Maerl-bed mapping and carbonate quantification on submerged terraces offshore the Cilento peninsula (Tyrrhenian Sea, Italy)

Geodiversitas

Alessandra Savini¹  Valentina Alice Bracchi¹  Daniela Basso¹  Cesare Corselli¹  Micla Pennetta¹ 

关键词: seafloor mapping;    submarine geomorphology;    marine terraces;    acoustic facies;    maerl distribution;    coralline carbonate;    Cilento peninsula;    Cartographie sous-marine;    géomorphologie sousmarine;    terrasses marines;    faciès acoustique;    distribution du maerl;    carbonate produit par des algues corallines;    Péninsule du Cilento;   

DOI  :  10.5252/g2012n1a5

学科分类：生物科学（综合）

来源: Museum National d Histoire Naturelle

【 摘 要 】

OnthecontinentalshelfofftheCilentopeninsula(easternTyrrhenianSea)theoccurrenceofmorethan13km2ofmaerlbedswasdocumentedthroughacousticsurveys.Swathbathymetricdataalongwithadensegridofchirp-sonarprofileswereacquiredovermorethan180km2.Themaerlfacieswascharacterizedonthebasisofthecomponentsanalysisof32grabsamplescollectedatselectedsites.Mappedmaerl-bedsarepredominantonsubmergedterraceslocatedatvariablewaterdepth(wd)between42and52m.Thispreferreddistributiononsubmergedterracesisprobablyassociatedwithrelativelyvigorousbottomcurrentsgeneratedbylocalcirculationthathindersthedepositionofterrigenoussediments.Calcareousredalgaeresulttobethemostimportantproducersofcarbonatesfrom40downto60mwd.Wecalculatedthecorallinecarbonateaccumulationfromthepercentagecoverofcorallinealgae(thinsectionmapping)×1cm-thicklayerofsediment×measuredcorallinedensity.Thetotalcorallinecover(livingplusdead)intheCilentoareais13.96km2,withatotal316800tonsofalgalcarbonateinthesurface1cmlayer,thatcorrespondto20430gm-2.Livingmaerlisrecordedatadepthof47m,withalivecorallinecoverofabout40%overaminimumareaofabout1.2km2.Thislivemaerlhasathicknessofabout1cmandiscomposedmainlyofunattachedbranchesofLithothamnioncorallioides(P.L.Crouanamp;H.M.Crouan)P.L.Crouanamp;H.M.Crouan,1867.ThemolluscanassociationofthemaerlbedisdominatedbycharacteristicspeciesoftheCoastalDetriticBiocoenosis.Theproductionofcarbonatebylivingcorallinealgaehasbeencalculatedasweightoflivecorallinesin1cm-thicklayer×100y-1×totalarea-1andcorrespondsto90.8gm-2y-1.

【 授权许可】

Unknown