TY  - JOUR
A1  - Pokorny, Richard
A1  - Krmicek, Lukas
A1  - Sudo, Masafumi
T1  - An endemic ichnoassemblage from a late Miocene paleolake in SE Iceland
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - In Porisdalur valley, a small relict of a sedimentary body was identified in southeastern Iceland. It probably represents a remnant of the deep, tectonically arranged paleolake (Late Miocene, 8-9 Ma), and filled by volcaniclastic material from nearby, active volcanic centers. In the profile of tuffitic sandstone, siltstone and claystone, the ripple-bedding layers, molds and flute casts indicate periodic mass flow episodes. In the sedimentary profile, the characteristic arrangement of sediments is evident, showing features of the Bouma sequences. In the claystone layers, deposited during episodes of lowest kinetic energy, a specific ichnoassemblage was found, represented by Thorichnus ramosus igen. et isp. nov., T. corniculatus igen. et isp. nov., Mammillichnis jakubi isp. nov., Helminthoidichnites multilaqueatus comb. nov., Vamaspor jachymi igen. et isp. nov. and five preliminarily identified trace fossils. The assemblage belongs to Mermia ichnofacies, the nonmarine representative of an ichnofacies, developed in a turbiditic environment; most of identified trace fossils are so far endemic. (C) 2017 Elsevier B.V. All rights reserved.
KW  - Turbidite
KW  - Mermia ichnofacies
KW  - Thorichnus-Vatnaspor ichnoassemblage
Y1  - 2017
U6  - https://doi.org/10.1016/j.palaeo.2017.07.033
SN  - 0031-0182
SN  - 1872-616X
VL  - 485
SP  - 761
EP  - 773
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Krmíček, Lukáš
A1  - Timmerman, Martin Jan
A1  - Ziemann, Martin Andreas
A1  - Sudo, Masafumi
A1  - Ulrych, Jaromir
T1  - 40Ar/39Ar step-heating dating of phlogopite and kaersutite megacrysts from the Železná hůrka (Eisenbühl) Pleistocene scoria cone, Czech Republic
JF  - Geologica Carpathica
N2  - (40)A/Ar-39 step-heating of mica and amphibole megacrysts from hauyne-bearing olivine melilitite scoria/tephra from the Zelezna hurka yielded a 435 +/- 108 ka isotope correlation age for phlogopite and a more imprecise 1.55 Ma total gas age of the kaersutite megacryst. The amphibole megacrysts may constitute the first, and the younger phlogopite megacrysts the later phase of mafic, hydrous melilitic magma crystallization. It cannot be ruled out that the amphibole megacrysts are petrogenetically unrelated to tephra and phlogopite megacrysts and were derived from mantle xenoliths or disaggregated older, deep crustal pegmatites. This is in line both with the rarity of amphibole at Zelezna hurka and with the observed signs of magmatic resorption at the edges of amphibole crystals.
KW  - Bohemian Massif
KW  - Zelezna hurka
KW  - Eisenbuhl
KW  - argon dating
KW  - mica
KW  - amphibole
KW  - melilitite
Y1  - 2020
U6  - https://doi.org/10.31577/GeolCarp.71.4.6
SN  - 1335-0552
SN  - 1336-8052
VL  - 71
IS  - 4
SP  - 382
EP  - 387
PB  - Veda
CY  - Bratislava
ER  -