Modern Rhodolith-dominated carbonates at Punta Chivato, Mexico

Geodiversitas

Steffen Hetzinger¹  Bernhard Riegl¹  Markus Eisele¹  Jochen Halfar¹  Lucio Godinez-Orta¹ 

关键词: Gulf of California;    coralline algae;    acoustic mapping;    rhodalgal;    golfe de Californie;    algues corallines;    cartographie acoustique;    faciès rhodalgal;   

DOI  :  10.5252/g2012n1a6

学科分类：生物科学（综合）

来源: Museum National d Histoire Naturelle

【 摘 要 】

Rhodolith-dominatedcarbonateenvironments,characterizedbyhighabundancesoffree-livingcorallinealgae,havebeendescribedgloballyfromawiderangeofRecentandfossilshallowmarinesettings.Inthepresent-daywarm-temperateGulfofCalifornia,Mexico,rhodolith-dominatedsystemsareimportantcontributorstocarbonateproduction.OneofthemostprolificrhodolithfactoriesislocatedonthePuntaChivatoshelf,inthecentralGulfofCalifornia,whereduetoalackofinputofterrigenousmaterialfromthearidhinterland,carbonatecontentaverages79%.PuntaChivatorhodolithsthriveabovetheshalloweuphoticzoneundernormalsaline,warm-temperateandmeso-toeutrophicconditions.Adetailedsedimentologicstudycombinedwithacousticseafloormappingindicatesthepresenceofextensiverhodolith-dominatedfaciesatsubtidalwaterdepthcoveringanareaofgt;17km2.Additionalfacies,surroundingtherhodolith-dominatedfaciesincludeafine-grainedmolluscan,atransitionalbivalve-rhodolithandabivalvefacies.WhilethePuntaChivatoshelfyieldsaverageabundancesof38%rhodolith-derivedcorallinealgalcomponentsinthegravel-sizedsedimentfraction,therhodolithfaciesitselfischaracterizedbymorethan60%corallinealgalcomponents.OtherimportantcarbonateproducersatPuntaChivatoincludebivalves(35%),bryozoa(11%)andgastropods(8%).Thepresentstudyshowsthatacousticsedimentmappingyieldshighlyresolvedcontinuouscoverageoftheseafloorandcandistinguishmodernrhodolithfaciesfromsurroundingsediment.Thishasimportantimplicationsforquantifyingrhodolith-dominatedsettingsglobally,aswellasforecologicalandconservationstudies.

【 授权许可】

Unknown