Integrated Middle Devonian chitinozoan and miospore zonation of the Amazonas Basin, northern Brazil
DOI | 10.1016/j.revmic.2004.03.001 |
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Year | 2004 |
Journal | Revue de Micropaleontologie |
Volume | 47 |
Number | 2 |
Pages | 71-85 |
Type | article in journal |
Language | English |
Id | 49678 |
Abstract
Middle Devonian chitinozoans were studied from 13 deep wells in the central part of the Amazonas Basin, northern Brazil, and compared with a newly established regional miospore zonation. Of the 23 chitinozoan species encountered, four are newly described: Ancyrochitina multibrachiata, Lagenochitina praeavelinoi, Ramochitina autasmirimense, and Ramochitina herculesi and seven species are retained in open nomenclature because of an insufficient number of well-preserved specimens. The stratigraphic intervals investigated herein correspond to three miospore interval range zones previously defined for the Amazonas Basin, namely, the Grandispora/Samarisporites spp. (GS); late Emsian–early Eifelian, Grandispora permulta (Per); late early Eifelian through the Eifelian–Givetian transition, and Geminospora lemurata-Chelinospora ex. gr. ligurata (LLi); early Givetian. A regional Middle Devonian chitinozoan biozonation, also consisting of three zones, is proposed for the investigated interval. These zones are the interval zone of Angochitina n. sp. A (early Eifelian), the interval zone of Alpenachitina eisenacki (late early to late Eifelian), and the total range zone of Ramochitina stiphrospinata (early Givetian).