Foraminifers as facies indicators in a tropical, macrotidal environment: Torres Strait-Fly River delta, Papua New Guinea
Cole, A.R.; Harris, P.T.; Keene, J.B. (1995). Foraminifers as facies indicators in a tropical, macrotidal environment: Torres Strait-Fly River delta, Papua New Guinea, in: Flemming, B.W. et al. (Ed.) Tidal Signatures in Modern and Ancient Sediments. Special Publication of the International Association of Sedimentologists, 24: pp. 213-223 In: Flemming, B.W.; Bartholomä, A. (Ed.) (1995). Tidal Signatures in Modern and Ancient Sediments. Special Publication of the International Association of Sedimentologists, 24. Blackwell Science: Oxford. ISBN 0-86542-978-2. 358 pp., more In: Special Publication of the International Association of Sedimentologists. Blackwell: Oxford. ISSN 0141-3600; e-ISSN 2054-6610, more |
| Authors | | Top | - Cole, A.R.
- Harris, P.T.
- Keene, J.B.
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| Abstract | Foraminifer assemblages are assessed as potential recorders of transportation and redistribution by tidal processes in tropical, tidally dominated carbonate shelf and fluvio-deltaic environments. Four facies are identified on the basis of grain-size distribution, carbonate content and energy: (i) a high energy carbonate sand facies; (ii) a low energy muddy carbonate sand facies; (iii) a transitional mixed terrigenous and carbonate sediment facies; and (iv) a terrigenous delta front facies. Up to 1300 tests were picked from nine representative samples and analysed using a computerized image analysis system. This method allowed the determination of maximum and minimum test dimensions, as well as two-dimensional shape and area, to produce a grain-size histogram of foraminifer tests for each site. The results show that each of the four facies can be identified from the combination of foraminiferal taphonomic and grain-size properties. Furthermore, such properties identified the mode of transport (i.e. suspension versus bedload) and transport pathways at the sample locations. A small amount of carbonate material is transported landwards in suspension and deposited among the mostly (>95%) terrigenous sediments comprising the prograding Fly delta. |
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