J 2017

Provenance analysis of heavy minerals in beach sands (Falkland Islands/Islas Malvinas) - A view to mineral deposits and the geodynamics of the South Atlantic Ocean

DILL, Harald a Radek ŠKODA

Základní údaje

Originální název

Provenance analysis of heavy minerals in beach sands (Falkland Islands/Islas Malvinas) - A view to mineral deposits and the geodynamics of the South Atlantic Ocean

Autoři

DILL, Harald (276 Německo) a Radek ŠKODA (203 Česká republika, garant, domácí)

Vydání

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES, OXFORD, PERGAMON-ELSEVIER SCIENCE LTD, 2017, 0895-9811

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10505 Geology

Stát vydavatele

Velká Británie a Severní Irsko

Utajení

není předmětem státního či obchodního tajemství

Impakt faktor

Impact factor: 1.639

Kód RIV

RIV/00216224:14310/17:00100315

Organizační jednotka

Přírodovědecká fakulta

DOI

UT WoS

000411775200002

Klíčová slova anglicky

Heavy minerals; Wave-dominated beach sands; Provenance analysis; Falkland Islands/Islas Malvinas; Gondwana break-up

Štítky

Změněno: 11. 4. 2018 08:41, Ing. Nicole Zrilić

Anotace

V originále

Beach sands are ideal traps to collect heavy minerals (HM) from different geodynamic settings and mineral deposits. The coastal sediments contain a mixture of HM derived from the submarine shelf and from source rocks in the hinterland. This is true in a transgressive periglacial regime, where drowned valleys and estuaries are instrumental in draining HM to the arenaceous beach sediments from more distal basement lithologies. A scenario like this can be found in the Falkland Islands/Islas Malvinas. The site under study is the missing link between South Africa and South America, the splitting-apart of which is mirrored by the HM distribution predominantly concentrated in the backshore and dune belt along the coast. The HM are subdivided into three HM associations reflecting the geodynamic evolution of the South Atlantic Ocean and of some of the prominent mineral deposits on the Gondwana Continent: (1) Gondwana cratons and Proterozoic orogens, with Cr and BIF deposits (rutile, zircon, ilmenite, tourmaline, garnet, Cr spinel), (2) rift-related and break-apart magmatic lithologies with mantle-derived pipe rocks such as kimberlites (zircon, pyroxene, spinel, Mg ilmenite), (3) Cordillera-type lithologies with poly metallic stratabound deposits (tourmaline, amphibole, chlorite, REE phosphates). The variation of the major HM from the stable craton (Kalahari-Kaapvaal Craton) in the East to the mobile fold belt (Andes) in the West follows the order of stability of HM. In addition to these 3 geodynamic HM groups, sporadic occurrences of HM originating from alteration (leucoxene, chlorite s.s.s. (= solid solution series)) are part of armored relics such as "nigrine" which on transport disintegrated and thereby released these HM. The major ultrastable and stable HM zircon, rutile, tourmaline s.s.s., spinel s.s.s., and garnet s.s.s. are displayed in a synoptical x-y plot showing the mantle and crustal trends of fractionation and formation of cumulates by means of particular mineral associations as well as the chemical composition of their s.s.s. Five different geodynamic-lithological patterns, each represented by a set of type-lithologies are established for the cratonic magmatic-metamorphic lithosphere. Based on the HM, the geodynamic setting under study is dominated by source rocks typical of a primitive, cratonic setting. (C) 2017 Published by Elsevier Ltd.

Návaznosti

MUNI/A/1653/2016, interní kód MU
Název: Geologické, geodynamické a environmentální procesy při východním okraji Českého masívu (Akronym: Geodyn)
Investor: Masarykova univerzita, Geologické, geodynamické a environmentální procesy při východním okraji Českého masívu, DO R. 2020_Kategorie A - Specifický výzkum - Studentské výzkumné projekty