GeolCarp_Vol62_No1_43

www.geologicacarpathica.sk

GEOLOGICA CARPATHICA

, FEBRUARY 2011, 62, 1, 43—53 doi: 10.2478/v10096-011-0004-0

Geomorphological, mineralogical, and geochemical evidence

of Pleistocene weathering conditions in the southern Italian

Apennines

PAOLA DI LEO

, DARIO GIOIA

, CLAUDIO MARTINO

, ANNA PAPPALARDO

and MARCELLO SCHIATTARELLA

CNR – Istituto di Metodologie per l’Analisi Ambientale, Tito Scalo, 85050 Potenza, Italy; pdileo@imaa.cnr.it; apappalardo@imaa.cnr.it

Dipartimento di Scienze Geologiche, Basilicata University, Campus Macchia Romana, 85100 Potenza, Italy; dario.gioia@unibas.it;

claudio.martino@alice.it; marcello.schiattarella@unibas.it

(Manuscript received June 8, 2010; accepted in revised form December 20, 2010)

Abstract: Pleistocene weathering, uplift rates, and mass movements have been studied and correlated in a key-area of
the Italian southern Apennines. The study area is the Melandro  River valley, developed in a tectonically-controlled
Quaternary intermontane basin of the axial zone of the chain. The goal of this paper is to assess ages and geomorphic
features of two paleo-landslides and to relate them to values of uplift rates and the climate conditions in the axial zone
of  the  chain  during  the  Pleistocene.  Uplift  rates  have  been  estimated  using  elevation  and  age  of  flat  erosional  land
surfaces. In the southern area of the basin, the landscape features a wide paleo-landslide which can be ascribed to the
upper part of the Lower Pleistocene on the basis of relationships with Quaternary deposits and land surfaces. Another
paleo-landslide,  in  the  northern  sector  of  the  basin,  can  be  referred  to  the  beginning  of  the  Upper  Pleistocene.  The
correlation between the ages of the two landslides and the temporal trend of the uplift rates allowed us to hypothesize
that mass movements occurred in response to uplift peaks that destabilized slopes. Additionally, deciphering weather-
ing conditions by means of the analysis of mineralogical and geochemical signals from landslide deposits and weath-
ered horizons allowed assessment of changes in paleoclimate scenarios during the Pleistocene. The deep weathering
was probably caused by the onset of warm-humid climate conditions, which may have acted as a further factor trigger-
ing landslide movements in an area already destabilized by the rapid uplift.

Key words: geomorphology, clay mineralogy, weathering indexes, Quaternary climate changes, Pleistocene landslides,
southern Italy.

Introduction

Paleo-landslides  in  southern  Italy  have  been  largely  studied
from a geomorphological viewpoint, but their genetic relation-
ships  with  tectonic  activity,  earthquakes,  erosion  base  level
modifications, climate changes, and weathering conditions are
still debated. In particular, it seems hard to relate the develop-
ment of huge ancient landslides to specific time intervals dur-
ing  the  Quaternary  in  which  one  or  more  of  the  above
mentioned  mechanisms  could  have  produced  the  necessary
conditions  for  the  activation  of  such  significant  phenomena.
The targets of this study are: i) knowledge of the genetic links
existing  between  ages,  texture,  weathered  surfaces  and  geo-
morphic features of two Pleistocene large landslides located in
an intermontane valley of southern Italy; ii) the correlation of
these  characteristics  with  the  values  of  uplift  rates  from  the
study area and with the major episodes of climate change, as
deduced  from  the  global  sea-level  reconstruction.  The  com-
parison  between  these  different  data-sets  is  a  useful  tool  for
understanding the genetic mechanisms of landslides.

The investigated key-area is located in the Melandro River

basin, a tectonic depression of the axial zone of the southern
Apennines  (Fig. 1).  This  chain  constitutes  a  Neogene  fold-
and-thrust  belt  strongly  uplifted  and  fragmented  by  neotec-
tonics,  and  therefore  characterized  by  many  Quaternary

longitudinal  and  transversal  morphostructural  depressions
(Ortolani et al. 1992). Among them, the Melandro River ba-
sin  is  particularly  suitable  for  the  study  of  paleo-landslide
generation  by  means  of  a  geomorphological  approach,  be-
cause of the presence of both weathered erosional land sur-
faces  and  many  morpho-structural  markers  which  can  be
used for uplift rate estimates (Widdowson 1997). The inter-
play  between  climate  and  tectonics    has  long  been  consid-
ered  a  basic  key  for  the  interpretation  of  the  landscape
evolution at different scales (Bloom 1978; Ollier 1981; Bull
1991;  Summerfield  2000;  Burbank  &  Anderson  2001;
Willett et al. 2006).

Geological and geomorphological features of the

study area

The southern Apennines were strongly uplifted during the

Quaternary, as shown by both Pleistocene displaced deposits
and ancient base levels of erosion at high elevations above the
present-day sea level (Schiattarella et al. 2003, 2006). The belt
is in fact fragmented by Late Pliocene to Quaternary neotec-
tonics (Schiattarella 1998), and therefore articulated by devel-
opment of longitudinal and transversal tectonic depressions
(Ortolani et al. 1992). The mountain belt tops are often charac-

DI LEO, GIOIA, MARTINO, PAPPALARDO and SCHIATTARELLA

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GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

terized  by  remnants  of  ancient  erosional  gently  dipping  or
sub-horizontal land surfaces, hung with regard to the present-
day base level of erosion due to Quaternary regional uplift and
dismembered  by  multistage  fault  activity  (Brancaccio  et  al.
1991; Amato & Cinque 1999; Schiattarella et al. 2003). Dif-
ferent Quaternary tectonic events have been recognized as re-
sponsible  for  the  greatest  part  of  the  chain  uplift.  Several
authors identified two main uplift stages in the Early Pleisto-
cene, and another relevant event was marked by uplift that oc-
curred  in  the  Middle  Pleistocene  (D’Argenio  et  al.  1986;
Brancaccio  et  al.  1991;  Schiattarella  et  al.  2003).  Finally,  in
the Late Pleistocene the chain was characterized by stability of
the  Tyrrhenian  belt  and  uplift  of  the  axial  zone  of  the  chain,
the  foredeep  basin,  and  the  foreland  area  (Westaway  1993;
Bordoni & Valensise 1998; Schiattarella et al. 2003, 2006).

The Melandro River basin (Fig. 1) is a tectonic depression

located in the “axial zone” of the chain (Ortolani et al. 1992).

Two wide thrust sheets crop out in the area: the Maddalena
Mts Unit and the Lagonegro units. The Maddalena Mts Unit
is composed of Triassic to Eocene shallow-water carbonates
locally covered by Upper Miocene siliciclastic sediments. It
thrust up the Lagonegro units and forms the western flank of
the basin, whereas the Lagonegro units, prevalently consti-
tuted by deep-sea successions, form the entire eastern side of
the valley.

Alluvial deposits crop out in the axial zone of the

Melandro River basin and have been attributed to the Early
Pleistocene  (Lippman  Provansal  1987).  Giano  &  Martino
(2003) recognized three lithostratigraphic units separated by
paleosols  and  erosional  surfaces.  Several  generations  of  ero-
sional surfaces have been identified on both sides of the valley
(Fig. 1) and divided into four orders on the basis of geomor-
phological  evidence  (Schiattarella  et  al.  2003;  Martino  &
Schiattarella 2006).

Fig. 1. Morphostructural map of the Melandro River basin (studied landslides in the frames).

DI LEO, GIOIA, MARTINO, PAPPALARDO and SCHIATTARELLA

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GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

In the area of the Melandro River basin, two large land-

slides  exhibiting  peculiar  characteristics  have  been  mapped
(Fig. 2)  using  modern  criteria  (Parise  2001,  and  references
therein) and classified following the internationally accepted
schemes  (Varnes  1978;  Cruden  &  Varnes  1996).  Both  the
landslides  have  to  be  ascribed  to  deep-seated  roto-transla-
tional  rock  slides  and  are  0.12  and  0.7 km

in size, respec-

tively,  in  the  northern  and  southern  sectors  of  the  valley
(Fig. 1).  The  larger  landslide  developed  into  earth  flows  in
its  frontal  part.  Mass  movements  probably  affected  weath-
ered rocks, as shown by some landslide deposit features. The
same deposits are cut by erosional surfaces which are in turn
deeply weathered.

In both cases, the landslide deposits are characterized by

large  rock  blocks  and  fragmented  beds  dispersed  in  a  fine-
grained  matrix.  The  rock  blocks  and  beds  belong  to  forma-
tions  (i.e.  Scisti  silicei  Formation  and  Calcari  con  selce

Formation,  Lagonegro  units  –  Pescatore
et al. 1999, and references therein; see also
Di Leo et al. 2002 and Tanner et al. 2006)
which are rarely involved in bedrock slide
in  the  present-day  geomorphic  system.  In
addition,  the  size  of  the  landslides,  the
thickness of the landslide deposits, and the
dimensions of the blocks are not common
features  in  recent  mass  movements  of  the
southern Apennines.

The age of the paleo-landslides has been

determined  considering  the  relationships
with the Quaternary deposits and the relat-
ed  landscapes.  In  the  southern  area  of  the
basin a wide paleo-landslide, whose middle
portion  is  cut  by  a  remnant  of  the  Middle
Pleistocene  land  surface  (Fig. 3,  morpho-
stratigraphic  section  in  the  middle,  and
Fig. 4),  is  recognizable.  Furthermore,  this
paleo-landslide  formed  a  morphological
high separating different sectors of the ba-
sin  in  which  Lower  Pleistocene  sediments
were  confined.  After  a  successive  stage  of
aggradation  of  the  Melandro  River  paleo-
valley, the landslide was partly “drowned”

Fig. 4. Paleo-landslide (marked by the dashed line) and S3 erosional land surfaces (marked by the dotted lines) in the southern area of the
Melandro basin. The S3 land surface cuts the intermediate sector of the landslide.

Fig. 5. Relationships between S3 and S4 erosional land surfaces and the paleo-landslide
located in the northern part of the basin.

by alluvial sediments and successively planated together with
the same fluvial deposits in response to a further change of the
local base level of the erosion. The progressive fall of the local
base level led to the vertical incision of the ancient (i.e. Early—
Middle Pleistocene) alluvial plain, isolating large remnants of
the S3 erosional land surface – sculptured both in bedrock
and Quaternary (alluvial and landslide) deposits – and ex-
huming also the lower part of the paleo-landslide. Based upon
this evidence, the landslide can be ascribed to the upper part of
the Lower Pleistocene, which is the age of the uppermost por-
tion of the fluvial succession.

Another paleo-landslide has been recognized in the northern

sector of the basin (Fig. 1). It is “morphologically inserted” in-
side the Upper Pleistocene land surfaces (i.e. the landslide de-
posits are placed on a topography modelled below the erosion
base level related to that order of land surfaces) and fossilized
by fan deposits and small erosional surfaces located 25 m

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GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

Fig. 6. Stratigraphic relationships between bedrock (BR), landslide
(LS) and slope (SD) deposits in the northern sector of the studied area.

above  the  present-day  valley  floor  (Fig. 5).  Further,  another
close  and  similar  landslide  deposit  is  fossilized  by  slope  de-
posits  incised  and  suspended  on  the  present-day  thalweg
(Fig. 6).  On  this  basis,  the  age  of  the  second  paleo-landslide
can be ascribed to the beginning of the Late Pleistocene.

Mineralogy and geochemistry

Materials and methods

In the present work the mineralogy and geochemistry of six

samples from weathered horizons and landslides deposits
have been investigated. ALT1 and ALT3 samples are from
weathered horizons developed on a bedrock constituted by the
Galestri Formation (Lower Cretaceous) and sculptured by the

third  order  erosional  surface  S3.  ALT2  sample  is  from  a
weathered  horizon  developed  on  the  bedrock  constituted  by
Scisti silicei Formation (Jurassic—Upper Triassic), and ALT6
sample  belongs  to  a  weathered  horizon  developed  on  Flysch
Rosso  Formation  (Oligocene—Upper  Cretaceous).  ALT4  and
ALT5  represent  landslide  deposits.  The  mineralogy  of  the
bedrocks is described in Di Leo et al. (2002) and for sake of
simplicity is summarized in the present paper in Fig. 7.

The mineralogical associations in the selected samples were

identified by X-ray diffraction using a Rigaku miniflex appa-
ratus, operating under the following conditions: CuK

radia-

tion,  0.02  steps,  0.5°/min  time,  sample  spinner.  The  XRD
analysis was carried out on powders crushed in an agate hand
mortar.  To  identify  clay  minerals,  a  known  amount  of  the
< 2  m  grain-size  fraction  –  isolated  through  settling  after
dispersion in deionized water – was dried at room temperature
and pipetted on glass slides to produce a well-oriented speci-
men.  Air-dried,  ethylene-glycol  solvated,  heated  (250 °C,
375 °C, 500 °C) and Mg-saturated mounts were X-rayed. The
MacDiff  software  (4.2  version),  with  JCPDS  mineralogical
cards database, was used to identify the mineralogical phases.
The  “illite  crystallinity”,  expressed  as  the  Kübler  Index  (KI;
Kübler  1964)  and  calibrated  to  the  CSI  scale  (Calibration
Standards Index scale, Warr & Rice 1994), and the “kaolinite
crystallinity”,  expressed  as  Hinckley  Index  (HI;  Hinckley
1963) have also been measured. The distribution of mineral-
ogical  phases  (expressed  in  weight  %)  of  studied  weathered
horizons and landslides deposits samples are showed in Fig. 8.

Major elements abundances (expressed weight % of ox-

ides) in the weathered horizons and landslide deposits were
estimated  by  X-ray  fluorescence  (XRF).  Total  loss  on  igni-
tion  (LOI)  was  gravimetrically  estimated  after  overnight
heating at 950 °C. Geochemical data together with weather-
ing indexes, i.e.  Chemical Index of Alteration (CIA; Nesbit
& Young 1982) and Weathering Ratio (WR; Chittleborough
1991) are showed in Table 1. The CIA represents the:

Fig. 7. Distribution of the mineralogical phases (expressed in weight %) in pelitic levels from the Scisti silicei and Galestri Fms (data from
Di Leo et al. 2002) which represent the bedrock of the studied weathered horizons. a – Qtz = quartz, Pl = plagioclases, Kfs = K-feldspars,
Cc = calcite, An = anatase, Gh = goethite, Hm = hematite,

CM = sum of clay minerals. b – Chl = chlorite, I/S = illite/smectite mixed

layers, C/V = chlorite/vermiculite mixed layers, C/S = chlorite/smectite mixed layers, Kaol = kaolinite, Ill = illite, Vm = vermiculite.

DI LEO, GIOIA, MARTINO, PAPPALARDO and SCHIATTARELLA

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GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

100

)

(

⎥

⎦

⎤

⎢

⎣

⎡

CaO

ratio,

where  the  CaO*  represents  the  CaO  associated
with  the  silicate  fraction  of  the  sample,  and  the
WR is estimated by normalizing the sum of the
mobile  elements  (CaO* + Na

O + MgO) to the

immobile element TiO

Results

The mineral association identified in the land-

slide  deposit  (ALT4)  and  weathering  horizons
(ALT1 and ALT3) developed on the Galestri For-
mation  is  mainly  constituted  by  clay  minerals
(75—69 %), quartz (9—16 %), calcite ( < 10 %), and
traces  of  plagioclases,  K-feldspars  and  anatase
(Fig. 8).  Goethite  has  also  been  identified,  al-
though in a low amount ( < 3 %), in these samples.
Among clay minerals, illite/smectite mixed-layers
with  a  60—70 %  of  illitic  layers  (I/S

ill

, R1;

Reynolds  1985)  are  the  most  abundant  (46—
63 %),  together  with  chlorite/vermiculite  and
chlorite/smectite (C/V and C/S respectively). Illite
content is variable (9—44 %), and its KI – rang-
ing between 0.69 and 0.86  °2  – indicates the
presence  of  a  mainly  poorly  crystallized  non-ex-
pandable 10 phase. Kaolinite (7—18 %) also ex-
hibits a low degree of “crystallinity” according to
the  low  Hinckley  Index  values  (0.17  and  0.20).
Besides,  the  position  in  the  XRD  patterns  of  its
d

(001)

reflection

at 7.2 – that shifts near to 8.0

after  treatment  with  ethylene-glycol  –  indicates
the presence of little mixed-layering with “chlori-
tized”  smectite.  A  great  amount  of  vermiculite
(14 %) has been identified only in the ALT3 sam-
ple. The presence in the XRD patterns of oriented
mounts, heated at 350° and 550 °C for 1 hour, of
two large peaks at about 13    and 11.8    and the
comparison with XRD pattern of the Mg-saturat-
ed mount, suggests the presence of a 2 : 1 mineral-
ogical phase like Al-rich vermiculite (Taveldal et
al. 1990).

Samples from the weathered horizon developed

on Scisti silicei Formation (ALT2) and from land-
slide deposit (ALT5) are constituted by clay min-
erals  (47—51 %),  quartz  (47 %),  and  traces  of
plagioclases  and  hematite  (Fig. 8).  Among  the
clay minerals, illite, with a KI value ranging from
0.77 to 0.86  °2  is the most abundant clay min-
eral  (20—27 %),  together  with  illite/smectite
mixed layers (18 % in ALT2) with 70 % of illitic
layers  (I/S

ill

, R1; Reynolds 1985) and chlorite/

vermiculite (20 % in ALT5) mixed layers. Ka-
olinite (10 %) is poorly crystallized, as suggested
by Hinckley Index value (HI= 0.15). Also for
these samples the position in the XRD patterns of
the its d

(001)

reflection

at 7.2 – that shifts near

Fig. 8. Distribution of the mineralogical phases (expressed in weight %) identi-
fied in the studied weathered horizons and landslide deposits. a – Qtz = quartz,
Pl = plagioclases, Kfs = K-feldspars, Cc = calcite, An = anatase, Gh = goethite,
Hm = hematite,

CM = sum of clay minerals. b – Chl = chlorite, I/S = illite/

smectite mixed layers, C/V = chlorite/vermiculite mixed layers, C/S = chlorite/
smectite mixed layers, Kaol = kaolinite, Ill = illite, Vm = vermiculite. KI is the
Kübler Index (Kübler 1964), HI is the Hinckley Index (Hinckley 1963).

Table 1: Distribution of main oxides (weight %) in samples of weathered hori-
zons and landslide deposits.

Sample

ALT1 ALT2 ALT3 ALT4 ALT5 ALT6

SiO

55.75

71.85

52.27

48.79

70.23

21.13

TiO

1.16

0.39

0.81

1.27

0.62

0.46

20.69

12.02

17.21

23.15

13.15

7.65

FeO

0.35

0.15

1.66

0.57

0.13

0.62

6.56

3.62

4.60

4.31

4.36

2.99

MnO

0.18

0.01

0.08

0.04

0.32

0.08

MgO

1.17

0.77

2.08

0.68

1.82

1.94

CaO

1.11

0.21

3.92

5.37

0.49

29.67

0.80

0.10

1.02

0.97

0.49

0.15

1.92

1.64

3.63

1.77

3.18

1.03

0.15

0.05

0.14

0.10

0.09

0.21

LOI

11.08

7.21

9.64

14.55

6.07

29.15

CIA

2.180 2.769 3.813 1.302 4.502 4.524

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to 8.0 after treatment with ethylene-glycol – suggests the
presence of a little mixed-layering with “chloritized” smectite.

In the sample from the weathered horizon developed on the

Flysch Rosso Formation (ALT6), calcite (53 %), clay miner-
als (36 %), quartz (8 %) are the main mineralogical phases.
Traces of hematite are also present in the sample. Interstrati-
fied chlorite/vermiculite and illite/smectite with 80 % of illitic
layers (I/S

ill

, R1; Reynolds 1985) are the most abundant clay

minerals (15 % and 12 %, respectively). Both illite (6 %) and
kaolinite are poorly crystallized as suggested by the KI and HI
indexes equal to 0.92 °2 and 0.15, respectively.

Paleoclimate implications

The peculiar mineralogical associations observed in the

sampled weathered horizons, compared to their relative bed-
rocks represented by the Scisti silicei and Galestri Forma-
tions, suggest that the alteration developed through two main
stages related to different paleoclimate scenarios (Fig. 9). In
the bedrocks on which the analysed weathered horizons de-
veloped, minerals such as vermiculite and chlorite/vermicu-

Fig. 9. Mineralogical associations recognized in
the weathered horizons and relative to different
weathering stages characterized by different pa-
leoclimate  conditions  (mineralogical  phase  la-
bels as indicated in Fig. 6). For comparison, the
mineralogical features of the bedrocks on which
the  horizons  developed  belonging  to  the  Scisti
silicei (a), Galestri and Flysch Rosso Formations
(b)  are  also  reported  (data  from  Di  Leo  et  al.
2002 and Schiattarella et al. 2003).

lite interlayers are totally absent (Fig. 4). Therefore, the for-
mation  in  the  weathered  horizons  of  such  minerals,  most
probably  at  the  expense  of  mica  (the  Scisti  silicei  and
Galestri Formations contain a well crystallized Na-rich mica;
Di  Leo  et  al.  2002),  is  likely  to  be  the  result  of  weathering
developed in a cold-temperate climate setting, with an alter-
nation  of  rainy  seasons  –  where  an  intense  leaching  oc-
curred  –  and  dry  periods.  Semi-arid  climate,  with  dry/
humid periods, is a necessary condition for the formation of
vermiculite  at  the  expense  of  mica  (Scott  &  Smith  1968;
Righi  &  Meunier  1995).  During  dry  seasons,  K

ions are in

fact  expelled  from  the  interlayer  region  of  mica  (a  2 : 1  clay
mineral) and, because of the leaching, is definitively removed
to form vermiculite (a 2 : 1 : 1 clay mineral). The alternation of
dry and humid climate periods (aerobic/anaerobic cycles) is a
necessary condition for the disappearance of 2 : 1 clay miner-
als  and  the  appearance  of  the  newly  formed  2 : 1 : 1  Al-  and
Mg-rich  “chloritized”  mineral  phases  (Schaetzl  &  Anderson
2005). Intense leaching joined to the weak soil acidity and low
organic matter lead to the formation of both pedogenic chlorite
and Al-rich vermiculite (Rich 1968; Barnhisel & Bertsch 1989).

The recognition of poorly crystallized

kaolinite  and  goethite  in  the  analysed
weathering horizons as well as of kaolinite/
smectite mixed-layers (K/S), which were not
observed in the bedrocks on which they de-
veloped  (Fig. 4)  –  kaolinite  is  only  ob-
served  in  correlated  levels  within  the
Galestri Formation, where it exhibits a high
crystallinity,  and  is  totally  absent  in  analo-
gously  correlated  levels  within  the  Scisti
Silicei  Formation  (Di  Leo  et  al.  2002;
Schiattarella  et  al.  2003,  2006)  –  suggest
that  a  more  intense  weathering  period  has
also  contributed  to  the  formation  of  these
weathered  horizons  and  that  a  change  to
climate  conditions  typical  of  a  mainly
warm/humid climate occurred (Fig. 9). The
K/S formation is in fact generally associat-
ed with the formation of soils in warm/hu-
mid  climate  contexts,  and  represents  an
important  stage  of  kaolinite  formation
(Bhattacharyya et al. 2006).

However, the co-existence of newly

formed minerals linked to weathering de-
veloped in a mainly cold/temperate climate
setting with those typical of a stage of alter-
ation developed in warm/humid conditions

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GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

clearly suggests that the latter stage, although intense, must
have lasted for a relatively short time span. Therefore, ver-
miculite, C/V and C/S interlayers were still preserved and
coexisted with newly formed kaolinite and K/S interlayers.

Using a multivariate statistical approach, carried out by

the Principal  Component  Analysis  (PCA)  method  (Fig. 10),
the  distribution  of  the  mineralogical  phases  in  the  weather-
ing  horizons  were  compared  to  the  ones  in  the  bedrock  on
which the horizons developed (data from Di Leo et al. 2002).
This allowed us to clearly identify the two main weathering
stages related to different paleoclimate scenarios that are re-
sponsible  for  the  development  of  the  weathered  horizons
(see  Fig. 10).  The  first  component  (29%  of  explained  vari-
ance), with high positive component loadings, group togeth-
er  kaolinite  and  goethite  abundance  normalized  to

quartz

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

qtz

kaol

. This component indicates the stage of

weathering  related  to  a  humid/warm  climate  context.  The
second  component  (23 %  of  explained  variance),  with  high
positive  component  loadings,  grouping  together  variables
such  as  vermiculite,  chlorite,  and  chlorite/smectite  mixed

layers abundances, normalized to quartz

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

qtz

chl

identifies the stage of the alteration developed in a cold/tem-
perate climate context, characterized by alternation of wet
seasons and dry periods (presence of vermiculite). The 1

Fig. 10. Orthogonal plot relative to the multivariate statistical analysis carried
out on mineralogical variables represented by the abundances of mineral phases
identified in the analysed samples, and their relative ratios, using the Principal
Component Analysis (PCA) method to extract components (for the description
of mineralogical phases labels see Fig. 6). Mineralogical data for bedrocks, rep-
resented by Scisti silicei, Galestri and Flysch Rosso Formations, are from
Di Leo et al. (2002) and Schiattarella et al. (2003). For analytical CIA values
(Chemical Index of Alteration) see Table 1.

Fig. 11. Variation plot of CIA (Chemical Index of Alteration)
versus WR (Weathering Ratio; Chittleborough 1991). CIA is the

ratio (where the CaO* represents

the CaO associated with the silicate fraction of the sample) and the
WR is estimated by normalizing the sum of the mobile elements
(CaO* + Na

O + MgO) to the immobile element TiO

(data for bed-

rocks formations from Di Leo et al. 2002).

component versus 2

component plot (Fig. 10) de-

picts an area where all the analysed weathered hori-
zons  produced by the onset of two different climate
settings fall, with CIA values  > 85 (Nesbit & Young
1982). The altered samples are far away from areas
where their relative bedrocks are located. These are
respectively  placed  in  the  direction  of  maximum
variation  of  quartz  and  illite  (mineralogical  phases
that predominate in samples from Scisti silicei For-
mation) and of illite/smectite mixed layers and well
crystallized kaolinite (mineralogical phases that pre-
dominate in samples from Galestri and Flysch Rosso
Formations).  Sample  ALT5  was  the  least-altered
sample for it falls within the group of the unaltered
bedrock constituted by the Scisti silicei Formation.

Similar considerations can be drawn from the

analysis  of  the  geochemical  features  of  both  the
landslide  deposits  and  the  weathered  horizons.
The variation plot (Fig. 11) of the CIA vs. the WR
indexes is also evidence of the evolutionary trend
of  weathering  where  ALT3  and  ALT5  represent
the  less  altered  samples,  closer  to  the  original
composition of their relative bedrocks, namely the
Galestri and Scisti silicei Formations respectively.

Discussion and conclusions

Uplift rates have been calculated using geomor-

phological, stratigraphical and structural data.

100

)

(

⎥

⎦

⎤

⎢

⎣

⎡

CaO

PLEISTOCENE WEATHERING IN THE SOUTHERN ITALIAN APENNINES

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

Geomorphic data consist essentially of elevation values, ages
and arrangement of erosional gently dipping land surfaces and
other  morphotectonic  indicators  such  as  suspended  valleys,
gorges, convex slopes, and strath terraces (Burbank & Ander-
son  2001).  The  morphostructural  evolution  of  the  Melandro
basin is characterized by stages of uplift alternated with slack
periods in which the erosional surfaces developed. In particu-
lar,  four  orders  of  erosional  surfaces  have  been  detected
through  field  survey  and  geomorphological  analysis  (Fig. 1).
The relative age of these surfaces have been defined on the ba-
sis of morphostratigraphic relationships with Pliocene to Qua-
ternary  deposits.  Specifically,  the  oldest  paleosurface  (S1)
cuts the Pliocene deposits at the tops of the Maddalena Moun-
tains  whereas  the  intermediate  surface  (S3)  cuts  the  Lower
Pleistocene deposits filling the main depression of the Melan-
dro River basin (Fig. 3). Another order of erosional flat sur-
faces  (S2)  is  interposed  between  the  oldest  and  intermediate
surfaces:  its  morphostratigraphic  position  suggests  that  the
genesis of this erosional landscape

occurred in the Early Pleis-

tocene. Finally, the youngest surface (S4) is Middle—Late
Pleistocene in age, as verified for similar terraces in adjacent
areas (Schiattarella et al. 2003). Local, less extended, fluvial
terraces (S5) are also present in the basin. The relative ages of
the different land surface orders (here assumed as the tectonic
episodes causing the morphological de-activation of a paleo-
surface order as an ancient base level of erosion) have been es-

Fig. 12. Local and stage uplift rates based on the morphological de-
activation (i.e. tectonic uplift) ages of the land surfaces.

tablished on the basis of the record of the well-known regional
tectonic stages found in southern Italy (Schiattarella et al.
2006, and references therein).

Local uplift rates have been estimated using the difference

in height between the local erosion base levels (i.e. present-
day thalwegs) and the several generations of land surfaces
(Table 2), whereas the stage (or partitioned) uplift rates (cf.
Schiattarella et al. 2006) have been calculated on the basis of
the difference in elevation between a given order of land sur-
faces and that immediately younger, with the aim of consid-

Fig. 13.  The  warm-humid  events  (black  ar-
rows)  in  the  global  sea  level  curve  (modified
after Bintanja et al. 2005, for the last 1 Ma, and
reconstructed for the remaining part by means
of marine oxygen-18 isotope curve after Grad-
stein  et  al.  2004)  were  responsible  for  the  in-
tense  weathering  of  the  bedrock  developed
before landslide generation.

Erosional

surface

Age

(Ma)

Elevation

range (m)

Local uplift rate

(mm/yr)

Stage uplift rate

(mm/yr)

Western flank of the basin

1.8

1100–1300

0.35

0.34

1.2

900–1000

0.36

0.43

0.73 800–600

0.26

0.27

0.125 500–550

0.39

0.42

Eastern flank of the basin

1.8

1400–1600

0.46

0.61

1.2

950–1100

0.40

0.64

0.73 800–600

0.22

0.18

0.125 500–550

0.39

0.42

Table 2: Morphometric characters of land surfaces from the Melandro
basin area and ages of their morphological de-activation (i.e. starting of
tectonic uplift), with related values of local and stage uplift rates.

DI LEO, GIOIA, MARTINO, PAPPALARDO and SCHIATTARELLA

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

ering the trend in specific time intervals. In the study area,
the stage uplift is characterized by two velocity increments:
the first during the upper part of the Early Pleistocene and
the second during the Late Pleistocene (Fig. 12).

The mineralogical associations identified in the analysed

landslide  deposits  and  weathered  horizons,  and  comparison
with the original composition of the rocks that represents the
bedrock on which they developed, suggest that the weathering
conditions evolved through two main stages related to differ-
ent paleoclimate scenarios (see Figs. 10 and 11). Climate con-
ditions  changed  from  a  relatively  cold/temperate  scenario,
characterized  by  the  alternation  of  dry/wet  seasons,  where  a
less intense weathering developed (CIA  ~ 76 and WR  ~ 4.5),
to a more warm/humid setting in which the weathering of the
bedrock  was  more  pronounced  (CIA  80—90  and  WR  <3.7).
The warmer climate stage, although intense, must have lasted
for a relatively short time so that the mineralogical association
developed  during  the  relatively  cold/temperate  climate  was
still preserved in the analysed weathered horizons.

The ages of the paleo-landslides surveyed in the Melandro

basin were determined on the basis of geomorphological ob-
servations  and  other  chronological  constraints,  such  as  the
presence  of  Quaternary  deposits  cut  by  the  same  erosional
surfaces affecting the ancient landslides. The correlation be-
tween  the  assigned  ages  of  such  paleo-landslides  and  the
temporal trend of the stage uplift rates allowed us to hypoth-
esize that the landslides occurred in response to peaks in the
tectonic uplift. During these peaks, strong earthquakes were
probably more frequent and the mountain slopes were there-
fore  destabilized  by  the  rapid  relief  growth.  On  the  other
hand,  the  peculiar  features  of  the  slide  material  seem  to  be
due to the deep weathering of the bedrock during a warm-hu-
mid climate stage (Fig. 13) and before the tectonic events, as
shown by two positive peaks in the most recent reconstruc-
tions  of  the  Quaternary  global  sea-level  changes  (Gradstein
et al. 2004; Bintanja et al. 2005). It is remarkable to note that
the  oldest  peak,  included  in  the  Donau-Günz  interglacial
stage, coincides with the formation of a sapropel, widely dif-
fused in the Mediterranean area, with an age spanning from
960  to  955  ka  (Meyers  &  Arnaboldi  2005),  whereas  the
youngest peak represents the debut of the Riss-Würm inter-
glacial stage at the beginnings of the Late Pleistocene.

Acknowledgments: This study was financially supported by
Fondi di Ateneo 2007 and 2008 (Basilicata University) grants
(Professor M. Schiattarella). We wish to thank Professor Brian
Whalley and Professor Alice Turkington for their useful com-
ments and suggestions in reviewing the manuscript.

References

Amato A. & Cinque A. 1999: Erosional landsurfaces of Campano-

Lucano Apennines (S. Italy): genesis, evolution and tectonic
implications. Tectonophysics 315, 251—267.

Barnhisel R.I. & Bertsch P.M. 1989: Chlorites and hydroxy-inter-

layered vermiculite and smectite. In: Dixon J.B. & Weed S.B.
(Eds.): Minerals in soils environments. Soil Sci. Soc. Amer.,
Madison, WI, 2

edn., 729—788.

Bhattacharyya T., Pal D.K. & Deshpande S.B. 2006: Genesis and

transformation of minerals in the formation of red (Alfisols)
and black (Inceptisols and Vertisols) soils on Deccan basalt in
the Western Ghats, India. European J. Soil Sci. 44, 159—171.

Bintanja R., van de Wal R.S.W. & Oerlemans J. 2005: Modelled at-

mospheric temperature and global sea levels over the past mil-
lion years. Nature 437, 125—128.

Bloom A.L. 1978: Geomorphology: A systematic analysis of Late

Cenozoic landforms. Prentice-Hall, Englewood Cliffs, 1—510.

Bordoni P. & Valensise G. 1998: Deformation of the 125 ka marine

terrace in Italy: tectonic implications. In: Stewart I. & Vita-
Finzi C. (Eds.): Late Quaternary coastal tectonics. Geol. Soc.
London, Spec. Publ. 146, 71—110.

Brancaccio L., Cinque A., Romano P., Rosskopf C., Russo F., Santan-

gelo N. & Santo A. 1991: Geomorphology and neotectonic evolu-
tion of a sector of Tyrrhenian flank of the southern Apennines
(Region of Naples, Italy). Z. Geomorphol., Suppl-Bd. 82, 47—58.

Bull W.B. 1991: Geomorphic responses to climatic change. Oxford

University Press, New York, 1—326.

Burbank D.W. & Anderson R.S. 2001: Tectonic geomorphology.

Blackwell Science, Oxford, 1—274.

Chittleborough D.J. 1991: Indices of weathering for soils and paleosols

formed on silicate rocks. Australian J. Earth Sci. 38, 115—120.

Cruden D.M. & Varnes D.J. 1996: Landslides types and processes.

In: Turner A.K. & Schuster R.L. (Eds.): Landslides: Investiga-
tion and mitigation. Transportation Research Board Special Re-
port 247. National Academy of Sciences, Washington, 36—75.

D’Argenio B., Ortolani F. & Pescatore T. 1986: Geology of south-

ern Apennines. A brief outline. Geologia Applicata e Idrogeo-
logia 21, 135—160.

Di Leo P., Dinelli E., Mongelli G. & Schiattarella M. 2002: Geology

and geochemistry of Jurassic pelagic sediments, Scisti silicei
Formation, southern Apennines, Italy. Sed. Geol. 150, 229—246.

Giano S.I. & Martino C. 2003: Morphostructural and morphostrati-

graphic setting of Pleistocene continental deposits of the Per-
gola-Melandro basin (Lucanian Apennine). Quaternario 16,
289—297 (in Italian).

Gradstein F.M. et al. 2004: A geologic time scale 2004. Geol. Surv.

Canada, Miscellaneous Report 86, 1 (poster).

Hickley D. 1963: Variability in “crystallinity” values among the

Kaolin deposits of the coastal plain of Georgia and South
Carolina. Clays and Clay Miner. 11, 229—235.

Kübler B. 1964: Les argiles, indicateurs de métamorphisme. Revue

Instituté de la Francais de Pétrole 19, 1093—1112.

Lippman Provansal M. 1987: L’Apennin méridional (Italie): étude

géomorphologique. Th

se de Doctorat d’Etat en Géographie

Physique, Université d’Aix-Marseille.

Martino C. & Schiattarella M. 2006: Morphotectonics and Quater-

nary geomorphological evolution of the Melandro Valley,
southern Apennines, Italy. Quaternario 19, 119—128 (in Italian).

Meyers P.A. & Arnaboldi M. 2005: Trans-Mediterranean comparison

of geochemical paleoproductivity proxies in a mid-Pleistocene
interrupted sapropel. Palaeogeogr. Palaeoclimatol. Palaeoecol.
222, 313—328.

Nesbit H.W. & Young G.M. 1982: Early Proterozoic climates and

plate motion inferred from major element chemistry of lutites.
Nature 299, 715—717.

Ollier C.D. 1981: Tectonics and landforms. Longman, London and

New York, 1—324.

Ortolani F., Pagliuca S., Pepe E., Schiattarella M. & Toccaceli R.M.

1992: Active tectonic in the southern Apennines: relationships
between cover geometries and basement structure. A hypothesis
for a geodynamic model. IGCP No. 276, Newsletter 5, 413—419.

Parise M. 2001: Landslide mapping techniques and their use in the

assessment of the landslide hazard. Physics and Chemistry Earth
26, 697—703.

Pescatore T., Renda P., Schiattarella M. & Tramutoli M. 1999:

PLEISTOCENE WEATHERING IN THE SOUTHERN ITALIAN APENNINES

GEOLOGICA CARPATHICA

GEOLOGICA CARPATHICA, 2011, 62, 1, 43—53

Stratigraphic and structural relationships between Meso-Ceno-
zoic Lagonegro basin and coeval carbonate platforms in south-
ern Apennines, Italy. Tectonophysics 315, 269—286.

Reynolds R.C. Jr. 1985: NEWMOD a computer program for the calcu-

lation of one-dimension diffraction patterns of mixed-layered
clays. R.C. Reynolds, Jr., 8 Brook Dr., Hanover, New Hampshire.

Rich C.I. 1968: Hydroxy interlayers in expansible layer silicates.

Clays and Clay Miner. 16, 15—30.

Righi D. & Meunier A. 1995: Origin of clays by rock weathering

and soil formation. In: Velde B. (Ed.): Origin and mineralogy
of clays. Springer, Berlin, 43—157.

Schaetzl R.J. & Anderson S. 2005: Soils: Genesis and geomorpholo-

gy. Cambridge University Press, New York, 1—817.

Schiattarella M. 1998: Quaternary tectonics of the Pollino Ridge, Ca-

labria-Lucania boundary, southern Italy. In: Holdsworth R.E.,
Strachan R.A. & Dewey J.F. (Eds.): Continental transpressional
and transtensional tectonics. Geol. Soc. London, Spec. Publ. 135,
341—354.

Schiattarella M., Di Leo P., Beneduce P. & Giano S.I. 2003: Qua-

ternary uplift vs tectonic loading: a case-study from the Luca-
nian Apennine, southern Italy. Quat. Int. 101—102, 239—251.

Schiattarella M., Di Leo P., Beneduce P., Giano S.I. & Martino C.

2006:  Tectonically  driven  exhumation  of  a  young  orogen:  an
example from the southern Apennines, Italy. In: Willett S.D.,
Hovius  N.,  Brandon  M.T.  &  Fisher  D.  (Eds.):  Tectonics,  cli-
mate,  and  landscape  evolution. Geol.  Soc.  Amer., Spec.  Pap.,
398, Penrose Conference Series, 371—385.

Scott A.D. & Smith S.J. 1968: Mechanism for soil potassium re-

lease by drying. Soil Sci. Soc. Amer. J. 32, 443—444.

Summerfield M.A. 2000: Geomorphology and global tectonics.

Wiley, Chichester, 1—367.

Tanner L.H., Schiattarella M. & Di Leo P. 2006: Carbon isotope

record of Upper Triassic strata of the Lagronegro Basin,
Southern Apeninnes, Italy: preliminary results. In: Harris et al.
(Eds.): The Triassic—Jurassic terrestrial transition. New Mexico
Mus. Nat. His. Sci. Bull. 37, 23—28.

Teveldall S., Jo

rgensen P. & Stuanes A.O. 1990: Long-term weath-

ering of silicates in a sandy soil at nordmoen, Southern Nor-
way. Clay Miner. 25, 447—465.

Varnes D.J. 1978: Slope movements types and processes. In:

Schuster R.L. & Krizek R.J. (Eds.): Landslides: Analysis and
control. Transportation Research Board Special Report 176
National Academy of Sciences, Washington, 11—33.

Warr A.W. & Rice A.H.N. 1994: Interlaboratory standardization

and calibration of clay mineral crystallinity and crystallite size
data. J. Metamorph. Geology 12, 141—152.

Westaway R. 1993: Quaternary uplift of Southern Italy. J. Geophys.

Res. 98, 21741—21772.

Widdowson M. 1997: Palaeosurfaces: Recognition, reconstruction

and palaeoenvironmental interpretation. Geol. Soc. London,
Spec. Publ. 120, 330.

Willett S.D., Hovius N., Brandon M.T. & Fisher D. 2006: Tecton-

ics, climate, and landscape evolution. Geol. Soc. Amer., Spec.
Pap., 398, Penrose Conference Series, 1—447.