V originále

The micromorphology of quartz grains in a sedimentary environment is determined by the transport mechanism and the nature of weathering. Both these aspects change during the transport history of grains. Thus important questions include how are quartz grains affected by possible changes in the transport medium, and how quickly do the different micromorphological features develop or disappear. The main goal of this study was to characterize the changes in the micromorphological features of quartz grains during the transition from a glacial to a glaciofluvial environment, and to identify a set of diagnostic microtextures that can be used to distinguish between glacial and glaciofluvial quartz grains. The samples came from the moraines of the Bertilbreen and Hřrbyebreen glaciers (Svalbard) and from the sediments of glacier-fed rivers in the forelands of these glaciers. A total of 30 different micromorphological features was observed on 800 different quartz grains from13 samples of glaciofluvial sediment and 3 samples of glacial sediment. Itwas found that the frequency of rounded grains, Vshaped pits, meandering ridges and cemented microblocks on glaciofluvial grains increased significantly with increasing length of fluvial transport, whereas the frequency of angular grains, straight steps, straight and curved grooves, adhering particles, pitting and oriented etch pits decreased significantly. Different types of micromorphological features of quartz grains change with fluvial transport at different rates. Adhering particles (after the first kilometer of fluvial transport), straight steps and meandering ridges (after the second kilometer of fluvial transport), and V-shape pits, angular shape and straight grooves (after the third kilometer of fluvial transport) are reliable mechanical micromorphological features for distinguishing between glacial and glaciofluvial quartz grains.