Gulf Of Orosei Research Articles

First record of microplastic in the environmental matrices of a Mediterranean marine cave (Bue Marino, Sardinia, Italy)

This study investigates for the first time the presence of microplastics in sediment, water, and benthic organisms (foraminifera) of a marine cave in the Gulf of Orosei (Sardinia, Italy). Microplastics were found in all water, and sediment samples with similar shapes, sizes, and compositions; identified items were mainly fragments and fibers constituted by PVC and polyethylene. Their provenance was supposed to be predominantly from the sea than from the seasonal freshwater supplies from the karst system. Foraminiferal assemblages were mainly constituted by calcareous hyaline taxa in the outer station, while in the inner ones, the agglutinated Eggerelloides advenus was dominant. FTIR analyses on agglutinated shells identified polyethylene. Microplastic items are collected by the foraminifers and sediment grains building the shell chambers. This is the first study providing evidence that marine caves may be collectors of microplastics and that, in these habitats, microplastics enter the biotic matrix at the protist's level.

Northward Spread of the Parrotfish Sparisoma cretense (Teleostei: Scaridae) in the Mediterranean Sea: An Update on Current Distribution with Two New Records from Sardinia

The parrotfish Sparisoma cretense, a marine species native to the eastern and southern coastal areas of the Mediterranean, has extended its distribution northward. Here, we provide an update on its distribution based on currently published data and two new records from the coastline of Sardinia, Italy (central-western Mediterranean). The survey methods were scuba diving and spearfishing: one specimen of S. cretense was caught along the Argentiera coastline (northwest Mediterranean) and the others were photographed in the Gulf of Orosei, Osalla Bay (central-eastern Mediterranean). A literature update, together with new records, documents the distribution of this species in the northernmost areas of the Mediterranean. Probably a result of global warming, the ongoing northward expansion of S. cretense highlights the need for sampling campaigns to obtain timely updates on population and distribution of this thermophilic species.

Benthic foraminifera as environmental indicators in extreme environments: The marine cave of Bue Marino (Sardinia, Italy)

The coast of the Gulf of Orosei (Sardinia, Italy) consists of impressive cliffs set up on dolostones and limestones characterized by wide karst systems connected to the sea. Marine caves, which are part of these system flooded by seawater through marine entrances, may be considered as extreme environments because of wide spatial and temporal environmental variability due to changing marine and terrestrial contributions. This study presents the results of the third survey carried out in summer 2016 in the Bue Marino cave, as part of a research project started in 2014 aimed at the application of Benthic Foraminifera (BF) as ecological indicators in Mediterranean marine caves for the identification of different habitats and their environmental interpretation. Sediment and water samples were collected from a total of 25 stations from two distinct sectors of the cave (North Branch and Middle Branch); sediments were analysed for living and dead BF and grain size, while Temperature, Salinity, pH and Dissolved Oxygen were measured in water samples collected close to sediment water interface. Two main foraminiferal assemblages, with distinct characteristics with respect to the typical Mediterranean shallow-water ones, were recognized by means of Hierarchical Cluster Analysis and Non-metric Multidimensional Scaling, and a Canonical Correspondence Analysis deduced their environmental significance. A well oxygenated, less saline environment with coarse bottom sediment, correlated with a mixed calcareous-agglutinated assemblage (Gavelinopsis praegeri, Rosalina spp., Eggerelloides advenus and Reophax dentaliniformis) with high species diversity (H-index 2.32–3.57) and low foraminiferal density, was exclusive of the North Branch. A scarcely oxygenated, more saline environment with fine bottom sediment enriched in vegetal debris was related to a prevalently agglutinated assemblage characterized by low species diversity (H-index 1.60–2.68), with high dominance of E. advenus (up to 83.6%) associated to Ammonia tepida, and high foraminiferal density, recognized in the Middle Branch. These different environments were interpreted considering the different modes of feeding the karst systems of the two branches. They also corresponded to two distinct ecozones, Entrance and Confluence, already recognized in earlier studies. The environmental significance of the foraminiferal ecozones recognized in this study and their comparison with the ones identified in the previous years, helped to consider the ecological zonation as a tool for detecting seasonal and, possibly, long term annual environmental variability in the marine system.

Benthic foraminifera as proxies of marine influence in the Orosei marine caves, Sardinia, Italy

Abstract As a result of their location at the boundary between marine and continental domains, marine caves are affected by wide spatial and seasonal environmental changes. Only recently have benthic foraminifera been recognized as reliable indicators for the ecological zonation of these environments. The present study is focused on two marine caves of the Orosei Gulf, Sardinia, Italy: Bue Marino and Bel Torrente. It investigates the spatial and seasonal variability of benthic foraminiferal assemblages relative to sediment grain size and water parameters (temperature, salinity, pH, and dissolved oxygen) collected during two campaigns in August 2014 and April 2015. The results from 2014 have been partially published. Based on a comparison of the results of the two campaigns, the considerable reduction of foraminiferal abundance in Bel Torrente was deduced to occur because of the strong freshwater flows occurring during the rainy season; in Bue Marino, the less severe water flow allowed the identification of both living and dead foraminifera, although strongly reduced in number. These identifications allowed benthic foraminifera to be used to define the ecological zonation. Entrance, confluence, and transitional ecozones were identified in Bue Marino cave on the basis of species abundance. The second ecozone, not recognized in 2014, was correlated with plant debris at the confluence of the two cave branches. The other two ecozones, which are characterized by the faunal shift from hyaline‐ to agglutinated‐prevalent assemblages, were attributed to the gradient of abiotic parameters detected from the outer to the inner portions of the cave. In both campaigns the same ecozones were recognized in terms of species composition, with exceptions being found to different extents as a result of seasonal variability. As the distribution of foraminiferal ecozones is conditioned by a decreasing gradient of marine influence, long‐term monitoring may be regarded as a promising tool for future studies on sea‐level change.

Sedimentary evolution of a coral-, microbialites- and debris-rich Upper Jurassic reef (upper Tithonian, eastern Sardinia, Italy)

This work investigates a portion of a poorly documented upper Tithonian reef (Lower Mt. Bardia Reef, LBR) developed along the northern platform margin of the eastern Sardinia Platform (ESP). The LBR was probably one of the most southerly reefs of the northern Tethys margin, and this study provides the first comprehensive description of facies and internal structure, giving insights for the depositional setting.Detailed compositional and facies analyses of LBR have been carried out in three quarries located in the Orosei Gulf (eastern Sardinia). The main reef components are represented by carbonate (bioclastic) debris, microbialites and microencrusters, and reef-building organisms (mainly corals and stromatoporoids). These components combine in various proportions, forming several facies and facies associations. Ten reef facies (RF), grouped into three main Facies Associations have been identified within the studied reef portion. The distribution and arrangement of facies reveal a sedimentary evolution, evolving from a microframework-dominated reef to a carbonate debris-dominated one, with the internal reef architecture evolving from massive, to patchy, to coarsely stratified and roughly bedded.The reef components and facies indicate that the investigated portion of the LBR corresponds to a shallow back-reef zone, characterized by well-lit and generally low-energy hydrodynamic conditions, possibly developed in back position with respect to a higher-energy zone that was closer to the edge of the platform. In this depositional context, the arrival of large amounts of debris and the evolving internal architecture are interpreted as the result of the infilling process of the back-reef zone due to the progradation of a sand apron, during a long-term regional regressive phase.

Foraminiferal ecozones in two submarine caves of the Orosei Gulf (Sardinia, Italy)

Because submarine caves are affected by wide spatial and temporal environmental variability, they are ideal environments for studying the effects of environmental changes on ecological indicators. Benthic foraminifera are protozoa living in marine and transitional habitats, developing typical assemblages as a response to different environmental conditions. For this, they have been increasingly used as ecological indicators for environmental characterization and monitoring. This study was the first one aimed to compare benthic foraminiferal fauna of two different submarine caves of temperate areas, Bel Torrente and Bue Marino, in the Orosei Gulf (Sardinia, Italy). It resumes the main results obtained in Bel Torrente cave by a previous research, implemented by new data acquired by the study of Bue Marino cave. The caves were surveyed and sampled by GUE (Global Underwater Explorers) divers for the first 450 m to recognize distinct ecozones, their ecological significance, and to compare them as regards species composition and extent. The succession of Marine, Entrance and Transitional Ecozones was recognized in both the caves. While the Marine Ecozone pointed out environmental conditions very similar to those of shallow water marine environment, the Entrance and Transitional Ecozones indicated increasing environmental stress. In the Entrance Ecozone, the dominance of tolerant species was probably due to the high environmental variability for the episodic high energy floods and, locally, reduced oxygenation events. In the Transitional Ecozone, the decrease of seawater salinity and temperature, especially after rainy periods, probably encouraged the prevalence of agglutinated taxa, which are normally rare in Mediterranean shallow water marine environment, while they are common in high latitude basins.

The distribution of benthic foraminifera in Bel Torrente submarine cave (Sardinia, Italy) and their environmental significance

The use of benthic foraminifera as ecological indicators in submarine caves of temperate seas have never been studied before and it represents a new approach, verified by this research. The Bel Torrente submarine cave (Gulf of Orosei, Sardinia, Italy) was surveyed by GUE (Global Underwater Explorers) scuba divers in order to georeferencing the cave before positioning the sampling stations, from the entrance to 430 m inside the cave. A total of 15 water samples were collected to investigate abiotic parameters (temperature, salinity, pH) while 15 sediment samples were collected to analyze grain size and benthic foraminifera. Benthic foraminifera, investigated for the first time in a submarine cave of temperate areas, were exclusively found from the entrance to 300 m inside the cave. Species distribution and assemblage diversity have been found to be correlated to the environmental gradient towards the inner cave, mainly due to the decreasing of temperature and salinity and the increasing of the flow energy. Water acidification seems responsible for the transition from a calcareous hyaline-dominated assemblage to an agglutinant-dominated one, occurring between 120 and 150 m from the entrance. Common taxa of the Sardinian coastal marine area are present only close to the entrance of the cave, while species found in the inner part are nearly exclusively epifaunal clinging/attached or infaunal taxa, with tolerance for wide variability of environmental parameters, such as Gavelinopsis praegeri, and opportunist infaunal taxa such as Eggerella advena. The agglutinant taxa found in the cave are conversely very rare in coastal marine assemblages of the area. This suggests a very efficient dispersal mechanism for the colonization of the caves, involving probably juvenile foraminifera at a “propagule” stage.

Geomorphologic Evolution of a Coastal Karst: The Gulf of Orosei (Central-East Sardinia, Italy)

Orosejski zaliv je eno najpomembnejsih obalnokraskih obmocij v Italiji. Stevilne nove meritve jam so omogocile boljse razumevanje speleogeneze na obmocju zaliva. Razvoj krasa na tem obmocju smo raziskovali z razlicnimi geomorfoloskimi raziskavami na povrsju in pod morjem, ter speloloskimi raziskavami v jamah. Glavni faktorji morfoloskih procesov so litologija, tektonika, paleoklima in nihanja morske gladine. Studija nekaterih pomembnih jamskih sistemov je pokazala kompleksen geoloski razvoj, kjer so kraski procesi igrali pomembno vlogo od zgodnjega terciarja in dosegli visek v pliokvartarju. In the past ten years cave surveying has allowed better understanding of speleogenesis in the Orosei Gulf (Central-East Sardinia, Italy), one of the most important coastal karst areas of Italy. Surface geomorphologic research has been accompanied by subterranean and submarine landform analysis in order to try and understand the evolution of this coastal karst since its emersion in Upper Eocene. The main factors influencing the geomorphic processes are lithology, tectonics, palaeo-climate and sea level changes. The study of several important cave systems demonstrates a complex geological history with karst processes that started in Early Tertiary and accelerated during Plio-Quaternary.

Marine Notches and Sea-Cave Bioerosional Grooves in Microtidal Areas: Examples from the Tyrrhenian and Ligurian Coasts—Italy

ABSTRACT Carobene, L., 2015. Marine notches and sea-cave bioerosional grooves in microtidal areas: Examples from the Tyrrhenian and Ligurian coasts—Italy. Modern and ancient marine notches are present along the cliffs and inside the sea caves of the Gulf of Orosei in Sardinia, the Gulf of Gaeta in Lazio, and in Western Liguria. A morphological quantitative study was undertaken to define the shape and size of notches and their altimetric correlation with the sea-level highstands that created them. The geometrical aspects of the notches along cliffs and the relationship between the mean sea level and the shape of the notch have allowed us to deduce that the main erosion process giving rise to the marine notches is wave action. Conversely, the bioerosive process is the most important cause leading to notch formation inside sea caves. These two types of notch differ in terms of their shape and size and while the former mainly develops above mean sea level, the latter extends below the mean high tide level. Fo...

Uplifted flank margin caves in telogenetic limestones in the Gulf of Orosei (Central-East Sardinia—Italy) and their palaeogeographic significance

This work reports the results of geomorphological observations carried out in the coastal Fico Cave and surrounding areas (Baunei, Central East Sardinia) in the Gulf of Orosei. A tidal notch, generally believed to be of Eemian (MIS 5e) age, is barely visible at 8.5 above present sea level (asl), some metres below the main entrance of the cave. Old cave passages, now partially opened by cliff retreat and parallel to the coastline, are clearly visible at around 14m asl and correspond to the main level of Fico Cave. Two more notches are located higher, at 22 and 50m asl. Fico Cave itself is composed of at least 6 clearly distinguished more or less horizontal levels (−10m below present sea level (bsl), and +14, +22, +40, +50, and +63m asl), independent of the stratal dip, arguing for a sea-level, and hence, fresh-water lens control. Cave passages develop along main fractures more or less parallel to the coastline and never extend landward for more than 150m, mostly ending blindly, or diminishing in their dimensions progressively landward. Most passages only contain clay deposits, lacking fluvial or marine sediments or typical fluvial erosion morphologies (i.e. scallops).It is suggested from this body of evidence that Fico Cave was formed in the coastal mixing zone along major discontinuities during several Quaternary interglacial periods, when sea level was high and relatively stable for enough time to develop large dissolutional voids. The geomorphological observations indicate the main +14m asl level of the cave to have formed during MIS 9, and was heavily reworked during MIS 5, while the higher levels are relative to older interglacial highstands that occurred between 1Ma and 325ka. The small active branch developed below present sea level has formed during MIS 7 (225ka). These observations shed new light on the position of the MIS 5e highstand markers in this area of the coast, much higher than previously thought.

Mid-Eocene mass-wasting mélanges in the context of wrench faulting along the oblique-convergent Corsica-Sardinia margin

The Mid-Eocene clastic wedge with olistoliths of the CaporalinoUnit and correlated units in Corsica are regarded as sedimentarymelanges emplaced at shallow structural level by means of submarine,gravity-driven mass wasting processes in fault-bounded basinsof the Corsican accretionary wedge. This occurred in the frame ofsynorogenic sinistral strike-slip motion generated by oblique convergencebetween the Iberia and Adria plates. During the final, LateEocene collisional stage the melanges were overprinted and structurallyreworked as olistostromal carpets at the base of the uppermostthrust sheets of the nappe stack (the Balagne-Nebbio Nappe).It is believed that the Corsica orogenic belt continued southwards,and that the present-day Sardinia behaved as foreland of the Alpinebelt, as suggested by evidence of forebulge migration from Late Cretaceousonwards. However, the NE and SE sectors of Sardinia showdifferent responses to the Mid-Eocene geodynamic event, as therelated wrench faulting and transpressional deformation are welldeveloped only in the NE part, the change being identifiable at thelevel of the Gulf of Orosei. We propose that the Orosei Canyon Line(OCL), an important lineament identified by SARTORI et alii (2001),could have been active in Eocene times as a transform boundarypreventing the southward prosecution of the Alpine subduction. Thetranspressional response of NE sector of Sardinia to the stress fieldwas accompanied by accumulation of elongate clastic wedges bymass-wasting processes at the base of tectonic scarps. The wedgesdisplay several features comparable to those of Corsican melanges,and, although obviously generated in different geologic contexts,both are considered to be the expression of a peculiar Mid-Eocenegeodynamic event of the Alpine orogenic belt.

CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF THE S’ADDE LIMESTONE (MT. ALBO, OROSEI GULF): INSIGHTS INTO THE MIDDLE-LATE JURASSIC EASTERN SARDINIA PASSIVE MARGIN EVOLUTION

Calcareous nannofossil biostratigraphy has been performed on tree sections cropping out in Eastern Sardinia (Orosei Gulf, Mt. Albo). Calcareous nannofossils are rare to few and poorly to moderately preserved. Nevertheless thirteen bioevents have been recognized (S’Adde valley section) and a Late Bathonian-Early Tithonian age is derived for the S’Adde Limestone (Lms.). The inferred age constraints, integrated with data from the literature, allow the revision of the S’Adde Lms. chronostratigraphy, and the formalization of the S’Adde Limestone (Dieni & Massari 1985) as a lithostratigraphic unit. Qualitative evaluations of carbonate production/sedimentation rates for the north Mt. Albo area are proposed: the Late Bathonian-Callovian and Oxfordian were times of pronounced reduction of carbonate production/exportation, in agreement with the European passive margin evolution, also affected by starvation fenomena and condensations. A Middle-Late Jurassic basin-and-swell setting related to regional tensional tectonic activity is reconstructed for the north Mt. Albo area. The comparison of new and literature data allows framing the local and Eastern Sardinia passive margin evolution in the broader geodynamic and paleogeographic context of the southern European margin.

The Endemic Vascular Flora of Supramontes (Sardinia), a Priority Plant Conservation Area

FENU, G., E. MATTANA, A. CONGIU & G. BACCHETTA (2010). The endemic vascular flora of Supramontes (Sardinia), a priority plant conservation area. Candollea 65: 347–358. In English, English and French abstracts.The main aim of this work is to present a checklist of the endemic vascular flora of the Supramontes region (Central Eastern Sardinia) in order to classify this area in the Sardinian biogeographic subprovince and to better assess its conservation priorities. It is one of the most interesting regions of the Island and spreads for 335 km2 from the inland limestone massif to the Orosei gulf. This work was based on bibliographic and herbarium studies, integrated by several field surveys carried out from 2004 to 2009. In this study 138 endemic taxa, belonging to 98 genera and 42 families, have been found, with 92 of which being species, 40 subspecies, 5 varieties and 1 hybrid. The analysis of biologic and chorologic data highlighted the peculiarities of this territory. Due to the relatively high number of Supramontes exclusive endemics and to the geologic and geomorphologic peculiarities, it is here proposed a biogeographic classification for these territories and the identification of an autonomous biogeographic sector divided in two distinct subsectors. According to the recent conservation policies at local level, we propose the definition of micro hotspots for this sector, which hold ca. the 40% of the endemic flora of Sardinia, and the concept of nano hotspots for three narrows areas with an exceptional concentration of endemic species, which represent less than 1% of the whole sector surface and whose in situ protection may allow conserving of more than 80% of the vascular endemic flora of this sector.

Sardinia Coastal Uplift and Volcanism

The low variability of MIS 5.5 sea level (M.I.S = Marine Isotopic Stage) with respect to the present day sea level, allows the Sardinian coast to be used as an eustatic reference for the entire Mediterranean region. This level is generally at 7 ± 2 m above current sea level along the Sardinian coast. One sector along the Orosei Gulf (eastern Sardinia) includes a characteristic and well conserved tidal notch that changes in elevation from 7.6 to 11.5 m over only 30 km, tilting upwards towards the north. Generally, height deviations of such a tidal notch would be due to tectonic or volcanic activity. The Sardinia coast however, is considered to have too little tectonic activity, and also too small post-glacial rebound in order to explain the anomaly. The remaining possibility is Neogene-Quaternary continental and/or submarine volcanic activity, which we investigate as a possible cause for the observed anomalies. In this paper, our goal is to explain the anomaly by modelling recent volcanic loading or updoming related to magmatic intrusion emplacement. We review the literature on the recent volcanic deposits, both on-shore and off-shore, and investigate to what extent volcanic loads can influence the coastline from a theoretical standpoint, using the isostatic flexure model and a range of loads. We find that the observed notch height anomaly cannot be explained by volcanic loading, but must be produced by an upward welling due to the emplacement of volcanic material, as produced for instance by a laccolith or batholith. The upward movement could be related to the submarine volcano only recently detected, or to a source located on the eastern Sardinia coast near Orosei.

Thermochronological evidence for Mesozoic–Tertiary tectonic evolution in the eastern Sardinia

AbstractApatite fission‐track analyses on samples from eastern Sardinia document a complex tectonic history, whose reconstruction is problematic because of the reactivation of faults and structures at different times from Jurassic to Miocene. The oldest ages (150–154 Ma) have been detected on the southern margin of the Gulf of Orosei and are related to the extensional tectonics that characterize the European passive margin during Early and Middle Jurassic times. Thermal modelling of these data allows reconstruction of the burial history of the Mesozoic basin and estimation of a sedimentary thickness of 2000 m. Part of these sediments was eroded during the following uplift, documented by mid‐Cretaceous fission‐track ages. A further exhumation episode of Eocene age has been revealed by fission‐track data on granite samples, and has been inferred to be related to the Alpine orogenic phase. This tectonic episode caused the exhumation of crustal blocks bound by faults that were finally reactivated during the Late Oligocene–Early Miocene.

The biology and ecology of a submarine cave: the Grotta del Bel Torrente (Central-East Sardegna, Italy)

Cave diving expeditions were conducted in the Golfo di Orosei in June/July 2003 and July 2004. The main site of the exploration was located 500 m north of Cala Sisine (Fig. 1). The cave system of Grotta del Bel Torrente is one of the biggest in Sardegna. To date, a total of more than 2.5 km dry and water-filled passages have been surveyed. A map of the cave was generated as the basis for further investigations. The focus of the biological work is on the diversity of the species and their distribution throughout the cave until 800 m from the entrance. Until 350 m from the entrance a clearly visible halocline is developed between the upper layer (20 °C, salinity about 22) and the underlying water column (22 °C, salinity about 33). A zone of intermediate water salinity and temperature, without halocline, follows over a distance of 100 m. In more than 450 m from the entrance the salinity drops to 1 and temperature is 15 °C. Up to 350 m from the entrance, marine sponges, molluscs, crustaceans, polychaetes, ascidians and fishes were observed. The occurrence of empty tubes of Serpulidae and shells of oysters in this zone may reflect oxygen deficiency. Some fish such as mullet (Liza sp.) migrate between the fresh and salt water columns. Figure 1Open in figure viewerPowerPoint Geographical location map of the Grotta del Bel Torrente (Italy, Sardegna, Gulf of Orosei).

A new Batillipedidae (Tardigrada, Heterotardigrada) from the Orosei Gulf, Sardinia, Tyrrhenian Sea

A new species of Batillipedidae, Batillipes spinicauda, has been found in subtidal sand sediments collected in Orosei Gulf (Sardinia, Tyrrhenian Sea). The most important peculiarities of the new species are the shape of the primary clavae, lateral processes and caudal apparatus. In the same samples, B. littoralis Renaud-Debyser, 1959 and Orzeliscus belopus Du Bois-Reymond Marcus, 1952 were found.

Ecological Impact of Economic Development on Sardinian Herpetofauna

The link between ecology and economies is manifest over the world as a result of long‐term processes. But because these processes are long term, it is hard to prove the link. On Sardinia serious economic development was late to arrive, having occurred only over the last few decades. As a case study, research was carried out for 10 years on the state of nature as well as the economic growth in one of the least developed areas abutting the Gulf of Orosei on the east coast. Based on research and lasting attention to political affairs concerning the project, we formulate general recommendations for the area. In 1995, the Italian Government will be asked by the European Government to undertake serious steps to save endemics (especially herpetofauna) of Europe's last pristine areas.

Neoarctus primigeniusn. g., n. sp., a new Stygarctidae of the Tyrrhenian Sea (Tardigrada, Arthrotardigrada)

Abstract A new Stygarctidae, Neoarctus primigenius n.g., n.sp. is described. It has been found in the sandy detritus of a rocky bottom covered with green algae at ‐ 38 m depth in the Orosei Gulf off Sardinia (Tyrrhenian Sea). The most important characteristics of this species are the dorsal cuticular elements, the distribution of the cephalic sense organs in both the cephalic and scapular plates and the presence of three pairs of clavae. Taking into account the cuticular plates, the number and distribution of the sense organs, and the claw morphology, the affinities of this species with Oreellidae, Neostygarctidae and Renaudarctidae are here discussed.

Thermal inertia of rocks—an HCMM experiment on Sardinia, Italy†

Abstract The usefulness of thermal inertia mapping for discriminating litholog-ical units was investigated using Sardinia and the Gulf of Orosei as test sites. Software designed forXANDSAT data was modified and improved for HCMM tapes. A first attempt was made to compare the geological cross-section, the topography, the infrared radiance and the thermal inertia along selected profiles of the test site. Thermal inertia profiles appear smooth in comparison with the thermal radiance. The lowest apparent thermal inertia (ATI) was found on granitic and basaltic outcrops of sufficient extent, while ATI is higher on carbonate and dolomitic or moist deposits, Almost every fault is marked by a jump in the ATI, the interval being sometimes of the order of I pixel. This seems to demonstrate the ability of ATI to detect contacts or tectonically disturbed zones with good resolution. It seems more difficult to measure the differences in ATI between homogeneous materials having different lithology. The results of ground surveys and a simulation model of diurnal temperatures of rocks having different thermal inertia are discussed.