LARGER FORAMINIFERA CATALOG
ON MEMBER OF CALCARENITE
PAMUTUAN FORMATION (Katalog Foraminifera Besar
pada Anggota Kalkarenit Formasi Pamutuan)
Written by :
Vijaya Isnaniawardhani
Edited by :
Adjat Sudrajat and Nana Sulaksana
i
Copyright@2018, Vijaya Isnaniawardhani Hak cipta dilindungi oleh undang-undang.
Dilarang mengutip atau meperbanyak sebagian
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Bahasa/Language : English dan Indonesia Editor : Adjat Sudradjat, Nana Sulaksana
Tata Letak dan Desain Sampul : Vijaya Inaniawardhani dan Trisatya
Katalog Vijaya Isnaniawardhani Larger Foraminifera Catalog On Member of Calcarenite Pamutuan Formation / Penulis Vijaya Isnaniawardhani; Penyunting, Adjat Sudradjat, Nana Sulaksana. Cet. I – Bandung; Unpad Press; 2018 115 h; 29 cm ISBN 978-602-439-308-3 I. Judul II. Vijaya Isnaniawardhani
ii
PREFACE
Catalog of larger foraminifera on Calcarenite Member of
Pamutuan Formation is arranged based on detail field
observation and laboratorium analysis on limestone in
Cintaratu, Pangandaran District, West Java, Indonesia. This
book is prepared to complement the references of foraminifera
in Indonesia. A little studies on larger foraminifera taxonomy
in Indonesia have been conducted by world researchers, among
all, by Boudagher-Fadel and Lokier (2005) in South Central
Java, Isnaniawardhani, et al. (2012) in Bogor - West Java,
Sharaf, et al. (2006) in East Java, Boudagher-Fadel and Wilson
(2000) in Southeast Kalimantan, van Vessem (1978) in Java
and Borneo, van de Vlerk and Postuma (1976) in East Java and
Madura, van der Vlerk (1966) in Moluscas, as well as compiled
by Bromfield and Renema (2011), Lunt and Allan (2004), van
Gorsel (1988), Adisaputra (1992) and Tan Sin Hok (1935).
This catalog book provides geological occurrence, samples
processing, systematic description, photograph and
stratigraphic range of numerous larger foraminifera species
recorded in limestone in Cintaratu. Loeblich and Tappan’s
classification (1988) is followed, and genera are alphabetical
systematically arrangement within the various superfamily or
family categories, and the family group taxa within the
suborders are arranged in order of presumed evolutionary
sequence or increasing the complexity. Descriptions are
generally focused on morphological test external and internal.
Photographs are included to give an illustration and clarify the
description. Stratigraphic range is given to level the geologic
series or epoch. The reference book will be very helpful for the
foraminifera workers at all level in identification of fossils as
well as applied to geological and environmental studies.
iii
The deep appreciation is extended to Rector of Universitas
Padjadjaran for encouragement and support to the
micropaleontological observation as part of research funded by
Academic Leadership Grants (ALG) no. 855/UN6.3.1/PL
/2017. The author is indebted to Prof. Dr. Ir. Adjat Sudradjat,
M.Sc and Prof. Dr. Ir. Nana Sulaksana, MSP for reading of
manuscript and giving the valuable suggestion. Thanks also to
colleges at the Department of Geoscience and geology
assistants (Sisca, Winda and Fakhrul) for supporting and
assistance during observation.
Bandung, February 19
, 2018
Vijaya Isnaniawardhani
ABSTRACT
iv
Detail field observation and laboratory analysis were
conducted on limestone in Cintaratu. Larger foraminifera
assemblages were found in the intraclast-larger foram
bioclastic packstone, the larger foram bioclastic packstone and
the larger foram bioclastic grainstone units of Calcarenite
Member of Pamutuan Formation. Twelve species/subspecies
can be determined in samples, among all, Alanlordia
banyakensis, Amphistegina quoyii, Amphistegina sp.,
Austrotrillina howchini, Cycloclypeus sp., Katacycloclypeus
annulatus, Lepidocyclina (Nephrolepidina) oneatensis,
Lepidocyclina (Nephrolepidina) rutteni quadrata,
Heterostegina (Vlerkina) borneensis, Heterostegina (Vlerkina)
sp., Planorbulinella solida and Victoriella sp. Systematic
description, stratigraphic range completed by photograph of
each taxa were clearly presented. The appearance of
Katacycloclypeus annulatus and Heterostegina (Vlerkina)
borneensis in the intraclast-larger foram bioclastic packstone
unit, the lowest part of Calcarenite Member, indicates Tf1
stage or early Middle Miocene aged. The appearance of
Austrotrillina howchini and Lepidocyclina (Nephrolepidina)
rutteni quadrata respectively in upper units indicates that the
formation of this limestone succession was running until Tf2
stage or late Middle Miocene.
v
ABSTRAK
Pengamatan lapangan dan analisis laboratorium secara detil
dilakukan pada batugamping di daerah Cintaratu. Kumpulan
foraminifera besar ditemukan pada unit-unit Packstone
bioklastik intraklas – foram besar, Packstone bioklastik foram
besar dan Grainstone bioklastik foram besar pada Anggota
Kalkarenit Formasi Pamutuan. Duabelas spesies/subspesies
dapat dideterminasi dalam sampel, yaitu, Alanlordia
banyakensis, Amphistegina quoyii, Amphistegina sp.,
Austrotrillina howchini, Cycloclypeus sp., Katacycloclypeus
annulatus, Lepidocyclina (Nephrolepidina) oneatensis,
Lepidocyclina (Nephrolepidina) rutteni quadrata,
Heterostegina (Vlerkina) borneensis, Heterostegina (Vlerkina)
sp., Planorbulinella solida dan Victoriella sp. Deskripsi
sistematis, kisaran stratigrafi yang dilengkapi oleh foto dari
setiap taksa disajikan dengan jelas. Kehadiran
Katacycloclypeus annulatus dan Heterostegina (Vlerkina)
borneensis dalam unit Packstone bioklastik intraklas – foram
besar, bagian paling bawah dari Anggota Kalkarenit,
menunjukkan zona umur Tf1 atau awal Miosen Tengah.
Kehadiran Austrotrillina howchini dan Lepidocyclina
(Nephrolepidina) rutteni quadrata berturut-turut dalam unit-
unit di atasnya menunjukkan bahwa pembentukan suksesi
batugamping ini berlangsung hingga zona umur Tf2 atau akhir
Miosen Tengah.
vi
CONTENTS
PREFACE .......................................................................... ii
ABSTRACT ....................................................................... iv
ABSTRAK ......................................................................... v
CONTENTS ....................................................................... vi
CHAPTER I LARGER FORAMINIFERA ....................... 1
CHAPTER II GEOLOGY ................................................. 3
CHAPTER III SAMPLE PROCESSING .......................... 15
CHAPTER IV SYSTEMATIC DESCRIPTION AND
STRATIGRAPHIC RANGE ............................................. 19
CHAPTER V AGE AND DEPOSITIONAL
ENVIRONMENT .............................................................. 43
REFERENCES................................................................... 48
1
CHAPTER I
LARGER FORAMINIFERA
Foraminifera are a group of microfossils, between 0.1 and 1
mm in size, generally average between 0.3 and 0.4 mm (fine
sand grained). This order is classified to Subkingdom Protozoa,
Kingdom Protista (Loeblich and Tappan, 1988)
The foraminifera have cytoplasmic body enclosed in test or
shell of one or more interconnected chambers. The wall of test
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. The calcareous wall may be porcelaneous,
microgranular, or hyaline and optically or ultrastructurally
radiate or granular; canal or stolon system of varied complexity
may be present. The tests are developed by agglutinated
foreign material, or of chitin, or of calcareous material secreted
by the animal itself. The test commonly has one or more main
apertures through which pseudopodia protrude. Sexual and
asexual generatio may be suppressed; gametes biflagellate,
triflagellate, or amoeboid.
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 2
The foramifera are free-living or rarely parasitic; benthic and
attached or motile, or pelagic, spread in Cambrian to Holocene
aged sediments. They are almost entirely marine animals,
though a very few live in brackish or even fresh water.
Larger foraminifera have large, complex calcareous tests
(generally 2-5 mm in diameter). The giant variants of some
taxa (Cycloclypeus, Eulepidina and Nummulites) reach more
than 5 cm.
The identification at the species level is generally allowed by
external features or random thin sections. Oriented thin
sections through the embryonic stage are usually required for
determination of species or degree of development within an
evolutionary series.
The large foraminifera live in shallow, clear, tropical or
subtropical marine waters, and are often associated with coral
reefs. Some are bottom dwellers, others live attached to sea
grasses. Most, or all, have a symbiotic relationship with algae
or diatoms and are thus restricted to the photic zone (van
Gorsel, 1988).
3
CHAPTER II
GEOLOGY
2.1. REGIONAL GEOLOGY
In Pangandaran, many lava flows and laharic breccias of
Jampang Formation are cropped out (Syafri, et al., 2016). The
lava flows are highly porphyritic basalt containing calc-
alkaline major and trace element. K-Ar age dating on Sukaraja
and Pangandaran samples gave values of respectively 25.0 –
28.0 MYBP and 17.6 – 17.9 MYBP. The age of Pangandaran
rock is the youngest among the volcanics of “Old Andesite”
belt; most likely representing the uppermost part of Jampang
Formation (Soeria-Atmadja, et al., 1994).
While in the west the tectonic activities already uplifted the
Southern Mountains, in Pangandaran the volcanic arc remains
under the sea. In the eastern part of Southern Mountains, this
activity was marked by development of Citanduy Fault.
Andesitic to laharic lava flows and volcanic breccia of
Jampang Formation are conformably overlain by sandstone,
calcarenite, marl, tuff, claystone and limestone of Pamutuan
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Formation. Calcarenite and clastic limestone intercalated with
marl (known as Calcarenite Member of Pamutuan
Formation/Tmpl) in mid succession are exposed. These strata
are intercalated with tuff and marl (Marly Tuff Member of
Pamutuan Formation/Tmpt). Alluvium covered the Tertiary
succession (Simanjuntak and Surono, 1992; Syafri, et al.,
2016) (Fig. 2.1).
Fig 2.1. Regional geologic map of Cintaratu and its
surroundings
(modified from Simanjuntak and Surono, 1992)
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2.2. GEOLOGY OF CALCARENITE MEMBER OF
PAMUTUAN FORMATION
Detail mapping was conducted in the area of approximately 5
km2
located in Cintaratu. This site geographically is situated at
the longitudes 108°29′39.29′′ and 108°31′34.27′′ West and
latitudes 7°38′21.68′′ and 7°39′ 36.22′′ South. This study area
is about 18 km from a tourist destination, Pangandaran, that
can be reached on 15 km of main road in the direction of
Cijulang (to West) and 3 km smaller access after turning left to
the North in Citumang junction (Fig. 2.2).
Fig. 2.2 Field observation on limestone was conducted in
Cintaratu, Pangandaran District.
The succession of Calcarenite Member exposed in Cintaratu
divided into five facies, namely:
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1. Intraclast-larger foram bioclastic packstone
2. Larger foram bioclastic packstone
3. Planktic foram bioclastic packstone
4. Interbedded calcareous mudstone-calcareous sandstone
5. Larger foram bioclastic grainstone
Lateral and vertical distribution of these facies is shown in Fig.
2.3 and 2.4 (Isnaniawardhani, et al., 2018). Lithological
characteristic of each facies be described as follow.
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 7
Fig. 2.3 The lateral distribution of Calcarenite Member of
Pamutuan Formation in Cintaratu
(redrawn from Isnaniawardhani, et al., 2018)
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Fig. 2.4 Vertical distribution of Calcarenite Member of
Pamutuan Formation in Cintaratu
(redrawn from Isnaniawardhani, et al., 2018)
Unit 1 - Intraclast-larger foram bioclastic packstone
Macroscopically, the fresh granular limestone is whitish
brown, the weathered rocks are brownish yellow, dominated by
medium to coarse sand grain sizes (½ mm to 1 mm), containing
lithified and intermediately lithified lime clasts (intraclast),
sedimentary rocks, and skeletal fossils fragments (Fig. 2.5).
Fragments embedded in matrix shows vary texture and
composition. Structure sediment (cross bedding and wavy
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 9
laminations) are recorded in some outcrops (Isnaniawardhani,
et al., 2018).
Fig.2.5 The surface expression of intraclast larger foram
bioclastic packstone
Microscopically, the rock dominantly consists of angular
shape, poorly sorted of lime clasts and rock fragments
(maximal 10%), K-feldspar mineral (1-3%), micro quartz or
poly-crystalline (1%) and fossil fragments (50-55%). The
various fragments are embedded in the micrite dominated
matrix (10-20%) and cement (2-6%). Many fossils appear
broken, weak or abraded. The crystallized calcite minerals with
the overgrowth texture were frequently identified in the outer
foram shells. Intraparticle, interparticle, moldic and vuggy
porosities are observed (2 %). The presence of intraclasts of
coral limestone indicated that the source rocks were closely
located. (Fig. 2.6) (Isnaniawardhani, et al., 2018).
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Fig 2.6. Thin section of intraclast larger foram bioclastic
packstone (parallel and cross nicol)
Unit 2 - Larger foram bioclastic packstone
Macroscopically, the clastic limestone are well cemented, grain
supported, poorly stratified, with the average thickness of 15
cm (Fig. 2.7) (Isnaniawardhani, et al., 2018).
Fig. 2.7 The surface expression of larger foram bioclastic
packstone
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Microscopically the bioclastic limestone composes of fossil
fragments (55% - 57%), carbonate fragments (<5%), K-
feldspar (1% - 2%) and pyroxene (1%). The fragments are
embedded in the micrite and clay matrix (20% - 28%) with
sparit cements (1% - 3%). The fossil shells are mostly whole,
undamaged, and are not abraded (Fig. 2.8). Intraparticle,
interparticle and vuggy porosities, in places moldic, are
observed (Isnaniawardhani, et al., 2018).
Fig 2.8 Thin section of larger foram bioclastic packstone
(parallel and cross nicol)
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Unit 3 - Planktic foram bioclastic packstone
This planktic foram bioclastic packstone unit consists of well
cemented clastic limestone. The fresh specimen shows broken
white to brownish, whereas in the weathered condition it is
brownish yellow; grains dominated by fine sand grain size
(1/16 mm to 1 mm). Parallel and cross beddings are found in
some places (Isnaniawardhani, et al., 2018).
Unit 4 - Interbedded calcareous mudstone-calcareous
sandstone
The clastic sediment composes of the interbedded between
grey calcareous mudstone and calcareous sandstone, poorly
cemented and moderately weathered at the surface
(Isnaniawardhani, et al., 2018).
Unit 5 - Larger foram bioclastic grainstone
Macroscopically, the larger foram clastic limestone,
characterized by predominated coarse sand grain size
fragments (1 mm – 2 mm). It is poorly cemented and
weathered at the surface with intensive cavities (Fig. 2.9).
(Isnaniawardhani, et al., 2018).
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Fig. 2.9 The surface expression of larger foram bioclastic
grainstone
Microscopically, in the thin section the limestone shows the
composition of fossil fragments (55 % - 65%) consisting
mainly of larger benthic foram and a small number of algae. It
also consists of K-feldspar (2%-5%) and carbonate minerals
(8% - 15%). The fragments are embedded in micrite matrix (<
5%) and carbonate cement (3-5%) (Fig 2.10). Fracture and
vuggy porosities are largely found (Isnaniawardhani, et al.,
2018).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 14
Fig 2.10 Thin section of larger foram bioclastic grainstone
(parallel and cross nicol)
15
CHAPTER III
SAMPLE PROCESSING
Limestone samples are collected more exact for observation
macroscopically and better determination in laboratory. Fresh
samples were broken directly from the outcrop. Sample size
varies with the grainsize and homogeneity of the rock. For
homogeneous rock with grains smaller than 0.15 cm samples
measuring about 7.2 x 9.6 x 2.4 cm are generally adequate, but
rocks with grains as large as 0.3 cm, likely require about twice
that size. Larger samples were collected in the area where the
rock consist of coarser grain or showing sedimentary structure.
The rock samples to be analyzed are cut with the machine. The
thin section is attempted to by-pass the structure of larger
foraminifera present in vertical and horizontal direction (Fig.
3.1).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 16
Fig. 3.1 The rock samples are cut by machine
After getting the direction of the thin section, the sample is
attenuated on both sides (Fig. 3.2).
Fig. 3.2 The sample is attenuated on both sides
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 17
Polish one side of the sample using abrasive (carbondum) and
water (Fig. 3.3).
Fig. 3.3 Polish the sample using carbondum and water
After that, paste the sides on the objective glass (international
size 43 mm x 30 mm) using canadian balsam (Fig. 3.4).
Fig. 3.4 Paste the sides on the objective glass using canadian
balsam
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 18
Thin the other side until the sample becomes transparent and
usually with a thickness of about 30-50 μm. After reaching this
thickness, drop the Canadian Balsam to taste and then covered
with cover glass. Give a label and the sample is ready to be
determined (Fig. 3.5).
Fig 3.5. Sample is ready to determinated
19
CHAPTER IV
SYSTEMATIC DESCRIPTION AND
STRATIGRAPHIC RANGE
Superfamily Acervulinoidea Schultze, 1854
Family Acervulinidae Schultze, 1854
Genus Alanlordia Banner and Samuel, 1995.
Biconvex shell, septal aperture, but some lattice, apertures such
as pores develop on the distal, outer part of the wall. The
beginning of the round produces the back and abdominal parts
by the lining of the small chambers added in a radial sequence
forming a successive layer.
Alanlordia banyakensis Banner and Samuel, 1955
In the horizontal section of the planispiral form, there is
proloculus, spinning well, rough pores at the end of wall cubic.
Stratigraphic range:
Middle Miocene (Tf2) to Late Pliocene.
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Superfamily Asterigerinoida d’Orbigny, 1839
Family Amphisteginidae Cushman, 1927
Genus Amphistegina d’Orbigny, 1826
Lenticular, asymmetrical biconvex trochospiral shell that may
be bi-involute or partially opposite on the spiral side. The
chambers are very spacious, and strong curved backs on the
edges to form an extension of the chamber. The umbilical side
is stellate, and has different umbilical plugs. The walls are
calcareous, thick, radial optical, smooth and curved surface as a
whole. Interiomarginal aperture gap on the umbilical side,
bordering the lips.
Amphistegina quoyii d’Orbigny 1826
On a vertical section has a secondary septa / tootplate in the
last chamber, an involute-shaped chamber, a simple wall, a
prolongation alar there, the last chamber round covered the
previous chamber round. In the horizontal section of the
planispiral form, there is septa, chambers are arranged 4-5
rounds, evolute-shaped chambers with clear marginal chord.
Stratigraphic range:
Eocene to Holocene.
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Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 22
Amphistegina sp. d’Orbigny, 1826
On the vertical section the shape is not symmetrical, has a
secondary septa / tootplate in the last chamber, the involute-
shaped chamber, the simple wall, the prolongation alar there,
the last chamber round covered the previous chamber.
Stratigraphic range:
Eocene to Holocene.
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Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 24
Superfamily Miliolacea Ehrenberg, 1839
Family Austrotrillinidae Loeblich and Tappan, 1986
Genus Austrotrillina Parr, 1942
A triloculina shell with a smooth to rough-covered alveolus,
that can be split into two, aperture with simple teeth in the
starting chamber, branching off into smaller openings. It has a
clear alveolus wall.
Austrotrillina howchini (Schlumberger, 1893)
Synonym:
Trillina howchini Schlumberger, 1893.
Austrotrillina howchini Schlumberger - Barberi, et al., 1987.
In a horizontal section, Austrotrillina howchini not only has a
triangular space in the transverse section (triangular), but also
most importantly has an alveolus which bifurcate, the interior
alveolus split or being divided peripherally into smaller
alveolus.
The greatest diameter 1.00 mm; alveolus bifurcating, d/b=4;
wall thickness between alveolus 10 µm (Boudagher-Fadel and
Lokier, 2005).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 25
Stratigraphic range:
Middle Miocene (Tf1).
Barberi et al. (1987) recorded it from the Tf1 (Upper
Burdigalian-Langhian) of the carbonate sequence of Sumbawa
island. It also found from the upper Tf1, top of the Langhian of
Kali Sambi section (SAM) in the Gunung Sewu area of South
Central Java (Boudagher-Fadel and Lokier, 2005).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 26
Superfamily Nummulitacea De Blainville, 1827
Family Nummulitidae De Blainville, 1827
Genus Cycloclypeus van der Vlerk
Large and thin shell, evolute, sub annular with planispiral
space, equatorial section showing large and small nepionic
chambers on the opposite side, large discoidal shells with
annular spaces divided into chambers with secondary septa.
Cycloclypeus sp.
On the vertical section of the equator chamber is clearly
visible, lateral chambers are absent. The edges, flat and in the
centre of the convex (protruding). It has a low centre umbo
surrounded by several additions to a very clear annular space in
the centre.
Stratigraphic range:
Oligocene to Recent.
This species was reported ranges Oligocene to Recent
throughout all the tropics (Boudagher-Fadel and Lokier, 2005).
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Genus Katacycloclypeus Tan Sin Hok, 1932
Tan Sin Hok (1932), in his description of Katacycloclypeus,
assigned it as a new subgenus of Cycloclypeus. However, there
is no direct evidence of intergradation, neither in the model of
the test nor in the embryonic structure between Cycloclypeus
and Katacycloclypeus. Therefore, it considers the two forms to
be generically different (Boudagher-Fadel and Lokier, 2005).
Katacycloclypeus annulatus (Martin, 1880)
Synonym:
Cycloclypeus annulatus Martin, 1880.
Cycloclypeus annulatus Martin - Douvillé, 1916.
Cycloclypeus (Katacycloclypeus) annulatus (Martin) - Cole,
1963.
Katacycloclypeus annulatus (Martin) - Boudagher-Fadel and
Wilson, 2000.
This species has two embryonic chambers, the third chamber
on Katacycloclypeus annulatus is smaller. On the vertical
section of the equator chamber is clearly visible, lateral
chambers are absent. The edges, flat and in the middle can
have multiple bulges. It has a large, thin test with a low central
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 29
umbo surrounded by several annular inflations of the solid
lateral walls, each inflation is separated by broad, flat annuli
from the next annular inflation to a very clear annular space in
the centre. It also has a clearly trilocular embryont.
Maximum diameter up to 6 mm; Diam. I/ Diam. II = 0.75
(Boudagher-Fadel and Lokier, 2005).
Stratigraphic range:
Middle Miocene (Tf1-Tf2).
Katacycloclypeus annulatus is found in Middle Miocene (Tf1-
Tf2) of the Indo-Pacific. This species was reported from the
Early Miocene of West Java. Boudagher-Fadel and Wilson
(2000) suggests it is found from the lower Mid Miocene, Tf2
(early Serravallian) of Borneo. It is found in the Tf1
(Langhian) and Tf2 (Serravallian) of Djatirago section (TAN)
and Kederakon section (WB13) in the Gunung Sewu area of
South Central Java (Boudagher-Fadel and Lokier, 2005).
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Superfamily Asterigerinacea DʼOrbigny, 1839
Family Lepidocyclinidae Scheffen, 1932
Subfamily Lepidocyclininae Scheffen, 1932
Genus Lepidocyclina Gümbel, 1870 emend. Boudagher-
Fadel and Banner, 1997
Large, discoidal, biconcave, multiple-chambered shells where
the connection between the chambers is connected to the stolon
(tubular pores). It has protoconch and deuteroconch of almost
the same size and is separated by a straight wall.
Subgenus Lepidocyclina (Nephrolepidina) Douvillé, 1911
emend. Boudagher-Fadel and Banner, 1997
Lepidocyclina (Nephrolepidina) oneatensis Cole, 1945
Synonym:
Lepidocyclina (Eulepidina) oneatensis Cole, 1945.
Lepidocyclina (Nephrolepidina) cf. sumatrensis (Brady) –
Barberi et al., 1987.
Lepidocyclina (Nephrolepidina) oneatensis Cole - Boudagher-
Fadel, et al., 2000.
In the vertical section of the equatorial chamber enlarged
toward the edge, the embryonic chamber is not visible, there
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 32
are lateral chambers that are cut off by pillars. The vertical wall
separating the lateral stack of chambers usually thickens.
Size generally diameter 8 mm; centrum cubiculae up to 50 µm
high and 200 µm broad; lateral chamberlet walls maximum
thickness 140 µm. The equatorial section showed the
protoconch to be subquadrate (sensu Boudagher-Fadel and
Banner, 1997), or “trybliolepidine” (sensu van der Vlerk and
Postuma, 1967). The biconvex and broadly flanged test
possesses no true pillars but the vertical walls separating
vertical stacks of lateral chamberlets (cubiculae) are commonly
thickened, producing dichotomising and anastomosing lateral
characteristic of Lepidocyclina (Nephrolepidina) oneatensis
(Boudagher-Fadel and Lokier, 2005).
Stratigraphic range:
Late Oligocene to Miocene.
This species is found in the Gomantong Limestone of the
Upper Te, Late Oligocene-Early Miocene, of North East
Borneo (Boudagher-Fadel et al., 2000). It is found in the Tf1
(Upper Burdigalian) and Tf2 (Serravallian) of Kali Sambi
section (SAM) in the Gunung Sewu area of South Central Java
(Boudagher-Fadel and Lokier, 2005).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 33
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 34
Lepidocyclina (Nephrolepidina) rutteni quadrata Boudagher-
Fadel and Banner, 1997
Synonym:
Lepidocyclina (Nephrolepidina) rutteni van der Vlerk, 1923.
Lepidocyclina (Nephrolepidina) rutteni quadrata Boudagher-
Fadel and Banner, 1997.
In the horizontal section of the equatorial chamber in the shape
of pointed arcuate, with the arrangement of concentric-shaped
chambers, the embryonic chamber is clearly visible where
protoconch is smaller than the deuteroconch, the lateral shape
of the chamber is angled. It has a quadrate proloculus.
Maximum length 4 mm; maximum wide 3.5 mm, centrum
cubiculae up to 54 µm high and 90 µm broad; megalospheric
nepiont ca. 200 µm, Diam. I/ Diam. II = 0.6. (Boudagher-Fadel
and Lokier, 2005).
Stratigraphic range:
Middle Miocene (Tf2).
Lepidocyclina rutteni s.l. was first reported from the
“Vindobonian” of Java. The quadrate forms of Lepidocyclina
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 35
rutteni are found in the Tf2 (Serravallian) of Kali Sambi
section (SAM) in the Gunung Sewu area of South Central Java
(Boudagher-Fadel dan Lokier, 2005).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 36
Superfamily Nummulitacea De Blainville, 1827
Family Nummulitidae De Blainville, 1827
Subfamily Heterostegininae Galloway, 1933
Genus Heterostegina d’Orbigny
Thick shells, involute to evolute with chambers divided by
secondary septa to form small chambers. The centre of the
shell is thickened, the initial chamber is undivided, which is
then divided by the secondary septa. No extension, with high
suture.
Heterostegina (Vlerkina) borneensis (van der Vlerk)
Chamber arranged planispiral, enlarging rapidly at 2 to 4.4
rounds, proloculus is clear, slippery walls, there is secondary
septa to form chamberlet (chambers).
Stratigraphic range:
Late Oligocene (Te) to Early Miocene (Tf1).
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Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 38
Heterostegina (Vlerkina) sp. (van der Vlerk)
In a vertical section no lateral chamber is found on the
calcareous masses found on either side of the equatorial layer,
there is a prolongation alar, the proloculus is not apparent. The
shape of a long flat section, the median chamber is cut into
pieces by the septa. The lateral chambers are not clear.
Stratigraphic range:
Upper Oligocene to Miocene.
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Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 40
Family Planorbulinidae Schwager, 1877
Genus Planorbulinella Cushman, 1927
Discoidal shell, trochospiral, retrovert aperture form
subsequent chamber rotation comes from an irregular orbitoid
form. The walls are calcareous, have rough holes, radiate
structures. After the establishment of a chamber with two
stolons, one or more gain has one stolon.
Planorbulinella solida (Belford)
The embryonic chamber is clearly visible, with the
arrangement of a trochospiral-shaped chamber, has a shorter
lateral chamber.
Stratigraphic range:
Middle Miocene to Late Miocene.
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Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 42
Subfamily Victoriellinae Chapman and Crespin, 1930
Family Victoriella Chapman and Crespin, 1930
Genus Victoriella Chapman and Crespin, 1930
Victoriella sp. Chapman and Crespin, 1930
The carbonate shell, the substrate, the rotaloid in the nepionic
chamber, then grows into a cylindrical shape composed of
irregular chamber, separated by a septa, surrounded by thick
cylindrical walls.
Stratigraphic range:
Oligocene to Early Miocene.
43
CHAPTER V
AGE AND
DEPOSITIONAL ENVIRONMENT
The larger foraminifera are the most important marker to age
determination and depositional environment interpretation in
shallow marine carbonate.
5.1 AGE
The appearance of larger foraminifera species marker,
Katacycloclypeus annulatus in association with Heterostegina
(Vlerkina) borneensis and Lepidocyclina (Nephrolepidina), in
the intraclast-larger foram bioclastic packstone unit, the lowest
part of Calcarenite Member of Pamutuan Formation, indicates
the Tf1 stage of Adam’s letter classification (Table 5.1). This
aged zone is identified within the early Middle Miocene period
(Isnaniawardhani, et al., 2018). This stage is determined
corresponds to 18.7 M.Y. before present (Sharaf, et al., 2006).
The presence of larger foraminifera species marker,
Austrotrillina howchini and Katacycloclypeus annulatus, in the
larger foram bioclastic packstone unit, that overlaying the
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 44
lowest unit, indicates the Tf1-Tf2 stage of Adam’s letter
classification. The last appearance of Austrotrillina howchini
marks the top of Tf2 (Table 5.1). This aged zone is identified in
Middle Miocene period (Isnaniawardhani, et al., 2018).
The appearance of larger foraminifera species marker,
Lepidocyclina (Neprolepidina) rutteni quadrata, in the larger
foram bioclastic grainstone unit, the upper part of Calcarenite
Member of Pamutuan Formation indicates the Tf2 stage of
Adam’s letter classification (Table 5.1). This aged zone is
identified within the latest Middle Miocene period
(Isnaniawardhani, et al., 2018).
Table 5.1. Stratigraphic ranges of larger foraminifera species
marker observed in Calcarenite Member of Pamutuan
Formation in Cintaratu
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 45
References to most papers on Indo-Pacific Tertiary larger
forams can be found in Adams (1970, 1983).
Table 5.2. Range of selected larger foraminifera marker species
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 46
5.2 DEPOSITIONAL ENVIRONMENT
The abundant larger foraminifera (genera Alanlordia,
Amphistegina, Cycloclypeus, Heterostegina and
Planorbilinela) associated with coral, red algae and planktic
foraminifera with a limited number of small miliolid and
rotaloid are found in the intraclast-larger foram bioclastic
packstone unit. This fossil assemblages reflects depositional
process occurring in the fore reef with high sun light intensity.
Many skeletal limestones fragments containing foraminifera
and stromatolite illustrate that this unit formed at a slope in
front of the reef’s body (Figure 5.1) (Isnaniawardhani, et al.,
2018).
The high diversity of larger foraminifera with abundant small
miliolid and rotaloid associated with few green algae
(Halimeda), coral, bryozoan and mollusk in the larger foram
bioclastic packstone unit as well as the larger foram bioclastic
grainstone unit indicate back reef environment (Figure 5.1)
(Isnaniawardhani, et al., 2018).
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation | 47
Figure 5.1. Models of Cenozoic larger foraminifera
distribution in carbonate facies (van Gorsel, 1988)
48
REFERENCES
Adisaputra, M.K (1992) Penentuan umur berdasarkan biometri
dan lingkungan pengendapan foraminifera besar Tersier-
Kuarter. Pusat Pengembangan Geologi Kelautan, 43 pp.
Bromfield, K., Renema, W. (2011) Comparison of 87 Sr/86 Sr
isotope and biostratigraphic ages of uplift fossil reef in the
Indo-Pasific: Indonesia, Papua New Guinea and Fiji.
Australian Journal of Earth Sciences, 58 (1), 61-73
Boudagher-Fadel, M.K., Lokier, S. W. (2005) Significant
Miocene larger foraminifera from South Central Java. Revue
de Paléobiologie, Genève, 24 (1), 291-309
Boudagher-Fadel, M.K, Wilson, M. (2000) A revision of some
larger foraminifera of the Miocene of Southeast Kalimantan.
Micropaleontology, 46, 153-165
Isnaniawardhani, V., Rinawan, R., Prianggoro, B. (2012) The
fossil assemblage features of limestone and clastic sedimentary
rock in Lulut area, Cileungsi District, Bogor, West Java.
Bulletin of Scientific Contribution, (10)2, 95-107
Isnaniawardhani, V., Adhiperdana, B.G., Sudradjat, A,
Sulaksana, N. (2018) The dynamics of the developing
calcarenite member of Pamutuan Formation in Cintaratu Area,
Pangandaran, West Java. International Journal on Advance
Science, Engineering and Information Technology (in
preparation)
Loeblich, A.R. Jr., Tappan, H. (1988) Foraminiferal genera and
their classification (1 and 2). van Nostrand Reinhold, New
York, 970 pp.
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation| 49
Lunt, P., Allan, T. (2004) A history and application of larger
foraminifera in Indonesian biostratigraphy, calibrated to
isotopic dating. GRDC Museum Workshop on
Micropaleontology, Indonesia, 109 pp.
Sharaf, E., Boudagher-Fadel, M. K, Simo, T. A, Carroll, A. R.
(2006) Biostratigraphy and strontium isotope dating of
Oligocene-Miocene carbonates and siliciclastics, East Java,
Indonesia. Stratigraphy, 2, 239-258
Simanjuntak, T. O., Surono (1992) Geological map of
Pangandaran quadrange, West Java, Sheet 1309 – 1, scale
1:100.000. GRDC Indonesia
Soeria-Atmadja, R., Maury, R. C., Bellon, H., Pringgoprawiro,
H., Polves, Priadi, B. (1994), Tertiary magmatic belt in Java.
Journal of Southeast Asian Earth Sciences, 9 (1/2), 13-27
Syafri, I., Sulastri, M., Sobarin, O., Rossa, Y., Khaerani, P.
(2016) Limestone potential in Cikatomas region and its role
towards development of southern part of West Java, Indonesia.
Proceeding of FIG Working Week 2016 Recovery from
Disaster, New Zealand
Tan Sin Hok (1936) Zur kenntniss der Miogypsiniden.
Ingenieur Nederland-Indie, Mijnbouw Geologie, 4(3), 45 - 61
van der Vlerk, I. M. (1966) Miogypsinoides, Miogypsina,
Lepidocyclina and Cycloclypeus of Larat, Moluccas. Eclogae
Geologicae Helvetiae, 59 (1), 421-429
van der Vlerk, I. M., Postuma, J. A. (1967) Oligo-Miocene
Lepidocyclinas and planktonic foraminifera from East Java and
Larger Foraminifera Catalog on Member of Calcarenite Pamutuan Formation| 50
Madura. Koninklijke Nederlandse Akademie van
Wetenschappen, Amsterdam, Proceedings, ser.B (76), 245-259
van Gorsel, J.T. (1988) Biostratigraphy in Indonesia: methods,
pitfalls and new directions. Proc. Indonesian Petroleum
Association, 17th
Annual Convention, 275 – 300
van Vessem, E.J. (1978) Study of Lepidocyclinidae from
Southeast Asia, particularly from Java and Borneo. Utrecht
Micropaleontological Bulletin, 19, 163 pp.
i
KATA PENGANTAR
Katalog Foraminifera Besar dalam Anggota Kalkarenit
Formasi Pamutuan disusun berdasarkan penelitian di lapangan
dan analisis laboratorium secara detil terhadap batugamping di
Cintaratu, Kabupaten Pangandaran, Jawa Barat, Indonesia.
Buku ini disusun sebagai pelengkap referensi foraminifera di
Indonesia. Hanya sedikit studi taksonomi foraminifera di
Indonesia yang telah dilakukan oleh peneliti-peneliti dunia,
diantaranya, oleh Boudagher-Fadel dan Lokier (2005) di Jawa
Tengah Selatan, Isnaniawardhani, dkk. (2012) di Bogor – Jawa
Barat, Sharaf, dkk (2006) di Jawa Timur, Boudagher-Fadel dan
Wilson (2000) di Kalimantan Tenggara, van Vessem (1978) di
Jawa dan Kalimantan, van der Vlerk dan Postuma (1976) di
Jawa Timur dan Madura, van der Vlerk (1966) di Maluku, serta
dikompilasi oleh Bromfield dan Renema (2011), Lunt dan
Allan (2004), van Gorsel (1988), Adisaputra (1992) dan Tan
Sin Hok (1936).
Buku katalog ini menyajikan keberadaan geologi, pemrosesan
sampel, deskripsi sistematis, foto dan kisaran stratigrafi dari
sejumlah spesies foraminifera besar yang terekam pada
batugamping di Cintaratu. Mengikuti klasifikasi Loeblich dan
Tappan (1988), dan genus disusun secara sistematis alfabetikal
ii
dalam kategori superfamily atau family, dan family kelompok
taksa dalam suborder disusun berdasarkan suksesi evolusi atau
penambahan kompleksitas. Deskripsi umumnya difokuskan
pada morfologi cangkang baik eksternal dan internal. Foto
disajikan untuk memberikan ilustrasi dan memperjelas
deskripsi. Kisaran stratigrafi diberikan sampai tingkat seri atau
masa. Buku referensi ini akan sangat membantu peneliti
foraminifera di segala tingkatan dalam mengidentifikasi fosil
maupun mengaplikasikan dalam studi geologi dan lingkungan.
Penghargaan mendalam ditujukan kepada Rektor Universitas
Padjadjaran atas dorongan dan dukungan dalam pengamatan
mikropaleontologi sebagai bagian dari riset yang dibiayai oleh
Academic Leadership Grants (ALG) no. 855/UN6.3.1/PL
/2017. Penulis berterimakasih kepada Prof. Dr. Ir. Adjat
Sudradjat, M.Sc dan Prof. Dr. Ir. Nana Sulaksana, MSP untuk
mengoreksi naskah dan memberi saran yang berguna.
Terimakasih juga kepada kolega di Departemen Geosains dan
asisten geologi (Sisca, Winda dan Fakhrul) untuk dukungan
dan bantuan selama penelitian.
Bandung, 19 Februari 2018
Vijaya Isnaniawardhani
iii
ABSTRAK
Pengamatan lapangan dan analisis laboratorium secara detil
dilakukan pada batugamping di Cintaratu. Kumpulan
foraminifera besar ditemukan pada unit-unit Packstone
bioklastik intraklas – foram besar, Packstone bioklastik foram
besar dan Grainstone bioklastik foram besar pada Anggota
Kalkarenit Formasi Pamutuan. Duabelas spesies/subspesies
dapat dideterminasi dalam sampel, yaitu, Alanlordia
banyakensis, Amphistegina quoyii, Amphistegina sp.,
Austrotrillina howchini, Cycloclypeus sp., Katacycloclypeus
annulatus, Lepidocyclina (Nephrolepidina) oneatensis,
Lepidocyclina (Nephrolepidina) rutteni quadrata,
Heterostegina (Vlerkina) borneensis, Heterostegina (Vlerkina)
sp., Planorbulinella solida dan Victoriella sp. Deskripsi
sistematis, kisaran stratigrafi yang dilengkapi oleh foto dari
setiap taksa disajikan dengan jelas. Kehadiran
Katacycloclypeus annulatus dan Heterostegina (Vlerkina)
borneensis dalam unit Packstone bioklastik intraklas – foram
besar, bagian paling bawah dari Anggota Kalkarenit,
menunjukkan zona umur Tf1 atau awal Miosen Tengah.
Kehadiran Austrotrillina howchini dan Lepidocyclina
(Nephrolepidina) rutteni quadrata berturut-turut dalam unit-
unit di atasnya menunjukkan bahwa pembentukan suksesi
batugamping ini berlangsung hingga zona umur Tf2 atau akhir
Miosen Tengah.
iv
ABSTRACT
Detail field observation and laboratory analysis were
conducted on limestone in Cintaratu. Larger foraminifera
assemblages were found in the intraclast-larger foram
bioclastic packstone, the larger foram bioclastic packstone and
the larger foram bioclastic grainstone units of Calcarenite
Member of Pamutuan Formation. Twelve species/subspecies
can be determined in samples, among all, Alanlordia
banyakensis, Amphistegina quoyii, Amphistegina sp.,
Austrotrillina howchini, Cycloclypeus sp., Katacycloclypeus
annulatus, Lepidocyclina (Nephrolepidina) oneatensis,
Lepidocyclina (Nephrolepidina) rutteni quadrata,
Heterostegina (Vlerkina) borneensis, Heterostegina (Vlerkina)
sp., Planorbulinella solida and Victoriella sp. Systematic
description, stratigraphic range completed by photograph of
each taxa were clearly presented. The appearance of
Katacycloclypeus annulatus and Heterostegina (Vlerkina)
borneensis in the intraclast-larger foram bioclastic packstone
unit, the lowest part of Calcarenite Member, indicates Tf1
stage or early Middle Miocene aged. The appearance of
Austrotrillina howchini and Lepidocyclina (Nephrolepidina)
rutteni quadrata respectively in upper units indicates that the
formation of this limestone succession was running until Tf2
stage or late Middle Miocene.
v
DAFTAR ISI
KATA PENGANTAR ....................................................... i
ABSTRAK ......................................................................... iii
ABSTRACT ....................................................................... iv
DAFTAR ISI ...................................................................... v
BAGIAN I FORAMINIFERA BESAR ............................. 1
BAGIAN II GEOLOGI ...................................................... 4
BAGIAN III PEMPROSESAN SAMPEL ......................... 15
BAGIAN IV DESKRIPSI SISTEMATIK DAN KISARAN
STRATIGRAFI .................................................................. 19
BAGIAN V UMUR DAN LINGKUNGAN
PENGENDAPAN .............................................................. 44
DAFTAR PUSTAKA ........................................................ 50
1
BAGIAN I
FORAMINIFERA BESAR
Foraminifera merupakan suatu kelompok mikrofosil, berukuran
antara 0,1 hingga 1 mm, biasanya kira-kira antara 0,3 hingga
0,4 mm (berbutir pasir halus). Jenis ini diklasifikasikan ke
dalam Subkingdom Protozoa, Kingdom Protista (Loeblich dan
Tappan, 1988).
Foraminifera memiliki tubuh sitoplasmik tertutupi oleh
cangkang atau rangka dari satu atau lebih kamar yang saling
berhubungan. Dinding cangkang mungkin homogen atau
berlapis-lapis atau lamina baik serupa atau berbeda, mungkin
tidak berpori atau berpori halus hingga kasar, pada dasarnya
protein-nan tapi mungkin mengandung partikel aglutinan, atau
mengandung mineral kalsit, aragonit, atau silika jarang
menempel pada zat organik. Dinding gampingan, mungkin
porselenan, mikrogranular, atau hialin dan secara optik atau
ultrastruktural memancar atau berbutir; sistem kanal atau
stolon dengan kerumitan bervariasi, mungkin ditemukan.
Cangkang ini terbentuk dari material asing aglutinan, atau
kitin, atau bahan gampingan yang dikeluarkan oleh hewan itu
sendiri. Cangkang umumnya memiliki satu atau lebih lubang
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 2
utama yang melaluinya pseudopodia muncul. Generasi seksual
dan aseksual; gamet biflagellata, triflagelata, atau amoeboid.
Foramifera hidup bebas atau jarang sebagai parasit; bentik dan
tertambat atau bergerak, atau pelagis, menyebar pada endapan
Kambrium sampai Holosen. Foraminifera hampir seluruhnya
merupakan hewan laut, meski ada sedikit yang hidup di air
payau atau bahkan air tawar.
Foraminifera besar memiliki cangkang gampingan yang besar
dan kompleks (umumnya berdiameter 2-5mm). Varian besar
beberapa taksa (Cycloclypeus, Eulepidina dan Nummulites)
mencapai lebih dari 5 cm.
Identifikasi pada tingkat spesies umumnya mengikuti fitur
eksternal atau random sayatan tipis. Pada sayatan tipis orientasi
melalui tahap embrio biasanya diperlukan untuk penentuan
spesies atau tingkat perkembangan dalam rangkaian evolusi.
Foraminifera besar hidup di perairan laut tropis atau subtropis
yang dangkal, jernih, dan seringkali berasosiasi dengan
terumbu karang. Beberapa organisma merayap, yang lainnya
hidup menempel pada rumput laut. Sebagian besar, atau semua,
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 3
memiliki hubungan simbiosis dengan alga atau diatom dan
karenanya terbatas pada zona fotik (van Gorsel, 1988).
4
BAGIAN II
GEOLOGI
2.1. GEOLOGI REGIONAL
Di Pangandaran, banyak aliran lava dan breksi laharik Formasi
Jampang tersingkap (Syafri, dkk., 2016). Aliran-aliran lava
berjenis basal porfiritik mengandung kalk-alkalin dan elemen
jarang. Pentarikhan umur K-Ar pada sampel dari Sukaraja dan
Pangandaran memberikan nilai berturut-turut 25,0 – 28,0 juta
tahun lalu dan 17,6 – 17,9 juta tahun lalu. Umur batuan di
Pangandaran merupakan yang termuda diantara gunungapi
jalur “Old Andesite”; kemungkinan besar merepsentasikan
bagian paling atas dari Formasi Jampang (Soeria-Atmadja,
dkk., 1994).
Pada saat di bagian barat aktifitas tektonik mengangkat
Pegunungan Selatan, di wilayah Pangandaran busur volkanik
masih berada di bawah laut. Di bagian timur Pegunungan
Selatan aktifitas ini ditandai oleh pembentukan Sesar Citanduy.
Aliran-aliran lava laharik dan breksi volkanik Formasi
Jampang ditutupi secara selaras oleh batupasir, kalkarenit,
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 5
napal, tuf, batulempung dan batugamping Formasi Pamutuan.
Kalkarenit dan batugamping klastika berselingan dengan napal
(dikenal sebagai Anggota Kalkarenit Formasi Pamutuan /Tmpl)
bagian tengah suksesi tersingkap di beberapa tempat. Lapisan-
lapisan ini berselang-seling dengan tuf dan napal (Anggota Tuf
Napalan Formasi Pamutuan/Tmpt). Aluvium menutupi suksesi
batuan Tersier (Simanjuntak dan Surono, 1992; Syafri, dkk.,
2016) (Gambar 2.1).
Gambar 2.1. Peta Geologi Regional Cintaratu dan sekitarnya
(dimodifikasi dari Simanjuntak dan Surono, 1992)
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 6
2.2. GEOLOGI ANGGOTA KALKARENIT FORMASI
PAMUTUAN
Pemetaan detil dilakukan pada daerah seluas kuranglebih 5 km2
yang berlokasi di wilayah Cintaratu. Daerah ini secara
geografis terletak di antara 108°29′39,29′′ dan 108°31′34,27′′
Bujur Barat dan 7°38′21,68′′ dan 7°39′ 36,22′′ Lintang Selatan.
Daerah studi berada sekitar 18 km dari tujuan wisata,
Pangandaran, yang dapat dicapai sekitar 15 km ke arah
Cijulang (ke Barat) dan 3 km melalui jalan lebih kecil setelah
berbelok ke utara di belokan Citumang (Gambar 2.2).
Gambar 2.2. Pengamatan lapangan terhadap batugamping
dilakukan di Cintaratu, Kabupaten Pangandaran.
Suksesi Anggota Kalkarenit yang tersingkap di Cintaratu dapat
dibedakan menjadi lima fasies, yaitu:
1. Packstone bioklastik intraklas – foram besar
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 7
2. Packstone bioklastik foram besar
3. Packstone bioklastik foram planktik
4. Selang-seling batulempung gampingan-batupasir
gampingan
5. Grainstone bioklastik foram besar
Distribusi lateral dan vertikal dari fasies-fasies ini diperlihatkan
pada Gambar 2.3 dan 2.4 (Isnaniawardhani, dkk., 2018).
Karakteristik litologi dari masing-masing fasies dideskripsikan
sebagai berikut.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 8
Gambar 2.3 Penyebaran lateral Anggota Kalkarenit Formasi
Pamutuan di Cintaratu
(digambar ulang dari Isnaniawardhani, dkk., 2018)
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 9
Gambar. 2.4 Penyebaran vertikal Anggota Kalkarenit
Formasi Pamutuan di Cintaratu
(digambar ulang dari Isnaniawardhani, dkk., 2018)
Unit 1 - Packstone bioklastik intraklas – foram besar
Secara makroskopis, batugamping granular yang segar
berwarna coklat keputih-putihan, batuan yang lapuk berwarna
kuning kecoklatan, didominasi oleh ukuran butir pasir sedang
sampai kasar (½ mm sampai 1 mm), mengandung fragmen-
fragmen clast batugamping terlitifikasi dan semi litifikasi
(intraclast), batuan sedimen, dan fragmen fosil (Gambar 2.5).
Fragmen-fragmen yang tertanam dalam matriks menunjukkan
tekstur dan komposisi yang bervariasi. Struktur sedimen
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 10
perlapisan silang-siur dan laminasi bergelombang terekam di
beberapa singkapan (Isnaniawardhani, dkk., 2018).
Gambar 2.5 Ekspresi permukaan packstone bioklastik intraklas
– foram besar
Secara mikroskopis, batuan didominasi oleh fragmen clast
batugamping dan batuan berbentuk menyudut, terpilah buruk
(maksimal 10%), mineral K-feldspar (1-3%), mikro kuarsa atau
poli-kristalin (1%) dan fragmen fosil (50 -55%). Berbagai
fragmen tertanam dalam matriks yang didominasi mikrit (10-
20%) dan semen (2-6%). Banyak fosil tampak pecah, kropos
atau terabrasi. Mineral kalsit terkristalisasi dengan tekstur
overgrowth sering ditemukan di bagian luar cangkang foram.
Porositas intrapartikel, interpartikel, moldic dan vuggy teramati
(2%). Kehadiran intraklas batugamping koral menunjukkan
sumber batuan yang dekat. (Gambar 2.6) (Isnaniawardhani,
dkk, 2018).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 11
Gambar 2.6. Sayatan tipis packstone bioklastik intraklas –
foram besar (paralel dan nikol bersilang)
Unit 2 - Packstone bioklastik foram besar
Secara makroskopis, batugamping klastik tersemen baik,
didukung butiran (grain supported), berlapis buruk, dengan
ketebalan rata-rata 15 cm (Gambar 2.7) (Isnaniawardhani, dkk.,
2018).
Gambar 2.7 Ekspresi permukaan packstone bioklastik foram
besar
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 12
Secara mikroskopis batugamping bioklastik terdiri dari
fragmen fosil (55% - 57%), fragmen karbonat (<5%), K-
feldspar (1% - 2%) dan piroksen (1%). Fragmen-fragmen itu
tertanam dalam matriks mikrit dan batulempung (20% - 28%)
dengan semen sparit (1% - 3%). Cangkang fosil sebagian besar
utuh, tidak rusak, dan tidak terabrasi (Gambar 2.8). Porositas
intrapartikel, interpartikel dan vuggy, di beberapa tempat
moldic, dapat teramati (Isnaniawardhani, dkk., 2018).
Gambar 2.8 Sayatan tipis packstone bioklastik foram besar
(paralel dan nikol bersilang)
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 13
Unit 3 - Packstone bioklastik foram planktik
Unit batuan biolastik foram planktik ini terdiri dari
batugamping klastik yang tersemen baik. Spesimen segar
menunjukkan warna putih tulang hingga kecoklatan, dimana
dalam keadaan lapuk berwarna kuning kecoklatan, butiran
didominasi oleh ukuran butir pasir halus (1/16 mm sampai 1
mm). Perlapisan sejajar dan silangsiur ditemukan di beberapa
tempat (Isnaniawardhani, dkk., 2018).
Unit 4 - Selang-seling batulempung gampingan-batupasir
gampingan
Sedimen klastik yang membentuk perselingan antara
batulempung gampingan abu-abu dan batupasir gampingan,
tersemen buruk dan agak lapuk di permukaannya
(Isnaniawardhani, dkk., 2018).
Unit 5 - Grainstone bioklastik foram besar
Secara makroskopis, batugamping klastik foram besar,
dicirikan oleh dominansi fragmen berbutir pasir kasar (1 mm -
2 mm). Tersemen buruk dan lapuk di permukaan dengan
rongga intensif (Gambar 2.9). (Isnaniawardhani, dkk., 2018).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 14
Gambar 2.9 Ekspresi permukaan grainstone bioklastik foram
besar
Secara mikroskopis, sayatan tipis batugamping menunjukkan
komposisi fragmen fosil (55% - 65%) yang terutama terdiri
dari foram bentik besar dan sejumlah kecil alga. Batuan ini
juga mengandung K-feldspar (2% -5%) dan mineral karbonat
(8% - 15%). Fragmen-fragmen tersebut tertanam dalam matriks
mikrit (<5%) dan semen karbonat (3-5%) (Gambar 2.10).
Rekahan dan porositas vuggy banyak ditemukan
(Isnaniawardhani, dkk., 2018).
Gambar 2.10 Sayatan tipis grainstone bioklastik foram besar
(paralel dan nikol bersilang)
15
BAGIAN III
PEMPROSESAN SAMPEL
Sampel-sampel batugamping dikumpulkan untuk diamati lebih
teliti secara makroskopis dan dideterminasi lebih baik di
laboratorium. Sampel segar diambil secara langsung dari
singkapan. Ukuran sampel bervariasi menurut ukuran butir dan
homogenitas batuan. Batuan yang homogen dengan ukuran
butir lebih kecil dari 0,15 cm sampel yang diambil sekitar 7,2 x
9,6 x 2,4 cm. Secara umum sepadan, batuan dengan ukuran 0,3
cm memerlukan sampel dua kali ukuran itu. Sampel yang lebih
besar dikumpulkan jika batuan memiliki ukuran yang lebih
besar atau menunjukkan struktur sedimen.
Sampel batuan yang akan dianalisis disayat dengan mesin
penyayat/gurinda. Sayatan diusahakan memotong struktur
tubuh foraminifera besar dalam arah vertikal dan horisontal
(Gambar 3.1).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 16
Gambar 3.1. Sampel batuan dipotong dengan mesin
penyayat/gurinda
Gambar 3.2. Sampel ditipiskan pada kedua sisinya
Poles salah satu sisi sampel tersebut dengan menggunakan
bahan abrasif (karbondum) dan air (Gambar 3.3).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 17
Gambar 3.3 Poles sampel dengan menggunakan karbondum
dan air
Setelah itu, tempel sisi tersebut pada gelas objektif (ukuran
internasional 43 mm x 30 mm) dengan menggunakan kanada
balsam (Gambar 3.4).
Gambar 3.4 Tempel sisi itu pada gelas objektif dengan
menggunakan kanada balsam
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 18
Tipiskan sisi lainnya hingga sampel tersebut menjadi
transparan dan biasanya dengan ketebalan sekitar 30-50 μm.
Setelah mencapai ketebalan tersebut, teteskan Kanada Balsam
secukupnya dan kemudian ditutup dengan gelas penutup. Beri
label, dan sampel siap dideterminasi (Gambar 3.5).
Gambar 3.5 Sampel siap dideterminasi
19
BAGIAN IV
DESKRIPSI SISTEMATIK
DAN KISARAN STRATIGRAFI
Superfamily Acervulinoidea Schultze, 1854
Family Acervulinidae Schultze, 1854
Genus Alanlordia Banner dan Samuel, 1995
Cangkang bikonveks, apertur septal, namun beberapa berkisi,
beberapa apertur seperti pori berkembang pada distal, bagian
terluar dinding. Putaran awal menghasilkan bagian punggung
dan perut oleh lapisan dari kamar-kamar kecil yang
berkembang secara radial membentuk suksesi lapisan.
Alanlordia banyakensis Banner dan Samuel, 1955
Pada sayatan horisontal bentuk planispiral, terdapat proloculus,
terputar baik, pori-pori kasar di ujung lengkungan dinding.
Kisaran stratigrafi:
Miosen Tengah (Tf2) hingga Pliosen Akhir.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 20
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 21
Superfamily Asterigerinoida d’Orbigny, 1839
Family Amphisteginidae Cushman, 1927
Genus Amphistegina d’Orbigny, 1826
Cangkang lenticular, trochospiral bikonveks asimetris yang
mungkin bi-involute atau sebagian berlawanan pada sisi
spiral. Kamar-kamar sangat luas, dan punggung melengkung
kuat di bagian tepi membentuk perpanjangan kamar. Sisi
umbilikal stellate, dan memiliki plugs umbilikal yang
berbeda. Dindingnya gampingan, tebal, optis radial, permukaan
halus dan melengkung secara keseluruhan. Celah apertur
interiomarginal di sisi umbilikal, berbatasan dengan bibir.
Amphistegina quoyii d’Orbigny 1826
Pada sayatan vertikal memiliki septa sekunder / tootplate pada
kamar terakhir, sebuah kamar berbentuk involut, dinding
sederhana, terdapat alar prolongation, putaran kamar terakhir
menutupi putaran kamar sebelumnya. Pada sayatan horisontal
bentuk planispiral, terdapat septa, tersusun dalam 4-5 putaran,
evolut, dengan marginal chord jelas.
Kisaran stratigrafi:
Eosen hingga Holosen.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 22
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 23
Amphistegina sp. d’Orbigny, 1826
Pada sayatan vertikal bentuk tidak simetris, memiliki septa
sekunder / tootplate pada kamar terakhir, kamar berbentuk
involut, dinding sederhana, terdapat prolongation alar, putaran
kamar terakhir menutupi putaran kamar sebelumnya.
Kisaran stratigrafi:
Eosen hingga Holosen.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 24
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 25
Superfamily Miliolacea Ehrenberg, 1839
Family Austrotrillinidae Loeblich dan Tappan, 1986
Genus Austrotrillina Parr, 1942
Cangkang triloculina dengan alveoli tertutup yang halus hingga
kasar, bisa terbagi menjadi dua, apertur dengan gigi sederhana
pada kamar pertama, bercabang menjadi bukaan yang lebih
kecil. Memiliki dinding alveoli yang jelas.
Austrotrillina howchini (Schlumberger, 1893)
Sinonim:
Trillina howchini Schlumberger, 1893.
Austrotrillina howchini Schlumberger - Barberi, dkk., 1987.
Pada sayatan horisontal, Austrotrillina howchini tidak hanya
memiliki ruang yang berbentuk segitiga pada bagian melintang
(triangular), tetapi juga yang paling penting memiliki alveolus
yang bercabang, alveolus interior terbagi atau membagi bagian
luar menjadi alveolus yang lebih kecil.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 26
Diameter terbesar 1,00 mm; alveolus bercabang, d/b = 4;
ketebalan dinding antara alveolus 10 μm. (Boudagher-Fadel
dan Lokier, 2005).
Kisaran stratigrafi:
Miosen Tengah (Tf1).
Barberi, dkk. (1987) merekam spesies ini dari Tf1 (Burdigalian
atas-Langhian) pada suksesi karbonat pulau Sumbawa. Juga
dijumpai dari bagian atas Tf1, puncak Langhian di penampang
Kali Sambi (SAM) di wilayah Gunung Sewu di Jawa Tengah
Selatan (Boudagher-Fadel dan Lokier, 2005).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 27
Superfamily Nummulitacea De Blainville, 1827
Family Nummulitidae De Blainville, 1827
Genus Cycloclypeus van der Vlerk
Cangkang besar dan tipis, evolut, agak melingkar dengan
bagian planispiral, bagian ekuatorial menunjukkan kamar-
kamar nepionik besar dan kecil di sisi yang berlawanan,
cangkang diskoid besar dengan bagian melingkar yang terbagi
menjadi kamar-kamar dengan septa sekunder.
Cycloclypeus sp.
Pada sayatan vertikal kamar ekuatorial terlihat jelas, kamar
lateral tidak ada. Di tepi, rata dan di tengah cembung
(menonjol). Memiliki umbo pusat rendah yang dikelilingi oleh
beberapa tambahan pada ruang annular yang sangat jelas di
tengahnya.
Kisaran stratigrafi:
Oligosen hingga Resen.
Spesies ini dilaporkan dari Oligosen hingga Resen di seluruh
daerah tropis (Boudagher-Fadel dan Lokier, 2005).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 28
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 29
Genus Katacycloclypeus Tan Sin Hok, 1932
Tan Sin Hok (1932), dalam uraiannya tentang
Katacycloclypeus, menandainya sebagai subgenus baru dari
Cycloclypeus. Namun, tidak ada bukti langsung integrasi, baik
dalam model cangkang maupun struktur embrio antara
Cycloclypeus dan Katacycloclypeus. Oleh karena itu, dirasakan
kedua bentuk tersebut secara generik berbeda (Boudagher-
Fadel dan Lokier, 2005).
Katacycloclypeus annulatus (Martin, 1880)
Sinonim:
Cycloclypeus annulatus Martin, 1880.
Cycloclypeus annulatus Martin - Douvillé, 1916.
Cycloclypeus (Katacycloclypeus) annulatus (Martin) - Cole,
1963.
Katacycloclypeus annulatus (Martin) - Boudagher-Fadel dan
Wilson, 2000.
Spesies ini memiliki dua kamar embrionik, kamar ketiga yang
ada pada Katacycloclypeus annulatus berukuran lebih kecil.
Pada sayatan vertikal kamar ekuator terlihat jelas, kamar lateral
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 30
tidak ada. Bagian tepi, datar dan di bagian tengah bisa
mempunyai beberapa tonjolan. Memiliki cangkang besar, tipis
dengan umbo pusat rendah yang dikelilingi oleh beberapa
lengkungan dari dinding lateral yang padat, setiap lengkungan
dipisahkan oleh annuli yang luas dan datar dari lengkungan
selanjutnya sampai bagian melingkar yang jelas di bagian
tengah. Memiliki embrion triangular yang jelas.
Diameter maksimal mencapai 6 mm; Diam I./ Diam. II = 0,75
(Boudagher-Fadel dan Lokier, 2005).
Kisaran stratigrafi:
Miosen Tengah (Tf1-2).
Katacycloclypeus annulatus ditemukan pada Miosen Tengah
(Tf1-Tf2) dari Indo- Pasifik. Spesies ini dilaporkan dari Miosen
Awal di Jawa Barat. Boudagher-Fadel dan Wilson (2000)
mengemukakan bahwa spesies ini ditemukan dari Miosen
Tengah bagian bawah, Tf2 (Serravallian awal) di Kalimantan.
Dijumpai dalam Tf1 (Langhian) dan Tf2 (Serravallian) di
penampang Djatirago (TAN) dan penampang Kederakon
(WB13) di wilayah Gunung Sewu di Jawa Tengah Selatan
(Boudagher-Fadel dan Lokier, 2005).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 31
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 32
Superfamily Asterigerinacea DʼOrbigny, 1839
Family Lepidocyclinidae Scheffen, 1932
Subfamily Lepidocyclininae Scheffen, 1932
Genus Lepidocyclina Gümbel, 1870 emend. Boudagher-
Fadel dan Banner, 1997
Cangkang besar, diskoid, bikonkaf, beruang banyak, dimana
sambungan antara kamar-kamar terhubung dengan stolon (pori-
pori berbentuk tabung). Memiliki protoconch dan
deuteroconch dengan ukuran hampir sama dan dipisahkan oleh
dinding lurus.
Subgenus Lepidocyclina (Nephrolepidina) Douvillé, 1911
emend. Boudagher-Fadel dan Banner, 1997
Lepidocyclina (Nephrolepidina) oneatensis Cole, 1945
Sinonim:
Lepidocyclina (Eulepidina) oneatensis Cole, 1945.
Lepidocyclina (Nephrolepidina) cf. sumatrensis (Brady) –
Barberi dkk., 1987.
Lepidocyclina (Nephrolepidina) oneatensis Cole - Boudagher-
Fadel, dkk., 2000.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 33
Pada penampang vertikal kamar ekuatorial membesar ke arah
tepi, kamar embrionik tidak terlihat, terdapat kamar lateral
yang terpotong oleh pilar. Dinding vertikal yang memisahkan
kamar-kamar lateral kamar biasanya menebal.
Ukuran umumnya berdiameter 8 mm; centrum cubiculae tinggi
sampai 50 μm dan luas 200 μm; Dinding chamberlet lateral
ketebalan maksimal 140 μm. Penampang ekuatorial
menunjukkan protoconch agak persegi (sensu Boudagher-
Fadel dan Banner, 1997), atau "trybliolepidine" (sensu van der
Vlerk & Postuma, 1967). Cangkang bikonveks dan luas,
memiliki pilar yang bukan sebenarnya tetapi dinding vertikal
yang memisahkan susunan vertikal chamberlets lateral
(cubiculae) biasanya menebal, menghasilkan dichotomising
dan anastomosing lateral yang khas dari Lepidocyclina
(Nephrolepidina) oneatensis (Boudagher-Fadel dan Lokier,
2005).
Kisaran stratigrafi:
Oligosen Akhir hingga Miosen.
Spesies ini ditemukan dalam batugamping Gomantong dari Te
bagian atas, Oligosen Akhir-Miosen Awal dari Kalimantan
Timurlaut (Boudagher-Fadel dkk., 2000). Ditemukan pada Tf1
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 34
(Burdigalian atas) and Tf2 (Serravallian) dari penampang Kali
Sambi (SAM) di wilayah Gunung Sewu di Jawa Tengah
Selatan (Boudagher-Fadel dan Lokier, 2005).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 35
Lepidocyclina (Nephrolepidina) rutteni quadrata Boudagher-
Fadel dan Banner, 1997
Sinonim:
Lepidocyclina (Nephrolepidina) rutteni van der Vlerk, 1923.
Lepidocyclina (Nephrolepidina) rutteni quadrata Boudagher-
Fadel dan Banner, 1997.
Pada sayatan horisontal kamar equatorial berbentuk pointed
arcuate, dengan susunan kamar berbentuk konsentris, kamar
embrionik terlihat jelas dimana protoconch lebih kecil dari
pada deuteroconch, bentuk kamar lateral menyudut. Memiliki
prolokulus persegi.
Panjang maksimum 4 mm; lebar maksimum 3,5 mm, centrum
cubiculae tinggi hingga 54 μm dan lebar 90 μm; megalospheric
nepiont ca. 200 μm, Diam. I / Diam II = 0,6. (Boudagher-Fadel
dan Lokier, 2005)
Kisaran stratigrafi:
Miosen Tengah (Tf2).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 36
Lepidocyclina rutteni s.l. pertama kali dilaporkan dari
"Vindobonian" Jawa. Bentuk persegi dari Lepidocyclina rutteni
ditemukan di Tf2 (Serravallian) pada penampang Kali Sambi
(SAM) di wilayah Gunung Sewu di Jawa Tengah Selatan
(Boudagher-Fadel dan Lokier, 2005).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 37
Superfamily Nummulitacea De Blainville, 1827
Family Nummulitidae De Blainville, 1827
Subfamily Heterostegininae Galloway, 1933
Genus Heterostegina d’Orbigny
Cangkang tebal, involut hingga evolut dengan kamar yang
dibagi oleh septa sekunder hingga membentuk kamar-kamar
kecil. Bagian tengah cangkang menebal, kamar awal tidak
terbagi, kamar selanjutnya dibagi oleh septa sekunder. Tidak
ada perpanjangan, dengan sutura yang tinggi.
Heterostegina (Vlerkina) borneensis (van der Vlerk)
Kamar tersusun secara planispiral, membesar cepat pada
putaran ke 2 sampai 4,4, proloculus terlihat jelas, dinding licin,
terdapat septa sekunder sehingga membentuk chamberlet
(kamar-kamar).
Kisaran stratigrafi:
Oligosen Akhir (Te) hingga Miosen Awal (Tf1).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 38
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 39
Heterostegina (Vlerkina) sp. (van der Vlerk)
Pada sayatan vertikal tidak dijumpai kamar lateral pada massa
gampingan yang terdapat pada kedua sisi lapisan ekuatorial,
terdapat alar prolongation, proloculus tidak terlihat jelas.
Bentuk sayatan pipih memanjang, kamar median terpotong-
potong oleh septa. Kamar lateral tidak jelas.
Kisaran stratigrafi:
Oligosen Atas hingga Miosen.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 40
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 41
Family Planorbulinidae Schwager, 1877
Genus Planorbulinella Cushman, 1927
Cangkang diskoidal, trochosipral, bentuk apertur retrovert dari
putaran kamar selanjutnya berasal dari bentuk orbitoid yang
tidak beraturan. Dinding gampingan, memiliki lubang yang
kasar, struktur memancar. Setelah pembentukan kamar dengan
dua stolon, satu atau lebih kembali memiliki satu stolon.
Planorbulinella solida (Belford)
Kamar embrionik terlihat jelas, dengan susunan kamar
berbentuk trochopsiral, memiliki kamar lateral yang lebih
pendek.
Kisaran stratigrafi:
Miosen Tengah hingga Miosen Akhir.
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 42
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 43
Subfamily Victoriellinae Chapman dan Crespin, 1930
Family Victoriella Chapman dan Crespin, 1930
Genus Victoriella Chapman dan Crespin, 1930
Victoriella sp. Chapman dan Crespin, 1930
Cangkang karbonat, substratum, rotaloid pada kamar nepionik,
kemudian tumbuh menjadi bentuk silinder yang tersusun dari
kamar-kamar yang tidak beraturan, yang dipisahkan oleh septa,
dikelilingi oleh dinding silinder yang tebal.
Kisaran stratigrafi:
Oligosen hingga Miosen Awal.
44
BAGIAN V
UMUR DAN
LINGKUNGAN PENGENDAPAN
Foraminifera besar adalah penciri yang paling penting untuk
penentuan umur dan interpretasi lingkungan pengendapan pada
karbonat laut dangkal.
5.1. UMUR
Kemunculan spesies petunjuk foraminifera besar,
Katacycloclypeus annulatus berasosiasi dengan Heterostegina
(Vlerkina) borneensis dan Lepidocyclina (Nephrolepidina),
dalam unit packstone bioklastik intraklas – foram besar, bagian
paling bawah dari Anggota Kalkarenit Formasi Pamutuan,
menunjukkan Tf1 stage dari klasifikasi huruf menurut Adam
(Tabel 5.1). Zona umur ini mengidentifikasikan periode awal
Miosen Tengah (Isnaniawardhani, dkk., 2018). Umur ini
ditentukan berkoresponden dengan 18,7 juta tahun lalu (Sharaf,
dkk., 2006).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 45
Kehadiran spesies petunjuk foraminifera besar, Austrotrillina
howchini dan Katacycloclypeus annulatus, dalam unit
packstone bioklastik foram besar, yang berada di atas unit
paling bawah, menunjukkan Tf1-Tf2 stage dari klasifikasi huruf
menurut Adam. Pemunculan akhir Austrotrillina howchini
menandai batas atas Tf2 (Tabel 5.1). Zona umur ini
mengidentifikasikan periode Miosen Tengah (Isnaniawardhani,
dkk., 2018).
Kemunculan spesies petunjuk foraminifera besar,
Lepidocyclina (Neprolepidina) rutteni quadrata, dalam unit
grainstone bioklastik foram besar, bagian atas dari Anggota
Kalkarenit Formasi Pamutuan, menunjukkan Tf2 stage dari
klasifikasi huruf menurut Adam (Tabel 5.1). Zona umur ini
mengidentifikasikan dalam periode akhir Miosen Tengah
(Isnaniawardhani, dkk., 2018).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 46
Tabel 5.1. Kisaran stratigrafi dari spesies petunjuk foraminifera
besar yang teramati dalam Anggota Kalkarenit Formasi
Pamutuan di Cintaratu
Referensi beberapa foraminifera besar di Indo-Pasifik dapat
ditemukan pada Adams (1970, 1983).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 47
Tabel 5.2. Rentang spesies petunjuk foraminifera besar
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 48
5.2. LINGKUNGAN PENGENDAPAN
Kelimpahan foraminifera besar (genera Alanlordia,
Amphistegina, Cycloclypeus, Heterostegina dan
Planorbilinela) berasosiasi dengan koral, ganggang merah dan
foraminifera planktik dengan sejumlah kecil miliolida dan
rotaloida kecil ditemukan dalam unit packstone bioklastik
intraklas – foram besar. Kumpulan-kumpulan fosil ini
merefleksikan proses pengendapan yang terjadi di depan
terumbu dengan intensitas cahaya tinggi. Banyak fragmen
batugamping skeletal yang mengandung foraminifera dan
stromatolite menggambarkan bahwa unit ini terbentuk pada
lereng di depan tubuh terumbu (Gambar 5.1) (Isnaniawardhani,
dkk., 2018).
Keanekaragaman yang tinggi dari foraminifera besar dengan
kelimpahan miliolida dan rotaloida kecil yang berasosaiasi
dengan beberapa ganggang hijau (Halimeda), koral, bryozoan
dan moluska dalam unit packstone bioklastik foram besar serta
unit grainstone bioklastik foram besar mengindikasikan
lingkungan belakang terumbu (Gambar 5.1) (Isnaniawardhani,
dkk., 2018).
Katalog Foraminifera Besar Pada Anggota Kalkarenit Formasi Pamutuan | 49
Gambar 5.1. Model distrubusi foraminifera besar Kenozoikum
pada fasies karbonat (van Gorsel, 1988)
50
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