DOI: 10.1016/j.palaeo.2016.04.014
论文题名: Morpho-structural heterogeneity of shallow-water coralligenous in a Pleistocene marine terrace (Le Castella, Italy)
作者: Bracchi V.A. ; Nalin R. ; Basso D.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 454 起始页码: 101
结束页码: 112
语种: 英语
英文关键词: Algal reefs
; Mediterranean Sea
; Morpho-structural heterogeneity
; Shallow-water carbonates
; Substrate type
; Water turbidity
英文摘要: Coralligenous is the most volumetrically significant type of autochthonous carbonate build-up in the Mediterranean, but its range of morphological variability at the macroscale, and potential link with environmental factors have not been fully documented. Well-preserved examples of coralligenous are exposed in shallow marine carbonate deposits from the Upper Pleistocene Le Castella marine terrace (Southern Italy). The coralligenous build-ups occur in the lower part of an unconformity-bounded, transgressive-regressive sequence. They show high structural and morphological heterogeneity in terms of framework type and build-up size, over a distance of several hundred meters. In northern exposures, coralligenous forms banks up to 4 m high, with a dense, coralline-dominated framework, laterally adjacent to paleo-channels devoid of build-ups and filled by coeval infra-circalittoral biogenic packstone. To the south, build-ups are smaller (up to 1.8 m high), with an open algal framework and local predominance of the coral Cladocora caespitosa as primary framework builder. At both locations, the most important framework-building coralline species is Mesophyllum philippii; Titanoderma pustulatum also occurs. Analysis of sedimentary structures, paleo-topographic indicators, faunal composition of associated mollusk assemblages, and predominance of M. philippii suggest the algal builds-ups grew within a shallow-water, possibly infralittoral setting, competing for space with other biocoenoses. Suitable substrate availability in the form of conglomerate blocks or shell accumulations was the primary factor controlling the inception and spatial distribution of coralligenous. Differences in hydrodynamism and water turbidity determined variability in size and internal composition between the northern and southern locations. To the south, abundant supply of fine suspended sediment resulted in smaller build-ups with more open framework, the growth of which was terminated abruptly by sediment burial. Eventually, relative sea level fall during regression prevented further growth of the coralligenous even in the northern area. This study contributes to a better understanding of the relationship between coralligenous morphology and environmental factors, highlighting the role of suitable substrate availability, turbidity, and sediment burial in influencing spatial and temporal variability of coralligenous assemblages. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68393
Appears in Collections: 过去全球变化的重建
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作者单位: University of Milano-Bicocca, Dept. of Earth and Environmental Sciences, Piazza della Scienza 4, Milano, Italy; CoNISMa, Milano-Bicocca Local Research Unit, Piazza della Scienza 4, Milano, Italy; Geoscience Research Institute, 11060 Campus Street, Loma Linda, CA, United States
Recommended Citation:
Bracchi V.A.,Nalin R.,Basso D.. Morpho-structural heterogeneity of shallow-water coralligenous in a Pleistocene marine terrace (Le Castella, Italy)[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,454