PALEO Field Report Ss

8/3/2019 PALEO Field Report Ss

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MIDDLE EAST TECHNICAL UNIVERSITY

DEPARTMENT OF GEOLOGICAL ENGINEERING

GEOE- 309 (02)

HISTORICAL GEOLOGY AND PALEONTOLOGY

MEMO TO: Prof. Dr. Demir Altıner

FROM: Selin Köroğlu, 1553205

SUBJECT: GeoE-309, Field Trip Report



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TABLE OF CONTENT

TABLE OF CONTENT ............................................................................................................. 1

TABLE OF FIGURES ............................................................................................................... 2

LIST OF TABLES ..................................................................................................................... 2 INTRODUCTION ...................................................................................................................... 3 STOPS ........................................................................................................................................ 3

Stop 1 (Gökçehöyük Village)................................................................................................. 5 Stop 2 (Çayraz Village) .......................................................................................................... 7

CONCLUSION ........................................................................................................................ 11 REFERENCES ......................................................................................................................... 11



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TABLE OF FIGURES

Figure 1: Principle types of chamber arrangement.

(source:http://www.ucl.ac.uk/GeolSci/micropal/images/fora/fordiag04.gif) ............................ 4

Figure 2: The permian aged, fussilinicea bearing outcrop ........................................................ 5

Figure 3: Equtorial section of a fussilinicea test ........................................................................ 6

Figure 4: Axial Section of a fusulinacea test ............................................................................. 6

Figure 5: Fossil bearing outcrop at the stop2. ........................................................................... 7

Figure 6: Involute Rotaliina , Nummulitides tests from field. .................................................... 8

Figure 7 : Evolute Rotaliina, Assilina tests from field (1-2 cm in size)...................................... 9

Figure 8: Anatomy of Discocycline

(source: http://jfr.geoscienceworld.org/content/31/3/173/F10.small.gif).................................. 9

Figure 9: 3D View of Equtorial section

(source:http://jfr.geoscienceworld.org/content/31/3/173/F10.small.gif)................................. 10

Figure 10, Apertural View of Family Alveolinidae

(source:http://jfr.geoscienceworld.org/content/31/3/173/F10.small.gif)................................ 10

LIST OF TABLES

Table 1: Taxonomy of Foraminiferidas ..................................................................................... 3

http://c/Users/Selin/Desktop/PALEO_field%20report_ss.docx%23_Toc310199934





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INTRODUCTION

The study was applied on the 13th of the November, comprises a part of Haymana region,

approximately 30km South West of Ankara. The objectives of the study were to determine

and classify the forominiferida fossil group found during the field trip, and correlate them

with the geologic time scale. During the excursion two stops were made. The study group

used apparatuses to determine and distinguish fossils, such as loupe, and hammer. In addition,

photo taking, surveying the structures, examining the fossils, and taking notes methods were

used. Related plans were added at the appendix.

STOPS

The overall geology of the area is Triassic aged greywacke overlying by Permian aged Neritic

limestone. This backward aging indicates a tectonic movement.

In this field trip we focused on fossils belongs to Foraminiferida found in all marine

environments, they may be planktonic or benthic in mode of life The name Foraminiferida is

derived from the foramen, the connecting hole through the wall (septa) between each chamber

The complete taxonomy of the order can be seen at table1..

Table 1: Taxonomy of Foraminiferida

Kingdom Protista

Subkingdom Protozoa

Phylum

Sarcomatigophora

Subphylum Sarcodina

Superclass Rhizopoda

Class Granuloreticulosea

Order Foraminiferida

Foraminiferida are classified primarily on the composition and morphology of the test. Three

basic wall compositions are recognised, organic (i.e. the allogromina), aranaceous and

calcerous. Araneceous forms,( i.e. the Textulariina) , may be composed of randomly

accumulated grains or grains selected on the basis of specific gravity, shape or size; some

forms arrange particular grains in specific parts of the test. Calcerous test foraminifera are

again subdivided into three major groups, microgranular (i.e. Fusulinina), porceleneous (i.e.

Miliolina) and hyaline (i.e. Globigerinina). Microgranular walled forms (commonly found in



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the late Palaeozoic) are composed of equidimensional subspherical grains of crystalline

calcite. Porceleneous forms have a wall composed of thin inner and outer veneers enclosing a

thick middle layer of crystal laths; they are imperforate and made from high magnesium

calcite. The hyaline foraminifera add a new lamella to the entire test each time a new chamber

is formed; various types of lamellar wall structure have been recognised, the wall is

penetrated by fine pores and hence termed perforate. The classification of Foraminifera is

based on test walls and test symmetry: (University College London)

The chamber arrangements of the order can be seen at figure 1.

Figure 1: Principle types of chamber arrangement.

(source:http://www.ucl.ac.uk/GeolSci/micropal/images/fora/fordiag04.gif)



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1. Uniserial: Chambers are added in a straight or curvilinear series.

2. Biserial: Chambers are added in an alternating fashion.

3. Triserial: Chambers are added every 120° in a spiral fashion.

4. Planispiral: Chambers are added around the periphery and are coiled in a single plane.

Planispiral tests are evolute when all previous chambers are visible, and are involute when

only the last spiral or whorl is visible.

5. Trochospiral: Chambers are added around the periphery, but each new chamber is slightly

offset so that a very low spire or cone results. The central part of the disc on the side of the

aperture is called the umbilicus.

Stop 1 (Gökçehöyük Village)

The first stop was made nearby of Gökçehöyük Village. In this stop we examined

Permian aged neritic limestone outcrops bearing fusulinacea fossils. (Figure 2)

Figure 2: The Permian aged, fusulinacea bearing outcrop



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We were able to date the lithology based on previously done radiometric studies and

faunal assemblages examinations. The Fusulinina contains those foraminifera with

calcareous, microgranular walls; advanced forms may have two or more layers. The

groups were largely Palaeozoic in age, becoming extinct in the Triassic. After that, we

focused on Fusulinacea. The Fusulinacea were larger forms which also had

microgranular perforate tests but with chambers arranged planispirally

Two kinds of wall structure are found. Fusulinids (suborder Fusulinina, Silurian-

Permian) possess: (1) walls with a granular, sugary appearance, (2) larger examples

which are commonly planispirally coiled and have a characteristic 'rugby-ball' shape,

(3) an entirely benthonic mode of life. Fusulinids are generally large and oval in shape.

The wall appears very fine grained and the apertures are often indistinct. Fusulinids

may also have penetrations in their test wall. Anatomy of fusulinacea can be seen on

both axial and equatorial sections on figures 3&4.

Figure 4: Axial Section of a fusulinacea test

Figure 3: Equatorial section of a fusulinacea test



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In some forms a tunnel was formed by selective absorption of the septa and secretion

of two bordering ridges called chomata, thereby connecting the mid-floor of each

chamber. In the Permian neoschwagerinids, which we saw in the field unconsciously,

there was a tendency to fill the central axial chambers with secondary calcite can be

easily seen on their axial sections.

Stop 2 (Çayraz Village)

Our second stop was at near Çayraz Village, which is a type-locality of Çayraz

Formation (rock stratigraphic unit). There were such sedimentary rocks full of fossils

in middle Eocene age. Rocks are specifically Luthetian in age (chrono stratigraphical

unit). Harhor formation (Late Middle Eocene) outcrops in a small syncline, situated to

the north of the Haymana Anticline. The formation overlies the Çayraz formation

(with abundant nummilites and assillinas) with a thin conglomerate and consists of

alternations of thick (50-200 cm.) sandstones and thin mudstone bands. There we saw

Nummilites, Assilina, Discocyclindae and Alveolinidae. (Figure 5)

Figure 5: Fossil bearing outcrop at the stop2.

Rotalines (suborder Rotaliina, Triassic-Recent) are very variable in form, but are

characterised by a hyaline, i.e. glassy, appearance, a perforated wall, an entirely

benthonic mode of life. The Rotalines are the most diverse group of the foraminifera,



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and are mainly distinguished by their perforated, glassy wall when viewed with

reflected light and grey to clear in transmitted light. However, thick walls, fine dense

perforations, granules, spines, pigments and diagenesis may all obscure this clarity.

In the field, we observed some Nummulites (Figure6) (Palaeocene-Oligocene) and

Assilina (Eocene). Their family is Nummulitidae and they belong to the suborder of

Rotaliina. The family of Nummulitidae range is Palaeocene to Recent, however we

found Nummulites with Assilina so our field work area was limited by Eocene since

Assilina (Figure 7) is only found in Eocene. Nummulites have planispiral test

symmetry which is planispiral involute, Assilina have also planispiral test symmetry

but which is planispiral evolute in the axial section

Figure 6: Involute Rotaliina , Nummulitides tests from field.



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Figure 7 : Evolute Rotaliina, Assilina tests from field (1-2 cm in size)

Besides, we checked Discocylina (Eocene). (Figure 8) Their family is Discocyclinidae

and again they belong to the suborder of Rotaliina. Their test composition is also

calcareous so we saw them glassy. The most important characteristic of them is that

equatorial chambers shape is rectangular in equatorial section. (Figure 9) We saw also

their pillar system, proloculus, lateral chambers.

Figure 8: Anatomy of Discocycline (source: http://jfr.geoscienceworld.org/content/31/3/173/F10.small.gif)



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Figure 9: 3D View of Equatorial section (source:http://jfr.geoscienceworld.org/content/31/3/173/F10.small.gif)

At the end, we examined Alveolina. Their family is Alveolinidae (Cretaceous-Recent)

and they belong to the suborder of Miliolina. Their test composition is calcareous but

in the reflected light they seem to be porceleneous. In the axial section, they are

involute and in the field, we saw their sutures, chambers, proloculus, septum and the

most importantly those we saw pre-septal and post-septal passages in the equatorial

section. ( Figure 10)

Figure 10, Apertural View of Family Alveolinidae.

(source:http://jfr.geoscienceworld.org/content/31/3/173/F10.small.gif)



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CONCLUSION

To sum up, by examining the field and observed faunal assemblages we tried to use relative

aging method. Moreover in the field by examining and collecting the fossils we learned their

names, properties and ages by combining with our theoretical knowledge given in courses. After

doing this scientific research, such as examining the geological structures, and paleontological

evidences we try to interpret possible ages of geological structures and chronological order of

them. In other words we try to read the field and linking the events with each other, just like

solving a gigantic puzzle. In addition we had the chance to see fossil types and rock types we

learned at the lectures and study them at their habitats. At the end of the field trip we

successfully achieve all of our goals.

REFERENCES

University College London. (n.d.). Foraminifera. Retrieved 11 21, 2011, from MIRACLE:

http://www.ucl.ac.uk/GeolSci/micropal/foram.html

Bates, R., L., Jackson, J., A., (1980), Glossary of Geology, American Geological Institute,

Virginia

Hancock, P., L., Skinner, B., J., (2000), the Earth, Oxford University Press, New York

Doyle, P., 1996, Understanding Fossils: An Introduction to Invertebrate Palaeontology, John

Wiley & Sons, Ltd.

Altıner, D., (2011) , “GeoE 309 Lecture Notes” , METU, Ankara

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PALEO Field Report Ss