REE‐Rich Turonian Phosphates in the Bohemian Cretaceous Basin, Czech Republic: Assessment as Source of Critical Elements and Implications for Future Exploration

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F21%3A00000099" target="_blank" >RIV/00025798:_____/21:00000099 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.mdpi.com/journal/minerals" target="_blank" >https://www.mdpi.com/journal/minerals</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/min11030246" target="_blank" >10.3390/min11030246</a>

Jazyk výsledku

angličtina

Název v původním jazyce

REE‐Rich Turonian Phosphates in the Bohemian Cretaceous Basin, Czech Republic: Assessment as Source of Critical Elements and Implications for Future Exploration

Popis výsledku v původním jazyce

Numerous phosphate occurrences are located in the Bohemian Cretaceous Basin (BCB) of the Czech Republic, within the Cenomanian–Turonian sequences. Small phosphate occurrences have been reported in the Upper Cenomanian, Lower Turonian, and Upper Turonian marine glauconitic siliciclasts. The phosphates are generally <;1 m thick, present as phosphatized hardgrounds,nodules, coprolites, skeletal remains, phosphatized shells, peloids, sponges, and tube‐fills, associated with black mudstone and other siliciclasts. Only recently the critical elements have been highlightedin these phosphates. The present study covers eight of these occurrences and provides information on petrography, mineralogy, and chemical composition of major elements, trace elements, and stable isotopes. The phosphate mineralogy is comprised of carbonate‐fluorapatite, associatedwith quartz, glauconite, smectite, kaolinite, and pyrite. Most of the phosphates are rich in organic matter. The phosphate chemistry is dominated by P2O5, CaO, F, Na2O, SO3, and CO2. Minor amounts of SiO2, Al2O3, K2O, and MgO are found, related to quartz and alumino‐silicate impurities.Evidence of fossil microbial structures is revealed. The indices derived from rare earth elements(REE) indicate phosphogenesis at various redox conditions, ranging from anoxic to oxic, whereas the carbon stable isotopes of the apatite suggest generally reducing conditions. The critical and othervaluable elements found in these Mid‐Cretaceous phosphates include P2O5 (18.9–26.76 wt. percent), F(1.67–3.25 wt. percent), REE (325–1338 ppm), Y (74–368 ppm), and U (10.4–37.9 ppm). The investigation of the Turonian phosphate occurrences show that those located at the base of the Bílá Hora Formation(earliest Turonian) are the most persistent in the southern margins of the BCB, and found in localities extending for about 200 km. They were developed at the onset of the Early Turonian global transgression and are strata‐bound to the base of the Bílá Hora Formation. Future exploration formarine sedimentary phosphorites should focus on thicker and better developed deposits at the base of the Turonian sediments as the main target.

Název v anglickém jazyce

REE‐Rich Turonian Phosphates in the Bohemian Cretaceous Basin, Czech Republic: Assessment as Source of Critical Elements and Implications for Future Exploration

Popis výsledku anglicky

Numerous phosphate occurrences are located in the Bohemian Cretaceous Basin (BCB) of the Czech Republic, within the Cenomanian–Turonian sequences. Small phosphate occurrences have been reported in the Upper Cenomanian, Lower Turonian, and Upper Turonian marine glauconitic siliciclasts. The phosphates are generally <;1 m thick, present as phosphatized hardgrounds,nodules, coprolites, skeletal remains, phosphatized shells, peloids, sponges, and tube‐fills, associated with black mudstone and other siliciclasts. Only recently the critical elements have been highlightedin these phosphates. The present study covers eight of these occurrences and provides information on petrography, mineralogy, and chemical composition of major elements, trace elements, and stable isotopes. The phosphate mineralogy is comprised of carbonate‐fluorapatite, associatedwith quartz, glauconite, smectite, kaolinite, and pyrite. Most of the phosphates are rich in organic matter. The phosphate chemistry is dominated by P2O5, CaO, F, Na2O, SO3, and CO2. Minor amounts of SiO2, Al2O3, K2O, and MgO are found, related to quartz and alumino‐silicate impurities.Evidence of fossil microbial structures is revealed. The indices derived from rare earth elements(REE) indicate phosphogenesis at various redox conditions, ranging from anoxic to oxic, whereas the carbon stable isotopes of the apatite suggest generally reducing conditions. The critical and othervaluable elements found in these Mid‐Cretaceous phosphates include P2O5 (18.9–26.76 wt. percent), F(1.67–3.25 wt. percent), REE (325–1338 ppm), Y (74–368 ppm), and U (10.4–37.9 ppm). The investigation of the Turonian phosphate occurrences show that those located at the base of the Bílá Hora Formation(earliest Turonian) are the most persistent in the southern margins of the BCB, and found in localities extending for about 200 km. They were developed at the onset of the Early Turonian global transgression and are strata‐bound to the base of the Bílá Hora Formation. Future exploration formarine sedimentary phosphorites should focus on thicker and better developed deposits at the base of the Turonian sediments as the main target.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10504 - Mineralogy

Projekt

—

Návaznosti

R - Projekt Ramcoveho programu EK

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Minerals

ISSN

2075-163X

e-ISSN

—

Svazek periodika

11

Číslo periodika v rámci svazku

3 : 246

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

21

Strana od-do

1-21

Kód UT WoS článku

000633912000001

EID výsledku v databázi Scopus

2-s2.0-85101575122