Microfacies studies of carbonate

in the north of Faro,

rocks from Jurassic outcrops

Southern Portugal

NIKOLAUS MALCHUS '*'

JOCHEN KUSS **

" Sonderforschungsbereich 69, TV Berlin, Ackerstrasse 71-76, D-1000Berlin 65 (West Germany).

"" Technische Universitiit Berlin, Ernsr-Reurer-Plarz I, D-1000 Berlin10, (West Germany).

Ciencias da Terra (UNL) Lisboa N.O 9 pp. 105-1281988

figs. 1-7, 4 pl.

RESUMO

Palauras-cbaue : Microfdcies - JI/rdssico medio e superior - Algarve.

Apresenta-se 0 esrudo das microfacies de rochas carbonatadas do ] uras­sico medic e superior a Norte de Faro.

As rochas carbonatadas estudadas foram subdivididas em nove tipos demicrofacies (MF). As primeiras quatro sao representadas por sedimentosde plataforma carbonatada, caracteristicas de pequena profundidade. Saocornpartveis com as zonas de facies 6 a 8 de Wilson. Nao estao represen­tados fragmentos de facies recifais ou calcarios clasticos litorais. Estes tiposde MF reperern-se varias vezes no tempo sem, rodavia, apresentarem ciclici­dade. 0 desenvolvimento vertical das diferenres facies indica inrerdigitacdoapertada.

As MF sao tipicas de ambiences intertidais ou subtidais de pequenaprofundidade; tanto 0 quarrzo aucigenico como a fraca diversidade faunisticae floristica verificada em varias camadas apontam para a ocorrencia de areasresrritas rernporarias.

A ocorrencia de Dictyoconus cnyenxi LUCAS e de arnonires do Calovianonos niveis superiores ao con junto esrudado, sugerem, para esre, idadebatoniana.

Os ripos de microfacies 5 a 9 (Oxfordiano/Kimetidgiano) revelarn condi­coes de sedirnenracao muito diferenres ; calcarios recifais alrernarn comsedimentos pelagicos de maior profundidade. Os calcarios micriticos doOxfordiano sao caracrerizados por conterem inrercalacoes halodapicasenquanto que as do Oxfordiano/Kimeridgiano com «fabrics" ruberoliricasestao, as vezes, fortemente silicificadas.

S6 se atingiram estadios iniciais de crescirnento de «patch reef" duranteo desenvolvimento dos calcarios de pequena profundidade do Oxfordiano//Kimeridgiano.

RESUME

Mols-cles: Microfacies - fnrassiqne moyen et Sllperiellr - Algarve.

Les microfacies des roches carbonarees du ] urassique moyen et superieurde la region au Nord de Faro SOnt presenres ; ils ont ete reporres en neuftypes (MF) successifs.

Les 4 premiers correspondent a des sediments de plate-forme carbonateede faible profondeur er sont compatibles avec les zones 6 a 8 de Wilson.Les debris recifaux et les calcaires clasriques Iicroraux sont absents.Les differenrs types de MF se reperent plusieurs fois dans Ie temps

sans rourefois presenter une disposition cyclique. Ces MF sont rypiquesd'environnements interridaux ou subtidaux de faible profondeur. La pre­sence de quartz aurigene aussi bien que la faible diversite des faunes er desflores observees dans les differenres couches indique l'exisrence de bassinstemporaires ferrnes.

La presence de Dictyoconus cayeuxi LUCAS er d'amrnonires du Calloviendans les niveaux susjacentes suggere un age bathonien pour ces 4 premierstypes.

Les types suivants (5 a 9 = Oxfordien a Kimrneridgien) montrent desconditions de sedimentation tres differences: calcaires recifaux alternant avecdes sediments pelagiques de profondeur plus forte. Les calcaires micritiquesde 1'0xfordien sont caracterises par la presence d'intercalarions alodapiquesrandis que ceux de l'Oxfordien-Kimmeridgien avec «fabrics" tuberoliriqueSOnt parfois forrernenr silicifies.

Seules les premieres phases de croissance des «patch-reef" ont ete atteintpendant la formation des calcaires de faible profondeur de l'Oxfordien­Kimrneridgien.

ABSTRACT

Key-words: Microfacies - Middle and Upper [urassic - AlgarlJe.

The Middle and Upper ] urassique limestones investigated were sub­divided into nine microfacies (MF) types. The firsts four representBathonian sediments with shallow water characteristics typical for carbonateplatforms. They are comparable with Wilson's facies zones 6 to 8. Reef andreef debris, near-shore c1astic-dominared limestones are not present. TheseMF-types are reiterated several times withour cyclicity. The vertical deve­lopment of the differentiated facies units indicates a close interfingering.

The microfacies data are typical of inter to shallow subtidal environ­ments; both authigenous quartz and low faunal and floral diversity ofseveral layers point to temporary restricted conditions.

The occurrence of Dictyoconns cayeuxi LUCAS and Callovian ammonitesfrom the above lying strata argue for a Bathonian age.

The MF-types 5-9 (Oxfordian-Kimmeridgian) show completely differentsedimentation conditions. Fully marine nearshore recifal limestones alter­nate with pelagic sediments formed at deeper shelf areas. The pelagicmicritic limestones of Oxfordian age are characterized by allodapic inter­calations whereas the Oxfordian/Kimmeridgian limestones with tuberolithicfabrics often show intensive silifications,

Only initial patch reef growth-stages were reached during the deve­lopment of the Oxfordian and Kimmeridgian shallow water limestones.

107

1. INTRODUCTION

There are onl y two broader Jurassic outcrops of signi­ficance in Portugal:

a) The Lusitanian basin in the North between Aveiroand Setubal;

b) A small ribbon stretching along the southern coastfrom Sagres to Vila Real de St . Antonio in theAlgarve area (fig. 1).

(A smaller outcrop exists between both near San­tiago de Cacern).

Algarve. The oldest strata in the eastern part are of Batho­

nian age. The carbonate rock column in the area inves­

tigated (about 10 ken north of Faro) stares with Bathonian

oolitic limestones representing the core of the west-east

striking Guilhim upfold ; they are flanked by Callovian to

Kimmeridgian marls and limestones (fig. 2). The limestones

here are exclusively shallow water deposits (representing the

eastern flank of the Portuguese trough) in contrast to

contemporaneous sediments of the western Algarve.

Fig. 1 - Distribution of the most important stratigraphic units of SouthernPortugal. Small square north of Faro indicates the mapped area (see fig. 2).T=Tertiary, K = Cretaceous , J = Jurassic, TR = Triassic, P= Paleozoic

The first comprehensive studies concerning the Mesozoicof Portugal were published by P. CHOFFAT (1880, 1883­1887, recent literature has been summarized by ROCHA,1976). The works of J. CH. PRATSCH (1958), R. B.ROCHA (976) and of B. MARQUES (1983) concernspecially the Algarve area.

The Lower Jurassic sediments consist of dolomites ofSinemurian age, ending with Portlandian limestones ordolostones. They are exposed in the western part of the

Q. QbQaClJ5J4-5J 4b,J4d

J3-4JZcJZbJZa

HolocenePh I s toceneLover CretlceousPorUand1lnPortllndlln/Klmm.Klmmerldg1lnKlmm./Oxford1lnClll ov1lnLover to Middle BlthonlanBljoc1ln

strutStra t. boundl ryflul t

109

radial structures with diagenetic alterations ; theradial elements were interpreted to be original Stru­ctures , based on comparison of their microstructurewith other descrip tions e. g . L. SIMONE (974),P . HELLER & aI, (980), P . SANDBERG (975).

b) Tangential ooids with radial substructure Tn.-ooids(PI. 1, fig . 2) : diameter, roundness and sphaericityof these ooids proove a formation under relativel yagitated water energies, as occurs in oolithic shoals(FLUGEL , 1982). The primary tangential structureis overprinted by subtle radial elements. This ooidtype. often shows intensive micritization.

c) Micritic ooids M-ooids (PI. 1, fig. 5) : These arecompletely (or almost completely) micritized ooidsof the TR-types , confirmed by morphologic compa­risons . They are a characteristic component type ofthe oopelsparites within the mixing zone.

d) Radial ooids R-ooids (PI. 1, fig . 7): This ooids arecharacterized by broad simple seams of prismaticcrystals with radial orientation. They are typicalcomponents of protected areas behind ooid bars andcan be compared with superficial ooids , as firstdescribed by L. ILLING (1954).

Fig. ;lb - Microscopic appearance of the four main ooid-types

e·""'·," . ,. .l 0 " ••

...: .

Ooid-types

RT-type TR·type M-type R-typeDe scrip tionParamete r

Diameter (mm) 0,3-0,5 0,4-1 ,0 0,4-1,0 0,3-> 1,0

Shape O~al-raund Predominantly Predominantly Variableround round

Sphaericity Law High High Law-High

Internal Radial Tangential Tangential Radialstructure subtangential subradial subradial

Number of 2, rarely Somemony 1-2la minae more (10)

Width of 40-70 5-15 20-100spa ritic la mina e micra~ micr on micron

Nucleus Peloid Peloid Divers

Fig. 3a - Summarized characrer istics of the four ma in ooid-rypes

Estoi....

b --=d Callovian

fM~;~~W:\Y~ Bathonian

o 4Km

8"

Fig . 2 - Geological map of th e investigated area between Faro (south)and S. Bras de Alporrel - modified after Carta Geol6gica de Porrugal,53-A Faro , 1985 . Bathonian section was raken near the arrow (l 19 m).Oxfordian/Kimmeridgian samples were taken from locations ind icated with

stars (0 )

2. DESCRIPTION OF THE NON-BIOGENIC BATHO­

NIAN COMPONENTS

§ Kimmeridgian

~ Kimm.lOxford.

_ Oxfordian

The Bathonian rocks investigated were sampled bed bybed ; the microfacies interpretation, based on both investiga­tions of thin-sections and acetate peels, resulted in a tenta­

tive facies model. The facial development of the youngerJurassic carbonates were also studied, but were not inte­grated in an extended model.

According to the classification of B. WILKINSON (985)

lillllllllllllll'~~!~===1~5~. these ooids are primary radial ooids with an original calcitic

fabric.

The description of non-biogenic components is based onthe nomenclature given by E. FLUGEL (1982). Ooids andoncoids were studied in detail:

Ooids: Four main types of ooids were disti nguished here(PI. 1, fig. 3, 4).

a) Radial ooids with tangential substructure RT-ooids:The RT-ooids represent a combination of primary

Oncoids: The oncoids were subdivided into two groups ,micritic oncoids (type I with Lm) and Bacinella-oncoids(types II-VI with Lo, Lob, Lg and Ld, all summarized infig.) The abbreviations stand for micritic laminae (Lrn),laminae with «birdseyev-structures (Lo), blistery laminae(Lb), granular laminae (Lg), laminae with domelike organicovergrowths (Ld), figured in PI. 1, fig. 6, PI. 4, fig. 1, 2, 3.

110

Oncoids are defined as biosedimentary structures, thatoriginated with the help of cyanobacteria (FLUGEL, 1982).Types II-VI re additionally formed by Bacinella irregularisand are therefore named Bacinella-oncoids. The morphologiccharacteristics of each type is drawn in fig. 4. They wereformed in subtidal environments with weak to moderatewater currents.

K. DAHAYANAKE (1977) described Bacinella-oncoidsfrom Kimmeridgian limestones and differentiated threemain types, each characteristic for different water depth.Though the morphologic characteristics are similar to thehere described oncoids, an environmental dependance, com­parable with K. Dahayanake could not be confirmed.

M. RAMALHO (1971) described Oxfordian/Kimmeridgianoncoids from Portugal and subdivided them in stromato­lithic structures, oncoids and cyanophycean lumps. Thelatter show more uniform structures with predominantlybirdseyes, possibly comparable to here described Lo-oncoids.

3. MICROFACIES TYPES OF THE BATHONIANLIMESTONES

Four subfacies-types were differentiated within the widelydistributed MF-type I, all representing deposits of Wilson'sfacieszone 6 (platform sands). They were distinguished as totheir variable contents of components (mainly different typesof ooids).

The limestones of MF 1/4 were interpreted as centraloolithic shoals, an assumption supported by the occurence ofexclusively RT-ooids, by their very good sorting and by thelow proportion of biogenic components. MF 1/1 and MF1/2 represent the lateral facies equivalents with mixing ofboth, shoals and the grapestone facies. MF 1/3 frequentlyshows resediments of all three other subfacies.

MF 1: Oolithic facies

MF 1/1: Oopelsparites with TR-ooids - grain/packstones(PI. 1, fig. 2).

The most frequent components are TR-ooids, followedby micritic ooids, ooids of the bahamite-rype, broken anddistorted ooids together with grapestones. The biogeniccomponents are recrystallized bivalves, fragments of echinidsand rare occurences of Dictyoconus cayeuxi LUCAS.

Though altered by neomorphic processes, an epitacticovergrowth of sparitic crystals is indicated by coarse blockycements. Broken, partly distorted ooids and detached ooidlamellae indicate an early diagenetic compaction. A youngercement generation was formed below the detached lamellaeand was subsequently leached out again, creating a cons­picuous secondary porosity.

MF 1/2: Oopelsparites of the mixing zone - grains tones(PI. 1, fig. 5).

Strongly micritized TR-, Rrooids and peloids occur;micritic and oolithic intraclasts are of subordinate impor­tance. Foraminifera of «type 1» Textularia sp., lnvolutina

sp., Placopsilina sp. occur together with Tubiphytes obscurus

MISIK, and fragments of porosrrornate algae. Larger bio­clasts were derived from bivalve shells and fragments ofechinids.

Within the neomorphic-sparitic groundmass, radiaxialfibrous dog-teeth cements and gravitatively reinforced faser

cements could be observed. Thin limonitic crusts occurtogether with brownish epigenetic dolomitrhomboeders.Both are parts of the matrix cements.

MF 1/3: Conglomeratic oointrasparites - grainstones.The composition of the components and neomorphic­

sparitic groundmass are the same as MF 1/2. Here addi­tionally well rounded clasts (several centimeters in diameter)occur, which contain the reworked component-assemblagesof MF 1/1 and 1/2.

MF 1/4: Oopelsparites - grain/packstones (PI. 1, fig. 3, 4).The main constituents are ooids of the RT-type together

with peloids, intraclasts and detrital quartz. They aretogether with textulariids and miliolids, Reophax sp. andwith rarely echinid fragments. The primary intergranularspaces (sometimes with geopetal internal sediments), werefilled with dolosparitic cements.

MF 2: I ntrapelmicrites with fenestral fabrics - bindstones

(PI. 1, fig. 1)

This faciestype with laminated fenestral fabrics in com­posed of micritic components, mostly algal peloids. BesidesR-ooids, fragments of mollusc shells and few foraminiferawere found. The laminated fabric is due to dark micriticlayers of sediment-binding algal structures. Both peloidalsediment and algal laminites are interrupted by verticaldessiccation fissures and variable forms of birdseye struc­tures. According to many authors (e.g. SHINN, 1983), thistype of sediment was formed in shallow subtidal/supratidalenvironments, corresponding to facies zone 8 - restrictedcirculation shelf and tidal flats (WILSON, 1975).

MF 3: Grapestonefacies

MF 3 was deposited in calm waters of the shallow sub­tidal, and interfingers with zones of more agitated water ofMF 3/2. Here the high diversity of organisms, the lack ofR-ooids and the predominance of sparitic interparticularfabrics indicate a normal marine deposition.

MF 3/1: Intrapelmicrites with quiet water ooids - bindstones.Peloids and light grey extraclasts are the main consti­

tuents of this subfacies. They occur in a micritic matrixwhich is partly altered to a microsparitic texture. Fewgrapestones and algal lumps occur. Nearly all componentsare surrounded by radial-oolithic cortices of the same type asknown from the R-ooids.

Fragments of echinids, gastropods and Cayeuxia sp. arevery rare.

MF 3/2: Intrapelsparites with Bacinella-oncoids - bind/grainstones (PI. 1, fig. 7).

Grapestones and lumps prevail within a micritic matrix,occurring together with R-ooids and extraclasts, TR-ooids,superficial ooids, and Bacinella-oncoids. Concerning thefossil content, a high diversity and a great number ofindividuals characterizes facies 3/2: Foraminifera «type 1»,«type 2», Haplophragmoides sp., Dictyoconus cayeuxi LUCAS,Textularia sp., Verneuilina sp., lnvolutina sp., sessile formsand undeterminable lituolids occur together with poros­tromate algae, different types of Cayeuxia sp., and Bacinella

irregularis RADOICIC, Thaumatoporella parvovesiculifera

RAINERI, Tubiphytes obscurus MISIK. Bioclasts of molluscs,

111

bryozoans, echinids and ostracodes furthermore contribute tothe sediment.

The former micritic groundmass is partly washed out.Vadose silts and coarse drusy neomorphous sparites indicatethat freshwater vadose diagenesis was active.

MF 4: Pelmicritic facies

MF 4/1: Oncopelmicrites with bioclasts - wackestones.Peloids, diagenerically altered RT-ooids R-ooids, M-ooids,

micritic intraclasts and lithoclasts (composed of oncoids andooids) occur. Among the oncoids types I-VI were formed(fig. 4). The following biota were found: Reophax sp.,textulariids, verneuiliids, trochamminids, involutinids,Placopsilina sp., foraminifera «type 2», Haplophragmoides sp.Besides them cyanophyceans, microproblematica such asTubiphytes sp., Problematicum A and Favreina sp. occur.Ruditic bioclasts consist of molluscs, brachiopods andechinids.

Echinids, bryozoans and foraminifera (textularians, lituolids)are of subordinate significance.

Many primary structures were overprinted by a strongdolomitization, which made classification very difficult.

MF 4/5: Oncopelsparites - grain/packstones (P. 1, fig. 6).This type is characterized by Bacinella-oncoids (types 1­

VI), peloids, intraclasts and coated grains on the one handand by foraminifera (clast of Dictyoconus, textulariids, lituo­lids) on the other. Gastropods are the most important nucleiof the oncoids.

A neomorphically altered microsparite forms up thegroundmass. It is interspersed with molds which were refil­led with vadose silt. Authigenic quartz is very frequent.

The depositional environment of the sediments of MF 4 isdue to unagited water, comparable to pool-like intraplat­form shallow basins, which were described by ]. KUSS(983) from Upper Triassic carbonates in the NorthernLimestone Alps.

4. DISTRIBUTION OF THE ORGANISMS

The micritic to microsparitic groundmass is penetrated bya network of stylolithic seams, from which fine limoniticconcretions start.

MF 4/4: Algal pelmicrites - bindstones.These rocks are made up of peloids, intraclasts, aggregate

grains, Cayeuxia sp., Thaumatoporella sp. and gastropods.

Fig. 4 - Sketches of the oncoid-types I-VI; abbreviations stand for:K = nucleus, Lm =laminae, Lo =birdseye-structure, Lob = blistery lamina,Lg =granular lamina, Ld =domelike biogenic overgrowth, Li = limonitic

particles

The distribution of biomorpha is of subordinate signi­ficance with regard to the microfacial subdivision of theBathonian section, as they do not exceed more than 3-7 %of the total volume. However some characteristic associa­tions enable a better interpretation of paleoecologic diffe­rences. The distribution of organisms is listed in Tabs. 1and 2; the following derivations are possible:

- Organisms as a whole show low to moderate diversi­ties. The most important components are foraminifera,echinids, molluscs, algae and microproblematica.

- Agglutinated lituolids and textulariids predominateamong the foraminifera. There are only rare miliolids,which indicate shallow shelf environments. Few nodosariidsonly occur within MF 4/1.

- Echinids occur in nearly all MF-types with changingvalues. They also occur together with authigenic quartzwhich were possibly formed within lagoonal/evaporiticenvironments. The mixing of stenohaline and hypersalineparticles is explained by the close facies-interfingering withrapid lateral and vertical changes.

- Concerning the extreme hypersaline conditions thegastropods are more resistant than lamellibranches. Theconspicuous predominance of gastropods (i.e. MF 3/2, 4/3,4/5) could be interpreted as an indication of a deteriorationof living conditions.

- Both porostromate and spongiostromate algae can bedifferentiated. Among the porostromata Cayeuxia sp. exclu­sively occur as allochthonous fragments. Spongiostromataoften occur together with microproblematics. They havetheir widest distribution within the grapestone facies andthe loferites.

- Dasycladaceans do not occur except few single frag­ments of Clypeina sp. and Terquemella sp.; they were des­cribed as typical shallow water indicators from differenttethyan Triassic, Liassic and Upper Jurassic localities(FLUGEL, 1982). The almost complete absence of thisgroup in the area investigated reflects the general scarcity ofdasycladacean algae within Dogger sediments (BASSOULETet al., 1978).

Three microproblematica were additionally described fromBathonian limestones, that could not be compared with others:

Lg

III

Ld VI

~P ' : : '"

\ .:.>;...::.::.:.'.~/.~ ..~.~.::.:.

II.

MF 4/3: Oncopelmicrites - wackestones.Besides micritic oncoids, peloids and aggregate grains

which are the main constituents, only rare organisms ­texrulariids, gastropods and echinids were found.

The groundmass is micrite with subordinate sparite;vadose silts were observed.

MF 4/2: Biopelmicrites - wackestones.The most frequent components are peloids followed by

foraminifera: «type 1», «type 2», Reophax sp., Haplopbra­gmoides sp., textularians, verneuilids, Dictyoconus cayeuxiLUCAS and lituolids, Nodosaria sp. and Lenticulina sp.

The pelmicritic groundmass can hardly been distinguishedfrom that of MF 4/1: here more authigenic quartz wasfound, and the participation of oncoids is much lower.

112

Tab. 1 - Distribution of the most important components, biota and sedimentological data which were taken into consideration for theclassification of MF-types 1-4

~components 1.1 1.2 1.3 1.4 2 3.1 3.2 4.1 4.2 4.3 4.4 4.5

ooids: TR 40 % • • - - - -RT - 13 % 18 % 40 % - - 10 %M -- - -- - -- • • - - - -R - - - - 80 % 10-35 % •

oncoids - - - - - - • • -- • - •aggregate grains • • • - • • • - • -- --peloids • • • • .. • • 6} • • • •coated grains • • • • - - • • - • • -intraclasts • • • • - • - • - • • •extraclasts - - -- - -- - • - - - -- --Ammodiscidae - • • • - - • - - - -- •("Type 1")Reophacidae - • • • - - .. • • • • -Lituolidae:

Placopsil ina - • • • - - • • • - • -"Type 2" - - - - - - • - - - • •Textulariidae - • CD • • - I) • • • • •Ataxophragmiidae - • • • • - 8 • • • • •Orbitolinidae:

"Dictyoconus" • - - -- - - • - .. - - •Involutinidae - • - • - - • • -- • • •Nodosariidae - -- - - - - - - • - - -not identified

foraminifera • • • - • • • • • • - •foraminifera/9 cm2 1 13 13 15 3/19 1 20 26 30 13 11 50

Porostroma ta • • • - - • • • - - • -Spongiostromata - - - - • • (0 -- - - - •Clypeina • • - - - -- - - • - -- -Terqueme11a - • - - - - - - - - - -Thauma topore11 a • -- - - - -- • - - -- • -Bacine11a - - - - -- - • CD - - - •Tubiphytes • • - - - - e e - - - -unknown algae - - - - - - - • • - - --other organisms:

bivalves • • • G • • 6) '. • - - -gastropods • • • • - • e • - • • •ostracods - - - - - - - • - • - -bryocoans - - - - - - • - - - • --brachiopods - - - - - - - • - - - -echinoderms • • • • - • • • - • • --Favreina - - - - -- -- - • -- - - --

dol.neo dol.neo- dol.neo- dol.neo- neospar dd vneo- dol.neo- micrit • ~ol.neo-groundmass partly micrit micrit micrit overprin

sparit sparit sparit sparit earlydia sparit sparit ted by spar i tgen. dol. dol.

size ofcomponents f.- m. f.- c. f.aren, - f.- m. f .are- f.- m. f.- m, f .are- f.aren. - f. aren. f.arero.- f .aren.arenitic arenitic ruditic arenitic nitic arenitic arenitic nitic ruditic rudit ic ruditic ruditic

roundness moderate moderate moderate good -- good good good -- good good- good- good - good - good moderate

grain/ grain/ grain/ grain/ mud/texture pack- grain- grain- pack- bind- pack- pack- wacke- wacke- wacke- wacke- wacke-

stone stone stone stone stone stone stonestone stone stone stone stone

113

Tab. 2 - Summarized presentation of all determined biota ranging from Bathonian to Kimmeridgian within Mf-rypes 1-9

xx

x

x

xx

xxxxxxxx

xxxxx

xx

ze:(I-tCl0:::ol.J...Xo

ze:(I-t

Zo:cl­e:(CO

Baeaanel/la sp. . ': ' .Pavreina ep, . . . . . . . . . .. . .. x

Echinoidea ....•........•........ '•.....•.... x

xxxx

Saooocoma sp• ••.••••••••.•.•••.••...••••.•••••••••••• xHolothuroidea ....•.......•................. x x

xx

Foraminifera:

Ammodiscidae:

Serpul ida .•.•..•................•..........••................•.••...Algae:

Dasycladacea: Clypeina sp..•.•••.••..•...•.•......•••.•. xTerquemel.la sp•••••••• ~ ••••••••••••••••••• x

Cyanophycea: caueuxia Sp. .........•.•........•••.... ..... xSpongiostromata .•....•......•.•..........•• x x

Solenoporacea: dive sp..............•........................ ~ ..•. xMikr6problematika: Tubiphytes obsaurus MISIK ..•........•. x x

BaaineZZa irreguZaris RADOICIC •......• xThawnatoporelZa parvovesiauZifera ,RAINERlx xProblematikum 2.. SENOWBARI-DARYAN .•....•••.••.••• x

x

"Typ 1" sp. indet xToZypClll'UTlina sp.. •..•••.••••.•••••.•••.••••• x

Reophacidae: Reophax sp. .. xLituoli.dae: "Typ 2" cf. Baplophraqmoidee sp..••...•..••• x

NautiZoaulina oolithiaa MOHLER •••.••.. ~r ••••••••••••• x xPseudoay~ina sp.•••••••••••••••.••••••••. x x xAnahispiroayalina lusitaniaa . EGGER •••.•••..•..•.•.••.•....••.•• x.HapLophraqmium sp• •••••••••••••••••••••••••••••.•••••• x xPlaaopei/ldna sp. •• 41 ••••••••••••••••••••••••• •x x x

Textulariidae: Textularia sp X X xAtaxophragmiidae: Vern.euiZina sp•.•.•..•.•........•..... x xTrocharmtntdaer -dtv. sp•.•••..•••..•..•.••.••...••...... xOrbitolinidae:"Diatyoaonus" aayeuxi .' LUCAS •. .•.....•...• xNubeculariidae: Nubeaulaxria sp.......•.......•..........•.•....... x

OphihaZrnidiwn sP• • •••••••••••••••.• III • • • • • • • • • • • • •• xNodophthaZmidiwn sp. x

Mi1i 01; dae: Quinque locu Zina sp. •- ' •••• III ••••••••••••• III •• Ill. xdive sp••••.•.•••••••••••••••••••••••••.•••• x x

Involutinidae: InvoZutina sp.•.•..•..........•..••.••... xTroahoZina alpina-elongata LEUPOLD xTrochol-ina sp. . .•.....•.•....•......•....•..•...... x x

Nodosariidae: Nodosaria sp.••......•....•........•...... xLeniricul.ina sp ..•......•..•...•..... .....•. X X x

Foraminifera: div. sp x x xPorifera: Hexactinellida ~ .•..•............••.....•... x xHydrozoa: E~lipsaatinia 'sp••..••••.••• Ill ••• Ill '. _._ ••••• 111 ••111 •••••••••••••••••••••••••• xAnthozoa: Thecoeni/lda sp.....•................................. •... x x

dive sp••••••••.•••••••••.•.••••..•.•••.•••••.•...•.•.••..• x xMollusca: Lamellibranchiata x x x

Amm6noidea:Lamell-Aptychus .•...•...•.•.......... xArtropoda: Ostracoda •.•. '.....•.•••..•.•.•.•....•...•...... xBryozoa ••..•............................•................. xBrach; opoda . .. xEchinodermata: Crinoidea x

114

a) Problematicum A - bowlike encrustations (PI. 4 , fig .10, 14). Ir often encrusts ooids and oncoids , and isformed by a halfmoon shaped spar itic dot 50-200/-tmin diameter which is embraced by an about 50/-tmthick m icritic envelope. It might be confused withforaminifers of the N ubecularia type . In contrast ,Problernaticum A yields only a single chamber with acharacteristic microgranulat wall structure; moreover ,it is much larger than Nabeculari« (occurrence withinMF 1,4) .

b) Problernaticum B (eKerrenalge», PI. 4, fig. 13): Th isstructure is formed by bricklike elements (40/-tmlong) which are linked at their small sides, thusforming chains with one above the other. They onlyappear in sponge-spicule limescones. Their outer shapeis reminiscent of bivalve shells, but the describedreticulate internal structure is either caused by diage­netic processes or by algal activity.

c) Problematicum C (PI. 4 , fig. 2): This form consists ofm icritic/sparitic intercalat ions with outer diameters of3-5 mm. N o criteria could be found co suggest parti­cipation of Bacinella sp . and T ubiphytes sp . ; cyano­phyceans probably produced these structures. (MF 4/2).

5. SPACIAL RELATIONS AND FACIES MODEL OFTHE BATHONIAN MICROFACIES TYPES

All four MF-types are characteristic formations of ashallow carbonate platform. Its distribution is limited to

areas which correspond to Wilson's facies zones 6 to 8.

Neither sediments of a platform slope nor of the uppermostinter and supertidal areas were observed . There are no indi­cations of a significant input of terri genous material. Th e

sediments nearest to the coast are formed by intrapelspariteswith fenestral fabrics (PI. 1, fig. 1) which are flankedseawards by pelmicrites .

At the outer seaward platform side , sedimentation starts

with an extended oolithic barrier which can be subdividedwith the help of different oolithic types. The follow ing

facies types can be traced from the seaward side cowards thecoast: Oolithic conglomerates with freshwater diagenesischaracterizing ep isodic fluctuations of the sea level. They are

interfingering with an rnixed -oolirhic facies (besides ooids,cortoids, intraelasts and micritized bioclasts occur). Furtheronto the coast bioclastic pelmicrites were deposited in

protected areas of FZ 7. Here oncoid-bearing pelmicriteswith grapestones , quitwarer-ooids and porosrromate algaewere formed within shallow basins and pools.

Different MF-types of facies zone 6-8 interfinger with inshort vertical distances, documenting rapid facies changes ;rhythmic cyelicities of the described microfacies types could

not be observed.

The tentative environmental model of fig. 6 is based on

both microscopic and field data: the vert ical sequence of theBathonian section (fig. 5) with rapid interfingering of ashallow carbonate platform. The spacial distribution of thedescribed MF-types is sketched (fig . 6).

~Loferite

MF1.4 L::l:J

Cross beddedoolithic limestone

Stylolites

Oolithic limestone

Icompact .

cavernous 1.1'\..11

Fig . 5 - Schemati c seccion of rhe Bachonian limestones north of Faro,compiled after field data and microscopic Investigations.

W Foraminifera 1~1 Oncoids

0 Echinoderms W t-ootas

[L] Lamel/ibranchs 0 R-Ooids

W Gastropods ~ Lumps

[£] Ostracods GI] Pseudopeloids

[L] Algae ~ Oolithic clasts

~ Porostromate EJ Quam detritus

[AJ Microproblematica~ Quarzt authigen

~ . j SpariticF?==Tl Limestone . . . .~ rmcnuc

o Dolomite

U(i) MF 1.2

it MF 1.1AQ Ij MF4.3 ·

1'f MF 4.3

US1

ret~--

f/OJ1l<. MF 4.2

..1-1'MF 3.1MF3.2

ff~ MF 4.4MF 2

MF2:Y'E. o MF 13

IIt1 MF 4.1

. ~.

~~~c~ ~ -n (;),.

M

~OJ- ..lliI

I <llID :)

'"I I

I

ICD LA-I. /I

'"I...1..,1 • 1am

~

I<JII~I c!OI_I

.1

~

E:!l? f!)~_ t!J(!)~~ '" ~Te e (!)

", .I.-t.JI e C!:lJ0 ".-;. VA' cip' . 010 0

o ~o v..::'M..II. ..-::;-

"e e e l!l,)a,;

10m

20m

30m

115

. I~}:..:;;:I Oolithic focies

6-~-j Mixed Oolithic focies

_ Gropeslone-focies

I~ Aol LF-Foc ies

I::::::;] Pelmicrite jSporite focies

Fig. 6 - Tentative environmental model of the carbonate platform during Bathonian time , showing the close interfingering of the described faciestypes 1-4 (signatures as fig . 5)

6. MICROFACIES TYPES OF THE OXFORDIANAND KIMMERIDGIAN

MF 5 ; Micrite-dominated pelagic mud-/wackestones (PI. 2,fig. 2, 3.

MF 5/1: Intrapelmicrites and dismicrites.The limestones of the Oxfordian/Kimmeridgian boundary

are characterized by pelagic sediments. Several hardgroundswhich were encrusted by serpulids are typical at the lowerpart , whereas rhythmic intercalations of granded grain-/packs tones (interpreted as allodapic limestones sensu MEIS­CHNER, 1964) characterize the Oxfordian micritic carbo­nates (PI. 2, fig. 3).

As regards the fossil content, both are nearly identical :Reophax sp., Placopsilin« sp. , Nubecularia sp., Tolypamminasp ., nodosariids and miliolids occur together with filaments,ostracodes, holothurids, crinoids , Saccocoma sp. Tubipbytessp . , spongiostromata and the finegrained debris of all men­tioned organisms.

The turbiditic layers are bedded or graded bioinrrasparites(grain-/packstones), which show a typical mixture of bothshallow marine and deep water elements. The followingorganisms could be determined: Haplopbragmium sp. , Nauti­locnlina oolithica MOHLER, Reopbax sp. , Nubecularia sp . ,Tolypammina sp. , Quinquelomlina sp. , Lenticulina sp. , togetherwith rexrulariids , filaments, ostracodes, lamellibranchs ,brachiopods, serpulids, echinids (mostly crinoids); fragmentsof unidentifiable corals and bryozoans occur with Thauma­toporella sp. and Tubipbytes sp.

Other components are peloids, micritic intraclasts, algalintraclasts , micritic oncoids and oncoids made up of red

116

algae. All these show bad sorting and roundn ess, often withgrading of those components which are arranged by currentprocesses.

The boundary between autochthonous and allochthonousparts is always very sharp . An erosive cutting of turb iditesin form of conspicuous bottom marks is visible at severalpositions in the section.

MF 5/2 : Intramicrites.They cons ist of intraformational breccias, which show

reworked micritic intraclasts , bedded within a micriticmatrix of the same pelagic habitus.

MF 6: Shallow subtidal and interdital carbonates

MF 6/1: Biomicritic boundsrones with LF-structures.Strongly recristallized biota are encrusted by thick spon­

giostrornare algae , which may also bind sandy particles,forming biosed irnentary structures. Several layers of thesedark micritic crusts (sometimes with fine lamination), showa conspicuous pattern of fenestral fabrics with oval-elongatedbirdseyes , which were partly leached out, creating a secon­dary porosity.

MF 6/2: Red algal oncosparires and rnicrites, wacke/grain­stones (PI. 2, fig. 5).

Two types of encrustation occur: the oncoids of type II

are made up of red algae, which encrust both Trocholina sp.and Nautiloculina sp.; they are very common within grain­stones. The oncoids of the micritic sediments yield frag­ments of echinids as nuclei, which also occur withoutencrustations.

and shells of molluscs are also present. There are no indicatorsof pelagic sedimentation.

Fig . 7 - Schematic section of the Bathonian-K immeridg ian sequence. Thestratigraphic subdivision is based on own observations on a neighbouringsection of B. MARQUES (1983), taken in the area of Moncarapacho. The

complete thickness is estimated 300-400 m (signatures see fig. 5)

Section Slage MALCHUS. 1984 MARQUES. 1983

Upper Kimmeridgian . no statement

~FIO til -7 7--5r ..;t.Li */ I /

~@a q lower Lowerq

Kimmeridgian Kimmeridgian.... MSF8.2~'c'T -if

.t:7

~@

Mf- @ Lower_I Kimmeridgian

v.2if---7-e

~

'0 ~a.

6 a.Upper Upper::>

Oxfordian Oxfordian-0

. . .. . · ""MSF 8.1

..., ~- .MF7 Upper

I 1-0> MF6 Oxfordian

I I @~ I -1 r---? - Middle

Oxford ian. _.-·1-·1-\ G Middle

- Oxfordian-1-1-1

~

'--':" I '~ I :I G{ 7

----(~

- - ~ Collovian

--:\ 01 61-0101 v

. , ~

V 0./0 @ e no statement

0/0 ~

"<!71 0 'S MF 1-5 '5-0

01 0 0\ ~

01 0 @ Bathonian

~1dZ9I 0 0or 0

.01 0

The second type consists of co-operating algal and fora­miniferal encrustations, forming irregular crusts of severalmm th ickness. Marly biogenic components yield a conspi­cuous late-diagenetic dolomit ization.

MF 7: R eef oid limestones - bound-/rudstones

MF 7/1 : Coral bafflestones of rhe Upper Oxfordian (PI. 2,fig . 4).

Corals of the Thecosmilia-type are th e most importantconstituents , which cannot be determined on species-levelbecause of their strong recrisrall izarion, S. ROSENDAHL( 1985) gave a summarizing description of Oxfordian/Kimme­ridgian corals from Algarve. The corals are often encrustedby Tubipbytes sp ., algae and foraminifera (Nubecularia sp.and Tolypammina sp.). Moreover, the corals and their debrisact as substrate for serpulids, bryozoans and Baccinella sp.The space between the coral branches has a pelmicriticcomposition with texrulariids, Nautiloculina sp., Quinque­loculina sp . , ostracodes, brachiopods and crinoids.

MF 7/2 : Frame-/rudstones of the Kimmeridgian.They are made up of predominantly reef-detritus ; primary

frame bui lders are hydrozoans (Ellipsactinia sp. together withother un identifiable species) and corals. Both act as subst ratefor encrusta tions of bryozoans, Tubiphytes/algae-associations,serpulids and sessile foram inifera (Tolypammina sp.); theform er framebu ilders show conspicuous borings and intenserecristallization. The matri x consists of pelmicrite/-sparitewith micritic intraclasts and reefoid bioclasts.

The following biota were recognized: textulariids, ver­neui liids , Haplophragmoides sp. , monaxone sponge spiculae,brachiopods, echinid-fragments, very fine networks of redalg al knobs, red algae wit h parallel tubes (70 P.ffi indiameter) and spongiostromate algae. Tubipbytes sp. andBacinella irregularis also occur.

MF 8 : Biomicrites of Upper Oxf ordian/Lower Kimme­ridgian - bioclastic wackestones.

MF 8/1 : Tuberolithic limestones with sponge spicules(PI. 2. fig . 9) .

Comparable facies types were described from Upper Juras­sic limestones from Southern Germany by G. FRITZ (1959) ,E. FUJGEL & T. STEIGER (981) and M. SCHORR &

R. KOCH ( 1986). The main consti tuents are monaxonesp icules of siliceous sponges , fragments of hexactellinids(parely calci fied) , filaments , crinoids (Saccocoma sp . ),tuberoids and Tubiphytes sp.; cextul ariids, ophtalmiids andencrusting foraminifera are of subordinate significance. Thelayered texture with thin beds enriched or depleted withbioclasts is sometimes reworked by endobiontic activit ies.

MF 8/2 : Bioinrrarnicrite with sponge spicules and echinids­wacke/ -packstones (PI. 2, fig. 7).

Here biod errirus occur together with subangular, micriticint raclasts and peloids. Textulariids, Reophax sp. , monaxonesponge spicules, bryozoans, crinoids, Tubiphytes/algae-associa­tions were observed together with Problem aticum sp. 2SENOWBARI-DARYAN and Problematicum B.

MF 9 : Foraminiferal mierites-mud-/wackestones (PI. 2, fig. 8).

The following biota are very common within these micritesof the Upper Kimmeridgian: Anchispirocyclina lusitanicaEGGER, N autiloculina oolithica MOHLER, Trocholina alpina­elongata LEUPOLD, Quinqueloculina sp. ; cryptalgal textures

~ limestone, pure

EEa l imestone, sandy

OE limestone, dolomitic

~ limestone/Dolomite, carstified

~ Reef?1 limestone

~ Oolithic limestone

~ Silicified limestone

~ Turbiditic limestone

~ Dolomite

~ Marly limestone

~Marl

~ Conglomera le

m Cora ls

m Lomellibranchs

~ Ammonites

m Belemnites

B Brachiopods

rn Crinoids

W Sponges

117

These sediments were not taken into consideration, thoughtheir outcrops connect directly south- of the Kimmeridgianreefoid limestones (fig . 2).

An following microfacies types of the Oxfordian/Kim­meridgian sequence (with the exception of MF 5) are charac­terized by a silicification which took only distinct biota(mainly ostracodes and echinids). This silicification is seenin connection with the deposition of siliceous sponge spicules.A conspicuous silicification is visible within facies 8/1,expressed QY em-thick layered lumps of Si02•

7. SUMMARY AND CONCLUSIONS

The different microfacies types of the Bathonian/Kimme­ridgian sediments also reflect the lithologic and facialcontrasts visible in the field . They were formed by trans­gressive/regressive fluctuations ; at the beginning of theBathonian an extended carbonate platform (MF 1-4) existed .

The transgressive Callovian sediments constitute a 60 mthick sequence of bituminous greenish/greyish marls and

shales which were not considered in microfacies investiga­tions. Small ammonites, belemnites and many small lamelfi­branchs (Bositra sp.) characterize these sediments.

The transition to the Middle/Upper Oxfordian is markedby a regressive phase with condensation hor izons in thewestern Algarve (ROCHA, 1976), which are overlain bypelagic limestones with filaments and Saccocoma sp. Theycontain turbiditic sediments of MF 5. Micrites and redalgal-oncosparites follow above, representing shallow areas(MF 4). They interfinger with small patches and biohermalstructures of MF 7/1 . The marls above with crinoids ,brachiopods and ammonites again indicate a deepening ofthe sedimentation area.

Sponge-spiculiric limestones were formed at the Oxfor­dian/Kimmeridgian transition (MF 8). The followingregression enabled the settlement of hydrozoan and coralcolonies (MF 7/2), which were overlain by micritic deeperwater limestones of the Upper Kimmeridgian.

The stratigraphic classification of fig. 7 was possibleby comparison with sections, described from Moncarapachoby B. MARQUES (1983).

UTERATURE

ARGENIO , B. d '; CAsTRO, B. ; EMIL/ANI, C. & SIMONE, 1. ( 97 5) - «Bahamian and apenninic limestones of ident ical lithofacies and age». Bull.A . A. P. G., Tulsa, vol. 59, pp . 525-530 .

BASSOULET, J. P.; BERNIER, P.; CoNRAD, M. A. ; DEWFFRE, R. & JhFREZO, M. (978) - «Les algues dasycladales du Jurassique et du Cretace». Geobios,Lyon, memo spec. 2, pp . 1-412 .

CHOFFAT, P. (980) - «Etude st ratig raphique er paieonrologique des terrains jurassiques de Porrugal. Premiere livraison. Le Lias et Ie Dogger au Norddu Tage ». Mem. Seer. Trab. Geol. Pors. , Lisboa, 72 p.

- -- (188 3- 1887) - «De I'imposs ibil ire de comprendre Ie Callovien dans Ie Jurassique superieur». Com. Comm. Trab . Geol, Porr. , Lisboa, e. I,pp . 69-87 , I corte geol.

DAHAYANAKE, K. (977) - «Classification of oncoids from the Upper Jurassic carbonates of the french Jura». Sedim. Geol., Amsterdam, vol. 18,pp . 337-353.

--- (978) - «Sequential position and environmental significance of different types of oncoids», Sedim. Geol. , Amsterdam, vol. 20, pp . 301- 316.FtUGEL, E. (1982) - «Microfacies Analysis of Limestones. Springer, Berlin, 633 p.FLUGEL , E. & STEIGER, T . (981) - «An Upper Jurassic sponge-algal buildup from the Northern Frankenalb, W est Germany». In : TOOMEY,

D . F. (ed .) - European fossil reef models. Soc. Econ, Paleont, Min . Spec. Paper, Tulsa, vol. 30 , pp, 37 1 -~ .

FRISHMAN, S. A. & BEHRENS, E. W . (969) - «Geochemistry of oolites, Baffin Bay, Texas». Geol. Soc. Am . , New York, abs. with programs, vol. 1/7,p. 71.

FRITZ, G. K. (1958) - «Schawammsrorzen, Tuberolithe und Schutcbrekzlen im weif3en Jura der Schwiibischen Alb (Wiirtemberg)>>. Arb. Geol. Paliiont,lnst., Stuttgart, n.° 40, pp . 1·90.

FURSICH, F. T.; RAMALHo, M. & SCHMITT-KITTLER, N. (1980) - "Biofacies analysis of Upper Jurass ic marginaly marine environments in Portugal.I. The carbonate-dominated facies at Cabo Espichel, Estremadura », Geol. Rdscb., Stuttgart, vol. 69, pp. 943-983.

HELLER, P.1.; KOMAR, P. D . & PEVEhR, D. R. (1980) - «T ransport processes in ooid genesis ». j our. Sed. Pur., Tulsa, vol. 50, pp . 943 -952 .ILLING, 1. V. (1954) - «Bahaman calcareous sands». Bull. A. A. P. G ., Tulsa, vol. 38, pp . 1-95.KAHLE , C. F. ( 1974) - "Ooids from the Great Salt Lake, Utah, as an analogue for the genesis and diagenesis of ooids in marine limestones ». fo um . Sedim,

Petr. , Tulsa , vol. 44, pp . 30-39 .Kuss, J . (1983) - «Faziesenrwicklung in proxirnalen Inrraplanforrn-Becken : Sedimentation Palokologie und Geochernie der Kossener Schichren (Ober­

T rias, Ndrdliche Kalkalpen)... Facies, Erlangen , n.° 9, pp. 6 1-172 .MALCHUS, N . (198 4) - «Mikrofazielle Untersuchungen an Mittel-bis Ober jurassischen KaJken im Gebler zwischen Faro und S. Bras de Alportel, Algarve,

Sudporrugal». Dipl. Arb. , Berlin , 120 p. (Unpublished).MEISCHNER, K. D . (1964) - .«Allodapische Kalke, Turbidite in riffnahen Sedimentationsbecken... D eu Sed. , Amsterdam, vol. 3, pp. 156-191, 3 pI., 5 figs.MARQUES , .B. (198 3) - «0 Oxford iano-Ki meridgiano do Algarve Oriental: esrratigrafia, paleobiologia (Ammonoidea) e paleobiogeografia ». Tese Uniu. N ova

Lisboa, 574 p. , 72 figs., 28 pI.MEDWEDEFF, M. A. & W ILKINSON, B. H. (1983) - «Cortical fabrics in calcitic and aragonitic ooids» , In: PERYT , T. M. (ed .) - Coated Grains, Springer,

Berl in , 665 p .FRATSCH , ]. C. (1958) - «Strarigraphisch-rektonische Untersuchungen im Mesozoikum von Algarve (Sudportugal)», Beih . Geol, j ahr . , Hannover, heft 30,

128 p., 14 figs ., 2 taf.RAMhLHO, M. M. (1971) - «Coneribuicao para 0 estudo micropaleontol6gico e esrrarigrafico do Jutass ico Superior dos arredores de Lisboa». Tese Unio.

Lisboa, 343 p.ROCHA, R. B. (976) - «Esrudo estratig rafico e paleontol6gico do JUrl\ssico do Algarve Ocidenral», Ciencias da Terra , Lisboa, n.? 2, 178 p., 6 esr.,

figs . 1.1-6.7 .ROSENDAHL, S. (1985 ) - «Die oberjurassische Korallenfazies von Algarve (Siidportugal)». Arb . lnst, Geol. Palaont. , Stuttgart, N . F. 82, pp . 1-1 26 .SANDBERG, P. A. (1975 ) - «New interpretat ion of Great Salt Lake ooids and ancient non skeletal carbonate mineralogy». Sedimentology, Oxford , vol. 22 ,

pp. 427-437.SCHORR, M. & KOCH, R. (1985 ) - «Fazieszonierung eines oberjurassischen Algen-Schwamm-Bioherms (Herrl ingen, Schwiibische Alb)», Facies, Erlangen ,

n.° 13, pp. 271-286.SHINN, E. A. (1983) - «Tidal flats . In: SCHOLLE, P. A., BEBOUT, D. G . & MOORE, C. H. (eds.) - Carbonate depositi onal environments». Mem. Amer. Ass.

Petrol. Geol., Tulsa, vol. 33 , pp , 171-210.SIMONE, 1. (1974) - «Genesi e significato ambientale degli ooidi a struttura fibroso-raggiata di alcuni dipositi mesosoici dell'area Appennino-dinarica

e delle Bahamas meridionali», Boll , Soc. Geol. Italia, Roma, n,° 93 , pp. 513-545.WILKINSON, B. H. (1985) - «Submarine hydrothermal weathering, global eustasy, and carbonate polymorphism in phanerozoic marine oolites ». j our . Sed.

Petroi. , Tulsa, vol. :>-5 (2), pp. 171-183.WILSON, J.1. (1975) - "Carbonate facies in geologic history », Springer, Berlin, 4 17 p.

118

-DOCUMENTA<.;AOFOTOGRAFICA

PLAn; I

1" 1. I _ In" . pd m;", ,,, with bjrd><y< <tt'U<t""" rI. "I f 2.

f ill, 2 _ Oopd' par;" wi,., T. _ido of r" " n,raj onO;j bar IMF 1111· FJ<>h" .", di........i' i. ino!O;atod

by oomokll ut<i ponl, diuol..d 1_10<,

f ill, 3 - w,1l ..,.-«<1 oopd,!",' ''' .."h R,.....ido, p<b .... in". d .." . cd ... ,., ,~... "' ........... rI. loll' l!<l.

f i. , 4 - Omil or RT-<>Oid•• ,lit ptloidol "..<I.... ;, """",od<d by • ' ''''''' d pr;nut)' rod ial ooodlo< ..irk• ",hoIdi""" ~'"';.] r.h,k IMP 1/41.

f ill 1 _ Oop<hpar;'" of , .. miai1ljl ,,>tl< ..i,k M-ooid,. It,-ooid>, ptlaid> oM inm d.." of MF 1/2.

fi~ , 6 _ O"'op<l,potj" wi,., dirr.c.n' 'l'P" of on,,,.., . (),IP 411),

Fill. 7 - ...,, :, -"<d_"", g<ap<'"'''' fa<i<. ..irk R-ooido of MF 312.

PI-AT E II

Fill . - Fra"""tOl><" of Kimmerid!lia" a!l~ with diffi,,.,nr sen io", of 1i.hif'h,,'rJ .h"." ." MIL~LOV , ~......nrlll!l

MF 712.Fill _ 2 - r.h ,l\nifi...d view of a l urbiJ il ic Jay~r ,",' ;Ih a;ooiJ., l oral. , lamd librand u and lfanophYICall-f~""""u

1",1\'''''''' ....ith T...i/'h),.. .....,"', MIL<;.I.QV. all yitJd inll an UllS<l ttn! Slrunu..., of MF "1/1.Fijt. } - Low~r pan of a tu rbidi.., la)'l'r cu lt i"..- ....ith .harp, e....iorW boa... i",o I .... undn-Iyin..- J'C'lagic mia ile.

MF "1/ 1.Fill . 4 - Baffks, ....., ....irh Klr-ralti"ian (Und., l""'Jy e-no:ruued by aJpc- and BMri.J1. >p•• MF 7/1 .

Fi,l: . ., - Red al,o:al oncomicnTe. ....ith b<yozo;urs and ed>inids as nud". Mf 612

Fi,l: . 6 - Sin .... le onIOid, t .... mnUSlin,l: alp ........ a fi and irrt,o:ularly arran,o:ed .,..-itic rubes .

Filt . 7 - Bi";nr ramicriTe ""ilh rud iric da.... It"",""",", "'AAluti red lIonminifen.. ...rarodn and fta,ll"""""

of ho:uc...,Uinid <pOI'I,0:e5 Mf Mf2.

Fill . 8 - Foram inifenl micrite ....ith T..eJ,.. >p. (lower righe), TA.u._ ""."w1. sp . (middle) and diffe~t

biod asrs of Mf 9 .

Fig . 9 - Tu b.-rolithic micriTe ""i. h <pOI'I~ ."inJln of Mf 8f l.

PLATE III

Fi,l:. I. 1 - For.ominifrn of ty pe' I.

Fi,l:. }. -t - M""... i..... 1• ..1.',.... op.

FiA: . ,- P~••'" op.Fi,ll: _ 6 - .........n-. op.

Fi,ll: . 7 - F. ncrus.inll P~."."".'4 op.FiS . S - H""<fthr,,~..... op.Fill· 9 - P!.K¥" It.. op.

FiS. 10 - R"';"'" op.Fi,l:. I I . 11 . B - 0 1<1,.-.. <4"""; LUCAS.Fi,l:. 14• ., - F<>.~min,f<".,. op. indn.

Fi,l:_ 16 - N""'f,,ri./ '1'.

Fi,l:. J7 - Pl«<¥,ili." ' I'.

Fi,l:. 1M - p"",kyd....;.... op.

Fi,l:. 19. 10 - 11",'hi'ft,m.-ydm" /",i"''';(11 EGGER.

Fill_ 1 I - N.Jq>JtII..sI",iJi"", '1'.

Fig _ 11 - N""I;("'''/;'''' ""'ilb;," MO HLER.

Fi,l:. 13 - Q"i"'I"r/«"Ii"" ' I' .

I'il(. 14, 1 ' , 1(, - C")W,.\";,, 'I'.

Fig . 21 - Clyf'ti"" "I'.

I'i,l: . 111, 1<) - ·[""'I" "",fI" ' I'.

pUo.n m

PLATE IV

f~. I _ 0Il<00d 'l'Pt II . <1>0........... b,- • ""3" .-..... .-l '0-. '. ,_""__ ~_-f,._ 1 - Oa«ood ..,.. V. ..,~ """"'- . ,..n. ..--.... _ In " ..._ .... -.-..l b,- -.. er-.a ~.,.,.,mf,. ~ _ 0--1 ..,.. N wd ...- ~..,. ........ __ _ <hr """"'.f" 4 - o.ow- __ .. r __ 1IIASlJ)Y • ..- _ ...

f,. )., _ ..-~ .woKX .>ttI """" __ = ._.__ '1iI:. \ • .., _ -'" "'"'

'...f " , _ 0....... ..,.. I ~ _ ....'" .-'..... ,__ a--i<~

f ,•• _ (M<aod .,.,., U ~ • -..0" , on.. _ -U _lob .."" Tho..-l _'--' •

.....-_ ,-..n dd . ' I d .................. r ........._f,. 9 -~ sp. 1 UNO~_{M,yA."f" 10. 14 _ Problr"'''K''''' A b,- • 1oסi_ aII<i • dlod; ..w ''''''f ill I I - N....o;d d n "J.<_~ RAI SERI "It " .ok d un

f;. 12 _ Probloma< ""m C "',"" d • mK'; 'KIOpoti<", ,~"r<&lo,_ .

f ,• . 1\ - P"",le""" " "" ~ . "'.. ,.....1...

PLATE IV