Fault gouge dating: history and evolution

Geological features and origin of gold deposits occurring in the Baotou–Bayan Obo district, south-central Inner Mongolia, People's Republic of China

Geology and He-Ar-S-Pb isotope constraints on the genesis of the Sidaogou gold deposit in Liaodong Peninsula, northeastern North China Craton

Systematic changes in REE patterns of fluorites with various colourations from the Ehrenfriedersdorf tin deposit, Germany, can be related to the evolution of the mineral forming hydrothermal fluid within the endo- and exocontact of a related Li-F granite. One possible geochemical model that may explain the fluorite REE patterns assumes that lanthanides derived from two distinct element sources. It is suggested that a mantle- or lower crust-derived fluid (LREEs n < HREEs n ) participated as one source of elements in the formation of the Li-F granitic magmas and in ore deposition. The metamorphic wall rocks (LREEs n > HREEs n ) were involved as a second source of elements due to assimilation and fluid-rock interaction (including admixing of crustal fluids). Minerals that crystallised in the relatively cool and/or oxidising environment of the exocontact incorporated the REEs from the ore-forming fluid and therefore exhibit REE patterns that result from simple mixing of the lanthanide distributions of the two element sources. Mineral precipitation in the exocontact vein system led to a successive decrease of the total lanthanide concentration of the migrating fluid. The fluorite REE patterns further suggest that the mineral-forming fluid in the exocontact showed a relative enrichment of Eu that can be attributed to fluid evolution within the endocontact. The large ionic radius of Eu2+ hampered the incorporation of Eu into minerals crystallising from the fluid-magma system in this high temperature and/or low oxygen fugacity environment. This process lead to an enrichment of Eu in the fluid that subsequently entered the exocontact and resulted in a corresponding Eu depletion of the altered granite. The lanthanide distributions of three differently coloured fluorite samples from a single zoned fluorite aggregate out of a cassiterite-bearing quartz vein of the exocontact are suitable for mathematical modelling because of their sample location in a sequence of homogeneous wall rocks and their well-constrained relative age relationships. Mathematical modelling has been carried out to test whether the geochemical mixing model can indeed explain the entire REE patterns of the three samples. In accordance with the proposed geochemical model, it is assumed that two endmembers with distinct REE patterns were mixed and that a process such as mineral precipitation reduced the total REE content of the mixture. The incorporation of REEs from the fluid into fluorite is described by a partition coefficient. Model values that are in closest possible agreement with the measured fluorite lanthanide concentrations were derived from the mathematical model by minimising the mean squared deviation between the two data sets. It is shown that the global minimum was found by application of the Gauss-Newton method and a specially designed evolutionary strategy. Ce and Eu were not considered in a first analysis because positive anomalies in the fluorite REE patterns indicate anomalous geochemical behaviour of these elements during the ore forming processes. The differences between the model values and the measured lanthanide concentrations were found to be smaller than the analytical errors of the REE measurements. In a second analysis the Ce and Eu concentrations of the three fluorites were taken into account and deviations between the model and measured values for these two elements were observed that could not be explained by analytical errors only. These findings suggest that the geochemical mixing model is a likely explanation for the measured fluorite REE patterns, while the observed Ce and Eu contents do not simply result from mixing processes.

The Jinshan gold deposit is located in the Northeast Jiangxi province, South China, which related to the ductile shear zone. It contains two ore types, i.e. the alteration‐type ore and the gold‐bearing quartz vein ore. Rb‐Sr age dating is applied to both gold‐bearing pyrite in the alteration‐type ore and fluid inclusion in the gold‐bearing quartz vein to make clear the time of the gold mineralization of the Jinshan deposit. Analytical results of this study yielded that the age of the alteration‐type ore bodies is about 838±110Ma, with an initial 87Sr/86Sr value of 0.7045±0.0020. However, the age of the gold‐bearing quartz vein‐type ore is about 379±49Ma, and the initial 87Sr/86Sr is 0.7138±0.0011. Based on the age data from this work and many previous studies, the authors consider that the Jinshan gold deposit is a product of multi‐staged mineralization, which may include the Jinninian, Caledonian, Hercynian, and Yanshanian Periods. Among them, the Jinninian Period and the Hercynian Period might be the two most important ore‐forming periods for Jinshan deposit. The Jinninian Period is the main stage for the formation of alteration‐type ore bodies, while the Hercynian Period is the major time for ore bodies of gold‐bearing quartz vein type. The initial values of the 87Sr/86Sr from this study, as well as the previous isotope and trace element studies, indicate that the ore‐forming materials mainly derived from the metamorphic wall rocks, and the ore‐forming fluids mainly originated from the deep metamorphic water.

Soils are weathering products of rocks and minerals. The rocks in Earth’s outer surface can be classified as igneous, sedimentary, or metamorphic rocks. Igneous rocks are formed from molten magma. They are composed of primary minerals, which are minerals that have not been altered chemically since they formed as molten lava solidified. Examples of primary minerals are the light-colored minerals quartz, muscovite, feldspars, and orthoclase, and the dark-colored minerals biotite, augite, and hornblende. In general, dark-colored minerals contain iron (Fe) and magnesium (Mg) and are more easily weathered than light-colored minerals. Coarse-grained igneous rocks, such as granite and diorite, contain mainly lightcolored minerals, while medium-grained igneous rocks such as gabbro, peridotite, and hornblendite are composed of dark-colored primary minerals. Rhyolite and andesite are medium-grained igneous rocks containing light-colored primary minerals. Basalt is dark-colored with an intermediate to fine rock texture, and basaltic volcanic glass has a fine texture. Examples of light-colored igneous rocks with a fine texture are felsite and obsidian. Sedimentary rocks are the most common type of rock, covering about 75% of Earth’s land surface. They are mainly composed of secondary minerals, which are minerals that are recrystallized products of the chemical breakdown and/or alteration of primary minerals. Sedimentary rocks form when weathering products from rocks are cemented or compacted. For example, quartz (SiO2) sand, a weathering product of granite, may become cemented into sandstone. Another common sedimentary rock is limestone. There are two types of limestone, namely, calcite (CaCO3), and dolomite (CaCO3.MgCO3). Clays may become cemented into a sedimentary rock, which is known as shale. A sedimentary rock with several dominant minerals is called a conglomerate, in which small stones with different mineralogy are cemented together. Metamorphic rocks are formed by the metamorphism of igneous or sedimentary rocks. Great pressure and high temperatures, caused by the shifting of continental plates, can compress, distort, and/or partially re-melt the original rocks. Igneous rocks are commonly modified to form schist and gneiss, in which light and dark minerals have been reoriented into bands. Sedimentary rocks, such as limestone and shale, may be metamorphosed to form marble and slate, respectively.

The Elba Island is located in the Northern Tyrrhenian Sea at midway between Tuscany (Northern Apennines Chain) and Corsica (Alpine Corsica structural pile). The complex Elba I. stack of nappes, which is considered the innermost outcrop of the Northern Apennines Chain, is also well known for its Fe-ore bodies and the relationships between the emplacement of the Mio-Pliocene magmatic bodies and tectonics. The geological survey of Elba I. performed at a scale of 1:10,000 and 1:5,000 (geological map at 1:15,000) allowed a revision of the stratigraphic and structural setting of the central and eastern Elba I. This new scheme results more complex compared to Trevisan’s classical one, which was based only on five tectonic “Complexes” (Trevisan, 1950; Barberi et al., 1969). Nine tectonic units were defined, and they all pertain to the Tuscan and Ligurian (including the Ligurian-Piedmontese Units) paleogeographic domains. Before their final emplacement in the Elba’s tectonic pile during the 8.5 to 5.4 Ma time interval, some of these units were intruded by two acidic plutons (Mt. Capanne and La Serra-Porto Azzurro monzogranites), and by dikes of variable composition. A total of nine units were recognised, from bottom to top: 1- Porto Azzurro Unit (PU). It is made up of phyllites, quartzites and micaschists (Mt. Calamita Fm.), probably of Paleozoic age. It shows a strong static recrystallisation due to the La Serra-Porto Azzurro intrusion and the related aplitic dike network (6.0-5.4 Ma). On top of the Mt. Calamita Fm., crystalline dolostones and dolomitic marbles were recognised and were attributed to its Mesozoic cover. The aplitic dikes are cut along the tectonic contact (Zuccale Detachment Fault) with the overlying units described below. 2- Ortano Unit (UO). It includes metavolcanites (Porphyroids) and quartzitic-phyllitic metasediments (Capo d’Arco Schists) which can be correlated to the Ordovician formations of Central Sardinia and Tuscany (Apuan Alps). A few aplitic dikes were also recognised, and they occur along the coast between Capo d’Arco and Ortano Valley. 3- Acquadolce Unit (AU). It is composed of marbles, grading upwards into calcschists and, finally, into phyllites, metasiltstones and metasandstones with intercalations of calcschists which contain fossils of Early Cretaceous age. At its top a serpentinite slice crops out. This Unit has been attributed to the Ligurian Domain (Ligurian-Piedmontese Units) and can be correlated with the “Calcschists with ophiolites” of the Gorgona Island. Near Capo d’Arco Residence, some lamprophyric dikes (Casa Carpini Lamprophyries) also occur. Locally, the carbonate lithotypes are transformed into Fe-skarn bodies (e.g., Torre di Rio skarn). 4- Monticiano-Roccastrada Unit (MU). This Tuscan Unit largely consists of Upper Carboniferous-Triassic metasiliciclastic rocks (the Permian-Carboniferous Rio Marina Fm. and the Triassic “Verrucano” Group). It also includes a Jurassic to Oligocene epimetamorphic succession (from the Capo Castello Calcschists to the Pseudomacigno) which crops out along the coast between Capo Pero and Capo Castello, and in the Valle Giove mining area. 5- Tuscan Nappe (TN). South of the locality La Parata, this unit is composed only of calcareous-dolomitic, at times vacuolar, breccias (“Calcare Cavernoso”), while northwards these rocks are overlain by Upper Triassic to Hettangian shallow marine carbonates, and Sinemurian to Dogger carbonatic, siliceous and marly pelagic sediments. 6- Grassera Unit (GU). It mostly consists of varicoloured slates with rare carbonate-siliceous and radiolarian cherts intercalations (Cavo Fm.). Between Cavo and La Parata, a basal decametric Calcschist Member also occurs. This anchimetamorphic unit, possibly of Cretaceous age, could have been originated in the Ligurian Domain: because of its peculiar lithologic association and metamorphic overprint it is considered a Ligurian-Piedmontese Unit.. 7- Ophiolitic Unit (OU). This Ligurian Unit is composed of seven tectonic subunits (Acquaviva “ASU”, Mt. Serra “SSU”, Capo Vita “CSU”, Sassi Turchini “TSU”, Volterraio “VSU”, Magazzini “MSU” and Bagnaia “BSU”), which are characterised by serpentinites, ophicalcites, Mg-gabbros, and by their Jurassic to Lower Cretaceous volcanic-sedimentary cover (Basalts, Mt. Alpe Cherts, Nisportino Fm., Calpionella Limestones and Palombini Shales). A shoshonitic dike (Mt. Castello Dike: 5.8 Ma) fills two ENE-WSW-trending normal faults cutting VSU in the Porto Azzurro area. Some calc-alkaline dikes (Mt. Capo Stella Dikes) were also identified in the Ligurian basalts along the western coast of Golfo Stella 8- Paleogene Flysch Unit (EU). It is constituted by shales with calcareous-marly, calcarenitic and arenaceous intercalations and, locally, by ophioliticcarbonate breccias (Colle Reciso Fm.). The fossiliferous content of the carbonate lithotypes points to a Middle Eocene age. This unit can be interpreted as a 98 syn-tectonic oceanic unit (Epiligurian Unit), which has the same paleogeographic origin of the Lanciaia Fm. in Southern Tuscany. Aplites (Capo Bianco Aplites: 7.9 Ma), locally sericitised (the so-called “Eurite”), and porphyries (Portoferraio Porphyries: 8.2 Ma and San Martino Porphyries: 7.4-7.2 Ma) intrude the sedimentary succession, but do not crosscut the basal contact with the underlying Ophiolitic Unit. 9- Cretaceous Flysch Unit (CU). It is a Ligurian, Helminthoid-type, oceanic succession. It consists of a basal tectonised complex, similar to OU (ophiolites, basalts and Jurassic-Cretaceous sedimentary cover slices), and of a sedimentary succession formed by Cretaceous Palombini Shales and Varicoloured Shales, which grade upwards into an arenaceous-conglomeratic (Ghiaieto Sandstones) and then to a calcareous-marly-arenaceous (Marina di Campo Fm.) flysch of Late Cretaceous Age. Similar to the EU, this unit is frequently intruded by locally thick acidic dikes and laccoliths. The structural setting of central and eastern Elba is characterised by a pile of eight structural units (Units 2-9), separated by low angle tectonic surfaces (thrusts and detachments), which lays onto the lowermost Porto Azzurro Unit 1, by a low-angle detachment fault marked by a decametric cataclastic horizon (Zuccale Fault and related cataclasite). The thrust surfaces (Late Eocene-Early Miocene) have been tentatively distinguished from the low-angle detachments, due to the extensional tectonics, which probably began during Burdigalian-Langhian, and continued during Messinian-Pliocene times, accompanied by magmatic intrusions. Other low angle tectonic surfaces are of complex interpretation because they derived from the superposition of tectonic events which occurred in different times and/or in different tectonic regimes. Among the high-angle faults, we recognised a NW-SE trending transfer fault system, which was preceded and followed by generations of normal faults, with WSW-NNE and N-S trends, respectively. The N-S-trending faults cut the whole tectonic pile, comprising all the detachment faults. The study of the tectonic relationships between the previous nine tectonic units and between these tectonic units and the Messinian-Pliocene magmatic events, suggests the following geological scenario for the evolution of the Elba Island: 1) Pre-magmatic stages (>8.5 Ma). They are recorded by: a- relics of the pre-Alpine schistosity within PU and UO, which can be attributed to the Sudetic phase of the Variscan orogeny; b- folding and thrusting of OU, EU and CU, with production of ophiolitic-carbonate breccias within PU, and the D1 tectono-metamorphic event (S1 relics) in AU, related to Eocene intra-oceanic deformation events; c- main deformation and metamorphic events of Tuscan (PU, UO, MU) and Ligurian-Piedmontese Units (and 19 Ma S2 in AU), overthrusting of the oceanic units (AU, OU, GU, EU+CU) onto the Tuscan ones, and a later refolding of the tectonic units, probably related to the Oligocene-Early Miocene collisional events; d- emplacement of AU between OU and MU, and of TN onto MU. The superposition of TN onto MU can be considered the older extensional event by low-angle detachments (Middle Miocene). 2) Syn-magmatic stages (8.5-5.4 Ma). This stage begins with the genesis and rise of anatectic melts due to the uplift of the asthenospheric mantle, within the stretched inner part of the Apenninic orogenic belt. During the uprise of the Mt. Capanne granitoid (6.8 Ma), the most of its cover, that was constituted by EU and CU (already injected by acidic dikes), was detached and shifted eastwards along a low-angle fault (Central Elba Fault, “CEF”). During this event the acidic dykes of the basal part of the flysch were sericitised (“eurite”: 6.7 Ma). Farther east, a shoshonitic dike intruded OU at 5.8 Ma and, possibly, lamprophyric dikes were emplaced within AU. A new uplift of the Mt. Capanne caused a further glide eastwards of EU+CU onto OU in the central Elba, and the development of transfer faults (as lateral ramps of detachments) within the Ligurian Units and, probably, the onset of the Zuccale Fault. At 6.0-5.4 Ma the emplacement of the La Serra-Porto Azzurro granitoid produced a wide thermometamorphic aureola and local skarn bodies within the host PU, UO, AU and MU. The uplift of this granitoid caused, or completed, the separation of the eastern and central Elba tectonic pile through the Zuccale detachment Fault. During this stage, the back-gliding of OU onto EU+CU in the Colle Reciso area, and the north- or north-eastwards gliding of CSU, completed the present tectonic pile of central and eastern Elba. 3) Post-magmatic events (

KEYWORD: detrital component characteristics; provenance analysis; Triassic. ABSTRACT: Triassic in the western Tabei uplift is detrital sedimentary. Based on the data of the conglomerate, sandstone framework components and heavy mineral to analyze the Triassic of research area, the result shows that the source rocks are metamorphic rocks, magmatic rocks and sedimentary rocks, whose sources come from Xiqiu Uplift and Luntai Uplift. The western of research area is magmatic and sedimentary rock deposit zone, where is mainly influenced by the Xiqiu Uplift. The middle part of research area is metamorphic and sedimentary rock deposit zone where is mainly influenced by the Xiqiu Uplift and Luntai Uplift. The eastern of research area is metamorphic, sedimentary and magmatic rock deposit zone where is mainly influenced by the Luntai Uplift. The proximal clastic deposits are mainly influenced by the hydrodynamic conditions, palaeohigh and tectonization, so provenance has the characteristics of region and multiple

PLATE 12. Geologic map of the Trinidad coal field._______________ In pocket FIGURE 18. Index map of the Trinidad coal field-_____________________ 19. Cokedale coal bed in the upper part of the Vermejo formation., 20. Frederick coal bed in the Raton formation,,______________ 143 21. Coal bed in the Raton formation intruded by an igneous sill__ 147 TABLES TABLE 1. Analyses of coals from the Trinidad coal field-_________-___--2. Classification of coals by rank_____________-__---_______--3. Total estimated

Soils of the southwestern part of the Dzhulukul Depression in Ulagan district of the Altai Republic have been studied. They belong to two soil divisions: Al-Fe-humus soils (with various types of podburs) and iron-metamorphic soils (rzhavozems). The soils within the eluvial part of the studied catena—iron-illuvial soddy podburs—are developed from the residuum of magmatic and metamorphic rocks with high (up to 80 vol %) content of gravels and coarse rock fragments. Their high porosity favors downward migration and precipitation of humus-iron compounds on the surface of gravels and mineral grains in the illuvial horizon. The soils of the accumulative part of the catena—permafrost-affected raw-humus pod-burs and gleyic podburs)—are developed from moraine deposits of loamy-sandy texture with up to 30 vol % of gravels. In these soils, the features of the Al-Fe-humus migration are weakly pronounced; the soils are underlain by the waterproof frozen horizon (permafrost), have high humus content, and have thixotropic properties in the lower horizons. Their reaction is slightly acid to neutral, and their base saturation is up to 80%. These characteristics do not meet the criteria of podburs as defined in the new Russian soil classification system. Their origin may be related to the local mixing of weathering products of different bedrock materials, including magmatic, metamorphic, and sedimentary rocks during the deposition of moraine sediments. Iron-metamorphic soils (rzhavozems) are formed on convex parts of slopes from the residuum and colluvial derivatives of magmatic and metamorphic rocks (granite, metamorphic slates, red-colored sandstone, etc.). A distinctive feature of these soils is their ocherous-brown color and a considerable content of gravels in the entire profile. The chemical properties of rzhavozems resemble those of the Al-Fe-humus soils of automorphic positions: acid and slightly acid reaction, low base saturation, and a relatively high content of organic carbon in the organic and mineral horizons.

The deformational and metamorphic history of the Georgetown Inlier, North Queensland: implications for the 1.7 to 1.5 Ga tectonic evolution of northeastern Proterozoic Australia

Relating Fault Mechanics to Fault Zone Structure

Titanite (CaTiSiO5) occurs as a rare mineral in magmatic and metamorphic rocks. It is commonly found in clastic sedimentary rocks as an accessory heavy mineral – a mineral of high density. Recently, U-Pb dating of single-grains of detrital titanite has been shown to be a useful tool in sedimentary provenance studies (e.g. McAteer et al. 2010; Thomsen et al. 2015). Titanite U-Pb geochronologies can add important information to constrain the sediment sources of rocks and basins, and can help date precipitation of titanite. However, there are a number of complicating factors that must be taken into consideration for reliable application of titanite U-Pb dating in provenance studies.&#x0D; First, titanite is less stable than zircon – the most commonly employed dating target. For example, in Palaeocene sediments in the North Sea, titanite rarely occurs as detrital grains at burial depths greater than 1400 m (Morton 1984). It can also show dissolution features due to weathering and burial diagenesis (e.g. Morton 1984; Turner &amp; Morton 2007). Second, titanite may precipitate during burial diagenesis, which would reflect the burial history of sediments and not their provenance. Precipitation of authigenic titanite is documented from deeply buried (i.e. at temperatures greater than 100°C) volcaniclastic sandstones and mudstones (Helmond &amp; Van de Kamp 1984; Milliken 1992) and intrusion-associated mineralisation in volcanic Permian sandstones (van Panhuys-Sigler &amp; Trewin 1990). Moreover, titanite also occurs in shallow-buried Jurassic sandstones with no volcanic affinity (Morad 1988). Thus, the formation of titanite is not necessarily linked to a volcaniclastic source, but nevertheless, the presence of volcanic material seems to promote titanite precipitation. If authigenic titanite precipitation was incorrectly identified as detrital, this would have considerable implications for provenance investigations, as apparently titanite-rich source rocks would be wrongly inferred to be present in the sediment source area. Here, we present examples from the Kangerlussuaq Basin in southern East Greenland of what appeared to be detrital titanite. However, new U-Pb dating reveals that the titanite formed authigenically, and hence contributed to the burial history, and not the provenance, of the sediments.

To determine the geographical distribution of dissolved inorganic phosphate (DIP) concentrations in stream water in Japan, 1,244 water samples were collected nationwide from watersheds unpolluted by any anthropogenic sources. DIP concentrations were logarithmically normally distributed, and showed a wide range from below the minimum limit of detection (1.5 μg · l-1) to 116 μg · l-1, with a median of 6.6 μg · l-1. The streams with higher concentrations (> 10 μg · l-1) were predominantly in the northern part of Ibaraki, the western parts of Saitama and Tokyo, the region from Ishikawa to Kyoto, and around the Shikoku and Kyusyu mountains. Those with lower concentrations (< 4 μg · l-1) were predominantly in central Hokkaido, Yamagata, the northern part of Gunma and the western part of the Chugoku district. A significant difference (P < 0.001) in DIP concentration was found among subsurface geologies. Watersheds with underlying sedimentary rocks had higher DIP concentrations in their stream water than those with underlying igneous and metamorphic rocks. Among sedimentary rocks, higher DIP concentrations were found in Paleozoic rocks than in Mesozoic and Cenozoic rocks. In igneous rocks, intermediate rocks (andesite) had higher DIP concentrations than acidic rocks (rhyorite and granite). The differences in DIP concentration among various types of igneous and metamorphic rocks coincided with the differences in phosphorus content obtained from the Geochemical Atlas of Japan. In other substances, DIP concentration positively correlated with SiO2 concentration except in Paleozoic and Mesozoic sedimentary rocks. These results indicate that DIP concentrations in stream water are partly controlled by phosphorus content and the mineral weathering of rock or soil.

Muarabungo Groundwater Basin,is locateed in Jambi and West Sumatra Province. Based on the four rainfall stations in Muaratebo, Dusun Rantau Pandan, Sungai Bengkal and Komplek Pengairan PU Station recorded in 2008 to 2011, the precipitation (ppt) in study area is 1799.09 mm/year. Value of evapotranspiration (Evpt) in the study area is equal to 1261.26 mm / year (70.1%). Groundwater Basin of Muarabungo has an infiltration debit of 2,516,791,750 m3 / year and run-off debit (Ro) of 798 042 638 m3 / year. Rock composer in the Muarabungo Groundwater Basin are dominated by Alluvium Deposition, Quaternary rocks, and also the surrounding areas are composed by igneous and metamorphic rocks. Aquifer with a good productvity can be found on Alluvium and sedimentary rocks such as tuff sandy, whereas region without exploitable groundwater are composed by igneous rocks and metamorphic rocks. Based on groundwater quality, Groundwater Basin is divided into 13 facies, namely Ca; Cl, ​​Mg; Cl, ​​Na + K, Cl, Ca; HCO3, Mg; HCO3, Na + K; HCO3, Ca; No. dominant type, Mg; Nodominan type, Na + K; No. dominant type, No. dominant type; Cl, ​​No. dominant type; HCO3, Nodominan type; SO4, and No. dominant type; No. dominant type. The result of water balance measurement in research area is used to show the areas for crisis and secure area. The water balance calculation and determining recharge and discharge areas are needed for developing conservation strategy.

All Earth Science students need to understand the origins, environments, and basic processes that produce igneous and metamorphic rocks. This concise introductory textbook provides students with the essential knowledge needed to understand how petrology relates to other topics in the geologic sciences, and has been written specifically for one-semester courses. Throughout, the emphasis is on interpreting the mineralogy and petrology of rock suites in terms of origin and environment, with the first half of the book concentrating on igneous rocks, and the second half on metamorphic rocks. This Second Edition has been thoroughly revised and brought completely up-to-date. It now includes a new chapter on the application of stable and radiogenic isotopes in petrology, introducing students to the concept of isotopic fractionation and describing the process of radioactive decay. The discussions of phase diagrams, connections between igneous and metamorphic rock suites, and convergent margin magmatism have also been expanded. There is a new glossary of terms, updated end-of-chapter exercises, and updated further readings.