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Accepted for Publication: SEPM Special Publication dedicated to the Deposits, Architecture and Controls of

Carbonate Margin, Slope, and Basin Systems: (Publication Release June/July 2013).

MAGNETIC SUSCEPTIBILITY (Χ STRATIGRAPHY AND CHEMOSTRATIGRAPHY

APPLIED TO AN ISOLATED CARBONATE PLATFORM REEF COMPLEX;

LLUCMAJOR PLATFORM, MALLORCA

DAVIES, E.J and RATCLIFFE, K.T.

Chemostrat Limited, Unit 1 Ravenscroft Court, Buttington Cross Enterprise Park, Welshpool, SY21 8SL, UK

MONTGOMERY, P.

Chevron Upstream Europe, Seafield House, Hill of Rubislaw, Aberdeen, AB15 6XL, UK

POMAR, L.

Universitat de les Illes Balears, Palma de Mallorca, Spain

ELLWOOD, B.B.

Department of Geology and Geophysics, Louisiana State University, Baton Rouge, Louisianna 70803, USA

WRAY, D.S.

School of Science, University of Greenwich, Chatham Maritime, Kent, ME4 4TB, UK

ABSTRACT

Inorganic whole rock geochemical and magnetic susceptibility (χ data have been gathered from 7 sections

through the Upper Miocene reef complexes of the Llucmajor Platform, Mallorca. The aim of acquiring these

data is to determine what chronostratigraphic information a combination of magnetic susceptibility stratigraphy

(MSS) and chemostratigraphy can provide in reef complexes of a carbonate platform with no nearby source of

terrigenous material.

χ values display short-term cyclical fluctuations, maximum values commonly being associated with the upper

bounding surfaces of sigmoids and sigmoid sets, the building blocks of the Llucmajor reef complexes. Values of

χ are low at the bases of the sigmoids, they reach a maximum at the top of the sigmoids, and then fall rapidly to

the base of the next sigmoid, indicating a base level control on χ values. No longer-term variation in the χ values

have been identified that would enable differentiation of an old reef complex from one that is demonstrably

younger in the cliff sections and there is no apparent facies control on χ values. While, the elemental data do not

vary in response to base level fluctuations and therefore do not define stratigraphic surfaces, they do show long

term variations, enabling reef complexes of differing ages to be geochemically characterized, the key to defining

chemostratigraphic schemes. The elements used to characterize different age reef complexes are Cr, Zr, Al2O3,

TiO2, Ga, Rb, which are controlled by changes in the amount and composition of wind-blown terrigenous

material and tuffaceous material. As such, the changes are chronostratigraphic events on the scale of the study

intervals here. Although the two datasets used are both ultimately controlled by the mineral composition of the

sediments, it has proved impossible to find a direct link between the elemental data and χ values.

Despite the lack of an understanding of the relationship between whole rock geochemistry and χ values for this

dataset, they clearly provide a means to a) define stratal surfaces that relate to base level fluctuation and b)

recognize reef complexes deposited at different times. Therefore, the combined approach adopted here for the

Llucmajor reef complex has the potential to provide cross-facies chronostratigraphic correlations in detached

platform carbonate settings and since both methods can be applied to core and cuttings samples, the approach

could work in subsurface settings where samples would be from well-bores.

KEY WORDS: Stratigraphy, Chemostratigraphy, Magnetic susceptibility (χ), carbonate platform, Llucmajor

MAGNETIC SUSCEPTIBILITY (Χ STRATIGRAPHY AND CHEMOSTRATIGRAPHY APPLIED TO AN ISOLATED

CARBONATE PLATFORM REEF COMPLEX; LLUCMAJOR PLATFORM, MALLORCA



INTRODUCTION Increasingly, “alternative” stratigraphic

methods, such as whole rock elemental

chemostratigraphy and magnetic susceptibility

stratigraphy (MSS), are being used to provide

stratigraphic correlation frameworks (see

Ratcliffe and Zaitlin, 2010 for review of

chemostratigraphic and MSS methods). Both

stratigraphic methods are being used in the

petroleum industry to help construct

correlations between well bores and therefore

enhance understanding of hydrocarbon

reservoirs. However, in most published

accounts the resultant stratigraphic correlations

cannot be compared against irrefutable

stratigraphic surface correlation that has been

derived from more conventional approaches or

from visual / physical correlations.

Furthermore, although MSS has been applied

to relatively pure carbonate lithologies,

including detached platform settings (da Silva

et al., 2009, Stage, 2001, Ellwood et al.,

2010a, 2010b), there are few published

accounts of chemostratigraphic applications on

pure carbonates (Wray and Gale, 2006) and

none on isolated carbonate platforms have

been found. The paucity of published

chemostratigraphic examples in carbonate

lithologies probably reflects the fact that most

accounts of chemostratigraphy in the literature

relate the elemental data to siliciclastic

components of the sediments (e.g. Hildred et

al., 2010, Pearce et al., 2005, Wright et al.,

2010 and Ver Straeten et al., 2011). The only

non-carbonate input into the sediments of

detached platform systems is wind-blown

material and while there are published

accounts of the mineralogy of wind-blown

detritus (e.g. Stuut, et al., 2009, Saukel, et al.,

2011) there is little published information on

the whole rock inorganic geochemistry of such

sediments (e.g. Castillo et al., 2008, Wang et

al., 2010) and no accounts have been found

using elemental data in wind-blown sediments

to make stratigraphic implications. It is

therefore questionable as to whether

chemostratigraphy, which is typically reliant

upon changes in the amounts and types of

terrigenous material, can be realistically used

in a detached carbonate platform setting.

In order to test the efficacy of the stratigraphic

methods in pure carbonate lithologies,

chemostratigraphy and MSS are applied to

Upper Miocene reef complexes of the

Llucmajor Platform (Figures 1 and 2). These

reef complexes crop out on the southern sea-

cliffs of the Balearic island of Mallorca and

have been extensively studied in the past,

being a “classic” example of how reef

complexes respond to sea level fluctuations

(Pomar and Ward 1994, 1995).

Although the Llucmajor reef complexes are

not strictly detached carbonate platforms since

they are attached to small emergent areas, the

emergent areas are carbonate lithologies and

therefore provided no siliciclastic detritus. The

almost perfect exposure and published studies

provides an exceptionally robust

understanding of their facies architecture and

Figure 1. Location map. Upper left inset shows location

of Mallorca in the Western Mediterranean Sea. Main map displays outline of Mallorca and the location of the reef platforms (light grey), carbonate highlands (dark grey.)

CB-TV denotes the extent of the cliff section displayed in Figure 2.

TVMALLORCA

50km

Reef platforms

Reef platform margin

Highlands

(Alpine thrust belts)

39 30’ N

3 EMarratxi

platform

Alcudia

platform

Santtanyi

platform

Cap Blanc

(CB)

Palma

basinLlucmajor

platform

Mallorca

500km

Cliff section in Figure 2





0 321 4

km

CB

Vallgornera

TVPC

PNC

CCCOSGW

Reef tract

Line of projection

1

CB SGW CO CC PNC TVPC

100m

50m

0m

Cala PiCala Beltran

Vallgornera

Cap Blanc

Pleistoceneeolianite



Pliocene post-reef grainstone

lagoon

lagoonreef

slope

stratigraphy, making them an ideal testing

ground for MSS and chemostratigraphy.

Specifically, they provide an opportunity to

see how elemental geochemistry and magnetic

susceptibility signals respond to changing sea

level in a well understood prograding reef

complex that is part of an isolated carbonate

platform with the only non-carbonate material

being wind-blown terrigenous and

volcanogenic detritus.

Figure 2. Sea cliffs of the Cap Blanc region. Lower right inset is an enlarged map of the SE coastline of Mallorca (see

Figure 1 for position of this coastline), with the location of each study interval displayed. The lower left photograph

shows the Cap Blanc to Cala Carril (cc) cliff section with facies interpretation over lain; horizontal length is 2 km.

Top panel is a composite sketch of the sea cliffs of from Cap Blanc to Vallgornera (TV), with vertical black bars

showing the approximate location of the sections referred to in the text (CB, SGW, CC, CO PNC and TV) and key

striatal surfaces shown in black.

SATorre(CBSection)

CalaCarril(CCSection)

Punta Negra(PNCSection)

Fore ReefSlope

ReefCoreReef

Core

Inner

Lagoon

Inner

Lagoon

Outer

Lagoon

Outer

LagoonOuter

Lagoon

Reef fa

cies

Reef fa

cies

Reef fa

cies

Lagoonal

Lagoonal

Lagoonal

Fore

reef fa

cies

Fore

reef fa

cies

sb

Ci

sbsb

sb

dls

2km0.3km 2km

0.3km

10m

10

m

Pliestocene

Pliestocene

SATorre(CBSection)

CalaCarril(CCSection)

Punta Negra(PNCSection)

Pliestocene

Pliestocene

Figure 3. Stratigraphic correlation of reef complexes from Punta Negra (PNC Section) to Cap Blanc (CB Section)

3a) probable correlation that would result if perfect exposure did not exist, or the only data available were wireline

logs and cuttings, i.e. well-bore data. 3b) Actual correlation, based upon interpretations of Pomar and Ward (1994).

Redrawn from Pomar and Ward (1995)





Being able to chronostratigraphically correlate

between well bores in subsurface carbonate

platforms is exceptionally difficult due to lack

of preserved diagnostic fauna and flora, strong

facies control and lack of contiguous surfaces

that can be recognized in the subsurface.

Figure 3a demonstrates how a correlation from

Punta Negra to Cap Blanc in the sea cliffs of

this paper may look if data were only available

from the subsurface (wireline logs and cuttings

samples). Figure 3b shows the actual

interpretation placed on the same section that

is afforded by the well exposed nature of the

sea cliffs highlighting the issues faced when

working with reef complexes in the

subsurface. The aim of this paper is to

demonstrate how the application of

chemostratigraphy and MSS could help move

a subsurface correlation toward the

interpretation shown in Figure 3b, rather than

Figure 3a. Although specific to the Llucmajor

Platform, the methods described here are

equally applicable to any setting where the

lithologies are predominantly pure carbonates.

Therefore, this work demonstrates that a

combined MSS and chemostratigraphy

approach can provide high resolution

stratigraphic correlation in any detached

carbonate platform. Both methods are proven

to work on well-bore cuttings samples

(Ellwood et al. 2001, Ratcliffe et al. 2010) and

therefore, the applications here can be applied

to creating stratigraphic frameworks in

subsurface settings.

Study Material The sea-cliff exposures of Upper Miocene reef

complexes on the southern coast of Mallorca

that are the focus for this paper (Figure 1) are

part of the Llucmajor Platform, one of several

reef complexes that developed in late Miocene

times in the region of the present day Balearic

Islands. For this paper, the carbonates near the

Cap Blanc area of southern Mallorca are

selected because of their excellent exposure

and their well-documented depositional

models and high resolution architectural facies

model (Pomar 1991, 1993, Pomar and Ward

1994, Pomar et al., 1996) (Figures 2 and 4).

The Llucmajor Platform has been extensively

studied and described by Pomar and Ward,

(1994; 1995; 1999) and Pomar et al. (1996).

The sediments analysed here comprise

proximal fore reef slope facies, reef core facies

and lagoonal facies. The fore reef facies are

characterized by seaward-dipping clinoforms

and are composed of skeletal floatstones to

grainstones and packstones with coral,

rhodolith and mollusc fragments. Reef core

facies have characteristic sigmoidal bedding

and are composed of skeletal grainstone

/packstone/wackestone within a coral

framework that is composed of massive coral

reefs. Sediments from lagoonal facies are

skeletal grainstones and packstones with

lenses of coral breccia and patch reefs in outer

lagoonal settings to mudstones-wackestones

and stromatolites in inner settings (Pomar,

1991; Pomar and Ward, 1994, 1995, 1999, and

Pomar et al. 1996.).

The study sections in this paper are a subset of

those described by Pomar and Ward (1999)

and the section names (CB, SGW etc.) refer to

the measured sections of those authors. Figure

4 displays the hierarchical stacking of

sigmoidal depositional units described by

Pomar and Ward (1994). The sigmoid is the

basic building block, representing a

depositional sequence related to the highest-

frequency sea-level cycle recognized (Figure

4A). Sigmoids stack in sets of sigmoids as

seen on the sea cliffs on Mallorca (Figure 4B)

and sigmoid sets stack in cosets of sigmoids

(Figure 4C). The sigmoid cosets stack into

megasets, three of which build the whole

Llucmajor Platform (Figure 4D). The reef-

crest line displayed on Figures 4A-4E (Pomar,

1991) follows the trajectory of successive

positions of the reef crest and it reflects the

amplitude of sea-level fluctuations.

http://www.sepmstrata.org/page.aspx?pageid=54







Figure 4. Facies architecture of the Llucmajor Platform. (A) The sigmoid represents a basic depositional sequence

related to the highest-frequency sea-level cycle. (B) Sigmoids stack in sets of sigmoids as seen on the sea cliffs on

Mallorca. (C) Sets stack in cosets of sigmoids (inset box outlined by red dashed line corresponds to B). (D) Cosets

stack in megasets and three megasets of sigmoids build up the whole Llucmajor Platform; sb: sequence boundary;

dls: downlap surface; ci: condensed interval. (E) Comparison between the reef-crest line, established from the

megasets of sigmoids in the Mallorca’s Llucmajor Platform, and the composite smoothed short-term oxygen

isotope record from Abreu and Haddad (1998), as a proxy for 3rd

-order eustatic sea-level cycles. (F) Wheeler

diagram of Sea cliff section in C. Redrawn from Pomar and Ward (1994).





The reef-crest line, established from the

megasets in the Mallorca’s Llucmajor

Platform, compares closely with the composite

smoothed short-term oxygen isotope record

from Abreu and Haddad (1998) (Figure 4E),

which is a proxy for 3rd

-order eustatic sea-level

cycles. Accordingly, the sigmoid cosets

represent 4th-order cycles, sigmoid sets

correspond to 5th

-order cycles, and sigmoids to

6th-order cycles. The bounding surfaces of the

sigmoids, sigmoid sets, sigmoid cosets and

sigmoid megasets are therefore 6th, 5

th, 4

th, and

3rd

order sequence boundaries respectively.

Figure 4F is a Wheeler diagram constructed

from interpretation of the cliff section shown

in Figures 2 and Figure 4C.

The reef complexes in the Llucmajor Platform

area developed on a small emergent platform

with no fluvial input, resulting in the

sediments being almost pure carbonate (calcite

and dolomite). The only impurities are wind-

blown terrigenous detritus, which is a

ubiquitous feature of all depositional settings,

and wind-blown volcanic ash, with a least one

sanidine biotite-rich tuff being recorded in the

sequence. (Al2O3 + SiO2) generally accounts

for <2% of the major elements analysed and

(CaO + MgO) accounts for > 97% of the major

elements (Table 2), indicating the almost pure

carbonate nature of the study interval

sediments. Unfortunately, after analysis for

this paper, plus analysis for carbon and oxygen

isotope analysis (that were not available at the

time this paper was prepared) insufficient

sample material remained to allow X-Ray

diffraction quantification of the non-carbonate

fraction of the lithologies.

Samples were taken from 7 cliff sections

extending from Vallgornera in the east to Cap

Blanc in the west (Figures 1, 2 and 4). A total

of 267 samples were collected and analysed

from the 7 sections (Table 1, Figure 2).

Samples were taken at an average spacing of

1m, although accessibility and ease of taking

plugs results in variation in sample spacing

from a maximum of 2.5m and a minimum of

0.3m. Each sample collected is a 1” diameter

core plug, c. 1-2” in length. Where possible,

the plug was taken to avoid large allochems,

targeting sediments between coral colonies in

the reef complexes. All surficial contamination

was removed prior to approximately half of

the plug being disaggregated. Half of the

disaggregated chips were analysed for

magnetic susceptibility and the remainder was

ground in an agate ball mill prior to being

prepared for inductively coupled plasma

optical emission spectrometry (ICP OES) and

inductively coupled plasma mass spectrometry

(ICP MS) analyses. The remaining material

has been sent for stable isotope analysis,

although the results are not available at the

time this paper was written.

Table 1 Sample Summary

Section Thickness

(m) Sample

No

Av sample spacing

CB 58.6 53 1.11

SGW 26.75 30 0.89

CO 60 41 1.46

CC 53.6 46 1.17

PNC 44 36 1.22

PC 26.1 32 0.82

TV 27.94 29 0.96

METHODOLOGIES

Magnetic Susceptibility Stratigraphy

All mineral grains are “susceptible” to

becoming magnetized in the presence of a

magnetic field, and the low-field, mass-

specific bulk magnetic susceptibility (χ is an

indicator of the strength of this transient

magnetism within a material sample (Nagata,

1961). Magnetizable materials in sediments

include not only the ferrimagnetic minerals

(such as magnetite or greigite), but also any

other less magnetic, or paramagnetic,

compounds. The important paramagnetic

minerals in marine sediments include clays





Table 2. Average element abundances in 3 main facies. Element abundance is expressed as a

percentage of the major elements summed. X values are average values for each facies.

(particularly chlorite, smectite and illite),

ferromagnesian silicates (biotite, tourmaline,

pyroxene and amphiboles), iron sulfides

(pyrite and marcasite), iron carbonates

(siderite and ankerite), and other iron- and

magnesium-bearing minerals (Ellwood et al.,

1989; Ellwood et al., 2000). Calcite, quartz,

and organic compounds typically acquire a

very weak negative χ when placed in inducing

magnetic fields; that is, their acquired χ is

opposed to the low magnetic field applied. The

presence of these diamagnetic minerals

reduces the χ in a sample, but because

diamagnetism is so small by many orders of

magnitude for an equivalent mass sample,

even very small amounts of paramagnetic

minerals will usually dominate over

diamagnetic components. Therefore, in marine

sediments, χ is generally considered to be an

indicator of iron, ferromagnesian, or clay-

mineral concentration (Ellwood et al., 2000;

Ellwood et al., 2010a, 2010b). In an isolated

carbonate setting, such as Llucmajor Platform,

χ values can be expected to relate to the

amount of terrigenous material in the

limestone lithologies (da Silva et al., 2009)

and should therefore be related to the whole

rock inorganic geochemistry.

All measurements reported herein were

performed using the susceptibility bridge at

Louisiana State University (LSU). It is

calibrated using standard salts for which

values are reported in the Handbook of

Physics and Chemistry and by Swartzendruber

(1992). The LSU bridge is very sensitive, is

easy and fast to use, and the measurement coil

is optimized for small samples, making it ideal

for measuring large numbers of samples

rapidly. χ is reported in terms of sample mass

because it is much easier and faster to measure

with high precision than is volume (Ellwood et

al., 1988b). Each sample is measured three

times and the mean and standard deviation of

these measurements is calculated. The mean of

these measurements is reported here.

Chemostratigraphy

Chemostratigraphy, as used here, refers to the

development of stratigraphies using variations

in elemental composition. Typically, the aim

of a chemostratigraphic approach is to identify

elements and element ratios that change

through time and which therefore enable

sediments of the same age to be correlated, or

differentiated from sediments that are

asynchronous. Published accounts of

chemostratigraphy are largely from petroleum

basins and are mostly on fluvial siliciclastic

systems and shale resource plays. In fluvial

settings, the elemental data are typically used

to recognize changes in paleoclimate (Pearce

2005, Ratcliffe 2010), changes in sedimentary

facies and changes in sediment provenance

Facies Average

(Al2O3+SiO2) Average

MgO Average

CaO

Average (CaO

+MgO)

Average Average

Calculated Calculated (m3/kg)

Dolomite Calcite

Lagoonal 1.4 13 83 96 18 79 6.40E-

09

Reef Core

0.7 29 68 97 41 57 4.70E-

09

Fore Reef

0.5 34 63 97 29 69 8.10E-

09





(Hildred 2010, Wright 2010, Ramkumar, et al.,

2011). In shale resource plays, the elemental

data are commonly used to recognize

terrigenous material influx and content (Algeo

et al., 2004, Soau, 2010, Ver Straeten et al.,

2011,) and as a proxy for bottom water

conditions during deposition (Tribovillard et

al., 2006, Rowe et al., 2012). These changes

are then used to build a stratigraphic

framework and provide stratigraphic

correlations. In the case of the Llucmajor

Platform carbonates, the vast majority of the

rock volume is calcite and dolomite, with CaO

plus MgO accounting for an average of 97% of

the major element total expressed as weight

percentage. Therefore, the aim here is to

determine whether changes in such minor

amount of non-carbonate material can be

detected using elemental geochemistry and

whether such changes show systematic

changes through time that would have the

potential to devise stratigraphic correlations in

a similar manner to how fluvial workers use

the technique.

In order to carry out chemostratigraphic

studies, data for a wide array of major and

trace element are required and require

instrumentation that can detect and quantify

these trace elements at very low abundances.

For this study, the elemental data have been

acquired using inductively couple plasma

optical emission spectrometry (ICP OES) and

inductively couple plasma mass spectrometry

(ICP MS), following a Li-metaborate fusion

(Jarvis and Jarvis, 1995). This methodology

provides data for 10 major elements (SiO2,

TiO2, Al2O3, Fe2O3, MgO, MnO, CaO, Na2O,

K2O, P2O5), 25 trace elements (Ba, Be, Bi, Co,

Cr, Cs, Cu, Ga, Hf, Mo, Nb, Ni, Pb, Rb, Sn,

Sr, Ta, Tl, Th, U, V, W, Y, Zn, Zr);and 14 rare

earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd,

Tb, Ho, Dy, Er, Tm, Yb, Lu).

RESULTS

Magnetic susceptibility (χ )

χ values for three sections (CB, CO and CC)

are displayed on Figure 5, together with the

stratigraphic interpretation taken from the cliff

section (Pomar and Ward 1994). It is apparent

from χ curves that there are numerous cyclical

fluctuations in the χ values that show a

gradual upward increase to a local maximum,

followed by a sharp upward decrease to the

base of the next cycle. Within the CB sections,

these are generally on the scale of 5-10m,

which is the same magnitude as the basic

sigmoid building block described by Pomar

and Ward (1994) and displayed in Figure 4A.

Maxima in χ values are very evidently

associated with condensed intervals (Ci) and

downlap surfaces (DLS) and some sequence

boundaries (sb). Not all sequence boundaries

appear to be defined by χ cycle tops (e.g. sb2

in CB Section). The cycles in the CC Section

are less clearly developed, but this may relate

to sample distribution (which in turn related to

accessible sample points). Although the χ

values show peaks at upper bounding surfaces,

the magnitude of the peaks do not distinguish

between sigmoid (6th order) and sets of

sigmoid (5th order) surfaces, nor between

sequence boundaries, downlap surfaces of

condensed intervals.

Neither the absolute χ values, nor the

character of the χ logs are markedly different

between fore reef, reef core and lagoonal

facies (Table2, Figures 5 and 6) indicating that

there is not a strong facies control on χ values.

Furthermore, when χ values from the same

facies, but different ages are compared (Figure

7) there is no obvious overall change in χ

values from the oldest reef facies in PC

Section through to the youngest reef facies in

CB Section. Similarly, χ values in the older

lagoonal facies in PNC Section show no clear

difference from values in the younger lagoonal

facies of SGW Section.

MAGNETIC SUSCEPTIBILITY (Χ STRATIGRAPHY AND CHEMOSTRATIGRAPHY APPLIED TO AN ISOLATED CARBONATE PLATFORM REEF COMPLEX; LLUCMAJOR PLATFORM,

MALLORCA

Accepted for Publication: SEPM Special Publication dedicated to the Deposits, Architecture and Controls of Carbonate Margin, Slope, and Basin Systems: (Publication

Release June/July 2013).

Figure 5. χ values curves for CB Section, CO Section and CC Section plotted against sketch logs of the sections and overlain with a stratigraphic interpretation based on

interpretation of cliff sketch shown in Figure 2.

Up

perM

ioce

ne

ReefC

om

ple

xPle

isto

cene

Reefc

ore

eolianites

and

red soils

Inner lagoon

Forereef

splope

Reef

crest

Massive

coral zone

Branching

coral zone

Dish

coral

zone

0

10

20

30

40

50

60

70

80

0

10

20

30

40

50

0

10

20

30

40

50

60

erosion su rface

erosion su rface

erosion su rfaceerosion su rface

downlap su rface

condensed i nterval

condensed i nterval

Section

CB

Section

COSection

CC

SB

SB

SB

DLS

DLS

Ci

Ci

Ci

Ci

sigmoid

sigm

oid

Set sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid

sigmoid?

sigmoid?

sigmoid?

sigmoid

c(m3/kg)

c(m3/kg)

c(m3/kg)

condensed i nterval

condensed

interval

erosion su rface

erosion surface





Available sampling resolution generally

precludes any more detailed analysis of

cyclicity in the χ values, Ellwood et al., (2008,

2010a and 2101b) arguing for a sampling

resolution of 0.25m or less, whereas here a

sampling resolution of 1m has been employed

and the sample spacing could not be regular

due to access.

Elemental data

Although a total of 50 elements are acquired

using ICP OES and ICP MS analyses,

chemostratigraphic studies typically rely upon

a smaller number of elements which are key to

a specific sequence. Here, the aim is to

determine which of the 50 elements acquired

are linked to terrigenous material and whether

those elements, or ratios of those elements,

show systematic changes within the reef

complexes. In order to identify which elements

are linked to terrigenous material, Eigen

vectors (EV), derived from principal

components analysis are plotted (Figure 8).

Plots of Eigen vector scores such as those on

Figure 8 are an effective method to understand

element – element relationships in sediments

(Pearce et al., 2005, Svendsen et al., 2007;

Ellwood et al., 2008; Pe-Piper et al., 2008,

Ratcliffe et al., 2010)). Elements that plot in

close proximity to one another are closely

associated in the sediments, therefore by

identifying groups of elements, their likely

mineralogical affinities can be postulated. The

elements plotted on Figure 8 fall into two

broad groups; those with negative EV1 scores

and those with positive EV1 scores. Elements

that plot with negative EV1 scores include

CaO and MgO and can therefore be assumed

to be associated with the carbonate minerals in

the samples. These carbonate-related elements

fall into two sub groups, those with negative

EV2 scores and those with positive EV2

scores. MgO has high positive EV2 scores and

CaO high negative scores, probably reflecting

the degree to which samples have been

dolomitized. Therefore, it can be assumed that

P2O5, MnO, Na2O, U, Cu, Mo and Co, with

plot in the same quadrant as MgO are all

elements that are associated with dolomite and

are therefore unlikely to be of use

chronostratigraphically. Similarly Ba, Ni, Sn

and Sr plot in the same quadrant as CaO and

are therefore associated with the amount of

calcite, again unlikely to provide meaningful

chronostratigraphic information from whole

rock samples.

The group of elements with high positive EV1

scores includes SiO2 and Al2O3 and is

therefore associated with siliciclastic minerals

in the sediments, which in the Llucmajor

platform must have been introduced by air fall.

Also included in this group of elements are

TiO2, Th, Zr, Cr and Nb, all of which are

typically associated with detrital input into

depositional systems (Scopelliti, et al., 2006,

Tribovillard et al, 2006, Ramkumar et al.,

2011, Ver Straeten et al., 2011). These

elements cluster around the zero EV2 axis

indicating that they are not influenced by the

amount of MgO versus CaO, i.e. they are not

affected by dolomitisation. It is this group of

elements that potentially provide a means of

chronostratigraphically significant

chemostratigraphic correlation and which are

used below to consider changes in elemental

composition through time.

Figure 9 displays a series of binary diagrams,

which provide another means to assess the

element-to-element associations in the

sediments. Figures 9a-d show that SiO2, TiO2,

K2O and Fe2O3 all have well defined linear

trends when plotted against Al2O3, indicating

that each of these elements is associated with

al-silicates. The few samples on Figure 9a that

have high SiO2 values relative to Al2O3 values

(i.e. plot off the main linear trend) may reflect

concentrations of detrital quartz grains, or

more probably reflects either biogenic or

diagenetic quartz. Although Cr and Zr plot in

the overall group of elements labeled

“terrigenous” on Figure 8, their linear





association with Al2O3 (and therefore with

SiO2 based on Figure 9a) is weak, implying

that there may be more than simple air fall

terrigenous material present (see Discussion).

Figure 6 shows that samples from the lagoonal

facies have higher average SiO2, Al2O3, Fe2O3

and K2O contents than reef core or fore reef

facies, this indicates that there is some degree

of facies control on the terrigenous-related

elemental data (Table 2).

Figure 6. χ values and selected major element values

in fore reef, reef and lagoonal facies. All samples from

the study have been assigned to a one of the three

main facies present (fore reef, reef core and lagoonal)

and are plotted here to demonstrate any changes in χ

values and elemental concentrations that are related

to facies.

On the scale of these reef complexes, the

composition of the terrigenous material

entering the reef complex is unlikely to have

changed laterally, therefore the facies control

likely reflects depositional sorting, i.e.

terrigenous material was preferentially ponded

in the lagoonal facies. Therefore, in order to

see how the trace element geochemistry of the

siliciclastic components change through time,

the elemental compositions of each facies has

been considered separately (Figures 7 and 10).

Changes in elemental composition

through time

Reef Core facies

The chemical logs displayed on the left of

Figure 7 are constructed from the reef core

facies in each of the study sections, the oldest

at the base (PC section), working through to

the youngest at the top (CB section). Within

each section the samples are plotted in

stratigraphic order. The chemical logs

demonstrate that from deposition of the reefs

in the PC section to deposition of reefs in the

CO section Cr values gradually increase,

reaching a maximum in the lower parts of the

CO section. Reef core facies of the CB section

have generally low Cr values, although toward

the top of the section, Cr starts to increase,

suggesting the onset of another upward

increase in Cr values. Zr/Cr values display an

overall upward decrease, with two notable

steps, one between samples from PC section

and PNC section and the other between

samples from the CO and CB sections (Figure

7).

Lagoonal facies

The chemical logs on the right of Figure 7 are

constructed from the lagoonal facies of the

PNC and SGW sections, which the Wheeler

Diagram clearly show to be of different ages.

The PNC Section samples high Cr/Nb and

Cr/Zr values compared the SGW lagoonal

samples.

Fore reef facies

The binary diagrams on Figure 9 show that the

fore reef samples from the CB section are

chemically different to those of the CC and

CO sections. The CB section fore reef samples

have higher Al2O3/TiO2 values and Ga/Rb

values than the CC and CO section fore reef

deposits. The fore reef deposits in the CC and

CO sections are almost synchronous and are

correlated using χ values in Figure 3, whereas

the fore reef sections from the CB Section are

younger than those of CC and CO Sections.

0.0

0.0

0.0

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.8

0.8

0.8

0.8

0.6

0.6

0.9

1.0

1.1

1.2

1.2

1.2-0 0 0 0 0 0 0 0 0 0

0.0

0.0

0.0

0.3

0.6

0.9

1.2

1.5

0.0

0.0

0.0

0.0

0.0

0.0

0.000000

0.0

0.3

0.6

0.9

1.2

1.5

0.0

0.0

MSS Al Si Fe Ti

Lagoon

Reef

Slope

0 - 8 0 - 1.20 - 0.60 - 1.50 - 1.5


MALLORCA



Figure 7. Changes in χ values and selected elemental ratios through time. On the left, samples from reef core facies are arranged such that the oldest reef core facies (PC Section) are at the

base and youngest (CB Section) are at the top. The thick grey lines and associated letter (A-E) show approximately where the sections are on the Wheeler diagram. On the right, samples from

lagoonal facies are arranged such that the oldest (PNC Section) are beneath the younger ones from SGW section. Block lines and associated numeral (1-2) show approximately where the

sections are on the Wheeler diagram. The data are arranged in this manner to show how selected element ratios within a single facies change through time, whereas no such secular change

is seen in the χ values. Refer to Figure 2 for section locations on cliff sections.





Lagoonal facies

The chemical logs on the right of Figure 7 are

constructed from the lagoonal facies of the

PNC and SGW sections, which the Wheeler

Diagram clearly show to be of different ages.

The PNC Section samples high Cr/Nb and

Cr/Zr values compared the SGW lagoonal

samples.

Fore reef facies

The binary diagrams on Figure 9 show that the

fore reef samples from the CB section are

chemically different to those of the CC and

CO sections. The CB section fore reef samples

have higher Al2O3/TiO2 values and Ga/Rb

values than the CC and CO section fore reef

deposits. The fore reef deposits in the CC and

CO sections are almost synchronous and are

correlated using χ values in Figure 3, whereas

the fore reef sections from the CB Section are

younger than those of CC and CO Sections.

Figure 8. Cross plot of Eigen vector 1 and 2 scores for

all elemental acquired from all sections.DISCUSSION

Elemental Data

Although the elemental data do not provide a

means to define stratal surfaces in the reef

complexes in the manner of χ values, they do

clearly show gradual and stepped changes

through time (Figures 7 and 10). This type of

change forms the basis for chemostratigraphic

characterization, i.e. units with different

elemental compositions that are shown to be

stratigraphically significant cannot be

correlative. Therefore, reef-core facies, for

example, with different elemental

compositions cannot be time correlative,

provided the elements and element ratios used

in the characterization can be shown to be

related to changes that took place through

time, not changes that relate to facies or

diagenesis. In Figure 3, for example, the

possible correlation displayed on the left (3a),

cannot be correct since the reef core facies in

the Cap Blanc Section are chemically different

to those in the CC and PNC sections (Figure

7). The chemical logs shown on Figure 7,

however do not contradict the correct

correlation on the right of Figure 3 (3b).

The elements used to characterise temporal

changes are Cr, Zr, Al2O3, TiO2, Ga and Rb

(Figures 7 and 10). These elements are all

linked to non-carbonate, non-diagenetic

minerals and must therefore somehow reflect

changes in the types and amounts of

windblown material, including tuffaceous

debris within the sediments.. Direct

determination of changes in mineralogy

associated the chemical changes is impossible

with the available sample material. The almost

pure carbonate nature of these sediments and

the available sample volume precludes

obtaining accurate determination of clay

mineral species using XRD and it would not

be possible to carry out the heavy mineral

analyses to determine the composition of

detrital grains. It is unlikely that sufficient non

carbonate material could be identified in thin

section or using scanning electron microscopes

to provide statistically meaningful data. The

limiting factor of sample volume is a common

one in subsurface samples, where non-

destructive or minimal destruction of sample is

a prerequisite for analyses. Therefore, methods

employed here for the interpretations of the

changing elements and element ratios are in

many ways typical of dealing with “pure”

carbonates in a subsurface environment.

Application of Eigen vectors to understanding

element-to-element

-0.5

-0.4

-0.3

-0.2

-0.1-0.2 0 0.1 0.2

CaO

Sr

Ni

Sn

-0.1

0

0.1

0.2

0.3

0.4

0.5

Al2O

3

SiO2

TiO2

Fe2O

3

MnO

MgO

Na2O

K2O

P2O

5

Ba

Be

Cr

Sc

Zn

Zr

V

Co

Cu

Ga

Y

MS Nb

MoCsLREE

MREEHREE

Th

U

Eigen vector 1Calcite

Terrigenous

Dolomite

Eig

en

Vect

or

2


MALLORCA



0.05 0.10 0.15 0.200.00.0

0.3

0.6

0.9

1.2

1.5

0 1 2 3 4 5 6 7 80.0

0.3

0.6

0.9

1.2

1.5

0.0 0.1 0.2 0.3 0.4 0.5 0.60.0

0.3

0.6

0.9

1.2

1.5

0.0 0.3 0.6 0.9 1.2 1.50.0

0.3

0.6

0.9

1.2

1.5

0.0 0.1 0.2 0.3 0.4 0.50.0

0.3

0.6

0.9

1.2

1.5

0 5 10 15 20 250.0

0.3

0.6

0.9

1.2

1.5

0 5 10 15 20 250.0

0.3

0.6

0.9

1.2

1.5

0 3 6 9 12 150.0

0.3

0.6

0.9

1.2

1.5

0.0 0.2 0.40.0

0.3

0.6

0.9

1.2

1.5

Al

Al 2O 3

Al 2O 3

Al 2O 3

Al 2O 3

Al 2O 3

Al 2O 3

Al 2O 3

Cr

Cr

Th

Th

Zr

TiO2SiO2

Fe2O3

KzO

c

High SiO2, low Al2O3biogenic or diagentic quartz ?

Lagoonal facies samplesReef core facies samplesFore reef facies samples

Figure 9. Binary diagrams constructed for selected elements and χ values to help understand the element-to-element and

element-to- χ values relationships.





and element-to-mineral relationships has

already been discussed for the entire dataset

(Figure 8). Figure 11 shows Eigen vectors 1

and 2 derived when principal components

analysis is carried out using just the group of

elements with high positive EV1scores on

Figure 8. These non-carbonate related

elements also fall into four clearly delineated

groups:

Group 1 includes SiO2, which plots on its own

in the bottom left quadrant. When dealing with

siliciclastic sequences, SiO2 is preferentially

associated with quartz (Pearce et al. 2005,

Ratcliffe et al., 2010), which here is likely to

be in the form of fine silt-size wind-blown

grains. It is assumed that the isolated platform

nature of Llucmajor precludes coarse dust of

and that here, the dust is all fine dust defined

by Stuut et al., (2009) as fine silt (4-8microns)

and very fine silt (2-4microns).

Group 2 includes Al2O3, K2O, TiO2, Fe2O3, Ga

and Rb which plot in a tight cluster in the

bottom right quadrant and K2O, TiO2, Fe2O3

are shown in Figure 9 to have a strong positive

linear association with Al2O3. When dealing

with siliciclastic sequences, Al2O3 is typically

associated with clay minerals (Pearce et al.

2005, Ratcliffe et al., 2010). Therefore it can

be assumed that elements associated with

Al2O3 are also primarily related to clay

minerals in the sediments. The fact that SiO2

and Al2O3 have an R2 coefficient of >.95

(Figure 9) indicates that quartz is also

somehow linked to clay minerals. Typically, in

a siliciclastic system, SiO2 vs. Al2O3 binary

diagrams produce negative linear associations,

because as quartz increases in volume within

siliciclastic sediment, clay decreases, resulting

in the silt-dilution trend of Pearce et al. (2005).

However, when the quartz and clay minerals

are being introduced into a carbonate system

by the same process, which here is by aeolian

processes, both will increase in a linear fashion

as the carbonate increase or decreases, i.e.

carbonate dilution trend of Sageman et al.

(2003).

Group 3 includes Cs, Nb, Sc, Ta and Th which

plot in the upper right quadrant, i.e. have

similar EV1 scores to Group 2 elements but

similar EV2 scores to Group 3 elements.

Although this group of elements is not readily

associated with a mineral phase or group, the

EV scores and their moderate R2 coefficients

with Al2O3 (Figure 9) suggest a fine grained

phase that is not simply wind-blown

terrigenous material. With reports of biotite in

ash-beds, these elements are here interpreted

to indicate dilute, background amounts of

biotite and associated minerals that are being

blown into the depositional environment.

Group 4 includes Cr and Zr, which plot in the

upper left quadrant. Because these elements

have similar EV1 scores to SiO2, it can be

suggested that they are somehow associated

with the silt-sized material in the sediment, but

their lack of a linear association with Al2O3

(Figure 9) indicates that neither elements are

simply related to windblown clay or silt of a

terrigenous source. Zr is typically associated

with the heavy mineral zircon, which is likely

to be in the form of silt sized grains. Cr can be

associated with spinels, again likely to be

present as silt-sized grains. Both minerals are

potentially reflecting the coarser parts of dilute

tuffaceous material.

The discussions above and the element

groupings on Figure 11, therefore suggest a

grainsize control on the wind-blown material,

which in itself has been used with varying

degrees of success infer changes of

provenance and changes in paleoclimate of the

hinterland for wind-blown detritus (Sun et al.,

2002, Weltje and Prins 2003, Stuut et al.,

2002, Saukel et al., 2011). Without a grainsize

analysis of the insoluble residue, however,

little more can be gleaned from the current

dataset with regards to grainsize distributions.





Furthermore, it is somewhat peripheral to the

stratigraphic aims of the paper.

The changing amount of Cr on Figure 7

therefore indicates that the amount of Cr-rich

detrital grains (spinels ?) fluctuated within the

reef core facies. This could represent a change

in overall amount of wind-blown detritus.

However, the change in Zr/Cr values indicates

the relative proportion of Cr-rich grains and

Zr-rich grains changed through time. Such

changes in fluvial systems are related to

change in fluvial provenance (Armstrong-

Altrin, et al., 2004, Ratcliffe et al., 2004, 2006,

2007). It is therefore suggested that here it

represents a change in aeolian provenance.

All four elements used to differentiate fore-

reef facies on Figure 7 plot in Group 2 on

Figure 10, which is taken to indicate they are

associated with clay minerals. Therefore,

changes in the relative proportions of the

elements within the group are probably

indicating subtle changes in the clay minerals

species entering the depositional environment.

Al2O3 and Ga tend to be associated with

kaolinite and Rb with illite (Pearce et al.,

2005, Ratcliffe et al., 2010) and TiO2 can have

more mixed affinities. Therefore the high

Ga/Rb values in CB section fore reef settings

suggest that these sediments have a higher

kaolinite : illite ratio than the same facies inCC

and CO sections.

Magnetic susceptibility (χ)

χ values clearly define bounding surfaces of

sigmoids and sets of sigmoids, which have

themselves been shown to reflect sea level

fluctuations (Pomar and Ward 1994). This

observation is very useful for the identification

and correlation of surfaces within the reef

complexes, the main aim of this paper. It is

also consistent with one of the standard

interpretations of MS data, where cyclical χ

values are used as a proxy for sea-level

fluctuations (Crick et al., 1997, 2000, Ellwood

et al., 2000, da Silva and Boulvain, 2006),

Ellwood et al. (2000) argue that χ values

relate to aquatic lithogenic input, although

Hladil (2002) and Hladil et al., (2005) suggest

aeolian suspension and atmospheric dust may

contribute to χ values. In both the aquatic and

aeolian delivery model, χ values are directly

proportional to non-carbonate terrigenous

material. At first appearance, the χ values in

the isolated carbonate setting of the Llucmajor

reef complex described here is consistent with

a terrigenous control; as accommodation

decreases toward the top of a sigmoid,

carbonate production diminishes and,

assuming a relatively constant supply of

Figure 9. Binary diagrams constructed for selected elements and χ values to

help understand the element-to-element and element-to- χ values relationships.





background terrigenous material from air fall,

the proportion of terrigenous material will

increase, so χ values increase toward the top

of a sigmoid and drop sharply into the base of

the overlying unit. Similarly in condensed

sections, carbonate sedimentation was slow,

allowing greater relative concentration of

terrigenous material.

Figure 11. Cross plot of Eigen vector 1 and 2 scores

for elements associated with terrigenous input. These

elements are those which tightly cluster around the

EV2 axis, with positive EV1 scores on Figure 8

Despite the χ values of this study behaving as

expected in this type of setting and reflecting

base level fluctuations, the driving mechanism

is not readily apparent with the current

available data and is definitely not a simple

one that relates to the amount of terrigenous

material in the carbonates. As discussed above,

elements in the group that plots with high

positive EV1 scores on Figure 7 are associated

non-carbonate minerals. Figure 10 shows that

the major elements in this group have almost

perfect linear associations with one another,

indicating that they are present in the same

mineral phases within the sediments, which

are likely to be wind-blown clays and

feldspars. However, χ values do not display a

positive linear association with Al2O3. The

correlation coefficients displayed on Table 3

show that χ has a negative R2 value with CaO,

MgO and other elements associated with

carbonates (Figure 8) and a positive R2 value

with terrigenous-related elements. However, χ

values do not possess a correlation coefficient

(positive or negative) over 0.6 with any single

element analysed (Table 2), i.e. there is no

significant association between the detrital

proxies Zr, Rb, Al2O3 and TiO2 (Da Silva, et

al. 2012) Therefore, there is something other

than a simple terrigenous vs. carbonate control

influencing the χ values.

Table 3. Correlation coefficients (R2) for χ values and all elements acquired. Values of R

2 >0.75

(positive or negative) are considered to suggest significant association of the two variables.

LREE (light rare earths) is the sum of La, Ce, Pr, Nd,, MREE (middle rare earths) is the sum of

Sm, Eu, Gd, Tb and Dy, HREE (heavy rare earth) is the sum of Ho, Er, Tm, Yb and Lu.

Al2O3 SiO2 TiO2 Fe2O3 MnO MgO CaO Na2O K2O P2O5

0.45 0.43 0.43 0.51 -0.04 -0.16 -0.12 0.19 0.43 0.01

Ba Be Cr Sc Sr Zn Zr V Co Ni

0.17 0.5 0.35 0.48 -0.05 0.36 0.41 0.17 0.14 0.29

Cu Ga Rb Y Nb Mo Sn Cs LREE MREE

0.01 0.5 0.47 0.33 0.48 -0.04 0.27 0.45 0.24 0.44

HREE Hf Ta Th U

0.37 0.08 0.48 0.5 -0.04

Numerous other origins have been postulated

for the source of magnetic minerals that will

influence χ values. Among those, volcanic

origin (Crick et al., 1997), pedogenic origin

(Tite and Lininington, 1975), biogenic

magnetite formation (Hladil et al., 2004) and

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0 0.02-0.02-0.04-0.06 0.04 0.04 0.06

Al2O3

SiO2

TiO2

Fe2O

3

K2O

CrSc

Zr

Ta

Ga

Rb

Nb

Cs

Th

Eigen vector 1

Eig

en

vect

or

2

Group 3

Group 2

Group 4

Group 1





diagenesis have potential to affect study

intervals here. Although tuffs are reported

from the Llucmajor reef complexes, it is

suggested here that their influence on the χ

values is unlikely to be a primary control;

tuffaceous material has distinctive trace

element chemistry and therefore the χ values

would be expected to show a positive

relationship to some of the trace elements,

which they do not (Table 2). There is no

marked increase in χ values associated with

erosive, subaerially exposed surfaces in the

study intervals and in fore reef facies that have

not been subaerially exposed at sigmoid-tops χ

values still display distinctive cyclicity (Figure

5). Therefore, it seems unlikely that pedogenic

processes are a key control on χ values.

Diagenetic processes can both increase and

decrease susceptibility (Zegers et al., 2003,

Henshaw and Merrill, 1980, Rochette, 1987),

often as a result of the alteration of Fe-

minerals from one phase to another. The whole

rock elemental data acquired for

chemostratigraphy does not differentiate

between different valencies of Fe, nor can it

differentiate between oxide, hydroxides,

oxyhydroxides etc. Therefore, diagenesis

cannot be ruled out as a control on χ values

with the current dataset. Biogenic magnetite

would be unlikely to have a distinctive

elemental signature and also cannot be ruled

out with the current datasets.

Magnetic mineralogy and magnetic grain-size

variations can be determined by acquiring and

manipulating rock magnetic measurements

(Da Silva et al., 2012). As part of ongoing

work on understanding stratigraphic

applications in reef complexes, it is intended

that thermal demagnetization of a 3 axis

isothermal remnant magnetization (IRM),

frequency-dependent magnetic susceptibility,

low-field susceptibility, high-field

susceptibility, Ferrimagentic susceptibility and

anhysteretic remnant susceptibility data will be

gathered on a subset of samples from this

study. These variables should provide a clear

indication of the controls on the χ values ,

enabling a full interpretation of the observed

cyclicity to be proposed.

Irrespective of the ultimate control χ values in

these sequences are in some way associated

with sea level fluctuations, yet remain

independent of facies.

Conclusions Sigmoid-set and coset bounding surfaces are

defined by high χ values, enabling surfaces to

be correlated between closely spaced sections.

In this dataset the high χ values cannot be

directly linked to the elemental chemistry, or

to a single mineral phase or group of mineral

phases, but rock magnetism work is ongoing to

help better understand the observed χ values.

In the Llucmajor Platform, without close-

interval, high-resolution sampling, χ data do

not show long-term, non-cyclic variation,

which means that without the context provided

by the sea cliffs, a bounding surface in the PC

section would look very similar to one in the

CB section and therefore would be difficult to

put into a regional framework without

additional stratigraphic information.

Chemical data do not readily define surfaces,

but they do define intra-facies secular changes.

These changes in elemental composition

through time are related to variation in the

composition of background windblown debris,

including dilute volcanic ash. The changes in

chemistry seen within the reef and fore reef

facies suggest that changes in silt-sized heavy

or opaque minerals and changes the clay

mineralogy, both occurred during deposition

of the study sections. Such changes provide

the building blocks for chemostratigraphic

correlations, i.e. rock units of differing ages

have different chemical compositions.

Therefore, this study shows that elemental

chemostratigraphy can be applied in pure

carbonates where only wind-blown detritus is





the only source of terrigenous input, assuming

changes in the composition of the windblown

detritus.

Elemental data and χ values can both be

determined readily from well bore cuttings and

core samples, making the techniques ideally

suited to subsurface stratigraphic applications.

It is unlikely that the correlation displayed on

Figure 3b would be achieved with no further

information than elemental and χ data from

the individual sections if they were in the

subsurface. However, by gathering and

interpreting MSS and chemostratigraphic

information, a closer approximation to the

actual correlation (Figure 3a) would be

achieved than could be achieved using more

traditional subsurface correlation techniques.

Therefore, by demonstrating responses of χ

values and elemental data in the Llucmajor

Platform carbonates, this paper indicates that

the two stratigraphic methods, magnetic

susceptibility and chemostratigraphy, can be

successfully deployed in understanding

stratigraphies of pure carbonate lithologies

such as those found in detached or isolated

carbonate platforms. It also highlights that X

values here are not a simple system that can be

readily related to the bulk composition of the

sediments via elemental data.

Acknowledgements We would like to thank all of our colleagues

for help and support during preparation of this

Manuscript. Specifically, Chemostrat wish to

thank Lorna Dyer at Greenwich University for

preparing and running the ICP analysis of the

samples and for providing Emma Davies and

Ken Ratcliffe time and support to prepare this

manuscript. Luis Pomar work was done under

Spanish DGI Project CGL2009-13254. We

also gratefully acknowledge the many

comments and suggestions made by the two

reviewers, incorporation of which into the

manuscript enormously improved the final

product.





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