First Note of Foraminifera Assembages last Jan akhir...
Transcript of First Note of Foraminifera Assembages last Jan akhir...
First Note of Benthic Foraminifera Assemblages in Serasan Sea, South Natuna, Indonesia
Isnaniawardhani, Vijaya1) Natsir, Suhartati 2)
1)Faculty of Geology, Padjadjaran University
2)Indonesia Institute of Science
ABSTRACT Foraminifera assemblages were studied in marine surface sediments from shallow open marine, reefal, mangrove and sandy coastal near Serasan, Riau Islands Province. The twelve deposits (sand, silty sand and clay) contain microorganism shell fragments. This study is conducted to identify foraminifera in study area, as well as determine abundance, dominant and typical of assemblages in this area based on quantitative data analyses. The study was done in several stages: literature study, field work and samples collection, laboratory analyses, identical and overview of the taxonomy of each taxon. The fifty nine genera of benthic foraminifera were identified in the sediment samples, in low to high abundance. The assemblages was dominantly composed of Suborder Rotaliina, the calcareous forms, reached more than 54% of total assemblages (average 78%). Reusella, Cancris, Eponides, Neoeponides, Orbitina, Neoconorbina, Rosalina, Siphoninoides, Discorbia, Lobatula, Planorbulinella, Gypsina, Cymbaloporetta, Epistomaroides, Amphistegina, Nonion, Nonionoides, Heterolepa, Gyroidina, Hanzawaia, Pararotalia, Rotalia, Ammonia, Asterorotalia, Pseudorotalia, Baculogypsinoides, Calcarina, Elphidium, Parrellina, Assilina, Heterostegina and unidentified rotaloid foram are classified into this group. Porceleneous shells that typified by subordo Miliolina and Lagenina, occur less than 29% (average 17%). Genera Adelosina, Spiroloculina, Agglutinella, Ammomasilina, Lachlanella, Massilina, Quinqueloculina, Miliolinella, Pseudomassilina, Pyrgo, Triloculina, Peneroplis, Archaias, Marginopora, and young miliolidae are classified into suborder Miliolina; whereas Lagena, Guttulina, Oolina, and Glandulina are Lagenina. Subordo Textulariina and Spirillinina with arenaceous shells are appears rarely in samples. Suborder Textulariina is represented by genera Ammobaculites, Spiroplectinella, Spirotextularia, Dorothia, Karreriella, Bigerina, Sahulia, Textularia, and Clavulina. Spirilina is the only genus of Suborder Spirillinina. The most frequently encountered genera are Eponides, Amphistegina, Heterolepa, Ammonia, Elphidium, and Assilina (suborder Rotaliina), Quinqueloculina (Miliolina) and Textularia (Textulariina). The most abundant benthic foraminifera is Asterorotalia (represented by A. trispinosa Thalmann) that recorded in open marine and near reef samples. It was found that high abundance and diversity of benthic foraminifera assemblages were recorded in open marine.
a. INTRODUCTION
Foraminifera is cytoplasmic body enclosed in test or shell of one or more interconnected chambers; wall
may be homogeneous or of similar or unlike layers or laminae, may be imperforate or finely to coarsely
perforate, basically proteinaceous but may have agglutinated particles, or may deposit the mineral
calcite, aragonite, or rarely silica on the organic base, calcareous wall may be porcelaineous,
microgranular, or hyaline and optically or ultrastructurally radiate or granular; canal or stolon system of
varied complexity may be present; commonly test has one or more main apertures through which
pseudopodia protrude. Sexual and asexual generatio may be suppressed; gametes biflagellate,
triflagellate, or amoeboid. It spreads in Cambrian to Holocene stratigraphic range, and occurrence as
free-‐living or rarely parasitic; benthic and attached or motile, or pelagic, in marine to brackish water,
rare in fresh water (von Eichwald, 1830 in Loeblich and Tappan, 1988; Haynes, 1981; Brasier, 1985).
The number of published information on the Quaternary smaller benthic foraminifera from sea
sediment in Indonesia and adjacent area is very low. The reports on Recent benthic foraminifera is also
relative limited compared to other area. According to previous study, the marine surface sediments (sea
bed) of Natuna Sea, eastern Shelf of Sunda, contain common benthic foraminifera (Isnaniawardhani and
Natsir, 2012). This study is important to identifying of foraminifera in this area and determining
assemblages based on quantitative data analyses (abundance, dominant and typical suborder/genus).
b. METHODS
The actual study was done in several stages; was started by literature study, field work and samples
collection, laboratory analyses, identical and overview of the taxonomy of each taxon. Six samples were
obtained from shallow open marine (depth of 28.26 – 52.54 m), and six samples from reefal, mangrove
and sandy coastal near Serasan, Riau Islands Province, from the area between coordinates 2.3940 N to
2.6650 N and 108.8810 to 109,1350 E (Figure 1,2 and 3). They collected during Natuna Sea Expedition, a
joint research between Indonesian Institute of Sciences and Directorate General of Higher Educations
Ministry of National Education.
Figure 1. The marine surface sediment sampling in Serasan Sea
Figure 2. The reefal sediment sampling in Serasan sea
Figure 3. The mangrove sediment sampling in Serasan sea
Laboratory analyses upon seabed surface sediment samples are conducted to identify foraminifera
microscopically. The each sediment sample was prepared a simple residu preparation method using
Sta. 10
Sta. 11
hydrogen peroxide. The residual sediment of each sample is examined in order to release foraminifera
assemblages using a slab binocular microscope of 40 magnifications. The research adopted some basic
methods for the identification and overview of taxonomy of species referred to published taxonomical
studies of foraminifera genera with an accompanying systematical classification, among all, by
D’Orbigny, 1826 and Brady, 1884 in Loeblich and Tappan (1988), Chapman (1902), Cushman (1927,
1931), Galloway (1933), Cushman and Stainforth (1945), Belford, 1966, Biswas, 1976, Haynes (1981),
Loeblich and Tappan (1988), and van Marle (1991).
c. RESULT
The climate of Serasan Sea is almost entirely maritime tropical. The area's relative average annual
rainfall is 2795 mm, with average monthly rainfall ranges between 140 – 200 mm in the dry season, and
up to 350 mm during the northwest monsoon/wet season in October through March. Temperatures on
area remain fairly constant, with the lowland plains averaging 250 C -‐ 320 C and the higher land region ±
180 C. It seen that the main variable of climate on this area is rainfall.
On the basis of geology regional by Harahap, et al. (1995), lithology of Serasan Island and and small
islands on its surrounding consist of (Figure 4):
a. Qp = coastal deposits: sand, gravels and plant remains. They are commonly found in the
Serasan island, thickness up to 25 m.
b. Qc = coral reef: reef limestone which are still growing or eroded and talus. These reef s have
elevation up to 10 m above sea level.
c. Tok = Kutei Formation: conglomerate & sandstone, poor to moderately bedded, greenish grey to
yellowish grey, as a river deposits. Conglomerate: moderately sorted, well rounded, comprise
chert, granite, silified rock, chalsedon, quartz, kaolinitic clay, with a sandstone matrix.
Sandstone: well sorted, medium to coarse grained, composition same as the conglomerate with
matrix of kaolinitic clay. This formation is might be correlated to the Oligocene Gabus Formation
in East Natuna Basin & West Natuna Basin (Pribadi & Simbolon, 1994). The thickness in up to
250 m.
d. Jkb = Balau Formation : interbedded well bedded sandstone & siltstone and in places hornfels,
greenish grey, hard, laminations, no fossils recorded, a flysch type deposit. In several places are
intruded by Serasan Pluton. This formation is might be correlated to the Pedawan Formation in
West Kalimantan. The thickness more than 200 m.
e. Ks = Serasan Plutonic Rocks: Biotite granodiorite & hornblende granite with xenolith of
metasediments. Subduction related granitoids, as a result the southwest subduction from the
Lupar Line Zone in Sarawak, Malaysia, according to Hutchison (1973) as a granitic arc. Based on
K/Ar dating of two samples rocks resulting 69.679 & 112.34 m.y or Maastrichtian and Aptian
respectively.
Figure 4. Geological map of Serasan Island and and small islands on its surrounding
The surface sediments in Serasan seas are grouped into: sand, silty sand and clay, contain
microorganism assemblages.
Table 1. Marine Surface Sediment from Serasan Sea Sta. Depth (m) Samples type Sediments texture 1 52.54 Open sea box corer Sand, greenish grey, shell fragments 2 36.93 Open sea box corer Sand, greenish grey, shell fragments 3 40.26 Open sea box corer Sand, greenish grey, shell fragments 4 46.30 Open sea box corer Silty sand, greenish grey, shell fragments 5 28.26 Open sea box corer Silty sand, greenish grey, shell fragments 6 42.98 Open sea box corer Silty sand, greenish grey, shell fragments 7 15.00 Batuberian reefal sampler Sand, light grey, shell fragments 8 17.00 Karanghaji reefal sampler Sand, light grey, shell fragments 9 14.50 Perayun besar reefal sampler Sand, light grey, shell fragments 10 7.00 Serasan mangrove sampler Clay, brown 11 12.00 Gordon mangrove sampler Clay, brown 12 0.75 Serasan sandy coastal Sand, light grey
Fifty nine genera of benthic foraminifera were identified in all sediment samples. They are classified into
nine genera of suborder Textulariina; a genus of Spirillinina; fourteen genera of Miliolina; four genera of
Lagenina; and thirty one genera of Rotaliina, as described follows.
1. Suborder Textulariina
This arenaceous shells group is represented by genera: Ammobaculites, Spiroplectinella,
Spirotextularia, Dorothia [D. rotunda (Cushman)], Karreriella, Bigerina [B. nodosaria d'Orbigny],
Sahulia [S. barkeri Hofker], Textularia [T. agglutinans d’Orbigny, T. sagittula Defrande], and
Clavulina (Table 2)
2. Suborder Spirillinina is represented by genus Spirilina [S. obconical (Brady)], as shown in Table 2.
Table 2. Textulariina and Spirillina benthic foraminifera assemblages in Serasan Seas
Suborder
1. No.
Species Stasiun & Depth
1 2 3 4 5 6 7 8 9 10 11 12
Textulariina 1. Ammobaculites spp. f c c 2. Spiroplectinella spp. f 3. Spirotextularia spp. c f 4. Dorothia rotunda (Cushman) c 5. Karreriella spp. f f 6. Bigerina nodosaria d'Orbigny c f 7. Sahulia barkeri Hofker f c f r 8. Textularia agglutinans d’Orbigny c c c f 9. Textularia sagittula Defrance c f a a 10. Textularia sp. a a a a c a f f f r r 11. Clavulina spp. r
Spirillinina 1. Spirilina obconical (Brady) f Note: a = abundant > 100, c = common 35-‐99, f = few 11-‐35, r = rare < 10
Figure 5. Textulariina: Sahulia barkeri Hofker(L); Textularia agglutinans d’Orbigny (C); Textularia sp.(R) (Sta. 4)
3. Suborder Miliolina
The porceleneous shells group is represented by genera: Adelosina [A. laevigata d'Orbigny],
Spiroloculina, Agglutinella, Ammomasilina [A. alveoliniformis Millett], Lachlanella [L. parkeri
(Brady)], Massilina, Quinqueloculina [Q. pseudoreticulata Parr, Q. seminulum Linnaeus],
Miliolinella [M. australis (Parr)], Pseudomassilina, Pyrgo, Triloculina [T. tricarinata d’Orbigny],
Peneroplis [P. pertusus (Forskal), P. planatus (Fichtel & Moll)], Archaias [A. angulatus (Fichtel &
Moll)], Marginopora [M. vertebralis Quoy & Gaimard], and young miliolidae (Table 3).
4. Suborder Lagenina, represented by genera: Lagena [L. laevis (Montagu), L. striata (d'Orbigny)],
Guttulina, Oolina, and Glandulina (Table 3).
Table 3. Miliolina and Lagenina benthic foraminifera assemblages in Serasan Seas
Suborder
No. Species
Stasiun & Depth 1 2 3 4 5 6 7 8 9 10 11 12
Miliolina 1. Adelosina laevigata d'Orbigny a c 2. Spiroloculina spp. a c c c f r 3. Agglutinella spp. a c a a f f 4. Ammomasilina alveoliniformis Millett f a a c 5. Lachlanella parkeri sp. (Brady) f f r r 6. Massilina spp. f 7. Quinqueloculina pseudoreticulata Parr f c c a f 8. Quinqueloculina seminulum Linnaeus r 9. Quinqueloculina sp. a a a a c a f c f f 10. Miliolinella australis (Parr) f 11. Miliolinella sp. c c f 12. Pseudomassilina spp. c 13. Pyrgo spp. f c r 14. Triloculina tricarinata d’Orbigny a f r 15. Triloculina sp. c f c c f r 16. Peneroplis pertusus (Forskal) c r 17. Peneroplis planatus (Fichtel & Moll) c f r 18. Archaias angulatus (Fichtel & Moll) r 19. Marginopora vertebralis Quoy & Gaimard a 20. Young Miliolidae a a c
Lagenina 1. Lagena laevis (Montagu) a 2. Lagena striata (d'Orbigny) syn Oolina
striata d'Orbigny a c
3. Lagena spp. a c 4. Guttulina spp. c 5. Oolina spp. a 6. Glandulina spp. c c
Note: a = abundant > 100, c = common 35-‐99, f = few 11-‐35, r = rare < 10
Figure 6. Miliolina: (from left to right) Quinqueloculina pseudoreticulata Parr; Spiroloculina spp. (Sta. 4); Pyrgo spp; Triloculina spp.; Marginopora vertebralis Quoy & Gaimard (Sta. 3)
Figure 7.Lagenina: Lagena laevis (Montagu) (L); Oolina spp. (R)
5. Suborder Rotaliina
This calcareous shells group is represented by genera: Reusella [R. simplex (Cushman)], Cancris,
Eponides [E. cribrorepandus (Asano & Uchio), E. repandus (Fitchtell & Moll)], Neoeponides,
Orbitina, Neoconorbina [N. terquemi (Rzehak)], Rosalina [R. globularis d'Orbigny], Siphoninoides
[S. echinatus (Brady)], Discorbia, Lobatula [L. lobatula (Walker & Jacob)], Planorbulinella [P.
larvata (Parker & Jones)], Gypsina, Cymbaloporetta [C. bradyi (Cushman), C. tabellaeformis
(Brady)], Epistomaroides [E. polystomelloides (Parker & Jones)], Amphistegina [A. lessonii
d’Orbigny, A. quoyii d’Orbigny], Nonion, Nonionoides [N. grateloupi d’Orbigny], Heterolepa,
Gyroidina [G. neosoldanii Brotzen], Hanzawaia [H. nipponica (Asano)], Pararotalia, Rotalia,
Ammonia [A. beccarii (Linnaeus)], Asterorotalia [A. bispinosa n.sp, A. gaimardii (d’Orbigny), A.
trispinosa Thalmann], Pseudorotalia, Baculogypsinoides [B. spinosa Yabe & Hanzawa), Calcarina
[C. calcar d’Orbigny, C. spengleri (Gmelin)], Elphidium [E. advenum (Chusman), E. crispum
(Linnaeus), E. macellum (Fichtel & Moll)], Parrellina, Assilina [A. ammonoides (Gronovius)],
Heterostegina and unidentified rotaloid foram (Table 4).
Table 4. Rotaliina benthic foraminifera assemblages in Serasan Seas
Suborder
1. No.
Species Stasiun & Depth
1 2 3 4 5 6 7 8 9 10 11 12
Rotaliina
1. Reusella simplex (Cushman) a f f 2. Cancris spp. a 3. Eponides cribrorepandus (Asano & Uchio) f f 4. Eponides repandus (Fitchtell & Moll) f c c c a f f f r 5. Eponides sp. f 6. Neoeponides spp. f f r 7. Orbitina spp. f 8. Neoconorbina terquemi (Rzehak) f 9. Neoconorbina sp. f 10. Rosalina globularis d'Orbigny c f r 11. Rosalina sp. c a f 12. Siphoninoides echinatus (Brady) f 13. Discorbia spp. c 14. Lobatula lobatula (Walker & Jacob) c c 15. Planorbulinella larvata (Parker & Jones) c c c a f 16. Gypsina spp. c c c a r r
Suborder
1. No.
Species Stasiun & Depth
1 2 3 4 5 6 7 8 9 10 11 12
17. Cymbaloporetta bradyi (Cushman) f r 18. Cymbaloporella tabellaeformis (Brady) f 19. Epistomaroides polystomelloides (Parker & Jones) c f 20. Amphistegina lessonii d’Orbigny c f c f f 21. Amphistegina quoyii d’Orbigny r f 22. Amphistegina sp. a a a a a a c f r f c f 23. Nonion spp. c 24. Nonionoides grateloupi d’Orbigny a 25. Heterolepa spp. a a a c a f r f 26. Gyroidina neosoldanii Brotzen c a c 27. Hanzawaia nipponica (Asano) c c 28. Pararotalia spp. c 29. Rotalia spp. c c 30. Ammonia beccarii (Linnaeus) c c a f 31. Ammonia sp. c c a a a a f c r c r 32. Asterorotalia bispinosa n.sp c c 33. Asterorotalia gaimardii (d’Orbigny) a c a c 34. Asterorotalia trispinosa Thalmann a a a a a a 35. Asterorotalia sp. a c a a f 36. Pseudorotalia spp. c c a r r 37. Baculogypsinoides spinosa Yabe & Hanzawa c c f 38. Calcarina calcar d’Orbigny c c c f f r 39. Calcarina spengleri (Gmelin) f f 40. Calcarina sp. c f f 41. Elphidium advenum (Chusman) a a a a 42. Elphidium crispum (Linnaeus) c c c c a f f f 43. Elphidium macellum (Fichtel & Moll) c 44. Elphidium sp. c a a a a c c r f r 45. Parrellina spp. c c c c 46. Assilina ammonoides (Gronovius) a a a a c a f r f 47. Heterostegina sp. a c f f r 48. Unidentified rotaloid foram c a a c a a f f f f
Note: a = abundant > 100, c = common 35-‐99, f = few 11-‐35, r = rare < 10
Figure 8. Rotaliina: Eponides repandus (Fitchtell & Moll) (L); Epistomaroides polystomelloides (Parker & Jones) (C); Planorbulinella larvata (Parker & Jones) (R) (Sta. 3)
Figure 9. Rotaliina: Amphistegina sp. (L); Nonionoides grateloupi d’Orbigny (C) (Sta. 3); Heterolepa spp.
(R) (Sta.4)
Figure 10. Rotaliina: Gyroidina neosoldanii Brotzen (L), Asterorotalia trispinosa Thalmann (C), Calcarina
calcar d’Orbigny (R)
Figure 11. Rotaliina: Elphidium crispum (Linnaeus) (L), Elphidium macellum (C); Parrellina spp (Fichtel &
Moll) (R) (Sta. 3)
Discussion:
1. Calcareous shells or suborder Rotaliina is the most abundantly appearing taxon, more than 54% of
total assemblages (average 78%). The most frequently encountered genera in this group are
Eponides, Amphistegina, Heterolepa, Ammonia, Elphidium, and Assilina.
2. Porceleneous shells that typified by subordo Miliolina and Lagenina, less than 29% (average 17%).
The most frequently encountered genus in this group is represented by Quinqueloculina.
3. Arenaceous shells or subordo Textulariina and Spirillinina are appears rarely in samples, less than
19% (average 5%) represented mostly by the genus Textularia.
4. The most abundant dominant is Asterorotalia, reachs the optimum abundancy of 23%, especially in
open sea and reefal samples (represented by A. trispinosa Thalmann). This genus is not recorded in
mangrove and sandy coastal samples.
5. High abundance and diversity of benthic foraminifera assemblages were indicated in open marine
samples. Less abundance and diversity were found in mangrove and sandy coastal area.
d. CONCLUSION
1. Samples collected in Serasan Sea have 59 genera of benthic foraminifera.
2. Suborder Rotaliina that has calcareous shells is the most abundantly appear and highest
diversity taxa. Eponides, Amphistegina, Heterolepa, Ammonia, Elphidium, and Assilina are
always found in all samples. The other genera observed in the samples are Reusella, Cancris,
Neoeponides, Orbitina, Neoconorbina, Rosalina, Siphoninoides, Discorbia, Lobatula,
Planorbulinella, Gypsina, Cymbaloporetta, Epistomaroides, Nonion, Nonionoides, Gyroidina,
Hanzawaia, Pararotalia, Rotalia, Asterorotalia, Pseudorotalia, Baculogypsinoides, Calcarina,
Parrellina, Heterostegina and unidentified rotaloid foram.
3. Subordo Miliolina and Lagenina that have porceleneous shells are common recorded in samples.
The most frequently encountered genus in this group is Quinqueloculina. Suborder Miliolina is
represented by genera Adelosina, Spiroloculina, Agglutinella, Ammomasilina, Lachlanella,
Massilina, Quinqueloculina, Miliolinella, Pseudomassilina, Pyrgo, Triloculina, Peneroplis,
Archaias, Marginopora, and young miliolidae. Suborder Lagenina, represented by genera:
Lagena, Guttulina, Oolina, and Glandulina.
4. Subordo Textulariina and Spirillinina with arenaceous shells are rare in samples. Ammobaculites,
Spiroplectinella, Spirotextularia, Dorothia, Karreriella, Bigerina, Sahulia, Textularia, and
Clavulina is classified into Suborder Textulariina, with Textularia as the most frequently
encountered genus. Spirilina is the only genus of Suborder Spirillinina.
5. The most abundant genus is Asterorotalia that recorded only in open marine and reefal samples
(represented by A. trispinosa Thalmann).
References:
Brasier, M.D., 1985, Microfossils, George Allen & Unwin (Publishers) Ltd., London, pp. 90-‐121.
Belford, D. J., 1966, Miocene and Pliocene smaller foraminifera from Papua and New Guinea,
Australia Bureau of Mineral Resources, Geology and Geophysics Bulletin, vol. 79, pp. 1-‐309.
Biswas, B., 1976, Bathymetry of Holocene Foraminifera and Quaternary sea-‐level changes on
the Sunda Shelf, Journal of Foraminifera Research, vol. 6 no. 2, pp. 119 -‐ 138
Chapman, F., 1902, On the foraminifera collected from the Funafuti Atoll from shallow and
moderately deep water, Linnean Society of London, Journal of Zoology, vol. 28 (1900-‐1903), no. 184, pp.
379-‐417.
Cushman, J. A., 1927 a, Recent foraminifera from off the west coast of North America, Scripps
Institution of Oceanography, Bulletin Technique, vol. 1, no 10, pp.119 – 188.
Cushman, J. A., 1927 b, An outline of re-‐classification of the foraminifera, Cushman Laboratory,
Foraminifera Research, vol. 3 no.1, pt.1-‐105, pls 1-‐21.
Cushman, J. A., 1931, The foraminifera of the Atlantic Ocean: Part VIII, Rotaliidae,
Amphistegenidae, Calcarinidae, Cymbaloporettidae, Globorotaliidae, Anomalinidae, Planorbulinidae,
Rupertinidae, and Homotremidae, U.S National Museum Bulletin, no. 104, pt.8, pp. 1 – 179, pls 1-‐26.
Cushman, J.A., and Stainforth, R. M., 1945, The Foraminifera of the Cipero Marl Formation of
Trinidad, British West Indies, Cushman Laboratory, Foraminifera Research, Special Pub., no. 14, pp. 3 -‐
75, pls 1-‐16.
Galloway, J.J., 1933, A manual of foraminifera, Bloomington, Indiana: Principle Press, pp. 1-‐483,
pls. 1-‐ 42.
Harahap, B.H, Mangga, S.A and Wiryosujono, S. 1995, Geological Map of South Natuna Sheet,
scale 1 : 100.000, Geological Research and Development Centre.
Haynes, J. R., 1981, Foraminifera, Macmillan Publishers Ltd., London and Bassingstoke, p. 1-‐59.
Isnaniawardhani, V., Natsir S., 2012, Tipe Sedimen Permukaan Dasar Laut Selatan Dan Utara
Kepulauan Tambelan Perairan Natuna Selatan, http://pustaka.unpad.ac.id/archives/123993/
Loeblich, A.R. Jr. & Tappan, H., 1988, Foraminiferal Genera and Their Classification, Book 1 & 2,
van Nostrand Reinhold, New York, pp. 1-‐970.
Van Marle, L., J., 1991, Eastern Indonesian, Late Cenozoic Smaller Benthic Foraminifera,
Verhandelingen der Koninklijke Nederlandse Akademie van Wetenschappen, Afd. Natuurjunde, Eeste
Reeks, deel 34, North-‐Holland, Amsterdam/Oxford/New York/Tokyo, pp. 1 -‐ 328, pls. 1 – 25.