Facies (2009) 55:523–538

DOI 10.1007/s10347-009-0186-4

ORIGINAL ARTICLE

Succession of rudistid lithosomes along the western coastal margin of the Iberian Basin (Coniacian, Castrojimeno Section, central Spain)

Javier Gil · Jose Maria Pons · Manuel Segura

Received: 2 January 2009 / Accepted: 19 April 2009 / Published online: 8 May 2009© Springer-Verlag 2009

Abstract Rudistid lithosomes cropping out near Castroji-meno, at the northern margin of the Central System innorth-central Spain, provide detailed information on theircomposition and structure, on their development and suc-cession, and about their relationship with the Coniaciansequence stratigraphy framework of the Iberian Basin.Most rudist assemblages are oligospeciWc, with a dominantspecies, or monospeciWc. The radiolitids Biradiolites angu-losus, Praeradiolites requieni, and Radiolites sauvagesiand the hippuritids Hippurites incisus and Vaccinitesgiganteus were identiWed. Radiolitids demonstrate wideintraspeciWc morphological variability. The following Rid-ing’s structural categories of organic reefs are represented:segment reefs, spaced and close cluster reefs, and closecluster/frame reefs. Bioclastic beds of reworked rudist frag-ments occur below or in between the rudist reefs. The verti-cal succession of all Wve types of rudistid lithosomesdistinguished evidences a shallowing-upward trend. Rudis-tid lithosomes developed on the coastal margin during thesuperposition of the highstand sea-level stage of third- andfourth-order depositional sequences.

Keywords Rudistid lithosomes · Sequence stratigraphy · Coniacian · Iberian Basin

Introduction

Rudists played an important role as carbonate producersand organic builders along the Peri-Tethyan margins duringthe Cretaceous, besides being useful biostratigraphic mark-ers and palaeogeographic indicators (see Philip 1998, forextensive review and references on all these aspects). Par-ticularly during the Upper Cretaceous, a global sea-levelrise Xooded wide peri-continental areas favoring an exten-sive development of shallow-marine platforms (Philip andFloquet 2000a, 2000b; Philip 2003); these were carbonateor mixed siliciclastic-carbonate platforms and displayed amore or less restricted character, depending mainly on theregional or local tectonic setting.

Development of rudist formations in most platform con-texts has been extensively described in the geologic litera-ture (see Philip 2003). Detailed analyses of radiolitid and/orhippuritid framework’s growth and development haverecently been carried out (Götz 2003, 2007; Vilardell andGili 2003; Korbar 2007).

The Castrojimeno outcrop is located in north-centralSpain, at the northern margin of the Central System(Fig. 1a), and corresponds to the westernmost coastal mar-gin of the Iberian Basin during the Coniacian (Fig. 1b),Wlled with an inner platform mixed siliciclastic-carbonatesuccession. An intense early diagenesis, mainly dolomitiza-tion, obliterated the primary sedimentary structures and fos-sil content of the carbonate sediments within the proximalshallow platform settings of the Iberian Basin. Neverthe-less, the Wne preservation of the radiolitid and hippuritidlithosomes succession cropping out at Castrojimeno can be

J. Gil (&) · M. SeguraDepartamento de Geología, Facultad de Ciencias, Universidad de Alcalá, 28871 Alcalá de Henares, Spaine-mail: javier.gil@uah.es

M. Segurae-mail: manuel.segura@uah.es

J. M. PonsDepartament de Geologia, Facultat de Ciències EdiWci Cs, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spaine-mail: josepmaria.pons@uab.cat

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524 Facies (2009) 55:523–538

considered as a fortunate exception in the area, because dis-solution processes in vadose zone selectively aVected thecarbonate matrix and the inner shell layer of rudists, andlater dolomitization processes did not take place there. Con-sequently, the outer shell layer characters of the rudists areenhanced, facilitating their recognition in the outcrops.

Considering the Castrojimeno outcrop as a Wne exampleof rudistid lithosome development in the landward wedgesof inner restricted mixed siliciclastic-carbonate platforms,the main aims of this paper are: to describe (1) the verticalsuccession of rudistid lithosomes and (2) the vertical evolu-tion of rudist associations and fabrics within each lithosometype; (3) to relate their occurrence with the high- and low-frequency depositional stacking pattern, and (4) to date thethird-order depositional sequence DS-2, thus contributingto set its chronostratigraphic framework in the coastal mar-gin of the Iberian Basin.

Geological setting

The Iberian Basin was a Peri-Tethyan area during the LateCretaceous. Located on the Iberian Microplate, it was along and narrow intracratonic basin between two emergedareas, the Hesperian Massif at the WSW and the Ebro Massifat the NE (Fig. 1b). Climate, regional tectonics, and globaleustasy were the three factors controlling, respectively,carbonate production, palaeogeographic links, and deposi-tional rhythms at the Iberian Basin.

During the Upper Cretaceous, the Iberian Microplatewas located in the Tethyan tropical belt, slightly north ofthe equator (Philip and Floquet 2000a, 2000b; Philip 2003)and exposed to the warm circum-global Tethyan current.This position, together with the lack of cold boreal currentsfavored a warm-humid climate during the Late Cretaceous,although, a pronounced cooling in the Middle Coniacianhas been claimed by Steuber et al. (2005) for the east ofTethys realm. This palaeogeographic and palaeoclimaticcontext favored the proliferation of benthic communities inthe Tethyan peri-continental areas, together with a remark-able development of carbonate platforms. As a conse-quence of large-scale carbonate production, a relativelythick carbonate sedimentary record developed in the basin.

The opening of the Biscay Gulf caused counterclock-wise rotation and eastwards displacement of the IberianMicroplate, and consequently of their mountains andbasins, and, concerning the Iberian Basin, was responsiblefor the alternate or simultaneous palaeogeographic con-nection with the Atlantic Domain (northwards) and theTethyan Domain (southwards) at diVerent times of theUpper Cretaceous (García et al. 1987, 1996, 2004;Floquet 1991; Alonso et al. 1993; Segura et al. 2001,2002). Nevertheless, at a detailed scale, there is noevidence of signiWcant local tectonic activity, since faciesand thickness are laterally continuous and homogeneous.Minor localized tectonic events have been recognizedonly in the Middle-Upper Turonian (Gil et al. 2006b) andthe Santonian (IGME 2009).

Fig. 1 Location of the Castrojimeno outcrop. a Geological scheme.Late Cretaceous outcrops, depositional environments, and type locali-ties of the mentioned stratigraphic units are indicated. b Palaeogeo-graphical scheme indicating main depositional environments of the

Iberian Basin within the Tethyan Domain during the Coniacian, basedon Giménez (1987), Floquet and Hennuy (2001) and Segura et al.(2004)

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Facies (2009) 55:523–538 525

Finally, the signiWcant Upper Cretaceous global eustaticsea-level rise was the main factor controlling the deposi-tional episodes in the Iberian Basin (Rat 1982; García et al.1996, 2004; García-Hidalgo et al. 1997; Segura et al. 2001,2002; Gil et al. 2004; Gil 2005). The sedimentary recorddisplays a complex internal stratigraphic framework, com-posed of third-order depositional sequences (in the sense ofVan Wagoner et al. 1988) that may correlate with the glo-bal eustatic charts (Haq et al. 1988) and regional eustaticcharts (Hardenbol et al. 1998; Haq and Al-Qahtani 2005).These sequences display a basic palaeogeographical pat-tern, composed of a siliciclastic facies belt towards thewestern coastal margin (Gil et al. 2006a; García-Hidalgoet al. 2007), and shallow carbonate platform facies in themiddle of the basin; the basin was connected to the AtlanticDomain, or the Tethyan Domain, or both, depending on themicroplate tilting (Segura et al. 2002).

Only two depositional episodes may be recognized, dis-playing open platform facies in most of the basin and reach-ing wide areas of the coastal margin. These episodescoincide with the globally recognized Upper Cenomanian–Lower Turonian and Coniacian-basal Santonian eustaticpeaks (Haq et al. 1988; Hardenbol et al. 1998). Develop-ment of thick platforms, prograding on open platform faciestowards the basin centre (Segura et al. 1989, 2001, 2002;Floquet 1991), took place during both episodes.

Stratigraphic succession and facies

The Cretaceous succession in the Central System has beenextensively investigated (Alonso 1981; Gil et al. 1993,

2002; Gil and García 1996; García-Hidalgo et al. 2001a,2001b, 2003, 2007). It is a mixed siliciclastic-carbonatesuccession representing the landward wedges of inner shal-low carbonate platforms developed in the central area of theIberian Basin. The Castrojimeno outcrop was Wrstdescribed by Alonso (1981), reporting rudist bioherms. Thesection (Fig. 3) is composed of a partially covered lowersiliciclastic interval and a thick upper carbonate interval.

The Wrst interval is composed of littoral to Xuvial-coastalsands, sandstones, silstones, and claystones (Utrillas For-mation), covered by a level of red tidal dolostones andsandy dolostones with wavy lamination and slightly globu-lar stromatolites (subfacies 41 in Table 1) of the CaballarFormation (Fig. 3). This level represents an important breakin the vertical facies evolution, constituting a regionalguide horizon.

The second interval, the main object of our study, iscomposed of outer to inner platform fossil-rich carbonatefacies organized in several marlstone–limestone bundleswith diVerent development and morphology (HortezuelosFormation). Other outcrops in the neighborhood ofCastrojimeno (Castro de Fuentidueña, Tejares, Cast-roserracín) illustrate the lateral continuity of the analyzedcarbonate bed sets. Facies and subfacies recognized inthis interval, as well as their environmental interpreta-tion, are summarized in Table 1. The vertical successionof facies (Fig. 3) shows repetitive evolution from outerplatform (subfacies 11–12) to inner platform (subfacies21–25) or even restricted littoral (subfacies 31), within amajor transgressive–regressive trend. At least four sedi-mentary cycles (in the sense of Strasser et al. 2006) withdiVerent development and morphology are recognized. Inthe Wrst cycle, bed sets 1–2, outer platform facies aremore developed than inner platform facies. In the secondcycle, bed sets 3–5, open platform facies are restricted tothe lower part (bed set 3), inner platform facies are pre-dominant (bed set 4), and restricted littoral facies devel-oped on top (bed set 5).

The third cycle, bed sets 6–8, is made of inner platformfacies, showing a well-deWned shallowing-upwards trend(bed sets 6–7), followed by predominantly restricted litoralfacies (bed set 8). The fourth cycle, bed set 9, is incom-plete; it is composed by shallow-inner platform facies,truncated by the regional unconformity at the base of thethick recrystallized dolomitic Montejo Formation (IGME2009).

Sequence stratigraphy framework

The succession (Fig. 3) displays a stacking pattern of super-posed low-frequency and great amplitude (second- andthird-order) and high-frequency and minor amplitudeFig. 2 Key to symbols used in Fig. 3

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526 Facies (2009) 55:523–538

(fourth-order) depositional sequences (Gil and García 1996;García-Hidalgo et al. 2001a, 2001b, 2003, 2007; Gil et al.2008). Although biostratigraphic data are generally scarce,

outer platform fossils occur in two, third-order depositionalepisodes: the Upper Cenomanian–Lower Turonian and theUpper Coniacian sequences, this last treated herein (DS-2).

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Facies (2009) 55:523–538 527

The DS-2 lower sequence boundary (LSB) is a majordiscontinuity on top of the red dolostones of the CaballarFormation (Gil 2005). The upper sequence boundary (USB)is the regional unconformity at the base of the thick recrys-tallized dolomitic Montejo Formation (IGME 2009). Thethickness of DS-2 is about 100 m.

An Upper Coniacian–Lower Santonian age was consid-ered in precedent papers for the rudist-bearing succession atCastrojimeno (Alonso 1981). As stated below, the rudistassemblage found at the upper part of DS-2 in Castroji-meno outcrop indicates the Coniacian. Moreover, the pres-ence of the ammonite Hemitissotia celtiberica Wiedmann1975 in the lower part (bed set 2), constraints to the UpperConiacian (turzoi biozone) the age of the Hortezuelos For-mation and, also, of the DS-2 depositional sequence at thecoastal margin. In platform areas located northeastwards,DS-2 ranges from Lower Coniacian to Lower Santonian(Floquet 1998); that evidences that the third-order sequenceboundary’s hiatuses (LSB and USB in Fig. 3) increasedtowards the coastal margin.

DS-2 displays an internal stacking pattern composed bysix minor sequences or fourth-order parasequence sets (DS-2.2–DS-2.7) that have been identiWed by their sequenceboundaries and by the break and repetition of the verticalfacies succession. The lower parasequence sets (DS-2.2 andDS-2.3) are partially covered and they have been inferredfrom the correlation with neighboring outcrops. This stack-ing pattern is similar to the other third-order episodes in theIberian Basin’s Upper Cretaceous (García et al. 1993, 1996;Segura et al. 1993; García-Hidalgo et al. 1997, 2003; Gilet al. 2006a, 2006b; Gil 2005).

The fourth-order sequence boundaries coincide with thethird-order sequence boundaries of DS-2 (e.g., base of DS-2.2 and top of DS-2.7) or with important sedimentarybreaks of the vertical facies succession, caused by suddenfacies belt retrogradation on top of DS-2.4, DS-2.5, andDS-2.6.

DiVerent interpretations are possible for the origin ofthese parasequences. Our interpretation of parasequencesets of eustatic origin is based on several arguments dis-cussed below.

Climate and oceanic circulation pattern control three fac-tors aVecting biotic carbonate production: (1) temperature(Milliman 1974; James 1997), (2) carbonate compositionand saturation (Hallock 1996; Stanley and Hardie 1998),and (3) nutrient availability (Hallock and Schlager 1986;Carannante et al. 1988; Hallock 1988, 2001). These factors,being closely dependent of the palaeogeographic locationof the Iberian Basin within the Tethyan realm, are responsi-ble for the presence of a relatively thick carbonate sedimen-tary record, due to their control on the distribution ofcarbonate producers along the platform and on their pro-duction rate.

Nevertheless, the depositional stacking pattern producingthis sedimentary record is not dependent of the above-mentioned factors, but of accommodation. Accommoda-tion, understood as the space of the basin that potentiallycan be Wlled by sediments, is created by subsidence (tec-tonic, thermal and sedimentary compaction) and eustasy(Jervey 1988; Homewood et al. 2000).

In the present case, sedimentary compaction was a negli-gible component of the accommodation due to the scarcethickness (30 m) of the underlying sedimentary record, andthe coarse siliciclastic character of these facies with verylow compaction ratios (Hillgärtner and Strasser 2003; Gilet al. 2006a). On the other hand, the Upper Cretaceous wasa period of relative tectonic quiescence in the Iberian Basin(Segura et al. 2002; García et al. 2004) and tectonic subsi-dence was insigniWcant during the Turonian and the Conia-cian (Reicherter and Pletsch 2000). Thus, the maincomponent of the basin subsidence was thermal in origin,following a Upper Jurassic–Lower Cretaceous tectonic sub-sidence phase related to the opening of the Biscay Gulf(Hiscott et al. 1990). Thermal subsidence rate is normallylow (Janssen et al. 1995) and it can be considered constantalong the sedimentation of this sequence; it might play,however, a role as an ampliWcation factor to other causes.As a consequence, accommodation is believed to be mainlyoriginated by eustasy, and the depositional stacking patternis related to eustatic oscillations having diVerent frequencyand amplitude. This eustatic signal was locally punctuatedby tectonic events of regional character, as it occurred inthe upper sequence boundary (USB).

The vertical succession of facies within the parase-quence set shows the diVerent phases of each eustatic epi-sode (systems tracts). The superposition of diVerent ordersof sequences causes a similar superposition of systemstracts. At fourth-order scale, the parasequence sets show asimilar sedimentary trend, they evolve from outer fossiliferousfacies to shallow platform bioclastic shoals, rudist-bearinglimestones and lagoon facies on third- and fourth-orderscale. Therefore, they are shallowing sequences, represent-ing the high stand systems tract (HST) or the high sea-levelstage of each eustatic episode. The transgressive stage is at

Fig. 3 Left Castrojimeno stratigraphical section: A age, B lithostrati-graphical units, C third-order depositional sequences, D third-ordersystems tracts scale, E parasequence sets (fourth-order), F fourth-ordersystems tracts, G subfacies (cf. Table 1), H bed sets, I, lithology, sedi-mentary and biogenic structures, and fossil content; Ca Caballar For-mation, Ut Utrillas Formation, USB third-order upper sequenceboundary, LSB third-order lower sequence boundary, TS third-ordertransgressive surface, sb fourth-order sequence boundaries, MFS max-imum Xooding surface. Middle detail of the stratigraphic stacking pat-tern in the rudistid lithosomes; 7a–7i reference key beds in Fig. 4; Wlledarrows sedimentary parasequences (Wfth-order). Right Types of verti-cal succession of rudist fabrics. See key to symbols in Fig. 2

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528 Facies (2009) 55:523–538

Tab

le1

Sum

mar

y of

mai

n fa

cies

and

sub

faci

es o

f th

e H

orte

zuel

os F

orm

atio

n, a

nd th

eir

char

acte

rist

ics

Fac

ies

Subf

acie

sL

ithof

acie

sB

iofa

cies

and

bio

turb

atio

nE

nvir

onm

enta

l int

erpr

etat

ion

Out

er c

arbo

nate

pl

atfo

rm1 1

Fos

sili

fero

us

mar

lsM

assi

ve, g

rey

mar

ls a

nd

calc

areo

us m

udst

ones

Oys

ters

, am

mon

ites,

irre

gula

r ec

hino

derm

s,

glos

sids

and

oth

er b

ival

ves,

gas

trop

ods,

br

achi

opod

s. O

yste

rs a

nd a

mm

onite

s sh

ells

are

fr

eque

ntly

fer

rugi

nize

d, b

ioer

oded

and

co

loni

zed

by a

nnel

ids.

Bio

turb

atio

n co

mm

on

Low

-ene

rgy,

ope

n-m

arin

e se

tting

with

low

-sed

imen

tati

on r

ate.

O

uter

car

bona

te p

latf

orm

en

viro

nmen

t bel

ow s

torm

wav

e ba

se

1 2 N

odul

ar

limes

tone

sN

odul

ar c

laye

y lim

esto

nes

(mud

ston

e to

wac

kest

one)

. Fe

rrug

inou

s su

rfac

es

Gre

en a

lgae

, dis

corb

ids,

bry

ozoa

ns,

mili

olid

s, b

ival

ves

and

gast

ropo

ds.

Bio

turb

atio

n co

mm

on

Inne

r ca

rbon

ate

plat

form

2 1 M

icri

tic

limes

tone

sT

hin-

to m

ediu

m-b

edde

d li

mes

tone

s (m

udst

one

to w

acke

ston

e).

Gra

ding

-upw

ards

to 2

2 an

d 2 3

sub

faci

es

Ben

thic

for

amin

ifer

a, b

ival

ves,

gas

trop

ods,

so

lita

ry c

oral

s, th

in-s

hell

ed b

ival

ve

frag

men

ts. B

iotu

rbat

ion

at to

p of

bed

s

Ope

n-m

arin

e se

ttin

gs r

angi

ng f

rom

di

stal

to p

roxi

mal

car

bona

te

plat

form

. Alt

erna

tion

of lo

w-e

nerg

y an

d sh

oal s

ettin

gs b

etw

een

stor

m

wav

e ba

se a

nd f

air-

wea

ther

wav

e ba

se.

Ope

n ca

rbon

ate

intr

apla

tfor

m

envi

ronm

ent

2 2 O

oliti

c lim

esto

nes

Ool

itic

and

bio

clas

tic

limes

tone

s (p

acks

tone

).

Intr

acla

sts

and

oolit

ized

bio

clas

ts.

Cro

ss-b

eddi

ng o

r m

assi

ve.

Rar

ely

quar

tz e

xtra

clas

ts

Gas

trop

ods

and

biva

lve

frag

men

ts.

Bio

turb

atio

n ab

sent

2 3 B

iocl

asti

c lim

esto

nes

Coa

rsen

ing-

and

thic

keni

ng-u

pwar

ds li

mes

tone

s (X

oats

tone

s to

rud

ston

es);

an

gula

r to

wel

l rou

nded

, and

imbr

icat

ed c

last

s

Oys

ter

frag

men

ts in

the

low

er p

aras

eque

nces

. R

adio

litid

and

bir

adio

litid

fra

gmen

ts in

the

uppe

r pa

rase

quen

ces.

Bio

erod

ed s

hells

co

mm

on. R

are

biot

urba

tion

2 4 B

ioca

lcar

enite

sM

ediu

m-

to th

ick-

bedd

ed b

ioca

lcar

enit

es (

grai

nsto

ne);

w

ell-

sort

ed b

iocl

asts

; lar

ge, t

roug

h an

d pl

anar

cro

ss-b

eddi

ng;

ferr

ugin

ous

and

kars

tic

surf

ace

at to

p

Red

alg

ae f

ragm

ents

, bry

ozoa

ns,

bent

hic

fora

min

ifer

a,

gast

ropo

ds, e

chin

oder

ms

and

radi

oliti

ds.

Bio

turb

atio

n ab

sent

2 5 B

uild

up-r

udis

t lim

esto

nes

Rud

ist r

eefs

, ope

n an

d de

nsel

y pa

cked

, au

toch

thon

ous

and

para

utoc

htho

nous

fa

bric

s al

tern

atin

g w

ith X

oats

tone

s to

rud

ston

es. C

lust

er, f

ragm

ent a

nd

segm

ent g

eom

etri

es

Mon

o- a

nd p

auci

spec

iWc

asso

ciat

ions

of

radi

olit

ids

and

hipp

urit

ids.

Poo

rly-

sort

ed r

udis

t fra

gmen

ts

Res

tric

ted

litto

ral

3 1 Y

ello

w

mar

lsM

arls

and

cla

yey

limes

tone

s. S

ilt la

yers

.N

one

reco

gniz

edL

agoo

nal s

ettin

gs a

nd lo

w-e

nerg

y su

b-tid

al p

onds

in b

ack-

barr

ier

ram

p-co

asta

l env

iron

men

ts

Sup

rali

ttora

l4 1

Red

do

lost

ones

Thi

n-be

dded

, red

dol

osto

nes

and

sand

y do

lost

ones

. W

avy

bedd

ing.

Pse

udoc

olum

nar,

late

rall

y-lin

ked

stro

mat

olit

es. B

urro

win

g ra

re to

abs

ent

Non

eIn

tert

idal

to s

upra

tidal

se

tting

s w

ith

com

mon

pre

senc

e of

met

eori

c w

ater

s

123

Facies (2009) 55:523–538 529

the base of the parasequence, or contained in the lowersequence boundary and does not develop a transgressivesystems tract (TST). At the base of the succession, theoolitic limestones (subfacies 22) represent the TST facies ofDS-2.1; similar facies occurring in the same stratigraphicalposition have been interpreted the same way in deeper areasof the Iberian Basin (Floquet 1998).

So, at third-order scale, DS-2 shows an easily recogniz-able transgressive–regressive character. The third-ordermaximum Xooding surface (MFS) coincides with those offourth-order DS-2.4. Then, the third-order TST basicallyWts with DS-2.1 and DS-2.2, partially covered, meanwhilethe third-order HST is composed of the HSTs of DS-2.4,DS-2.5, and DS-2.6. Finally, the upper part of DS-2.6, andDS-2.7 may be interpreted as the third-order forced regres-sive systems tract (FR, sensu Posamentier et al. 1992; Huntand Tucker 1992; Catuneanu et al. 2009) or, as it shows anevident progradation of the restricted lagoon environmentsover the rudist-bearing barrier of the lower part of DS-2.3.Similarly, at smaller scale, bed sets 5 and 8 may be inter-preted, respectively, as the fourth-order FR of DS-2.5 andDS-2.6.

These internal stacking pattern and system tracts distri-bution are similar to those recognized in other lower third-order sequences along the Iberian Basin, especially in theLate Turonian third-order episode (DS-1 in Gil et al. 2006a,2006b). The high-frequency sequences (fourth- and Wfth-order) in DS-1 have been related to Milankovitch’s eccen-tricity cycles (Gil 2005; Gil et al. 2009).

Rudist fabrics and vertical successions

Both open or densely packed autochthonous fabrics, as wellas parautochthonous fabrics, have been identiWed in therudistid lithosomes (subfacies 25); furthermore, bioclasticbeds of reworked rudist fragments with Xoatstone or rud-stone textures (subfacies 23) occur below any of both or inbetween. Cestari and Sartorio (1995) used for these fabrics,respectively, the terms rudist facies A, B, and C.

In view of their genesis, the lithosomes described belowcan be considered as organic reefs in the sense of Riding(2002) “calcareous deposits created by essentially in placesessile organisms” and correspond to Riding’s structuralcategories: matrix-supported cluster reefs “in place skele-tons close but not in contact”, matrix-supported segmentreefs “skeletons disarticulated” and even, skeleton-sup-ported frame reefs “in place skeletons in contact”.

Five types of vertical successions (Type A–Type E inFig. 3) have been recognized along the studied section atCastrojimeno considering the distribution of these rudistfabrics and reef structural categories. Radiolitids, hippurit-ids, or both, are the main components of the rudist reefs that

normally correspond to oligospeciWc or monospeciWc asso-ciations.

Succession type A

This is the simplest succession, made up of bioclastic inter-vals predominantly composed of radiolitid fragments,showing Xoatstone texture below and rudstone above,within coarsening-upwards well-bedded strata (subfacies23) of 50–70 cm in thickness.

They are either arranged as forming the upper term ofshallowing-upwards pairs, the lower term being massivemicritic limestones with benthic foraminifera (subfacies21), or simply superposed. The contact between both termsin the shallowing-upwards pairs is either transitional in asingle bed or sharp, forming two diVerent beds; moreover,the upper terms sometimes wedge laterally.

Interpretation: the alternating micritic and well-sortedbioclastic beds show auto-cyclic sedimentary pattern andhave been interpreted as related to high-energy stormevents in close to fair-weather wave base sub-tidal settingsof an inner carbonate platform. Bioclasts originated byrudist shell fragmentation when Wne sediment supportingthem was eroded during a storm event. The micritic bedsformed when a low-energy hydraulic regime was re-estab-lished.

Succession type B

It consists of rudist segment reefs intervals developedabove bioclastic beds, similar to those formerly describedalthough poorly sorted and with angular and larger clasts.Thick-shelled lower valves of Radiolites sauvagesi andsmall bouquets of Hippurites incisus in parautochthonousopen fabric (Radiolites:Hippurites ratio approximately 3:1)are supported in a bioclastic wackestone-packstone matrix.Laterally, rudists may become scarce and only the bioclas-tic matrix is recognized. Both intervals are successivelyrepeated, although with unequal development; when oneinterval is completely missing, stratiWcation becomesevident.

Interpretation: diVerences between the bioclastic beds ofthis succession and those of the previously described (larger,angular, and less sorted clasts) suggest that they were depos-ited closer to the shell production area; furthermore, the lackof the micritic term with foraminifers points to consider thebioclastic beds of this succession as being deposited in ahigher hydraulic regime setting. As in the rudist-bearing inter-val, the specimens of both rudist species, although toppledand lacking their upper valves, are not fragmented, it can beassumed that they grew very close to the area of deposition.

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Succession type C

This type of succession is more complex than the one previ-ously described (Fig. 4a). It is composed of three rudistreefs, each one developed on bioclastic beds.

The Wrst is a spaced cluster reef composed of isolatedlarge thick-shelled Radiolites sauvagesi and either smallbouquets or isolated Hippurites incisus in autochthonousopen fabric (Radiolites:Hippurites ratio 1:1) embedded in arudist-derived packstone matrix. This reef is truncated andtopped by a thin segment reef that includes complete top-pled Hippurites bouquets, serving as a substrate for the sec-ond one.

The second is a cluster reef composed of small bouquetsof Hippurites incisus (Fig. 5a), with scarce attached Biradi-olites angulosus, and isolate Radiolites sauvagesi in awackestone-packstone matrix. The autochthonous fabric

evolves from spaced to close upwards; R. sauvagesi is pre-dominant in the lower part and H. incisus in the upper. Thisreef is truncated and topped by a bioclastic bed.

The third is a close cluster/frame reef composed ofthick-shelled Radiolites sauvagesi, elongate thin-shelledBiradiolites angulosus, and scarce Hippurites incisus inan autochthonous dense fabric, with most shells attachedone to the other and scarce wackestone–packstone matrixbetween some other shells (Fig. 5d). R. sauvagesi is thedominant species at the lower part, and B. angulosus atthe rest. This reef is truncated and topped by a Type Asuccession.

The mean sizes of rudist shells are similar in the threereefs: R. sauvagesi is 150–200 mm high and has a diameterof 60–70 mm; H. incisus is 200 mm high and has adiameter of 15 mm; B. angulosus is 70 mm high and has adiameter of 15–30 mm.

Fig. 4 Top and middle outcrop view of the upper part of the parase-quence set DS-2.6 at Castrojimeno; 7a–7i bed sets, Wlled arrows Wfth-order sedimentary parasequences 7a–7e and 7f–7i, 5A–5E location ofthe photos in Fig. 5. Bottom outcrop details, location on the scheme is

indicated by thin arrows; a complete Type C succession, diameter ofphoto-cap for scale is 60 mm; b upper Hippurites incisus thicket inType D succession, scale bar represents 200 mm; c Vaccinites gigan-teus in Type D succession, pencil for scale measures 150 mm

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Interpretation: the open fabric, the rudist-derived pack-stone matrix, and the length of the Radiolites specimens inthe Wrst reef indicates a moderate sedimentation rate ininner platform setting close to or above the fair-weatherwave base. Conditions were stable enough between two

storm events to allow complete development of large Radi-olites and development of small bouquets of Hippurites.

The second reef, although interpreted as having developedin a similar setting, indicates a probably slightly lower sedi-mentation rate, and still more stable and/or lasting conditions

Fig. 5 Outcrop view of diVerent rudist reef structures. a Slightly in-clined Hippurites incisus bouquets, cluster reef, Type C succession.b Radiolites sauvagesi (below), Biradiolites angulosus (above), andscarce Hippurites incisus, close cluster/frame reef, Type D succession.c Very elongate Radiolites sauvagesi, spaced cluster reef, Type D suc-

cession. d Radiolites sauvagesi (below) and Biradiolites angulosus(above), close cluster/frame reef, Type C succession. e Toppled Radi-olites sauvagesi, top of close cluster/frame reef, Type D succession.Diameter of photo-cap for scale is 60 mm, and coin diameter is 23 mm.Location of photos is indicated on Fig. 4

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between two storm events. This is also indicated by the pro-gressively less open fabric, by the wackestone–packstonematrix, and by the increased turnover and diversity of species.

The evolution from cluster to frame structure and thescarcity of matrix in the third reef suggest that sedimenta-tion rate in this one is the lowest amongst the three, withrudists growth controlling the thickness of the build-up.The vertical turnover from the Radiolites–Hippurites–Biradiolites association below, to a monospeciWc one withBiradiolites above, thinner and still more closely packed,suggests the evolution to more restricted conditions, linkedto a shallowing-upwards trend. This trend can be recog-nized across all three reefs and ends in sub-aerial exposure.

Succession type D

This type of succession starts also above a radiolitid rud-stone bed and is composed of three reefs.

The Wrst is a spaced cluster reef composed of bouquetsof large (up to 23 cm high) Radiolites sauvagesi and fewHippurites incisus (Radiolites:Hippurites ratio 20:1) inautochthonous open fabric, with wackestone–packstonematrix (Fig. 5c). Shells are slightly inclined at the base ofthe reef and truncated at the top.

The second starts directly on the Wrst, without develop-ment of a bioclastic bed. It is a close cluster/frame reefcomposed of Radiolites sauvagesi, Biradiolites angulosus,and Hippurites incisus shells (ratio 15:2:3, respectively);many shells are attached one to the other and matrix isscarce (Fig. 5b). Some toppled or fragmented shells accu-mulated at the top and were used as substrate for the nextreef (Fig. 5e).

The third is a close cluster/frame reef, a thicket of thinslender (up to 600 mm high and 30 mm in diameter) Hippu-rites incisus with scarce R. sauvagesi shells (ratio 50:1) inan autochthonous dense fabric, with most shells attachedone to the other and scarce matrix localized only in fewareas (Fig. 7a). The thicket is truncated and bioeroded at itstop (Fig. 4b).

Interpretation: the main diVerences between this typeand the previous one are, for each reef: the relative thick-nesses, the relative abundances of each species (speciesratio), and the presence of bioclastic beds between succes-sive cluster, or, close cluster/frame reefs. As a conse-quence, although interpreted as developed in a similardepositional setting, diVerences in these aspects indicate astill more pronounced shallowing-upwards trend. Particu-larly, the lack of a bioclastic bed on top of the truncatedWrst cluster reef suggests a sub-aerial exposure episode,besides the last one on top of the succession. The Hippu-rites thicket constituting the third and last reef is interpreted

as having developed in a very shallow setting, before itstruncation and sub-aerial exposure.

Succession type E

This type is formed by single micritic limestone beds, up to500 mm thick, between nodular marly limestones. SomeVaccinites giganteus shells, toppled and colonized by smallHippurites incisus, a few in upright position (Fig. 4c), as wellas scarce Praeradiolites requienii, and some big fragments ofRadiolites sauvagesi occur. Most rudist shells are allochtho-nous, deeply bioeroded, and some of them ferroginized.

Interpretation: occurrence of these beds in the FR of theparasequence set DS-2.6 (see “Sequence stratigraphy frame-work” and Fig. 3) bring us to interpret them as a wash-overdeposit in a lagoonal setting, link to storm events aVecting awell-developed and more diverse rudist reef.

Remarks on the rudist fauna

Biradiolites angulosus d’Orbigny 1842

Although Wrst described from the Turonian of Pons (Cha-rente, SW France), this species has been widely reportedfrom the Upper Turonian and the Coniacian of the Mediter-ranean Tethys. All specimens recognized are from the clus-ter or close cluster/frame reefs in successions Type C and D(Figs. 5b, d, 6a–c). The complete outer surface is notobservable in any of the individuals. Nevertheless, the largenumber of specimens, together with the transverse sections,allowed to recognize all diagnostic characters as well as tostate the important variability in shell ribbing and radialbands width, as also reported by Korbar (2007). Shells mayreach up to 100 mm high and 25 mm wide.

Praeradiolites requieni (d’Hombres-Firmas 1838)

This species was Wrst described from the Coniacian of Gat-tigues (Gard). At Castrojimeno it appears only in the TypeE successions, as isolated specimens (Fig. 7c). Some speci-mens are conical (120 mm high, 70 mm wide) but othersare Xat (40 mm high, 80 mm wide) and reclined on their Xatdorsal margin.

Radiolites sauvagesi (d’Hombres-Firmas 1838)

First described from the Coniacian of Gattigues (Gard), ithas been frequently reported from deposits of the same ageall along the Mediterranean Tethys margins. At Castroji-meno, it occurs in nearly all reefs of the above-described

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succession types (Figs. 5b–e, 6a, b). This implies thatspecimens collected represent a wide spectrum of shellgrowth conditions. Radial ribbing ranges from acute andnarrow to rounded and broad. Spacing of growth laminaeis highly variable. Width of radial sinuses (always up-foldsof growth laminae) is also variable. Interband down-fold iseither simple, subdivided, or formed by three folds whenradial sinuses are deep and their margins well deWned; anundivided interband fold was considered a primitive fea-ture by Toucas (1908) justifying the proposal of R. prae-sauvagesi, but, as already stated by Steuber (1999), itappears as being related to growth constrains andecological factors.

Hippurites incisus Douvillé 1895

This species was Wrst described, as a variety of H. resectus,from the Coniacian of Espluga de Serra (southern Pyre-nees) and has been quoted from other, distant areas sincethen. At Castrojimeno, it occurs in most reefs as a minorcomponent associated with radiolitids (Figs. 5a, b, 6a, b), orin monospeciWc thickets (Figs. 4b, 7a).

Vaccinites giganteus (d’Hombres-Firmas 1838)

This species was Wrst described from the Coniacian of Gat-tigues (Gard). It has a wide geographical distribution. At

Fig. 6 Rudists from the upper close cluster/frame reef of Type C suc-cession. a Side view of a group of right valves, PUAB-43748. b Trans-verse section of a group of right valves, PUAB-43743. c Biradiolitesangulosus, transverse section of right valve, PUAB-43735. R, Radio-

lites sauvagesi; B, Biradiolites angulosus; H, Hippurites incisus; VSventral radial sinus; VB ventral radial band; PS posterior radial sinus;PS posterior radial band; scale bars represent 10 mm

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Castrojimeno, it occurs only as isolated specimens in TypeE successions (Figs. 4c, 7b).

Discussion

The rudist successions described above may be consideredan exception amongst other successions of similar age anddepositional environment in the Iberian Basin because ofboth abundance and preservation of rudist shells, as well asoutcrop exposition. Moreover, their study contributes newdata on rudist palaeoecology and the relation of their occur-rence with low- and high-frequency depositional patterns.

Biosedimentary trends

When the entire succession is considered (HST of DS-2.6parasequence set in Fig. 3), a shallowing-upwards trend isobserved and at least two sedimentary sequences are clearlyrecognized, one formed by Type B and C successions, andthe other by Type A and D successions (Wlled arrows inFig. 3). In carbonate platform settings, minor sequences asthe two above-mentioned (Wfth-order parasequences) areusually shallowing-upwards sequences, as originally deW-ned by Van Wagoner et al. (1988). At lower scale, all rec-ognized succession Types (A–E) contain storm layers and,moreover, Types C and D end with sub-aerial exposure.

In the described succession types with autochthonousfabric (Type C and D), a vertical evolution from spacedoligospeciWc cluster reef, with a large Radiolites as domi-nant species, to close oligospeciWc cluster reef, with thinHippurites and Biradiolites as dominant species, and toclose oligospeciWc cluster/frame reef, with thin Biradio-lites as dominant species, or close monospeciWc cluster/frame reef, with long slender Hippurites, has beenobserved.

In a shallowing context, some physicochemical parame-ters (e.g., hydraulic regime, sediment supply, salinity)change with time and, as a consequence, it is reasonable toconsider that originate a vertical evolution of rudist com-munities, favoring the development of dense monospeciWcassociations in response to a higher regime hydraulic and alower sediment supply.

Fig. 7 a Hippurites incisus, transverse section of right valves, PUAB-43745, upper thicket of Type D succession. b Vaccinites giganteus,transverse section of right valve, PUAB-74419, Type E succession.c Praeradiolites requieni, postero–ventral side view of both valves,left valve partially eroded, PUAB-74442, Type E succession; VS ven-tral radial sinus, PS posterior radial sinus. Scale bars represent 10 mm

�

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Palaeoecological implications

Both succession Types (C and D) start as spaced clusterreefs, with R. sauvagesi as dominant species and B. angu-losus and H. incisus as minor components. Both evolve toclose cluster reef, increasing the density of individuals,but not the species diversity, ending as a close cluster/frame reef with B. angulosus as highly dominant speciesin Type C succession, or H. incisus in Type D, after astorm event in both cases. No other macrofauna appears inany of the organic reefs in these successions; they areexclusively formed by rudists, with low to very lowdiversity.

All the above-mentioned characteristics point to veryrestricted conditions, allowing development of only a fewspecies of rudists. Several explanations for the low diver-sity due to restricted conditions in similar settings havebeen proposed in rudist literature: Schumann (2000) pointsto high salinity due to diurnal heating and, as a conse-quence, low oxygenation of seawater; and Steuber (2000)discusses anoxic conditions of the bottom surface due toaccumulation of rudist biodeposits. We have no relevantdata to contribute to these explanations but we can state that(1) storm layers are frequent in all recognized successiontypes, (2) no signiWcant organic matter appears in thematrix of any of the described rudist reefs, and (3) there areno sulphates in the surrounding areas.

Time estimation, sediment accumulation, and shell growth rates

Sediment accumulation rate may be inferred from therudists shell growth rate calculated by measuring theirgrowth rings (Cestari and Pons 2007); the outer shell layergrowth rings represent the yearly growth cycles of the shell(Amico 1978). A time estimation of the interval representedby each rudist reef, and also by each succession type, canbe approached using these data.

Only R. sauvagesi, amongst the rudist species abovedescribed, shows well-marked growth rings at the outershell surface. The analysis of growth rings in several iso-lated specimens from cluster reefs of the Type C and D suc-cessions, indicates a mean growth rate (GR) of 11 mm/year.This GR value is similar to the values of Regidor Herreraet al. (2007) and clearly lower than the 40 mm/yearreported by Steuber (1996) for Gorjanovicia cf. costata andby Cestari and Pons (2007) for Radiolites dario, and thanthe 50 mm/year reported by Dullo (2005) for pocilloporidcorals. Assuming this growth rate as similar to the sedimentaccumulation rate, a value between 40 and 50 years hasbeen estimated for the growth of the cluster reefs withR. sauvagesi in Type C and D successions.

The time represented by the sediment of a completeType C or D succession has been estimated between 132and 286 years, assuming similar sediment accumulationrates for all the succession. This assumption introducessome error in the estimation, as it does the fact of not con-sidering compaction and evidently, the time represented inthe sedimentary surfaces has not been included. Finally, thetime represented in the sediment of a complete sedimentarycycle as B + C and A + D, considered as Wfth-order cyclesand indicated with Wlled arrows in Fig. 3, has been esti-mated between 363 and 395 years, with the same assump-tions and source of errors as before.

Currently, in cyclostratigraphical studies, the relation-ship between high-frequency sedimentary cycles and thepalaeoclimatic orbital cycles of the Milankovitch band iswidely assumed (see Strasser et al. 2006, for detailedreview of these aspects), and Wfth-order sedimentary cycleshave been related to eccentricity cycles of 100–95 kyr(Bádenas et al. 2008; Gil 2005; Gil et al. 2009).

Comparison of our estimated values of the time repre-sented by the sediment with this orbital periodicity, evenconsidering that the parameters not considered in our esti-mation would double our values, the time represented bythe hiatuses is, at least, ten times that represented by thesediment.

This fact should be taken into account when estimationsof sediment accumulation rates are deduced from the ratiobetween thickness of stratigraphic sequences and the timeattributed to these sequences, either considering it as relatedto Milankovitch orbital forcing and/or dated by biostrati-graphic markers.

Eustatic control of the faunal distribution

There are numerous examples of rudistid lithosomes avail-able in the literature that have been related both to TSTsand to HSTs, as those from Oman (Schumann 2000), Croa-tia (Moro 1997), Mexico (Schafhauser et al. 2007) or thosefrom the Pyrenees or the Alps (Sanders and Pons 1999,2001). However, in the Castrojimeno Section, rudist-bear-ing lithosomes are only located at the fourth-order HSTs ofDS-2.5 and DS-2.6, and no rudist faunas have been foundat the TSTs (see Fig. 3). Meanwhile, beds with ammonites,ostreids, and echinoids are located below, at the base of thethird-order HST, close to its MFS.

These data suggest that the vertical distribution of rudistswas controlled by the interaction of long- and short-termeustatic episodes because maximal rudist developmentcoincides only when the HSTs of the third- and fourth-order sequences are superimposed. This eustatic control isalso a common observation for the Late Cretaceous acrossthe entire Iberian Basin (Floquet 1998; Gil 2005) and suggests

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that the more suitable conditions for rudist larvae disper-sion and settlement could have developed during the super-position of HST’s of diVerent order. That relation might beexplained by the epeiric character of the Iberian Basin(Fig. 1b) and, consequently, of their carbonate platforms, inwhich open sea communication could be only possible dur-ing the superposition of high sea-level stages.

Conclusions

Coniacian rudistid lithosomes at Castrojimeno developed ina shallowing-upwards context and present diVerences intheir faunal composition and structure. Five types of verti-cal successions have been distinguished, composed of sev-eral structural categories of organic reefs: segment reefs,spaced cluster reefs, close cluster reefs, and close cluster/frame reefs, as well as bioclastic beds.

Most reefs correspond to oligospeciWc assemblages witha dominant species, with Radiolites sauvagesi, Biradiolitesangulosus, and Hippurites incisus, or monospeciWc assem-blages, with Biradiolites angulosus or Hippurites incisus.This, together with the absence of other macrofauna, indi-cates these rudist reefs developed under very restricted con-ditions.

The evolution of both reef structure and rudist diversityobserved within each succession type, as well as the evi-dences of sub-aerial exposure present at top of some, indi-cates a shallowing-upwards trend also within mostsuccession types.

Tentative estimation of the time represented in the sedi-ment of a complete sedimentary cycle, based on shellgrowth and sediment accumulation rates, when comparedto currently assumed periodicity of orbital cycles, indicatesthat the time represented by the hiatuses is at least ten timesthat represented by the sediment.

The age of the Castrojimeno’s rudist assemblage is rec-ognized as Coniacian. This, together with the identiWcationof the ammonite Hemitissotia celtiberica in the lower partof the section, settles an Upper Coniacian age for both, theHortezuelos Formation and the DS-2 depositional sequenceat the western coastal margin of the Iberian Basin contrast-ing the Lower Coniacian–Lower Santonian age of the DS-2depositional sequence in the northeast. That evidences thatthe sequence boundaries (LSB and USB) hiatuses increasedin duration towards the coastal margin.

Occurrence of fossils in the inner platform and in thecoastal margin appears to be related to the superposition ofeustatic episodes of diVerent amplitude. Ammonites occurslightly above the maximum Xooding surface (MFS) ofboth the third-order sequence DS-2 and the fourth-orderparasequence set DS-2.4. Rudistid lithosomes developed inthe high stand systems tract (HST) of the third-order

sequence DS-2 and in coincidence with the respective HSTof the fourth-order parasequence sets, particularly with thatof DS-2.6.

Acknowledgments This research has been Wnanced under projectsBTE2003-03606 and CGL2007-60054/BTE of the Spanish DirecciónGeneral de Investigación, and PAI08-0204-1312 of the Junta de Com-unidades de Castilla-La Mancha. The paper has beneWted greatly fromthe insights and revision of Stefan Götz, André Freiwald, and twoanonymous referees.

References

Alonso A (1981) El Cretácico de la provincia de Segovia (borde Nortedel Sistema Central): Seminarios de Estratigrafía, Serie Monogra-fías 7, Universidad Complutense, Madrid, p 271

Alonso A, Floquet M, Mas R, Meléndez A (1993) Late Cretaceous car-bonate platforms: origin and evolution, Iberian Range, Spain. In:Simo JA, Scott RW, Masse JP (eds) Cretaceous carbonate plat-forms, vol 56. Am Assoc Petrol Geol Mem, Tulsa, pp 297–313

Amico S (1978) Recherches sur la structure du test du Radiolitidae.Travaux, Marseille, Université de Provence. Laboratorie Geolo-gie Hist Paleontologie 8:1–136

Bádenas B, Aurell M, Ipas J (2008) Facies architecture and timing ofhigh-frequency sequences recorded from inner to mid-carbonateramp areas (Kimmeridgian-Tithonian, NE Spain). Abstracts ofthe 26th IAS Meeting of Sedimentology: 41

Carannante G, Esteban M, Milliman JD, Simone L (1988) Carbonatelithofacies as paleolatitude indicators: problems and limitations.Sediment Geol 60:333–346. doi:10.1016/0037-0738(88)90128-5

Catuneanu O, Abreu V, Bhattacharya JP, Blum MD, Dalrymple RW,Eriksson PG, Fielding CR, Fisher WL, Galloway WE, GiblingMR, Giles KA, Holbrook JM, Jordan R, Kendall CGSC, MacurdaB, Martinsen OJ, Miall AD, Neal JE, Nummedal D, Pomar L,Posamentier HW, Pratt BR, Sarg JF, Shanley KW, Steel RJ,Strasser A, Tucker ME, Winker C (2009) Towards the standardi-zation of sequence stratigraphy. Earth Sci Rev 92:1–33.doi:10.1016/j.earscirev.2008.10.003

Cestari R, Pons JM (2007) Radiolitids, sediment accumulation ratesand hydrodunamic regimes in Cretaceous carbonate platforms,Italy. In: Scott RW (ed) Cretaceous rudists and carbonate plat-forms: environmental feedback, vol 87. SEPM Spec Publ, Tulsa,pp 27–36

Cestari R, Sartorio D (1995) Rudists and facies of the Periadriaticdomain. Agip SpA., S. Donato Milanese, p 207

d’Hombres-Firmas LA (1838) Mémoire sur les Hippurites et les Sphéru-lites du département du Gard. In: Recueil de mémoires et d’obser-vations de Physique, de Météorologie, d’Agriculture et d’Histoirenaturelle: Imprimerie Ballicot et Fabre, Nimes, pp 169–201

d’Orbigny A (1842) Quelques considérations zoologiques et géologi-ques sur les rudistes. Anales des Sciences naturelles 17:173–192

Douvillé H (1895) Études sur les rudistes. Distribution régionale desHippurites. Les Hippurites de la Catalogne. Mémoires de la SociétéGéologique de France. Paléontologie 5 (Mémoire n. 6):139–186

Dullo WC (2005) Coral growth and reef growth: a brief review. Facies51:33–48. doi:10.1007/s10347-005-0060-y

Floquet M (1991) La plate-forme Nord-Castillane au Crétace supérieur(Espagne). Mém Géol Univ Dijon 14, p 925

Floquet M (1998) Outcrop cycle stratigraphy of shallow ramp depos-its: the Late Cretaceous series on the Castilian Ramp (NorthernSpain). In: de Graciansky P-C, Hardenbol J, Jacquin T, Vail P(eds) Mesozoic and Cenozoic sequence stratigraphy of Europeanbasins, vol 60. SEPM Spec Publ, Tulsa, pp 343–360

123

Facies (2009) 55:523–538 537

Floquet M, Hennuy J (2001) Anatomy of resedimented carbonates inthe latest Turonian–earliest Coniacian South-Provencal Basin.Geol Mediterr 28:67–71

García A, Segura M, Carenas B, Pérez P (1987) Transgressions, dis-continuités, eustatisme et tectónique dans le cretacé moyen dusecteur central de la Chaine Ibérique (Espagne). In: Salomon J(Coord) Transgressions et regressions au Crétacé (France et ré-gions voisines). Mém Géol Univ Dijón 11:81–89

García A, Segura M, García-Hidalgo JF, Carenas B (1993) Mixedsiliciclastic and carbonate platform of Albian—Cenomanian agefrom the Iberian Basin, Spain. In: Simo JA, Scott RW, Masse JP(eds) Cretaceous carbonate platforms, vol 56. Am Assoc PetrolGeol Mem, Tulsa, pp 255–269

García A, Segura M, García-Hidalgo JF (1996) Sequences, cycles andhiatuses in the Upper Albian-Cenomanian of the Iberian Ranges(Spain): a cyclostratigraphic approach. Sediment Geol 103:175–200. doi:10.1016/0037-0738(95)00109-3

García A, Mas R, Segura M, Carenas B, García-Hidalgo JF, Gil J,Alonso A, Aurell M, Bádenas B, Benito MI, Meléndez A, Salas R(2004) Segunda fase de post–rifting: Cretácico Superior. In: VeraJA (ed) Geología de España. Sociedad Geológica de España-Instituto Geológico y Minero de España, Madrid, pp 510–522

García-Hidalgo JF, Segura M, García A (1997) El Cretácico del bordeseptentrional de la Rama Castellana de la Cordillera Ibérica. RevSoc Geol Espana 10:39–53

García-Hidalgo JF, Gil J, Segura M (2001a) Sedimentología de la suc-esión carbonatada del Cretácico en el borde sur del Sistema Cen-tral (Madrid). Geotemas 3(2):193–196

García-Hidalgo JF, Gil J, Segura M (2001b) Sedimentología de la suc-esión cretácica basal en el borde sur del Sistema Central (Madrid).Geotemas 3(2):197–200

García-Hidalgo JF, Gil J, Segura M (2003) Sedimentología de los tér-minos basales de la sucesión cretácica en el borde sur del SistemaCentral. J Iber Geol 29:55–71

García-Hidalgo JF, Gil J, Segura M, Domínguez C (2007) Internalanatomy of a mixed siliciclastic-carbonate platform: The LateCenomanian–Mid Turonian at the southern margin of the SpanishCentral System. Sedimentology 54:1245–1271. doi:10.1111/j.1365-3091.2007.00880.x

Gil J (2005) Estratigrafía de alta resolución en el Turoniense Superior–Coniaciense Inferior de la Cordillera Ibérica Septentrional. PhDThesis, Universidad Complutense, Madrid, p 218

Gil J, García A (1996) El Cretácico del borde meridional del SistemaCentral. Unidades litoestratigráWcas y secuencias deposicionales.Estud Geologicos 52:37–49

Gil J, García A, Segura M (1993) Secuencias deposicionales del Cret-ácico en el Xanco sur del Sistema Central. Geogaceta 13:43–45

Gil J, Pons JM, Segura M (2002) Redescripción de Bournonia gardo-nica (Toucas, 1907) (Radiolitidae, Bivalvia) y análisis de lasfacies en que aparece (Coniaciense, Sistema Central, España).Rev Esp Paleontol 17(2):245–256

Gil J, Carenas B, Segura M, García-Hidalgo JF, García A (2004)Unidades litoestratigráWcas del Cretácico Superior en el centro deEspaña: correlación y revisión. Rev Soc Geol Espana 17:249–266

Gil J, García-Hidalgo JF, Segura M, García A, Carenas B (2006a)Stratigraphic architecture, palaeogeography and sea-level chang-es of a third order depositional sequence: the Late Turonian–EarlyConiacian in the northern Iberian Ranges and Central System(Spain). Sediment Geol 191:191–225. doi:10.1016/j.sed-geo.2006.03.023

Gil J, Segura M, García-Hidalgo JF, Carenas B (2006b) High-fre-quency cyclicity in the Upper Cretaceous of the Northern IberianRange (Spain). Z Dtsch Geol Ges 157:667–685

Gil J, García-Hidalgo JF, Segura M, Carenas B, García A, Temiño J,Díaz de Neira A (2008) Arquitectura estratigráWca de alta frecu-encia de una secuencia de 3er orden en el margen costero de la

Cuenca Ibérica (Provincia de Segovia, España). Bol Real Soc EspHist Nat Seccion Geol 102:15–33

Gil J, García-Hidalgo JF, Mateos M, Segura M (2009) High-frequencyorbital cycles in a late cretaceous shallow platform (Iberian Ranges,Spain). Palaeogeogr Palaeoclimatol Palaeoecol 274:40–53.doi:10.1016/j.palaeo.2008.12.017

Giménez R (1987) Estratigrafía y sedimentología del Cretácico Superioren el sector de Almansa-Requena (Provincias de Albacete y Valen-cia). Tesis Doctoral, Universidad Complutense, Madrid, p 224

Götz S (2003) Biotic interaction and synecology in a Late Cretaceouscoral-rudist biostrome of southeastern Spain. Palaeogeogr Palae-oclimatol Palaeoecol 193:125–138. doi:10.1016/S0031-0182(02)00719-8

Götz S (2007) Inside rudist ecosystems: growth, reproduction and pop-ulation dynamics. In: Scott RW (ed) Cretaceous rudists and car-bonate platforms: environmental feedback, vol 87. SEPM SpecPubl, Tulsa, pp 97–113

Hallock P (1988) The role of nutrient availability in bioerosion: conse-quences to carbonate buildups. Palaeogeogr Palaeoclimatol Pal-aeoecol 63:275–291. doi:10.1016/0031-0182(88)90100-9

Hallock P (1996) Reefs and reef limestones in Earth history. In: Birke-land C (ed) Life and death of coral reefs. Chapman & Hall, NewYork, pp 13–42

Hallock P (2001) Coral reefs, carbonate sedimentation, nutrients, andglobal change. In: Stanley GD (ed) The history and sedimentol-ogy of ancient reef ecosystems. Kluwer, Dordrecht, pp 387–427

Hallock P, Schlager W (1986) Nutrient excess and the demise of coralreefs and carbonate platforms. Palaios 1:389–398. doi:10.2307/3514476

Haq BU, Al-Qahtani AM (2005) Phanerozoic cycles of sea-levelchange on the Arabian platform. Geoarabia 10(2):127–160

Haq BU, Hardenbol J, Vail PR (1988) Mesozoic and Cenozoic chro-nostratigraphy and cycles of sea level change. In: Wilgus CK,Hastings CK, Kendall CGSC, Posamentier H, Ross CA, VanWagoner JC (eds) Sea level changes. An integrated approach, vol42. SEPM Spec Publ, Tulsa, pp 71–78

Hardenbol J, Thierry J, Farley MB, Jacquin T, De Graciansky PC, VailPR (1998) Mesozoic and Cenozoic sequence chronostratigraphicframework of European Basins. Chart 1, Mesozoic and Cenozoicsequence chronostratigraphic chart. In: De Graciansky PC, Hard-enbol J, Jacquin T, Vail P (eds) Mesozoic and Cenozoic SequenceStratigraphy of European Basins Vol 60. SEPM Spec Publ, Tulsa,Appendix

Hillgärtner H, Strasser A (2003) QuantiWcation of high-frequency sea-level Xuctuations in shallow-water carbonates: an example of theBerriasian-Valanginian (French Jura). Palaeogeogr Palaeoclima-tol Palaeoecol 200:43–63. doi:10.1016/S0031-0182(03)00444-9

Hiscott RN, Wilson RCL, Gradstein FM, Pujalte V, García-MondejarJ, Boudreau RP, Wishart HA (1990) Comparative stratigraphyand subsidence history of Mesozoic rift basins of north Atlantic.Am Assoc Pet Geol Bull 74:60–76

Homewood P, Mauriaud P, Lafont F (2000) Vademecum de Stratigra-phie Séquentielle. Elf Edition memoire 25:81

Hunt D, Tucker M (1992) Stranded parasequences and the forcedregressive wedge systems tract: deposition during base-level fall.Sediment Geol 81:1–9. doi:10.1016/0037-0738(92)90052-S

IGME (2009) Memoria del Mapa Geológico a escala 1:200.000 deSegovia (Hoja n° 38). Servicio Publ Inst Geologico Minero Es-pana Madr (in press)

James NP (1997) The cool-water carbonate depositional realm. In:James NP, Clarke JAD (eds) Cool-water carbonates, vol 56.SEPM Spec Publ, Tulsa, pp 1–20

Janssen ME, Stephenson RA, Cloetingh S (1995) Temporal and spatialcorrelations between changes in plate motions and the evolutionof rifted basins in Africa. Geol Soc Am Bull 107:1317–1332.doi:10.1130/0016-7606(1995)107<1317:TASCBC>2.3.CO;2

123

538 Facies (2009) 55:523–538

Jervey MT (1988) Quantitative modelling of siliciclastic rockssequences and their seismic expression. In: Wilgus CK, HastingsCK, Kendall CGSC, Posamentier H, Ross CA, Van Wagoner JC(eds) Sea level changes. An integrated approach, vol 42. SEPMSpec Publ, Tulsa, pp 47–70

Korbar T (2007) Intra-association development and paleobiology ofUpper Cretaceous rudist Biradiolites angulosus. In: Scott RW(ed) Cretaceous rudists and carbonate platforms: environmentalfeedback, vol 87. SEPM Spec Publ, Tulsa, pp 141–150

Milliman JD (1974) Marine carbonates. Springer, Berlin HeidelbergNew York, p 375

Moro A (1997) Stratigraphy and paleoenvironments of rudist biostro-mes in the upper Cretaceous (Turonian–Upper Santonian) lime-stones of southern Istria, Croatia. Palaeogeogr PalaeoclimatolPalaeoecol 131:113–131. doi:10.1016/S0031-0182(96)00144-7

Philip J (1998) Biostratigraphie et paléobiogéographie des rudistes:évolution des concepts et progrés récents. Bull Soc Geol Fr169:689–708

Philip J (2003) Peri-Tethyan neritic carbonate areas: distributionthrough time and driving factors. Palaeogeogr Palaeoclimatol Pal-aeoecol 196:19–37. doi:10.1016/S0031-0182(03)00311-0

Philip J, Floquet M (2000a) Late Cenomanian. In: Crasquin S (coord)Atlas Peri-Tethys, Palaeogeographical Map 14 and explanatorynotes. CCGM/CGMW, Paris, 129-136, 1 Wg

Philip J, Floquet M (2000b) Early Campanian. In: Crasquin S (coord)Atlas Peri-Tethys, Palaeogeographical Map 15 and explanatorynotes. CCGM/CGMW, Paris, 137–144, 1 Wg

Posamentier HW, Allen GP, James DP, Tesson M (1992) Forcedregressions in a sequence stratigraphic framework: concepts,examples and exploration signiWcance. Am Assoc Pet Geol Bull76(11):1687–1709

Rat P (1982) Factores condicionantes en el Cretácico de España. CuadGeol Iberica 8:1059–1076

Regidor Herrera I, García Garmilla F, Skelton PW (2007) Sclerochro-nology and diagenesis of Late Cretaceous Radiolitids (Bivalvia,Hippuritoidea), Spain. In: Scott RW (ed) Cretaceous rudists andcarbonate platforms: environmental feedback, vol 87. SEPMSpec Publ, Tulsa, pp 115–140

Reicherter KR, Pletsch TK (2000) Evidence for a synchronous circum-Iberian subsidence event and its relation to the African-Iberianplate convergence in the Late Cretaceous. Terra Nova 12:141–147. doi:10.1046/j.1365-3121.2000.00276.x

Riding R (2002) Structure and composition of organic reefs and car-bonate mud mounds: concepts and categories. Earth Sci Rev58:163–231. doi:10.1016/S0012-8252(01)00089-7

Sanders D, Pons JM (1999) Rudists formations in mixed siliciclastic-carbonate depositional environments, Upper Cretaceous, Austria:stratigraphy, sedimentology, and models of development. Palaeo-geogr Palaeoclimatol Palaeoecol 148:249–284. doi:10.1016/S0031-0182(98)00186-2

Sanders D, Pons JM (2001) Stratigraphic architecture of a Santonianmixed siliciclastic-carbonate succession (Catalonian Pyrenees,Spain). Facies 44:105–136. doi:10.1007/BF02668170

Schafhauser A, Götz S, Stinnesbeck W (2007) Rudist decline in theMaastrichtian Cardenas Formation (East-central Mexico). Palae-ogeogr Palaeoclimatol Palaeoecol 251:210–221. doi:10.1016/j.palaeo.2007.03.047

Schumann D (2000) Paleoecology of Late Cretaceous rudists settle-ments in Central Oman. In: Alsharshan AS, Scott RW (eds) Mid-dle East models of Jurassic/Cretaceous carbonate systems, vol 69.SEPM Spec Publ, Tulsa, pp 143–153

Segura M, Pérez P, Carenas B, García A, Calonge A (1989) Le Céno-manien supérieur–Turonien dans la zone centrale de la ChaîneIbérique (Espagne): une étape sédimentaire trés particuliére dansl’evolution de la plate-forme Crétacé. Geobios Mem Spec11:161–167. doi:10.1016/S0016-6995(89)80053-1

Segura M, García-Hidalgo JF, Carenas B, García A (1993) Late Ceno-manian–Early Turonian platform from Central Eastern Iberia,Spain. In: Simo JA, Scott RW, Masse JP (eds) Cretaceous carbon-ate platforms, vol 56. Am Assoc Petrol Geol Mem, Tulsa, pp 283–296

Segura M, Carenas B, Gil J, García-Hidalgo JF, García A (2001) Anat-omy of the carbonate bodies in relation to their position withrespect to the maximum transgressive in the 2nd-order cycles ofthe Upper Cretaceous from the Iberian Range. Geol Mediterr28:163–168

Segura M, García A, Carenas B, García-Hidalgo JF, Gil J (2002) UpperCretaceous of the Iberian Basin. In: Gibbons W, Moreno MT(eds) The geology of Spain. Geol Soc, Lond, pp 288–292

Segura M, García-Hidalgo JF, Carenas B, Gil J, García A (2004) Evo-lución paleogeográWca de la Cuenca Ibérica en el Cretácico Supe-rior. Geogaceta 36:103–106

Stanley SM, Hardie LA (1998) Secular oscillations in the carbonatemineralogy of reef-building and sediment-producing organismsdriven by tectonically forced shifts in seawater chemistry. Palae-ogeogr Palaeoclimatol Palaeoecol 144:3–9. doi:10.1016/S0031-0182(98)00109-6

Steuber T (1996) Stable isotope sclerochronology of rudist bivalves:growth rates and Late Cretaceous seasonality. Geology 40:315–318. doi:10.1130/0091-7613(1996)024<0315:SISORB>2.3.CO;2

Steuber T (1999) Cretaceous rudists of Boeotia, central Greece. SpecPap Palaeontol 61:1–229

Steuber T (2000) Skeletal growth rates of Upper Cretaceous rudistbivalves: implications for carbonate production and organism—environment feedbacks. In: Insalaco E, Skelton PW, Palmer TJ(eds) Carbonate platform systems: components and interactions,vol 178. Geol Soc Lond Spec Publ, Lond, pp 21–32

Steuber T, Rauch M, Masse J-P, Graaf J, Malkoc M (2005) Low-lati-tude seasonality of Cretaceous temperatures in warm and coldepisodes. Nature 437:1341–1344. doi:10.1038/nature04096

Strasser A, Hilgen FJ, Heckel PH (2006) Cyclostratigraphy—con-cepts, deWnitions, and applications. Newsl Stratigr 42(2):75–114.doi:10.1127/0078-0421/2006/0042-0075

Toucas A (1908) Études sur la classiWcation et l’évolution des Radiol-itidés. Sphaerulites et Radiolites. Mémoires de la Société Géolog-ique de France. Paléontologie 16 (Mémoire n. 36):47–78

Van Wagoner JC, Posamentier HW, Mitchum RM, Vail PR, Sarg JF,Loutit TS, Hardenbol J (1988) An overview of the fundamentalsof the sequence stratigraphy and key deWnitions. In: Wilgus CK,Hastings CK, Kendall CGSC, Posamentier H, Ross CA, VanWagoner JC (eds) Sea level changes: an integrated approach, vol42. SEPM Spec Publ, Tulsa, pp 39–45

Vilardell O, Gili E (2003) Quantitative study of a hippuritid rudistlithosome in a Santonian carbonate platform in the southern Cen-tral Pyrenees. Palaeogeogr Palaeoclimatol Palaeoecol 200:31–41.doi:10.1016/S0031-0182(03)00443-7

Wiedmann J (1975) Subdivisiones y precisiones bio-estratigráWcas enel Cretácico superior de las Cadenas Celtibéricas. Actas 1er Sym-posium sobre el Cretácico de la Cordillera Ibérica, Cuenca, pp135–153

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