Bat guano minerals and mineralization processes in Chameau Cave, Eastern Morocco

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F21%3A00541565" target="_blank" >RIV/67985831:_____/21:00541565 - isvavai.cz</a>

Result on the web

<a href="https://scholarcommons.usf.edu/ijs/vol50/iss1/8/" target="_blank" >https://scholarcommons.usf.edu/ijs/vol50/iss1/8/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5038/1827-806X.50.1.2374" target="_blank" >10.5038/1827-806X.50.1.2374</a>

Result language

angličtina

Original language name

Bat guano minerals and mineralization processes in Chameau Cave, Eastern Morocco

Original language description

The decay of bat guano deposits in caves produces mineral accumulations, mainly phosphates and secondary sulfates. Chameau Cave, Eastern Morocco, is located in the semi-arid Bni Snassen Mountains. It is composed of semi-active and dry passages, and is featured by strong condensation-corrosion on the walls, presence of fluvial sediments, and old corroded flowstones. Due to forced and convective airflow, the cave is generally very dry, with some damp sites related to condensation. Samples collected on the surface of different passages and along two sediment profiles yielded minerals related to bat guano decay. On recent or fresh guano, precursor minerals correspond to sulfate (gypsum), phosphate-sulfate (ardealite) and phosphate (brushite). Phosphates (hydroxylapatite, fluorapatite) occur at the interface with host rock or carbonate speleothems. At the contact of phyllosilicates contained in allogenic fluvial deposits or shale partings, or with pyrite-rich sediments, various phosphates occur (Alrich strengite, Fe rich variscite, phosphosiderite, leucophosphite, spheniscidite, crandallite, minyulite, variscite, and strengite), the latter two minerals being the stable end-members. Black seams of oxyhydroxides (goethite, hematite, birnessite) line the contact between carbonate host rock and weathered fluvial deposits. After “digestion” by acidic guano leachates, fluvial deposits only display the most resistant minerals (quartz, muscovite, K-feldspars, and Na-plagioclases) and weathering byproducts (kaolinite). We discuss the origin of a pure gypsum particle cone, possibly related to evaporation at the edge of a wet cupola and subsequent detachment of sulfate particles. Among environmental conditions, humidity is required for decay. In this dry cave, most of the damp originates from either permanent or seasonal condensation. Dust particle advection seems to be essential in providing compounds that are not present on fresh guano (quartz, clay minerals). Bat guano phosphatization has probably occurred since >100 ka. The Chameau Cave appears as an outstanding site for bat guano-related minerals (n = 12), including rare phosphates (spheniscidite and minyulite).

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10504 - Mineralogy

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

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

Name of the periodical

International Journal of Speleology

ISSN

0392-6672

e-ISSN

1827-806X

Volume of the periodical

50

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

19

Pages from-to

91-109

UT code for WoS article

000643550700006

EID of the result in the Scopus database

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