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 and Martin HANÁČEK

Basic information

Original name

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

Authors

KŘÍŽEK, Marek (203 Czech Republic, guarantor), Klára KRBCOVÁ (203 Czech Republic), Peter MIDA (703 Slovakia) and Martin HANÁČEK (203 Czech Republic, belonging to the institution)

Edition

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

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10500 1.5. Earth and related environmental sciences

Country of publisher

Netherlands

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 2.575

RIV identification code

RIV/00216224:14310/17:00097622

Organization unit

Faculty of Science

UT WoS

000410018500003

Keywords in English

Micromorphology; Microtextures; Glaciofluvial environment; Fluvial transport; Svalbard

Tags

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

Abstract

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.