investigation of organism heterogeneity … sob-06...chemistry aspect, the calcimetry analysis of ms...

PROCEEDING, SEMINAR NASIONAL KEBUMIAN KE-9 PERAN PENELITIAN ILMU KEBUMIAN DALAM PEMBERDAYAAN MASYARAKAT

6 - 7 OKTOBER 2016; GRHA SABHA PRAMANA

745

INVESTIGATION OF ORGANISM HETEROGENEITY AND ITS POROSITY IN

LIMESTONE BASED ON INTEGRATED OUTCROP DATA: IMPLICATION FOR

DETERMINING DEPOSITIONAL FACIES OF BULU FORMATION

Putri Ramadhina1*, RianCahya Rohmana2, Tara Shinta Dewi2,

Megasari Widyastuti3, I Made Dwi Setiadi3 1Dept. of Geology, UPN “Veteran” Yogyakarta

2GeoPangea Research Group (GPRG) 3Dept. of Geology, UPN “Veteran” Yogyakarta

*Email : PutriRamadhina ([email protected])

SARI Bulu Formation is part of North East Java Basin that has widespread distribution especially in the North

Rembang Anticlinorium. This formation composed of larger foraminifera limestone and fossiliferous

sandy limestone which was deposited during Middle Miocene to Early Late Miocene time (N13-N15).

This paper focuses on heterogeneity of large foram organisms and their porosity, implication for

determining depositional facies. This study uses outcrop data and petrography analysis to determine

the species of large foraminifera as well as calculating visible porosity. Large foram is clustered into

three groups based on shell test character, the first group consists of Amphistegina and Miogypsina, the

second group consists of Cycloclypeus, Lepidocyclina, Operculina, Heterostegina, and plankton,

whereas the third group consists of Alveolinella, Flosculinella, Calcarina and Amphistegina. Porosity

calculation shows poor to very good classification, with value ranging from 5 to 25%.Large Foram is

used to analyze the depositional environments based on the shell shape, genus and quantity. The analysis

showed that the Formation of Bulu in the research area is deposited in open-shelf facies and toe-of-

slope facies. Open-shelf facies is characterized by genus Amphistegina, Cyclolypeus, Miogypsina, and

Lepidocyclina. Toe-of-slope facies is characterized by genus that is similar to open-shelf facies but

dominated with Cycloclypeus genus. The abundance of the certain organisms could be an indication of

depositional environment of the organism.

Keywords: Carbonate, Large Foraminifera, Bulu Formation, Porosity, Stratigraphy.

I. INTRODUCTION

Bulu Formation is one of the formations

which deposited in North East Java Basin that

has widespread distribution especially in the

North Rembang Anticlinorium according to

Pringgoprawiro (1983). Bulu Formation

composed by well layered limestones rich in

large foraminifera and fossiliferous sandy

limestones (Sharaf, et al., 2005). At its

limestones encountered many enormous size

of foraminifera from Cycloclypeus

(Katacycloclypeus) annulatus, Lepidocyclina

(N.) ngampelensis, Orbulinasp. And

Orbulinasuturalis species according to

Sharaf, et al., (2005). Pringgoprawiro (1983)

used the name of Bulu Formation as the

official name, by using the type location in

Besek River, near Bulu village,

Rembang.Large foraminifera is one of the

depositional environment indicator (Frost

and Langenhim, 1974; Chapronier, 1975;

Fermont, 1982; Setiawan, 1983; in Hallock,

1986) eventhough its rarely used by

reasearcher. Hallock & Glenn (1986) showed

that large foraminifera can be used as

depositional environment based on their

research in the northwest of Palawan Island,

Philippines on 1985. This method based on

the test morphology and distribution of large

foraminifera which refers to carbonate facies

classification by Wilson (1975).

Lithological conditions and the content of

fossil showed that Bulu Formation is

commonly deposited on shelf margin or slope

depositional environment (Wilson, Moyra

R.J, 2002) during Middle Miocene to Early

Late Miocene time (N13-N15) based on the



746

presence of Cycloclypeusannulatus

(Ardhana, et al.,1993; Lunt, et al., 2000,

inSharaf,et al.,2005). The purpose of this

research is to create a research study to solve

the differences of results between the

previous researchers based on large

foraminifera abundance using Hallock and

Glenn (1986) research in order to know

which depositional environment that Bulu

Formation were deposited and how is the

relation between a typical large foraminifera

in Bulu Formation with that depositional

environment by integrating of all data fields

that have been investigated.

II. GEOLOGICAL SETTING

North East Java Basin stretches from West

toEast from Semarang to Surabaya 250 km

(width of 60-70 km). In the northern part of

the basin bounded by Meratus High, in the

southern restricted by Volcanic Belt Southen

Mountain Java (magmatic arc), in the west

and southwest restricted by Karimunjawa

Arc and stable Sunda Shelf and in the eastern

of the basin bounded by Masalembo-Doang

High. North East Java Basin to the north

changed gradually into a basin of North Java

Sea, to the west associated with West Java

Basin.Based on aspects of the structure and

stratigraphy, Smyth et al. (2005) divides the

eastern part of Java into four zones

tectonostratigraphy, from south to north: (1)

Southern Mountain Zone, (2) Present-day

Volcanic Arc, (3) Kendeng Zone, and (4)

Apex Zone.

Rembang zone extends from the northern

Java and the western part separated by Lusi

Depression of Randublatung zone. This zone

is formed by a depression in the middle and

Depression Solo or Kujung curved in the

eastern part. Generally, this zone is a tectonic

hills with higher intensity in Zone

Randublatung, but lower intensity compared

to Kendeng zone. This zone is characterized

by the presence of anticline

AntiklinoriumRembang in the form of lines

that overlap each other (superimposed). The

dominant lithology in this zone are sand and

carbonate sediments with interbedded marl

and clay. The lithology is expected deposited

on the continental shelf. Rembang zone has

coarse grained sediments more than fine-

grained sediments, the deposition rate is

slower than the rate of decline of the basin.

Rembang zone exposes rocks with a high

sand content in addition to the absence of

carbonate rocks and pyroclastic sediment.

Sediment in this zone is interpreted deposited

on the sea not far from the beach, the sea

bottom is not uniform in terms of depth due

to fault - the fault of lumps (block faulting).

As a result, it was found facies changing

encountered on this path.In the Middle

Miocene sandy limestone Bulu deposited on

top of Ngrayong quartz sandstone in the

Middle neritic-outer Neritik on the good

abiotic water condition where components of

foraminifera and other organisms are very

abundant. This unit is dominated by sandy

limestone and calcarenite rich large

foraminifera (open shelf sediment -toe of

slope) (Hallock& Glenn, 1986).

III. METHODS AND DATA

Methods and data from this research basically

done by mapping. The methods in this

research are divided into three stages. On the

Preliminary stage, the research area, literature

view and all the preparation are needed on

this stage (Figure 1).

Observation stage; Primary data acquired

from observation including rock description

along with rock sampling, detailed profile,

and measuring section.

Following that, various analysis has been

done which is measuring section analysis,

petrography analysis, calsimetry analysis,

microfossil analysis and structure analysis

based on acquired data on field.The method

that has been used in the determination of

depositional environments based on rock

porosity and large foraminifera assemblages

is petrographic analysis. The researcher used

27 thin sections to determine the name of

rock on each rock sample-based texture,

structure and mineral composition of

microscopically. Additionally, knowing the

type of foram as well as the porosity of the

rock.The content of large foraminifera in thin

section petrographic samples which have

been determined and known types of large



747

foraminifera then calculated and plotted to

the triangular diagram Hallock and Glenn

(1986). The plotting results will be obtained

in an environment where the Bulu Formation

was deposited.

IV. DEPOSITIONAL FACIES:

BASED ON LARGE FORAM

IV.1. Large Foram Group

Based on test morphology, large foraminifera

are divided into three groups:

a. Group I, Larger rotaliine foraminifera

with ovate tests or known shallow water

affinites, i.e., Amphistegina, ovid

nummulitids, and miogypsinids.

b. Group II, Planktonic foraminifera,

flattened larger rotaliines, and larger

rotaliines with known deeper water

affinities, i.e., lepidocyclinids,

Cyclopleus, Heterostegina, and

Operculina.

c. Group III, Smaller rotaliines and

porcellaneous foraminifera including

soritids, peneroplids, alveolinids, and

miliolids.

All of foraminifera belonging to the above

three groups were analyzed, determined and

counted by its quantity in each thin section.

Researchers conducted petrographic thin

section on the sample in the track of

measuring section and analyzed the quantitiy

and quality of large foraminifera. From 27

thin sections, only 6 thin sections which did

not meet the criteria to be analyzed by

Hallock & Glenn method. The foraminifera

which analyzed by researcher are divided into

three groups based on characteristic of the

shell tests (Figure2):

a. Group I, Large rotaliine foraminifera with

ovate tests, i.e., Amphistegina, and

Miogypsina.

b. Group II, Planktonik foraminifera,

flattened larger rotaliines, and larger

rotaliines with known deeper water

affinities, i.e., Cycloclypeus,

Heterostegina, Lepidocyclina,

Operculina, and plankton.

c. Group III, Smaller rotaliines and

porcellaneous foraminifera including

soritids, peneroplids, alveolinids, and

miliolids, i.e., Alvolinella, Flosculinella,

Calcarina and Amphistegina.

Based on the result of the analysis and then

plotted by Hallock & Glenn’s triangular

diagram, in general, Bulu sandy limestone

units deposited on open shelf facies and toe of

slope facies (Figure 2).

IV.2. Open Shelf Facies

Open shelf facies in the research area

characterized by abundant of genus

Amphistegina, Cycloclypeus, Miogypsina,

and Lepidocyclina. The foraminiferas largely

have abraded test especially genus

Cycloclypeus from Group II. This is because

of the flattened shell and Cycloclypeushave

longer size than any other genus, so the shell

partially intact when it deposited on the open

shelf.

The result of petrography analysis represent

most of the deposited facies are larger

foraminifera packstone (Figure 3), red algae

packstone (Figure 4) and larger foraminifera

grainstone (Figure 5). Sedimentary

structures that can be found only parallel

stratified, massive and lapies. Based on

chemistry aspect, the calcimetry analysis of

MS I 200-220 represent the samples were

found have high CaCO3 content that is 91,9

%(Figure 8)

IV.3. Toe of Slope Facies

Open Shelf facies in the research area

characterized by genus Amphistegina,

Cycloclypeus, Miogysina and Lepidocyclina.

Similar to open shelf facies, this facies is

dominated by Cycloclypeus genus, but the

differences with open shelf facies, large

foraminifera groups II has >70% percentage

and groups I and II has a little percentage.

Based on tes shells, most of armsfrom broken

test or abrated, but there are shells that still

intact.Genus Amphistegina are also abundant

and almost all of the test shells are also intact.

The reason is because the shape of the test

shells are ovate and smaller, unlike the other

large foraminifera group II which most af all

are flattened and longer rotaliines.



748

The result of petrography analysis represent

most of the lithofacies are larger

foraminifera packstone (Figure 6) and red

algae wackestone (Figure 7). Sedimentary

structures that can be found are parallel

startified, massive and lapies. Based on

chemistry aspect, the calcimetry analysis of

MS I 540-560 represent that the sample has

89,7% of CaCO3 content (Figure 8)

Each of facies indicated with the abundance

of Cyclocypleus genus (Figure 9). All of the

explanation above shows that the abundance

of a particular genus can indicate spesific

depositional environment. on this area

showed that this unit were deposited in open

shelf – toe of slope.

V. POROSITY

Based on petrographic thin section analysis

on the sample in the track of measuring

section, from 27 thin sections, only 2 thin

sections that is not represent its porosity.

Porosity calculation shows poor to very good

classification, with value ranging from 5 to

25% (Figure10)

VI. CONCLUSION

1. In the research area, developed within

three groups of large foraminifera, which

are group I (Amphisteginaand

Miogypsina), group II (Cycloclypeus,

Heterostegina,

Lepidocyclina,Operculina, and plankton),

and group III (Alvolinella, Flosculinella,

Calcarina and Amphistegina).

2. Based on the abundant of large

foraminifera, sandy limestone unit of Bulu

Formation were deposited in open shelf –

toe of slope. One of the indication that

depositional environment is the abundant

of large foraminifera group II, which is

Cycloclypeus genus.

3. The abundance of a particular genus can

indicate spesific depositional

environment. As the sandy limestone unit

of Bulu Formation in the abundance of the

genus Cyclocypeus on this area showed

that this unit were deposited in open shelf

– toe of slope.

4. Based on petrographic thin section

analysis, the porosity of the sample shows

poor to very good classification (ranging

from 5% to 25%).

VII. ACKNOWLEDGEMENT

The authors gratefully to thank all of

SEMNAS UGM committee for publishing

this paper. We would like to thank Mr. Ir. H.

Kuwat Santoso, M.T. and Mr. Ir. Mahap

Maha, M.T. and the last we would like to

thank for all GPRG members for their

support.

REFERENCES

Hallock, Pamela and E. Charlotte Glenn. 1986. Larger Foraminifera: A Tool for Paleoenviromental

Analysis of Cenozoic Carbonate Depositional Facies. Palaios: The Society of Economic

Paleontologists and Mineralogist. Research Reports, Vol 1, p. 55 – 64.

Pringgoprawiro, Harsono. 1983. BiostratigrafidanPaleogeografiCekunganJawaTimur Utara:

suatupendekatanbaru. DisertasiGeologi. FakultasPascasarjana, Bandung: InstitutTeknologi

Bandung.

Sharaf, Essam., J.A. (Toni) Simo., Alan R. Carroll., and Martin Shields. 2005. Stratigraphic Evolution

of Oligocene-Miocene Carbonates and Silisiclastics, East Java Basin, Indonesia.AAPG

Bulletin, v. 89, no. 6 (June 2005), pp. 799–819

Smyth,H.,Hall,R.,Hamilton,J.P.,andKinny,P.,2003,VolcanicOriginOfQuartz-

RichSedimentsInEastJava:Jakarta,Proceedings,IndonesianPetroleumAssociationAnnual

Convention, 29th, p. IPA03-G-014.



749

Wilson, J. L. 1975. Carbonate Fades in Geologic History, xiv+471 pp., 183 figs,. 30 pis. Springer-

Verlag, Berlin, Heidelberg, New York.

FIGURES

Figure 1. Flow chart of methods and data.

Figure 2. Data tabulation percentage of each class of foraminifera in each sample that have been

analyzedand percentage of each class of large foraminifera.



750

a b

Figure 3. The appearance of petrographic thin section larger foraminifera packstone, parallel nicol (a)

and cross nicol (b) in sample MS I 260-280, consisting Cycloclypeus which the arms are

abraded and Amphistegina which the test relatively intact.

a b

Figure 4. The appearance of petrographic thin section red algae packstone, parallel nicol (a) and cross

nicol (b) in sample MS I 380-400, red algae is seen as fiber sheet and the test of Amphistegina

is relatively intact.

a b

Figure 5. The appearance of petrographic thin section larger foraminifera grainstone, parallel nicol (a)

and cross nicol (b) in sample MS I 460-480, Miogypsina are looks intact and another

Miogypsina looks not. Amphistegina relatively intact and there are arms fracture on

Cycloclypeus.



751

a b

Figure 6. The appearance of petrographic thin section red algae wackstone, parallel nicol (a) and cross

nicol (b) in sample MS I 420-440, red algae are long and fibrous, and from thin section,

Cycloclypeus’s arms are fractured.

a b

Figure 7. The appearance of petrographic thin section larger foraminifera packstone, parallel nicol (a)

and cross nicol (b) in sample MS I 540-560, Cycloclypeus and Miogypsina are looks intact,

and the others are not.



752

Figure 8. (A) Calcimetry analysis on sample MS I 200-220. (B) Calcimetry analysis on sample MS I

540-560

Figure 9. Modifications of depositional environment models from Wilson (1975) by Hallock and Glenn

(1986) based on the foraminifera.



753

TABLE

Table 1. Porosity Data from Each Samples

.

1 88 5% larger foram wackestone

2 MS I 160-180 15% larger foram packstone











13 MS I 380-400 10% red algae packstone


15 MS I 420-440 20% red algae wackestone


17 MS I 460-480 10% larger foram grainstone


19 MS I 500-520 10% red algae packstone



22 MS I 560-580 - larger foram packstone





27 MS I 830-850 10% larger foram wackestone

28 LP 67/MS I 120-140 - foraminifera packstone

Lithology (Dunham, 1962)No Samples Porosity

investigation of organism heterogeneity … sob-06...chemistry aspect, the calcimetry analysis of ms...

Documents