Facies analysis of a higly cyclic sedimentary unit: the Late Hauterivian to Early Barremian Agua de la Mula Member of the Agrio Formation, Neuquén Basin, Argentina

Journal article


Publication Details

Author(s): Archuby FM, Fürsich F
Journal: Beringeria
Publication year: 2010
Volume: 41
Pages range: 77-127
ISSN: 0937-0242
Language: English


Abstract


is article contains the facies analysis of the highly cyclic Upper Hauterivian to Lower Barremian Agua de


la Mula Member of the Agrio Formation (Neuquén Basin, Argentina). e study was developed to test the hypothesis


that the occurrence of particular facies can be predicted every time the sequence stratigraphic model can be applied.


e multi-facetted approach based on detailed bed-by-bed collection of sedimentological, stratigraphic, ichnological,


taphonomic, and palaeoecological data led a precise palaeoenvironmental interpretation within a controlled bio- and


sequence-stratigraphic framework.


e facies and facies associations are based mainly on lithological aspects. ree main groups of facies and facies as-


sociations are distinguished: (a) siliciclastic, (b) mixed, and (c) carbonate. e rst group comprises facies and facies


associations linked to regressive phases of short sequences (so-called dilution hemi-sequences) and is characterised by


deposition of terrigenous siliciclastic material, while the second and third group include rocks varying widely in terms


of composition that share a condensed nature (so-called starvation hemi-sequences). Together they form starvation/


dilution sequences. Siliciclastic facies dominate over mixed ones. Carbonate facies are the least represented.


e distinct heterogeneity of facies types and successions correlates with both, the observed cyclic patterns and the


upward reduction in siliciclastic input. e starvation/dilution sequences, which shape the cycle pattern, are present


throughout the sections. ey consist of alternations of terrigenous-starved and terrigenous-diluted beds. Features of


starvation/dilution sequences change according to their position within the sections, but there is always a contrast


between the lower starved and the upper diluted hemisequence.


Facies of starvation/dilution sequences are ner- or coarser-grained, following the deepening and shallowing trend,


respectively of major sedimentary sequences. Predictions of facies occurrence can be improved, if the position within


the sedimentary sequence (transgressive systems tract or regressive systems tract) is also considered. In this way, facies


of starvation/dilution sequences corresponding to the early/late transgression and regression as well as to the maxi-


mum ooding zone can be predicted. Superimposed cyclicities of dierent hierarchies alter the resulting patterns.


Most of the Agua de la Mula Member of the study area can be interpreted to represent a siliciclastic open ramp.


Carbonate-rich beds formed as concentrations of invertebrate hard-parts produced during terrigenous starvation in a


siliciclastic system during transgressions rather than by increased carbonate production. e reduced terrigenous input


observed in the last 150 m of the two investigated sections resulted in facies that can be better explained by carbonate


models. However, even in this setting siliciclastic facies are well represented during major regressions.


FAU Authors / FAU Editors

Fürsich, Franz Prof. Dr.
Naturwissenschaftliche Fakultät


Additional Organisation
Lehrstuhl für Paläoumwelt


How to cite

APA:
Archuby, F.M., & Fürsich, F. (2010). Facies analysis of a higly cyclic sedimentary unit: the Late Hauterivian to Early Barremian Agua de la Mula Member of the Agrio Formation, Neuquén Basin, Argentina. Beringeria, 41, 77-127.

MLA:
Archuby, Fernando Miguel, and Franz Fürsich. "Facies analysis of a higly cyclic sedimentary unit: the Late Hauterivian to Early Barremian Agua de la Mula Member of the Agrio Formation, Neuquén Basin, Argentina." Beringeria 41 (2010): 77-127.

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Last updated on 2018-08-08 at 02:54