GeolCarp_Vol68_No6_505

GEOLOGICA CARPATHICA

, DECEMBER 2017, 68, 6, 505–516

doi: 10.1515/geoca-2017-0033

www.geologicacarpathica.com

Ammonites and magnetostratigraphy

of the Berriasian–Valanginian boundary

deposits from eastern Crimea

VLADIMIR V. ARKADIEV

, VLADIMIR A. GRISHCHENKO

, ANDREI YU. GUZHIKOV

ALEKSEY G. MANIKIN

, YULIYA N. SAVELIEVA

, ANNA A. FEODOROVA

and OLGA V. SHUREKOVA

Saint-Petersburg State University, University emb. 7/9, 199034 Saint-Petersburg, Russia; arkadievvv@mail.ru

Saratov State University, Astrakhanskaya str. 83, 410012 Saratov, Russia; grishenko-vladimir@bk.ru; aguzhikov@yandex.ru; agmanikin@mail.ru

Federal State Unitary Enterprise “Geologorazvedka”, Knipovich str. 11/2, 192019 Saint-Petersburg, Russia; julia-savelieva7@mail.ru;

annafedoroff@yandex.ru; o.antonen@gmail.com

(Manuscript received November 30, 2016; accepted in revised form September 28, 2017)

Abstract: Euthymi, Crassicostatum and Callisto ammonite subzones, correlable with Paramimounum, Picteti, and

Alpillensis subzones and probably with the Late Berriasian Otopeta Subzone of the Boissieri Standard Zone have been

recognized in calcareous clays of the Berriasian–Valanginian boundary sequence in the Feodosiya district (eastern

Crimea). The ammonite Leptoceras studeri (Ooster) suggests Late Berriasian to Early Valanginian age. Geomagnetic

polarity indicates M16–M14r magnetozones. Therefore, the base of the Valanginian sequence in eastern Crimea should

be placed within the M14r magnetozone.

Keywords: Mountainous Crimea, Berriasian, Valanginian, ammonites, biostratigraphy, magnetostratigraphy,

geomagnetic polarity, correlation.

Introduction

The matter of fixing the Berriasian–Valanginian boundary in

the Tethyan super-region has not been settled up to now. This

is accounted for by ambiguous data on ammonite occurrences

in the boundary interval. The authors have earlier considered

the background of the problem (Arkadiev et al. 2016). In the

current western Tethyan zonal ammonite scale, the Otopeta

subzone is regarded as the upper subzone of the Boissieri zone

(Reboulet et al. 2014). At the Brussels Congress (Bulot 1996),

it was decided to draw the Berriasian–Valanginian boundary

in accord with the first occurrence of Calpionellites darderi

(Colom) at the base of the Calpionella E zone. It is at about

this level that the typically Valanginian species Tirnovella

pertransiens (Sayn) first appears. Analogous data has recently

been acquired from examination of the Berriasian–Valanginian

sections in Bulgaria (Petrova et al. 2011).

In the early publications on Mountainous Crimea,

Valanginian ammonite occurrences were recorded in the lists

of clays from the Novobobrovsk “series” where developed in

south-western Crimea, resting on underlying Tithonian and

Berriasian beds with a substantial stratigraphic break. These

ammonites were: Kilianella roubaudiana (d’Orb.), Neocomites

neocomiensis (d’Orb.) (Lysenko 1964; Astakhova et al. 1984).

The south-western Crimea is the only place provided with

the Valanginian zonal scale (Baraboshkin & Yanin 1997;

Baraboshkin & Mikhailova 2000).

The aim of this work is to study the Berriasian–Valanginian

boundary in the bio- and magnetostratigraphic data.

Location of the studied sections

Continuous Berriasian–Valanginian sequences are known

only from the Feodosiya district of eastern Crimea. In 2009–

2015, the authors of the present paper made thorough bio- and

magnetostratigraphic examinations of the Zavodskaya Balka,

Koklyuk and Sultanovka sections (Fig. 1). The Zavodskaya

Balka profile is in an active clay quarry in the northern suburbs

of Feodosiya. Results on the Berriasian at Zavodskaya Balka

have been published earlier (Arkadiev et al. 2010, 2015;

Guzhikov et al. 2014; Arkadiev 2015). In 2015, the overlying

Berriasian–Valanginian boundary interval in that section

was sampled (outcrop 3058, coordinates: N 45°01’49.1”,

E 35°20’59.5”). The examination results are presented in this

paper. The profile at Koklyuk (outcrop 3030: N 45°00’08.5”,

E 35°12’27.5”; outcrop 3060: N 45°00’08.6”, E 35°12’31.3”)

lies near the village of Nanikovo, in ravines on the slopes of

Koklyuk Mountain. The Sultanovka locality (outcrop 2926:

N 45°00’09.9”, E 35°17’38.2”) lies near the village of

Sultanovka (Yuzhnoye), in the core of the Sultanovka

syncline.

Geological setting

The geological structure of eastern Crimea was studied in

detail by M.V. Muratov (1937), who developed a tectonic map

of the region and singled out the Feodosiya block. Within that

block, he recognized the Tepe-Oba, the Sultanovka and

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the Dvuyakornaya Valley synclines, affecting Upper Jurassic–

Berriasian carbonate-clay rocks. The beds are complicated

by plicative (folds) and disjunctive (faults) dislocations.

Many of those are hard to fix in homogenous clay series.

In the context of the present-day concepts, the study area

is a part of the Orta-Syrt tectonic cover (Kazantsev et al.

1989).

Sediments are represented by monotonous grey clays with

rare intercalations of marls and limestones.

Biostratigraphic and palaeomagnetic methods

Macrofauna (ammonites, belemnites, aptychi etc.) were

collected throughout the section. In addition, samples were

taken on microfauna (foraminifers, ostracods) and palyno-

morph (dinocysts). Foraminifera, ostracods and dinocysts are

described in a separate article (Savelieva et al. 2017).

Oriented masses of clay were selected from 146 strati-

graphic levels in the examined sections (Figs. 2, 3, 4); the

spacing between varied from 0.3 m to 0.6 m (generally 0.5 m).

Three or four 2-cm cubes were sawn out of each lump and

subjected to a standard complex of palaeo- and petromagnetic

examinations: magnetic cleaning with alternating magnetic

field in a LDA-3 unit, remanent magnetization (J

) measure-

ment in a JR-6 spin-magnetometer, magnetic susceptibility

(К) and its anisotropy measured in a MFK1-FB kappabridge,

and thermomagnetic analysis (ТМА) with a TAF-2 device

(ferromagnetic fraction thermoanalyser — the device for

recording the change in magnetization from sample heating to

700

C), and magnetic saturation experiments with the sub-

sequent determination of the saturation field (H

), remanent

satu ration magnetization (J

) and remanent coercivity (H

Magnetic saturation was acquired with a controllable electric

magnet with a maximum field strength of 700 mT.

Analyses of the data on anisotropy of magnetic suscepti-

bility (AMS) and the component analyses were performed

using, respectively, Anisoft 4.2 and Remasoft 3.0 software.

The examinations were carried out in the petrophysics labo-

ratory at the Geology Faculty of Saratov University.

Biostratigraphy

Ammonites, aptychi and belemnites

V.V. Arkadiev was the first to find the Upper Berriasian–

Lower Valanginian Leptoceras studeri (Ooster) ammonites

(Fig. 5 A) in the vici nity of Sultanovka (site 2926) (Arkadiev

et al. 2011). No ammonites assignable to the Valanginian have

been found in the Koklyuk or Zavodskaya Balka sections, but

the microfaunal (Savelieva et al. 2017) and magnetostrati-

graphic data suggest the presence of Lower Valanginian beds

there.

Some important Upper Berriasian ammonite finds were

previously made by the authors at Zavodskaya Balka and

Koklyuk. In 2009, the Neocosmoceras euthymi (Pictet)

(Fig. 5 B, C, D, E), Fauriella cf. boissieri (Pictet) (Fig. 5 K) and

Malbosiceras malbosi (Pictet) (Fig. 5 F) ammonites were

found for the first time in the Zavodskaya Balka profile. In

2014, in the same section, above the levels with Neocosmoceras,

the genus Riasanites was found, initially defined as Riasanites

sp. (Arkadiev 2015). Additional collecting was carried out in

2015, and some good specimens were identified as Riasanites

crassicostatum (Kvant. and Lys.) (Fig. 5 H, I, J). At Zavod-

skaya Balka, a Berriasella callisto (d’Orb.) (Fig. 5 G) was

found above levels with Riasanites crassicostatum.

In the course of examining the Koklyuk section in

2014–2015, Neocosmoceras euthymi (Pictet) specimens were

found for the first time, and aptychi and belemnites

(Didayilamellaptychus sp. and Pseudobelus cf. bipartitus

Blainville) were found about 40 m above the Neocosmoceras

finds. The aptychi Didayilamellaptychus didayi (Coq.) and

D. angulicostatus (Pict. et Camp.) are also found in the

Sultanovka section, from the Nanikovo “series” clays

(Kozlova & Arkadiev 2003).

The ammonites recorded in this paper are kept in the Central

Scientific and Geological Survey Museum named after

F.N. Chernyshev (No. 13175, 13220) and in the Palaeontology–

Stratigraphy Museum at Saint-Petersburg University (No. 381,

409).

Magnetostratigraphy

Finely dispersed magnetite was found to be the principle

carrier of J

in the Sultanovka formation clays at Zavodskaya

Balka (Arkadiev et al. 2010, 2015; Guzhikov et al. 2014) and

confirmed by the data of the present investigations at the

Koklyuk and Sultanovka sections. Magnetite can be diagnosed

by a magnetization drop in the TMA curves at temperatures of

about 578

°С (Fig. 6 A), and the presence of magnetically

‘soft’ phase is confirmed by the magnetic saturation data

(Fig. 6 B). Samples from Koklyuk and Sultanovka as well as

those from the Zavodskaya Balka are peculiar because they

contain iron hydroxides, which are detected by bends in the

plots of the TMA second derivative in the 100–200 °С (Fig. 6 A)

region at the first heating and the gentle increase of remanent

saturation magnetization (J

), up to 700 mT (Fig. 6 B).

- location of the examined sections

Yalta

Alushta

Sudak

Feodosiya

Kerch

Sevastopol

Simferopol

Black Sea

Azov Sea

Crimea

Nasypnoe

Yuzhnoe

Feodosiya

Nanikovo

Otvazhnoe

Klyuchevoe

Nasypnoe

site 3030 /

3060

site 3058

site 2926

3.5 km

Black Sea

Fig. 1. Location chart of the examined sections: Sultanovka (site

2926), Koklyuk (site 3030/3060), Zavodskaya Balka (site 3058).

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GEOLOGICA CARPATHICA

, 2017, 68, 6, 505–516

The character of the anisotropy of magnetic susceptibility

(AMS) in the uppermost part of the Zavodskaya Balka profile

is different from that in the underlying Berriasian beds.

The earlier-published data on the lower part of the section

(Guzhikov et al. 2014) in the stratigraphic coordinate system

records a distribution of projections of magnetic susceptibility

ellipsoids that is typical of the Upper Jurassic–Lower

Cretaceous clays in eastern Crimea (Bagayeva & Guzhikov

2014): the short axes projections (K3) tend to be clustered in

the centre of the stereogram, thus, indicating sediment forma-

tion in calm hydrodynamic settings, whereas the long axes

projections (K1) are arranged with a sublatitudinal direction,

generated by collisional compression (Fig. 7-1А and B). More

significant variance of K3 projections may be observed on the

stereoprojections, corresponding to the upper part of the sec-

tion (Fig. 7-2A, B). Such character of AMS may be related to

the viscous-plastic deformations in clay that could happen

during the diagenesis or are probably caused by landslide pro-

cess near the surface (Arkadiev et al. 2015, 2016). A similar

pattern is characteristic of the clay magnetic texture at Koklyuk

(Fig. 7-3A and B) and is probably accounted for by the same

causes. In this section, intense landslide dislocations can be

detected visually in the marl layers in the base of outcrop

3030. There is no reason to assume that the anomalous nature

of AMS in the studied sections is associated with mineralo-

gical effects, for example, with the presence of siderite,

because thermomagnetic susceptibility data (controlling of

phase transition of siderite to strongly magnetic magnetite at

a temperature above 350 °C) do not indicate the finely dis-

persed siderite in the clays.

A paradoxical AMS character was also observed in

Sultanovka. A peculiarity of the data in those sections, sam-

pled from three natural exposures in various limbs of the

Sultanovka syncline (Grishchenko & Bagayeva 2014), is that

distribution of the magnetic ellipsoid axes seems to be regular,

not in the stratigraphic coordinate system (Fig. 7-4B), but in

the geographical coordinate system (Fig.7-4A). In the latter, it

corresponds to the model of the deposits formed in calm

hydrodynamic conditions which were subsequently subjected

to weak tectonic compression (Bagayeva & Guzhikov 2014).

Samples

Stage

Subzone

Polarity

Zone

Substage

Lithology

Fauriella boissieri

crassicostatum

callisto

Berriasian

alangi- nian

Upper

Lower

10 m

D°

0 90

270

180

I°

-90

9 18 24 32 40

SI units

(10

)

-5

(10 А/ )

-3

Site

3058

Berriasella callisto

Riasanites crassicostatum

-1

-3

-4

-5

-2

Zavodskaya Balka section

Fig. 2. The Zavodskaya Balka (site 3058) magnetostratigraphic section of the Berriasian–Valanginian. Legend: 1, 2 — normal and reverse

geomagnetic polarity, respectively (in half of the column thickness – tentative determination of the polarity sign); 3 — no palaeomagnetic data

available; 4 — clays; 5 — ammonite finds. D and I — palaeomagnetic declination and inclination in stratigraphic coordiantes; K — magnetic

susceptibility.

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GEOLOGICA CARPATHICA

, 2017, 68, 6, 505–516

One may surmise that the Sultanovka syn-

cline represents a synsedimentary structure

formed at about the Berriasian–Valan gi nian

boundary. This is reasonable, because the end

of the Late Cimmerian folding event in

Crimea falls at the end of the Berriasian age

(Nikishin et al. 1997). Presumably, within

slightly lithified sediment with an anoma-

lously high water content, flat clay particles

with finely dispersed magnetite aggregated

on them, might remain during folding. This

accounts for the parado xical character of the

AMS anomalous character. Grishchenko &

Bagayeva (2014) earlier specified low clay

visco sity as the cause of the abnormal AMS.

Component analysis results are presented

in Fig. 8. It was impossible to recognize

a stable J

component characterized by maxi-

mum deviation angles of less than 15° in

some samples; their number did not exceed

5 % of the total amount of the palaeomag-

netic collection. According to Zijderveld

diagrams, in most cases, a two component J

composition is recorded: a low-coercivity

component that is disintegrated after 5–15 mT,

and a high- coercivity (stable) one, sustai ned

up to 35–50 mT (Fig. 8). J

directions close to

the high-coercivity compo nent vectors have

also been recognized after the control thermal

cleaning of duplicate cubes. Repro ducibility of the results

applying two different types of magnetic cleaning increases

the reliability of the acquired palaeomagnetic data.

Analysis of the palaeomagnetic data from outcrop 3058 in

the Zavodskaya Balka section shows that the inter-strata clus-

tering of the J

stable components in the lower parts of the

section, unaffected by landslides (Fig. 9 А, Table 1), is 3 to 4

times higher than in the highly deformed upper part of the

quarry (Fig. 9 B, Table 1). In the lower part of the section,

a clear tendency is observed of clustering into two groups on

the stereograms: in the N-NW rhumbs of the lower hemisphere

and in the SE sector of the upper hemisphere (Fig. 9 A

and B), corresponding to a normal geomagnetic field (N) and

reverse (R) polarities, respectively. In the uppermost beds of

the profile, the characters of many palaeomagnetic directions

are abnormal (e.g., negative dips with northern declinations)

(Fig. 9 B), which prevents any contemplations on the pola rity

direction, however provisional.

Nevertheless, analyses of the distributions of the magnetic

ellipsoid axes and palaeomagnetic vectors through the entire

Zavod skaya Balka section, with earlier data reconsidered

(Arkadiev et al. 2010, 2015; Guzhikov et al. 2014), reveal

a close relationship bet ween distortions of petromagnetic and

palaeomagnetic parameters (Fig. 10А). As an AMS “abnor-

mality” measure (Δ

AMS

) for each sample, the deviation of the

K3 projection from the K3 average direction in the lowermost

parts of the section (lower most Boissieri zone), probably

alanginian

Samples

Stage

Subzone

Zone

Substage

Lithology

Upper

Lower

(10 SI units)

-5

(10 А/ )

-3

Koklyuk section

-1

-4

-3

-2

Samples

Lithology

120 0

10 15 20

15 25

0.6 1.2

Neocosmoceras euthymi

Pseudobelus cf. bipartitus

Didayilamellaptychus sp.

euthymi

Boissieri

Occi

tanica

Jaco-

Berriasian

10 m

Site

3060

Site

3030

Malbosiceras cf. malbosi, Berriasella sp., F

auriella cf. rarefurcata

Fauriella sp.

Berriasella subcallisto

Spiticeras orientale, Pseudosub

planites lorioli

Samples

Stage

Zone

Substage

Lithology

Upper

Lower

SI units

(10

)

-5

(10 А/ )

-3

Sultanovka section

Ber-

riasian

Site

2926

10 m

Didayilamellaptychus angulicostatus

6.71

-
ois

sieri

Leptoceras studeri

Fig. 4. The Sultanovka magnetostratigraphic section of the Berriasian–

Valanginian. See Figs. 2, 3 for the Legend.

Fig. 3. The Koklyuk magnetostratigraphic section of the Berriasian-Valanginian.

Legend: 1 — marl; 2 — ankerite and siderite intercalations; 3, 4 — belemnite and

aptychi finds, respectively. See Fig. 2 for other explanations.

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non-affected by deformations during diagenetic processes,

because the maximum of the folding epoch falls on the end of

the Berriasian age (Nikishin et al. 1997) . The angle between

the stable component J

and the average palaeomagnetic

vector in the lowermost of the section served as the palaeo-

magnetic “abnor ma lity” measure (Δ

). The linear cor relation

coefficient between Δ

AMS

and Δ

, determined from 132 sam-

ples and equal to 0.35, is significant at the level of p = 0.001.

This means that

significant variance of K3

in the AMS stereo-

grams and low interlayer palaeomagnetic clus tering in the

uppermost of the Berriasian most probably resulted from the

same cause — viscous-plastic deformations at the end of the

Berriasian age (or deformation by landslides at the Quaternary)

Similar changes in the magnetic fabric and remanence of clays

due to the close interaction of weak tectonic deformation and

diagenetic processes are indicated in (Parés et al. 1999; Parés

Sample
2926/20

(А/m)

H (m )

0.04

0.08

0.12

0.16

0.2

0.4

0.6

0.8

-100

100

200

300

400

500

600 700

Sample 2926/20

Sample 2926/7

Sample
2926/7

Sample

3030/23

-0.5

0.5

1.5

2.5

-0.2

0.2

0.4

0.6

0.8

1.2

100

200

300

400

500

600 700

, d /d

(*10 A/m)

-5

second

heating

, d /d

(10 A/m)

-4

heating

2 heating

(A)

(B)

Before t.c.

After t.c.

Before t.c.

After t.c.

180

270

n = 300

180

n = 134

180

n = 97

180

( - )

2 A

( - )

1 A

( - )

4 A

( - )

4 B

(

)

3-A

180

n = 123

- 1

- 2

- 3

- 4

- 6

- 5

270

( - )

1 B

( - )

2 B

(

)

3-B

Fig. 6. Results of magnetic-mineralogical examinations: A — The curves characterizing dependence of the magnetization on temperature

(dotted line) and second derivatives of these curves: the wide curve corresponds to the first heating, the thin curve is related to the second.

B — The curves of magnetic saturation.

Fig. 7. Anisotropy of magnetic susceptibility: 1-А, B — the lowermost of the Zavodskaya Balka section (Guzhikov et al. 2014, site 2900);

2-A, B — the uppermost of the Zavodskaya Balka section (site 3058); 3-А, B — Koklyuk (sites 3030 and 3060); 4-А, B — Sultanovka

(site 2926). Legend: 1, 2 — projections of the long (K1) and short (K3) axes of magnetic ellipsoids, respectively; 3, 4 — K1 and K3 average

directions respectively; 5, 6 — confidence ellipsoids for K1and K3 respectively, n — the number of samples.

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2926 /

J
/

= 2.73e

-3

3058 /

Down

Unit

3.40e

-3

J
/

= 25.4e

-3

3058 / 32

Down

Unit

322.e

-6

J
/

= 2.53e

А/

-3

3058 / 40

Down

Unit

419.e

-6

J
/

= 2.56e

-0

3058 / 10

Down

Unit

509.e

-6

J
/

= 2.62e

-3

()

( C

)

3060 /

Down

Unit

184.e

-6

J
/

= 1.02e

А/

-3

()

3030 /

Down

J
/

= 1.03e

-3

Unit

203.e

-6

Down

Unit

389.e

A/m

-6

Down

Unit

263.e

A/m

-6

J
/

= 1.34e

A/m

-3

2926 /

Before t.c.

After t.c.

Before t.c.

Fig. 8.

Component

analyses

results

for

the

Zavodskaya

Balka

(A,

Koklyuk

(С

) and

Sultanovka

) sections.

From

left

right:

stereographic

projections

changes

the

course

magnetic

cleanings

diagrams

Zijderveld,

thermal

demagnetization

graphs.

Legend

projections

the

directions:

—

the

lower

and

the

upper

semispheres

respectively;

3, 4 — on the horizontal and the vertical planes respectively

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, 2017, 68, 6, 505–516

( )

- 1

270

Before t.c.

After t.c.

180

Before t.c.

180

270

2004 and others). Therefore we think, ChRM directions in the

uppermost of Zavodskaya balka section may be reasonably

used for polarity sign determinations after having turned them

through an angle equal to the angle of the K3 deviation from

the average direction of the magnetic ellipsoid short axes.

We think, the magnetic polarity interpretation of the data for

Koklyuk and Sultanovka clays premature, because, for the

time being, there is no satisfactory explanation of all the fea-

tures of their magnetic textures. Despite the fact that in

Koklyuk a significant relationship between the Δ

AMS

and Δ

the level of p = 0.05 (Fig. 10B) has been revealed, also.

Reversal tests (McFadden & McElhinny 1990) were nega-

tive in the uppermost of Zavodskaya Balka, and fold test

results (McFadden 1990) were either incorrect or they indi-

cated the presence of a post-folding component.

The negative reversal test does not contradict the hypothesis

of magnetization ancient age, because it may be explained by

distorting of palaeomagnetic directions due to the clay visco-

plastic deformations (or mineralogical effects of AMS coupled

with remagnetization).

If the model of the formation of the remenence due to the

close interaction of weak tectonic deformation and diagenetic

processes at the top of the Zavodskaya balka section is valid,

then the negative results of the reversal test are natural.

We carried out a magnetic polarity interpretation of the

data in the assumption that for weak deformations the magne-

tization vector is distorted by no more than a few tens of

degrees.

The data thus acquired (Figs. 2–4) supply a number of

indicators of primary magnetization (Van der Voo 1993;

Zhamoida et al. 2000; Guzhikov 2013): (1) determinations of

different polarity signs are regularly grouped throughout the

sequence, making large N- or R-magnetozones; (2) polarity

sign is indifferent to lithological composition, since hetero-

polar magnetozones are recognized within a homogeneous

clay sequence; (3) palaeomagnetic structures in the examined

sections are in conformity one another (Galbrun et al. 1986;

Aguado et al. 2000; Ogg & Ogg 2008; Grabowski et al. 2016;

Satolli & Turtù 2016) (Fig. 11).

Thus, the entire set of acquired data does not fit into the

framework of rock remagnetization theory, but may conform

to a model of magnetization development in partially lithified

sediment in the course of synsedimentary deformations.

Therefore, in spite of negative fold and reversals tests, we

consider them fit to be used for magnetostratigraphic

interpretation.

Discussion

Finds of Leptoceras studeri at Sultanovka (site 2926) sup-

port the view that there are Lower Valanginian beds present

(Thieuloy 1966; Nikolov 1967; Company & Tavera 1985;

Arkadiev et al. 2011). Neocosmoceras euthymi, Fauriella cf.

boissieri and Malbosiceras malbosi, found at Zavodskaya

Balka, characterize the Euthymi subzone of the Upper

Berriasian Boissieri zone (Arkadiev et al. 2010). This allows

comparison of those levels with the Paramimounum subzone

in France etc

(Le Hégarat 1973; Tavera 1985). Riasanites

crassicostatum, found in the higher part of the same section,

characterize the Crassicostatum subzone of the Boissieri zone

(Arkadiev et al. 2012). This subzone correlates with the lower

part of the Picteti subzone of the Boissieri zone in the

Mediterranean Tethys. The species R. crassicostatum was pre-

viously known only from the Berriasian of the central Crimea

(Kvantaliani & Lysenko 1982). The Callisto subzone was pre-

viously assigned to the upper Berriasian of France (Le Hégarat

Fig. 9. Stereoprojections of the J

stable components:

А, B — Zavodskaya Balka, outcrop 3058 (the lowermost and

the uppermost parts of the section respectively — should be before

and after tectonic corrections. Legend: 1 — average direction of the J

stable components. See Fig. 8 for other symbols.

Table 1: Statistical palaeomagnetic characteristics of the examined

sections. Legend: Before t. c. — before tectonic correction;

After t. c. — after tectonic correction; n – number of samples in the

selection;

Dec/Inc — average palaeomagnetic declination / inclina-

tion; k — palaeomagnetic precision parameter; α

— radius of the

vector confidence circle.

Polarity

Dec

/ Inc

3058

Uppermost

before t.c.

337.2 / 62.8

8.7

13.7

73.3 / −34.2

6.8

38.0

after t.c.

17.4 / 31.3

11.1

12.0

127.3 / −55.2

6.8

38.0

Lowermost

before t.c.

338.0 / 58.1

47.4

4.8

111.2 / −46.0

16.4

23.4

after t.c.

16.1 / 43.3

48.5

4.7

144.6 / −60.8

22.9

19.6

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AMMONITES AND MAGNETOSTRATIGRAPHY OF THE BERRIASIAN–VALANGINIAN BOUNDARY (E. CRIMEA)

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, 2017, 68, 6, 505–516

& Remane 1968). A.Y. Glushkov earlier (1997) proposed the

distinction of a Berriasella callisto zone in the Berriasian of

Crimea, but without proper grounds at that time, however.

Discovery of that species in the continuous section in eastern

Crimea makes it possible to reconsider Glushkov’s chart and

to recognize a Callisto subzone. This may be correlated with

the upper part of the Picteti subzone, the Alpillensis subzone

and probably with the Otopeta, since in Spanish sections

B. callisto is known from the Otopeta subzone (Tavera 1985).

Obviously, the same Callisto subzone may be traced into the

North Caucasus (Sey & Kalacheva 2000).

Specimens of Neocosmoceras euthymi from Koklyuk sug-

gest the presence of the eponymous subzone of the Boissieri

zone.

The belemnite P. bipartitus has traditionally been regarded

as a Valanginian marker, but the recent study of the occurrence

of that species in the Río-Argos section in Spain has shown its

stratigraphic range to comprise the Upper Berriasian (the

Picteti subzone) to the Lower Valanginian (the Pertransiens

zone) (Janssen 2003). Aptychi, D. angulicostatus, from

Crimea and Spain have been described from the Upper

Hauterivian and D. didayi from the Valanginian (?) of Crimea

and the Valanginian–Lower Hauterivian of the Mediterranean

region (Kozlova & Arkadiev 2003; Vašíček et al. 2015). On

the whole, belemnites and aptychi indirectly confirm the iden-

tification of beds attributable to the Valanginian Stage in the

examined sections.

The set of palaeontological data allows reliable identifica-

tion of the magnetozones M16n, M15r, M15n and M14r within

the complicated alternating palaeomagnetic zonation of the

Zavodskaya Balka sequence (Arkadiev et al. 2010, 2016;

Guzhikov et al. 2014) (Fig. 11). Since the Neocosmoceras

euthymi subzone is the age analogue of the lower

Paramimounum subzone of the Boissieri zone (Arkadiev et al.

2010; Guzhikov et al. 2014), the lower reverse-polarity mag-

netozone in the Zavodskaya Balka (site 2900) should corre-

spond to M16r. Discovery of Berriasella callisto (Arkadiev

et al. 2016) in the topmost reversely magnetized beds

of site 3058 allow us to regard them as being not younger

than M14r.

Comparison of the Zavodskaya Balka palaeomagnetic

record with current notions of magnetozone, calpionellid and

ammonite subzone interrelations in the Berriasian–Valanginian

boundary interval (Aguado et al. 2000; Ogg & Ogg 2008;

Grabowski et al. 2016) confirms the correlation of the Euthymi

and Paramimounum subzones, and does not contradict the

correlation of the Crassicostatum and Picteti subzones, but

leads to the conclusion, that only the lower part of the

Crassicostatum subzone may correspond to the Picteti sub-

zone. In any case, the Crassicostatum subzone, the whole of it

or just the upper part, should be correlated with the Alpillensis

subzone, because the finding of R. crassicostatum (Fig. 11) is

associated with the analogue of the M15r chron, peculiar for

this Tethyan subzone. The Callisto subzone in Crimea in terms

of palaeomagnetic correlation (Fig. 11) should correlate with

the Otopeta subzone, but the uppermost of the Crassi-

costatum subzone (Fig. 11) may correspond to the lowermost

of the Otopeta.

Regrettably, solitary ammonite finds do not allow unambi-

guous conclusions, but the outlined version of scale compa-

risons is a first attempt at a comprehensive (bio- and

magnetostratigraphic) Upper Berriasian correlation from

Western Europe to Crimea. We hope it will be fully worked

out in the near future.

Conclusions

In the Zavodskaya Balka section, Upper Berriasian biostra-

tigraphic subdivisions have been recognized for the first time

in a continuous succession: the Euthymi, Crassicostatum and

Callisto subzones and magnetozone analogues from M16n to

Fig. 10. Graph of the angular distance of the short axes projections from the projection average direction K3 (Δ

AMS

) and the angular distance of

palaeomagnetic direction J

against the average direction of stable component J

(Δ

) for the Zavodskaya Balka (А) and the Koklyuk (B)

sections. Average directions of the K3 projections and of the J

stable components in the Zavodskaya Balka are taken from (Guzhikov et al.

2014). Legend: 1 — the lowermost part of the Zavodskaya Balka section: outcrops 2900, 2925, 3032, 3031 (Guzhikov et al. 2014; Arkadiev et

al. 2015); 2 — the lowermost part of the outcrop 3058; 3 — the uppermost part of the outcrop 3058.

514

ARKADIEV, GRISHCHENKO, GUZHIKOV, MANIKIN, SAVELIEVA, FEODOROVA and SHUREKOVA

GEOLOGICA CARPATHICA

, 2017, 68, 6, 505–516

Composite section

2009

year

2010

year

2014

year

2015

year

Zavodskaya Balka section

Samples

Fauriella cf. boissieri,

Neocosmoceras euthymi,

Malbosiceras malbosi

Riasanites crassicostatum

Pseudobelus cf. bipartitus

Berriasella callisto

Site

3031

Site

2925

Site

3032

Site2900

M16n.1r

“”Feodosiya

2014

year

Site

3030

Site

2926

Site

3058

Neocosmoceras euthymi

Malbosiceras cf. malbosi, Berriasella sp., Fauriella cf

. rarefurcata

Fauriella sp.

Berriasella subcallisto

Berriasella sp., Spiticeras orientale

Leptoceras studeri

M12

1А

M10N

M10

M13

M12

M14

M15

M16

Geomagnetic Polarity

ime

(GPTS)

Scale

(Gradstein et al., 2012)

140

135

Age [Ma]

Valanginian

Hauteri-

vian

Berriasian

Zone

Subthurmannia

boissieri

Subthurmanni

occitanica

Th.

otopeta

Ml.

parami-

mounum

Be.

picteti

Ti.

alpillensis

Tirnovella

pertransiens

Busnardoites

campylotoxus

Saynoceras

verrucosum

Neocomites

peregrinus

A. radiatus

Crioceratite

lory

nodosoplicatus

Criosarasinella

furcillata

M16r

M16n

M15r

M15n

M14r

Stage

Subzone

Fauriella boissieri

euthymi

Didayilamellaptychus sp.

Didayiamellaptychus angulicostatus

R. crassiocostatumB.callisto

Koklyuk

section

Sultanovka

section

201

1 year

Polarity

chron

Polarity

chron

Polarity

Subzone

Zone

Stage

Valanginian

Berriasian

Tintinnopsella

D 1

Calpionellopsis D

D 2

D 3

Occitanica

Callisto

Privasensis

Dalmasi

Paramimounum

Picteti

Boissieri

Polarity

Ammonites

Calpionelles

Berriasian -

Valanginian

meters

Berriasian stratotype

(Galbrun et al., 1986)

Berriasian -

Valanginian

Fig. 1

Magnetostratigraphic correlation of the Berriasian–V

alanginian boundary interval in the Feodosiya district. See Figs. 2, 3, 4 for the Legend.

515

AMMONITES AND MAGNETOSTRATIGRAPHY OF THE BERRIASIAN–VALANGINIAN BOUNDARY (E. CRIMEA)

GEOLOGICA CARPATHICA

, 2017, 68, 6, 505–516

M14r. With the magnetostratigraphic data considered, the

described interval correlates with the upper part of the

Paramimounum subzone and with the Picteti, Alpillensis,

Otopeta subzones of the Boissieri zone from the Tethyan

region (Aguado et al. 2000; Reboulet et al. 2014).

In the Koklyuk profile, the Upper Berriasian Euthymi

subzone was substantiated for the first time. Discovery of

Leptoceras studeri at Sultanovka allows the deposits to be

referred to the Upper Berriasian–Lower Valanginian. Disco-

very of the analogue of the M14r magnetic polarity zone in the

Koklyuk and Sultanovka sections allows us to use it for sub-

stantiating the level of the base of the Valanginian in eastern

Crimea, by the analogy with Western European sections where

the Berriasian–Valanginian boundary occurs in the lower part

of M14r.

Acknowledgements: The research has been carried out in the

framework of a government assignment from the Russian

Ministry of Education and Science in the field of scientific

work (assignment No. 1757). We thank the reviewers for the

comments made. We are grateful to E.V. Serebryakova for

translating the article into English.

References

Aguado R., Company M. & Tavera J.M. 2000:

The Berriasian–

Valanginian boundary in the Mediterranean region: new data

from the Caravaca and Cehegı´n sections, SE Spain. Cretaceous

Res. 21, 1–21.

Arkadiev V.V. 2015: New occurrences of the genus Riasanites

(Ammonoidea) in the Upper Berriasian of the Eastern Crimea.

Contributions to current cephalopod research: Morphology, Sys-

tematics, Evolution, Ecology and Biostratigraphy. In: Leonova

T.B., Barskov I.S. & V.V. Mitta (Eds.):Proceedings

of confe-

rence (Moscow, 2-4 April, 2015). Paleontological Institute,

Moscow, 4, 109–111 (in Russian).

Arkadiev V.V., Bagayeva M.I., Guzhikov A.Yu., Manikin A.G.,

Perminov V.A. & Yampolskaya O.B. 2010: Bio- and magneto-

stratigraphy characteristic of the Upper Berriasian section

“Zavodzkaya balka” (Eastern Crimea, Feodosia). Bull. Saint

Petersburg St. Univ., Geology, Geography 7, 2, 3–16 (in Russian).

Arkadiev V.V., Rogov M.A. & Perminov V.A. 2011: New occurrences

of heteromorph ammonites in the Berriasian–Valanginian of the

Crimean Mountains. Paleontolog. J. 45, 4, 390–396.

Arkadiev V.V., Bogdanova T.N., Guzhikov A.Yu., Lobacheva S.V.,

Myshkina N.V., Platonov E.S., Savelyeva Yu.N., Shurekova

O.V. & Yanin B.T. 2012: Berriasian of Crimean Mountains. Pub

lishing house LEMA, Saint-Petersburg, 1–472 (in Russian).

Arkadiev V.V., Guzhikov A.Yu., Savelieva J.N., Feodorova A.A.,

Shurekova O.V., Bagayeva M.I., Grishchenko V.A. & Manikin

A.G. 2015: New data on bio- and magnetostratigraphy of Upper

Berriasian section “Zavodskaya balka” (Eastern Crimea, Feodo-

siya). Bull. Saint Petersburg St. Univ., Geology, Geography 7, 4,

4–36 (in Russian).

Arkadiev V.V., Guzhikov A.Yu., Grishchenko V.A., Manikin A.G.,

Saveľeva Yu.N., Feodorova A.A. & Shurekova O.V. 2016:

Berriasian–Valanginian boundary in the Crimean Mountains.

In: Michalík J. & Fekete K. (Eds.): XII

Jurassica Conference.

Workshop of the ICS Berriasian Group and IGCP 632. Field Trip

Guide and Abstracts Book. Smolenice, Slovakia, April 19–23,

2016. Earth Science Institute, Slovak Academy of Sciences,

Bratislava, 79–82.

Astakhova T.V., Gorak S.V., Kraeva E.Y., Kulichenko V.G., Permya-

kov V.V., Plotnikova L.F., Semenenko V.N., Barchenko O.I.,

Blagodarov M.I., Bugaets A.T., Bondarenko V.G., Borisenko

L.S., Vanina M.V., Vdovenko M.V., Voronov M.A., Gorbach

L.P., Grigoriev A.V., Gurevich K.Y., Dulub V.G., Isagulova E.Z.,

Korbut Y.B., Kotlyar O.E., Konenkova D.I., Makarenko D.E.,

Menkes M.A., Nerodenko V.M., Novik N.N., Naga V.I., Plakhot-

nogo L.G., Pyatkova D.M., Romanov L.F., Savron E.B. Slyusar

B.S., Sulimov I.N., Teslenko Y.V., Fedorov P.V., Tsegelnyk P.D.

& Yanovskaya G.G. 1984: Geology of shelf of the UkrSSR. Stra-

tigraphy (shelf and Black Sea coast). Naukova Dumka, Kiev,

1–184 (in Russian).

Bagayeva M.I. & Guzhikov A.Yu. 2014: Magnetic textures as indica-

tors of formation of Tithonian–Berriasian rocks of the Mountain

Crimea. Izvestiya of Saratov University. New. ser., Ser. Earth

Science. 14, 1, 41–47 (in Russian).

Baraboshkin E.Y. & Mikhailova I.A. 2000: New and poorly known

Valanginian ammonites from South-West Crimea. Bull. Inst.

Roy. Sci. Natur. Belgique. Sci. Terre 70, 89–120.

Baraboshkin E.Y. & Yanin B.T. 1997: The correlation of the

Valan gi nian of the South-Western and Central Crimea.

In: Geology Essays on the Crimea. In: Milanovsky E.E. (Ed.):

Proceedings of the Crimean geological scientific and educa-

tional center named after Professor A.A. Bogdanov. Moscow

State University, Geological Faculty Press, Moscow, 1, 4–26

(in Russian).

Bulot L. 1996: The Valanginian Stage. In: Rawson P.F., Dhondt A.V.

et al. (Ed.): Second International Symposium on Cretaceous

Stage Boundaries. Brussels, 1995. Bull. Inst. Roy. Sci. Natur.

Belgique. 66 (Supplement), 11–18.

Company M. & Tavera J.M. 1985: The Berriasian–Valanginian

Protancyloceratinae (Ancyloceratinae) of the Mediterranean.

Factors involved in its distribution [Los Protancyloceratinae

(Ancyloceratina) del Berriasiense–Valangiense en el Mediterra-

neo. Factores implicados en su distribution]. Cuad. Geol. 12,

157–167 (in Spanish).

Galbrun B., Rasplus L. & Le Hégarat G. 1986: Données nouvelles sur

le stratotype du Berriasien: corrélations entre magnétostrati-

graphie et biostratigraphie. Bull. Soc. Géol. France 8, 4,

575–584.

Glushkov A.Yu. 1997: Berriasellids of the Mountain Crimea and

justification of the General stratigraphic scale of the Berriasian

in the Crimea. Bull. Saint Petersburg St. Univ. 7, 2, 98–99 (in

Russian).

Grabowski J., Lakova I., Petrova S., Stoykova K., Ivanova D.,

Wójcik-Tabol P., Sobien K. & Schnabl P. 2016: Paleomag-

netism and integrated stratigraphy of the Upper Berriasian

hemipelagic succession in the Barlya section, Western Balkan,

Bulgaria: implications for lithogenic input and paleoredox

variations. Palaeogeogr. Palaeoclimatol. Palaeoecol. 461,

156–177.

Gradstein F.M., Ogg J.G., Smitz M.D. & Ogg G.M. 2012: A Geologic

Time Scale 2012. Elsevier, 1–1144.

Grishchenko V.A. & Bagayeva M.I. 2014: Anisotropy of magnetic

susceptibility of the boundary Berriasian–Valanginian interval

near village South (East Crimea) as an indicator of the relative

age of the last deformation of clays and their degree of plasticity.

Geophysical Bulletin. 6, 23–26 (in Russian).

Guzhikov A.Yu. 2013: Solving unsolvable problems in stratigraphy

(Comments to the paper “New data on the magnetostratigraphy

of the Jurassic–Cretaceous boundary interval, Nordvik Penin-

sula (northern East Siberia)” by V.Yu. Bragin, O.S. Dzyuba,

A.Yu. Kazansky & B.N. Shurygin). Russian Geology and

Geophysics, 54, 349–354.

516

ARKADIEV, GRISHCHENKO, GUZHIKOV, MANIKIN, SAVELIEVA, FEODOROVA and SHUREKOVA

GEOLOGICA CARPATHICA

, 2017, 68, 6, 505–516

Guzhikov A., Bagayeva M. & Arkadiev V. 2014: Magnetostrati-

graphy of the Upper Berriasian “Zavodskaya balka” section

(East Crimea, Feodosiya). Vol. Jurassica. 12, 1, 175–184.

Janssen N.M.M. 2003:

Mediterranean Neocomian belemnites, part 2:

the Berriasian–Valanginian boundary in southeast Spain (Río

Argos, Cañada Lengua and Tornajo). Scripta Geol. 126,

121–183.

Kazantsev Yu.V., Kazantseva T.T., Argavitina M.Yu., Arzhavitin P.V.,

Becher N.I., Terekhov A.A. & Popovych S.V. 1989: Structural

Geology of the Crimea. Bashkir sci. center, Ural branch USSR

Acad. Sci., Ufa, 1–152 (in Russian).

Kozlova N.V. & Arkadiev V.V. 2003: Tithonian–Lower Cretaceous

aptychi (Ammonoidea) of the Mountain Crimea. Paleontol. J. 4,

36–44 (in Russian).

Kvantaliani I.V. & Lysenko N.I. 1982: New Berriasian Ammonites of

the Crimea. Proc. Geol. Soc. Georgia. 9, 1–2, 3–12 (in Russian).

Le Hégarat G. 1973: Le Berriasien du Sud-East de la France.

Doc. Lab. Géol. Fac. Sci. 43, 1, 1–309.

Le Hégarat G. & Remane J. 1968: Tithonique supérieur et Berriasien

de la bordure cévenole. Corrélation des Ammonites et des

Calpionelles. Geobios 1, 7–70.

Lysenko N.I. 1964: To the stratigraphy of Tithonian–Valanginian

deposits in the southern edge of the Baydar valley, Crimea.

Reports Acad. Sci. USSR 159, 4, 806–807 (in Russian).

McFadden P.L. 1990: A new fold test for paleomagnetic studies.

Geophys. J. Int. 103, 163–169.

McFadden P.L. & McElhinny M.W. 1990: Classification of

the reversal test in palaeomagnetism. Geophys. J. Int. 103,

725–729.

Muratov M.V. 1937: Geological sketch of the Eastern tip of the

Crimean mountains. Proceedings of the Moscow Geol. Expl.

Institute 7, 21–122 (in Russian).

Nikishin A.M., Bolotov S.N., Baraboshkin E.Yu., Brune F.M., Ershov

A.V., Clouting S., Kopaevich L.F., Nazarevich B.P. & Panov D.I.

1997: Mesozoic–Cenozoic history and geodynamics of the

Crimean–Caucasus–Black Sea region. Bull. of Moscow State

University 4, 3, 6–16 (in Russian).

Nikolov T. 1967: Les ammonites Berriasiennes du genre Protolepto-

ceras Nikolov. Bull. Geol. Inst., Ser. Paleont. 16, 35–40.

Ogg J. & Ogg G. 2008: Late Jurassic (139–169 Ma time-slice).

http://www.nhm.uio.no/norges/timescale/5_JurCret_Sept08.pdf

Parés J.M. 2004: How deformed are weakly deformed mudrocks?

Insights from magnetic anisotropy. In: Martin-Hernandez F.,

Aubourg C., Jackson M. (Eds.) Magnetic fabrics: methods

and applications, vol 238. Geol. Soc. London, Spec. Publ.

191–203.

Parés J.M. van der Pluijm B.A. & Dinares-Turell J. 1999: Evolution

of magnetic fabrics during incipient deformation of mudrocks

(Pyrenees, northern Spain). Tectonophysics 307, 1–14.

Petrova S., Lakova I. & Ivanova D. 2011: Berriasian–Valanginian

boundary in Bulgaria. Review of the Bulgarian Geol. Soc. 72,

1–3, 91–97.

Reboulet S., Szives O., Aguirre-Urreta B., Barragán R., Company M.,

Idakieva V., Ivanov M., Kakabadze M.V., Moreno-Bedmar J.A.,

Sandoval J., Baraboshkin E.J., Çağlar M.K., Fözy I.,

González-Arreola C., Kenjo S., Lukeneder A., Raisossadat S.N.,

Rawson P.F. & Tavera J.M. 2014: Report on the 5

International

Meeting of the IUGS Lower Cretaceous Ammonite Working

Group, the Kilian Group (Ankara, Turkey, 31

August 2013).

Cretaceous Res., 50, 126–137.

Satolli S. & Turtù A. 2016: Early Cretaceous magnetostratigraphy of

the Salto del Cieco section (Northern Appenines, Italy). News

letters on Stratigraphy 49, 2, 361–382.

Savelieva Yu. N.,

Shurekova O.V., Feodorova A.A., Arkadiev V.V.,

Grishchenko V.A., Guzhikov A.Yu. & Manikin A.G. 2017:

Microbiostratigraphy of the Berriasian–Valanginian boundary in

the eastern Crimea: foraminifers, ostracods, organic-walled

dinoflagellate cysts. Geol. Carpath. 68, 517–529.

Sey I.I. & Kalacheva E.D. 2000: Biostratigraphic analysis and cor-

relation issues. Ammonites. In: The Berriasian of Northern Cau-

casus (Urukh section). VNIGRI, Saint-Petersburg. 20–31.

Tavera J.M. 1985: Los ammonites del tithonico superior–berriasense

de la zona Subbetica (Cordilleras Beticas). Tesis Doctoral,

Universidad de Granada, Granada, 1–381.

Thieuloy J.-P. 1966: Leptoceras berriasiens du massif de la

Grande-Chartreuse. Trav. Lab. Géol. Grenoble. 42, 281–295.

Vašíček Z., Company M. & Měchová L. 2015: Lamellaptychi from

the Lower Cretaceous of south-east Spain (Murcia and Jaen

provinces). Neues Jahrb. Geol. Palaeontol. Abh. 276, 3,

335–351.

Van der Voo R. 1993: Palaeomagnetism of the Atlantic, Tethys

and Iapetus oceans. Cambridge University Press, Cambridge,

1–412.

Zhamoida A.I., Kovalevsky O.P., Koren T.N., Margulis L.S.,

Predtechensky N.N., Rublev A.G., Simikhatov M.A.,

Khramov A.N. & Shkatova V.K. 2000: Supplement to the

Stratigraphic Code of Russia. VSEGEI, St. Petersburg, 1–112

(in Russian).