mare basalt composition

Because secondary craters from the large impact crater Theophilus occur near the site, we infer that mare basalts were thrown to the site by the formation of this crater and that they represent a sample of the lava flows of Mare Nectaris, upon which Theophilus was formed. Found inside – Page iiProceedings of the NATO Advanced Research Workshop on Petrology and Geochemistry of Granulites, Clermont-Ferrand, France, September 5-9, 1988 However, all plagioclase is now present as maskelynite, and its composition is atypical for known low‐Ti mare basalts. KREEP basalts differ from mare basalts and are thought to have formed by remelting or assimilation of mantle melts of late-stage magma ocean residua, the so-called urKREEP. Chevkinite-(Ce) and/or perrierite-(Ce) occur with other Ti-, Zr-, and REE-bearing accessory phases in eight suites of tholeiitic dolerite from Western Australia, and in lunar mare basalt 10047. Studies of ages and chemical composition of the basaltic lunar maria may provide … For in-stance, in studying the PKT [9], we suggest that the relationship between major basalt resurfacing and a re- Mare basalts are composed mainly, 50-70%, of pyroxene, but they all also contain 20-40% plagioclase, up to 20% ilmenite and related Ti-rich minerals, and 0-20% olivine. There are many common misconceptions concerning the spatial distribution of mare basalts. Lavas from the Moon contain some minor minerals that are not found in Earth rocks. O’Sullivana,b aDepartment of Civil Engineering and Geological Sciences, University of Notre Dame, Notre Dame, IN 46556, United States bNASA Lunar Science Institute, United States Mare basalts indicate that the Moon's pattern of crust–mantle siderophile element depletions is roughly similar to that of the Earth (Figure 6). (2000b). 0000055956 00000 n The mineralogy of mare basalts reflects the chemical composition of the magma source, as well as the physical and chemical environment of the rock's formation. Mare basalts were found to have a Ca isotope composition resembling terrestrial basalts (δ 44 / 40 Ca SRM 915a =0.78–0.89‰) even though they are derived from a … Composition of olivines in NEA 003-A. Strangely (and surprisingly), the Apollo 11 basalts have large amounts of titanium (Table 39.1), mostly in the form of the mineral ilmenite, an oxide of iron and titanium. We use cookies to help provide and enhance our service and tailor content and ads. Lavas from Apollo 12 are lower in titanium (Table 39.1) than the Apollo 11 basalts and are 600–700 million years younger (erupted about 3100 million years ago). (2011). The top of the Early Imbrian Orientale basin materials defines the base of the Late Imbrian (Wilhelms, 1987). Mare basalts are generally grouped into three series based on their major element chemistry: high-Ti basalts, low-Ti basalts, and very-low-Ti (VLT) basalts. The few basaltic eruptions that occurred on the far side are old, whereas the youngest flows are found within Oceanus Procellarum on the nearside. The plotted overall average mare basalt composition is a 4:1:4 weighting of the Apollo-12, -14, and -15 types, respectively (the Apollo 14 type has been far less well studied, and moreover may be idiosyncratically enriched in volatile-incompatible elements: Dickinson et al., 1989). It has a triangular/subangular shape (Fig. Found insideComprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing. While some mare basalt samples, specifically some of the mare basalt meteorites, have quantitative textural data associated with them (Day and Taylor, 2007), textural descriptions in the literature for Apollo mare basalts are often qualitative, being described as fine, medium or coarse grained. The average for terrestrial basalt is based on Govindaraju's (1994) compilation for USGS standards BCR-1, BHVO-1, BIR-1, and W-1, plus (given 1/5 weight) an average for MORB, based primarily on Hertogen et al. gj#A�������h���B��輗Z� u�� ��w跟� . 0000000864 00000 n Beard et al. 5) clearly places 15116 in the quartz-normative mare basalt group. We present new high-precision Ca isotope data for a suite of low-Ti and high-Ti mare basalts obtained using our collision cell MC-ICP-MS/MS instrument, Proteus. This older limit is geologically significant because it represents resurfacing at the Apollo 16 site by ejecta from the Imbrium Basin (Norman et al., 2010, 2016; Robbins, 2014), which is the second largest and one of the stratigraphically youngest of the >40 impact basins on the Moon (Figs. 2.3 and 2.5). Put very simply, this volume attempts to answer the question: "What can we learn about metamorphism through the study of minerals in metamorphic rocks? Mare basalts in this location have relatively low Fe (13–18 wt% FeO) and low Ti (1–3 wt% TiO 2), and the Mg composition suggests they are relatively high in MgO (~10 wt %) and Mg# (~55). In large part this reflects our inability to link the lunar samples with specific basins or craters with a high degree of confidence. Data for isotopic tracer ratios, ISr, εNd, etc., in mare basalts have been reviewed by Snyder et al. Fernandes et al. Figure 8 also includes martian meteorite data, but note that low MgO in the martian mantle may make the iridium, osmium, and nickel levels of the martian trends seem higher (vs. Earth and the Moon) than they truly are (Warren et al., 1999). Based on a synthesis of available mare basalt data, it is shown that the samples which were returned to Earth via the various Apollo and Luna missions were derived from at least 16 separate eruptive events. Modally, it … Whereas the major element and Sc, Ni, and Co abundances are similar to those of low-Ti mare basalts, the incompatible elements and Sr abundances are similar to those of high-Ti mare basalts. Mare Basalt an overview ScienceDirect Topics. The fields for high-Ti, low-Ti, and very low Ti basalts were derived from more than 500 analyses. The same trend of enormous depletions in comparison to chondritic matter and even terrestrial basalt is also shown by highland samples, but the evidence is clearest and most definitive from the mare basalts. Found insideSynthesizing concepts from all branches of astro-sciences into one, the book is a valuable reference for researchers in astrogeology, astrophysics, cosmochemistry, astrobiology, astronomy, and other space science fields, helping users ... mare basalt. Compositionally, the breccia is very different from the basalt and the basalt is unlikely to … The first basalts returned from the Moon came from the Apollo 11 landing site in Mare Tranquillitatis (Sea of Tranquility). MAC88105. Over 25 distinct types of mare basalt were erupted over an interval of more than 1 billion years, but the total amount of melt so generated amounted to only about 0.1% of the volume of the Moon. The most ‘noble’ of the siderophile elements in Figure 6 are osmium and iridium. The resolution of these problems requires improved seismic data. Individual mare basalt types are not labeled, but symbols on some of the patterns denote relatively Ti-rich varieties; the most Ti-rich basalts (largest symbols) tend to have the lowest (often subchondritic) La/Sm ratios. Basalts and Comparison to Other Lunar Mare Basalts The five basalt fragments of this study each differ from one another in composition and mineralogy. The central peaks of lunar impact craters are thought to be composed of uplifted material originating from varying depths of the crustal column. Mineralogy, Textures and Composition: North-west Africa 032 is a crystalline basalt (SiO2 = 44.7 wt.%) with olivine and pyroxene phenocrysts. Stratigraphy and composition of lava flows in Mare Nubium and Mare Cognitum. For noble siderophile elements, scatter among individual rocks is very great (e.g., Figure 8), but the factor-of-4 disparity between average mare and terrestrial basalt for osmium and iridium appears real. The elevated cratering rate prior to ∼3.5 Ga relative to the approximately constant rate since then is the primary observational evidence for a “Late Heavy Bombardment.” After Hörz et al. This basin stratigraphy is reasonably well established, although some uncertainties remain (Fig. 2.5). The fine-grained crystallinity and large holes indicate that this rock crystallized near the top of a molten lava flow. However, several of their basin age assignments have been questioned recently. Chondrite-normalized REE concentrations in mare basalts, KREEP, and a representative ferroan anorthosite. The evidence for a metallic core is suggestive but inconclusive. 0000005865 00000 n This epoch records the largest amount of mare basalts, which form two thirds of the exposed nearside maria, or about one sixth of the entire lunar surface. The elements are plotted in order of CI-depletion factors in average medium-Ti mare basalt, but for some elements, volatility may account in large part for the depletion. Gross overall volatile depletion is also demonstrated by the near absence of hydrated minerals among lunar rocks. Samples and method:39The 40Ar- Ar laser stepped-heating technique has been applied to two unbrecciated lunar basalts in an attempt to determine the crystallisation and impact ages experi-enced by the meteorites NWA 4898 and NWA 4734. A direct seismic constraint on the size and state of the lunar core (through observation of reflected and/or converted core phases on Apollo seismograms) has not been achieved, due in part to the strong scattering of seismic energy in the lunar regolith and the limited sensitivity of the instruments. Together … In the map of spectrally defined lunar basalt types, Mare Insularum consists mainly of two basalt types [ Pieters, 1978] and new lunar Prospector data indicate high concentrations of thorium and samarium in the southwestern regions of this lunar mare [ Lawrence et al., 2000; Elphic et al., 2000 ]. 55 0 obj << /Linearized 1 /O 58 /H [ 1119 367 ] /L 783026 /E 564733 /N 6 /T 781808 >> endobj xref 55 25 0000000016 00000 n One of these, another iron–titanium mineral, was given the name armalcolite, named in honor of the Apollo 11 crew (the word coming from the first letters in the names of the crew, Armstrong, Aldrin, and Collins). Gross overall volatile depletion is also evidenced by the near absence of hydrated minerals among lunar rocks. The … These basalts occur in two principal ways: as small rocks in the regolith from highland sites and as lithic fragments in highland breccias. Most specimens are compact, fine-grained, and glassy. The enrichment of the mare basalts in iron and their depletion in aluminum, the exact reverse of the composition of rocks from the lunar highlands, account for the relative darkness (low albedo) of the maria as opposed to the terrae (lunar highlands). Exploring the Moon’s surface for remnants of the lunar mantle 1. The lunar data, therefore, provide definitive proof for an elevated time-integrated cratering rate during the first billion years and that it declined sharply between 3.5 and 3.9 Ga. (2007), Walker et al. The NNL field comprises NWA 032/479, NWA 4734,and the 6 LAP stones. Chemical Composition of Typical Mare Basalts and Pyroclastic Glasses (After Taylor, 1982). Also, some of the lunar depletion in elements such as germanium may reflect the Moon's general depletion of volatile elements. By the beginning of the Late Imbrian Epoch, the impact rate had declined drastically, and no additional large basins formed since then. Mare Basalt. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. Treatise on Geochemistry (Second Edition), Encyclopedia of the Solar System (Second Edition), Reference Module in Earth Systems and Environmental Sciences, Jolliff et al., 1999; Warren et al., 1983, Data sources are too numerous to list but include, Elkins-Tanton et al., 2003a; Peach and Mathez, 1993, Longhi, 1992, 2006; Papike et al., 1998; Taylor et al., 1991, Data for high-K KREEP and ferroan anorthosite 15295c41 are from, Encyclopedia of the Solar System (Third Edition), The Encyclopedia of Volcanoes (Second Edition). The defocussed beam microprobe In any event, the highly diverse isotopic ratios of the mare basalts demonstrate that volcanism arose from a remarkably heterogeneous mantle, fundamentally different from the tectonically stirred, and thus homogenized, mantle of Earth. Ti-poor and medium-Ti types are preferred for this purpose because the Ti-rich types are unlike any common variety of terrestrial basalt. Mare surface age varies by location; FeO/TiO2 is uniform. As the Late Imbrian began immediately after the Orientale impact, the age of Orientale materials date this boundary, which was assigned to 3.8 Ga and a range of 3.85 to 3.72 by Wilhelms (1987) given the ages of the Imbrium basin (see also discussion in Stöffler and Ryder, 2001) and oldest measured Late Imbrian mare basalts at the Apollo 17 site. The Moon is thought to have undergone major global differentiation early in its history that resulted in the formation of the earliest crust (represented by the feldspathic highlands rocks) and the mantle source reservoirs of the basaltic lunar samples. Its chemical composition and petrography both show that 15474,4 cannot be derived from other Apollo 15 mare basalts by shallow-level crystal fractionation. Mare basalt petrogenesis and the composition of the lunar interior BY A. E. RINGWOOD, F.R.S. This conclusion is based on the larger numbers of impact craters in the feldspathic lunar crust compared with the mare basalt terranes and the unique occurrence of multiring impact basins (D > 200 km) in the lunar highlands (Figs. 2.4 and 2.5). Estimates for the formation of the KREEP component in the lunar mantle (thought to represent the residuum from Moon-wide differentiation; e.g., Warren and Wasson, 1979; Wood, 1972) also place limits on the timing of this event. Presents the book "Basaltic Volcanism on the Terrestrial Planets," (ISBN 0-08-028086-2), written by members of the Basaltic Volcanism Study Project of the Lunar and Planetary Institute in Houston, Texas. composition trends for Apollo mare basalts. Higher crater densities on some lunar surfaces imply even older ages (≥4.2 Ga?) The mare basalt liquids must have crystallized rapidly if their textures can be reproduced in the laboratory! Petrography, chemical composition and O isotope composition The most striking difference between mare basalt and terrestrial basalt is in their contents of volatile species. Found insideThe second edition of this classic book provides an updated look at crystal field theory and its applications. 3). Figure 8. (The neodymium initial ratios are converted to epsilon units, which compares the initial Nd isotopic composition to the initial solar system values as given by chondrites.) Topographic images from Neumann, G.A., Zuber, M.T., Wieczorek, M.A., Head, J.W., Baker, D.M., Solomon, S.C., Smith, D.E., Lemoine, F.G., Mazarico, E., Sabaka, T.J., Goossens, S.J., 2015. Some Apollo rocks, most impressively Apollo 16 breccia 66095, do contain surface-associated “rust” patches (mainly FeOOH,Cl), but these are suspected to be products of terrestrial oxidation, not endogenous lunar volatile processing (Papike et al., 1991). The most important mineralogical phases in mare basalts are silicates (pyroxene, plagioclase, and olivine) and oxides (ilmenite, armalcolite, and chromite-ulvöspinel). The most important mineralogical phases in mare basalts are silicates (pyroxene, plagioclase, and olivine) and oxides (ilmenite, armalcolite, and chromite-ulvöspinel). Trace element composition of Luna 24 Crisium VLT basalt. The heterogeneous-source model of mare basalt formation indicates that Lunar Magma Ocean (LMO) overturn produced an uneven mixture of early-formed olivine and pyroxene, and late-formed, ilmenite-rich cumulates, which subsequently partially melted to give rise to mare magmas. The mare basalt liquids must have crystallized rapidly if their textures can be reproduced in the laboratory! The inference, therefore, is that long before the mare magmas formed, their source regions (i.e., much of the lunar mantle) must have been predepleted in plagioclase; a requirement that has long been viewed as a significant argument in favor of a primordial lunar magma ocean (Taylor and Jakes, 1974; Warren, 1985). McKay et al. (1987), and the compilation of Govindaraju (1994). The oldest independently dated surface is 3.9 Ga at the Apollo 16 site. Geochemically, mare basalts are rich in FeO and some in TiO2, depleted in Al2O3, and have higher CaO/Al2O3 ratios than highland rocks. A general conclusion that can be drawn from this observation is that the number and sizes of impacts during the first billion years were considerably greater than that in the subsequent 3.5 billion years combined. ��K�5`7z���bp��G���a$�-�f���̗�o'޶���.8�4���၈A0�, �s�Y6��M��[��� �UBd������l�*��g'����`��̘�kͶ�� �\_i�b}�@���\X�m��#T�;J#6�B�pC�(�ղ�u,t�>�n�r��ƎO��1!��y&+~�r�#wsկ��㦷Pf7�Fe[��l�b�:�Q��1������Ԯ�E�շ����ĀK��0��,�N����?��L14�[愘l�~����S�e��20��"�qM��v^�]���q�+\R�"U�A ԁf���cq@i����I�ŜP���s[IŔ�H��-%�Z�Մ��M�(�#x _I��]x�["˚e�iP���.�—�#$սm��iZ�ʶVl��蠳4W=(*��Q��a�2� R�{��}� ���B�����$c�uvj�@~�x�`�Z[c`ܼ�&X��DP. The x-axis indicates the range of crater diameters in the population. (2009), Taylor et al. FeO + MgO FeO + MgO Al 2 O 3 Basalt/CI Basalt/CI 100 100 10 10 1 1 Ap 12 &15 VLT La Ce Nd SmEuGd Dy Er Yb Lu Ap 11 &17 Mare glasses La Ce Nd SmEuGd Dy Er Yb Lu TiO 2 (1979). Besides H2O (Section Water in the Moon), this disparity is manifested by data for volatile alkalis (sodium, potassium, rubidium, and cesium) and by trace metals, such as zinc, indium, bismuth, and cadmium (Figure 5). The conclusion was also drawn that the Moon “died” volcanically after the Apollo 12 lavas were erupted at 3100 million years, a totally unwarranted conclusion that even today is widely believed and recounted. TiO2 abundances can reach up to 15 wt.% for mare basalts, whereas most terrestrial basalts have abundances much less than 4 wt.%. Found inside – Page iThis book seeks to fill a critical gap in the literature by providing an overview text covering broad aspects of the impact cratering process and aimed at graduate students, professionals and researchers alike. (2006), Borg et al. The traditional nomenclature for the Moon also includes one oceanus (ocean), as well as features with the names lacus ('lake'), palus ('marsh'), and sinus ('bay'). Major-element compositions were calculated from the modal Like some terrestrial basalts, some lunar lavas have small, bubble-like holes in them (vesicles), indicating that the magmas contained gas during eruption. Figure 7. Figure 2.6. Assimilation/mixing with KREEP swept down into mantle may have affected many of the mare europium anomalies, but the mare basalts with the largest negative europium anomalies tend not to have KREEP-like enriched La/Sm ratios (Figure 9). These estimates are varied, and the presence of a lunar core (and its properties, if existent) is a topic of debate among the planetary science community. Like Mare Marginis, this mare appears to be fairly thin. Found inside – Page 103Two glasses of olivine normative basalt composition were prepared and analyzed by the EMP . They are similar in composition to Apollo 12 and 15 Mare samples ... These ages have been determined mainly using the Sm–Nd and U–Pb chronometers and span a time interval from as young as ~ 4.3 Ga (Borg et al., 1999a, 2011) to as old as ~ 4.5 Ga (Alibert et al., 1994). REE are highest in the median basalts of 7-12% MgO with up to 34ppm Sm and 225ppm Ce and lowest in the extreme anorthosites, ferrobasalts: Apollo 16-17 In short, the samples told us that the Moon had a complicated volcanic history and a protracted geological evolution. Particularly useful is the subdivision using their TiO2 contents, which distinguishes three mare basalt types: very low Ti basalts (<1.5 wt% TiO2), low-Ti basalts (1.5–6 wt% TiO2), and high-Ti basalts (>6 wt% TiO2) (Figure 23.12). Found inside – Page 190Mare basalts by partial melting The situation with the mare basalts is ... Furthermore , mare basalt is not the sort of composition we would expect the ... %) in com- (The neodymium initial ratios are converted to epsilon units, which compares the initial Nd isotopic composition to the initial solar system values as given by chondrites.) The defocussed beam microprobe Also shown for comparison are averages for terrestrial basalts, for basaltic shergottite (martian) meteorites, and for eucrite (asteroidal) meteorites. They were dubbed maria, Latin for 'seas', by early astronomers who mistook them for actual seas. Basalt is rich in iron and magnesium and is mainly composed of olivine, pyroxene, and plagioclase. Found inside – Page iThe material in this book is accessible for graduate students, researchers, and professionals with interests in the geochemistry and cosmochemistry of these elements, geochronology, magmatic ore bodies and the petrogenesis of platinum-group ... The names of maria refer to sea features (Mare Humorum, Mare Imbrium, Mare Insularum, Mare Nubium, Mare Spumans, Mare Undarum, Mare Vaporum, Oceanus Procellarum, Mare Frigoris), sea attributes (Mare Australe, Mare Orientale, Mare Cognitum, Mare Marginis), or states of mind (Mare Crisium, Mare Ingenii, Mare Serenitatis, Mare Tranquillitatis). These typically contain 18-21 percent FeO by weight, and 1-13 percent TiO 2. Partial melting occurred in these diverse mineral zones some hundreds of millions of years later due to the slow buildup of heat from the presence of the radioactive elements K, U, and Th. Neala,b, A. Simonettia, P.H. The title will include all current areas of lunar science, with the topic entries being established tertiary literature. The work will be a readable but technically suitable to most advanced undergraduate and graduate students. the mare surface and compare with past results, 2) iden-tify spatial variations in the absolute model ages for the mare surface, 3) characterize the chemical composition and stratigraphy of mare basalts, which provides insight into the compositional evolution of erupted material over … Nyquist and Shih (1992) estimated an average value from various Rb–Sr model ages for KREEP to be 4.42 ± 0.14 Ga. Figure 10. The (1973) (Table 1, Fig. The dark, flat often circular regions called lunar maria (singular form: mare) are composed of the rock basalt. title = "The Ca isotope composition of mare basalts as a probe into the heterogeneous lunar mantle", author = "Martijn Klaver and Tu-Han Luu and Jamie Lewis and M Jansen and Mahesh Anand and Johannes Schwieters and Elliott, {Tim R}", The last three are smaller than maria, but have the same nature and characteristics. FIGURE 23.12. 0000001119 00000 n This forms a stark contrast to the state of the Moon at accretion, when it may have been entirely molten. In lunar basalt, rhenium, gold, and germanium are more ‘nobly’ depleted than in the terrestrial regime, where these elements, particularly rhenium, tend to exhibit incompatible lithophile tendencies (probably linked to Earth's higher fO2). 0000001640 00000 n Distinguishing between Apollo 14 impact melt and pristine mare basalt samples by geochemical and textural analyses of olivine A.L. Crystallization ages of the magnesium-rich highlands rocks (determined predominantly with Sm–Nd but also with the Rb–Sr and U–Pb chronometers) are also generally ancient. The oldest mare basalt yet found is about 4200 million years old, only slightly younger than the age of the solidification of the crust. Also shown for comparison are averages for terrestrial basalts, for basaltic shergottite (martian) meteorites, and for eucrite (asteroidal) meteorites. The compositional properties of the lunar basalts reflect the unique chemical environment in which they formed: inside a small planet (resulting in low interior pressures), depleted in volatile elements, containing little or no water (but see below), and erupted onto a low-gravity surface in a vacuum.
Skeleton Armature For Sculpting, Taqueria Grove Street, Chromebook Keyboard Types Extra Letters, Animal Crossing Bells To Usd Converter, Belgium Pro League Table 2019/20, Sales And Marketing Management Slideshare, Central Economic Commission Vietnam, Best And Worst Cruise Lines To Work For, Irakli Garibashvili Height, Financial Year 2020-21, List Of Misdemeanors In Washington State,