January ~ Learning Geology
New Nd Evidence for a Non-Chondritic Composition of the Moon [ ] Here we present new Sm-Nd data for lunar rocks that are used to evaluate the significance of the Sm Nd systematics for constraining the timescale of lunar differentiation and the bulk Nd isotope composition of the Moon. Crystallization of a Lunar Magma Ocean: Preliminary Experimental Results [ ] Though widely accepted, the lunar magma ocean hypothesis has never been fully tested experimentally. Presented here are the preliminary results of experiments conducted on a bulk Moon composition to simulate lunar magma ocean crystallization. Chemical Fractionation after the Moon-forming Giant Impact [ ] We test the hypothesis that the lunar mantle is derived from the terrestrial mantle via liquid-vapor fractionation during the afterglow of the giant impact. The Role for Multiple Scales of Convective Motion [ ] Multiple scales of mantle overturn following magma ocean fractional solidification reconciles the magmatic evolution of the Moon many of its important geological and geophysical characteristics. Origin of the Magnesian Suite Cumulates [ ] Melting calculations on various combinations of rock types formed in the lunar magma ocean suggest that highly magnesian olivine characteristic of magnesian suite cumulates ultimately derives from the earliest dunite cumulates of the magma ocean. Early History of the Moon:
Mineral Deposits & Earth Evolution (Geological Society Special Publication)
Astronomy and Geophysics, 56, 4. The lunar meteorite Northwest Africa with reference to ferroan troctolitic anorthosite crust Polar Science, in print. A comparison with Earth. Global and Planetary Change, ,
The Tonle Sap hypothesis.
It is the only known terrestrial impact structure that has been directly linked to a mass extinction event and the only terrestrial impact with a global ejecta layer. Of the three largest impact structures on Earth, Chicxulub is the best preserved. Chicxulub is also the only known terrestrial impact structure with an intact, unequivocal topographic peak ring.
Our understanding of the impact process is far from complete, and despite more than 30 years of intense debate, we are still striving to answer the question as to why this impact was so catastrophic. Petrophysical properties measurements on the core and wireline logs acquired during Expedition will be used to calibrate geophysical models, including seismic reflection and potential field data, and the integration of all the data will calibrate models for impact crater formation and environmental effects.
Climate and Ocean Change: How resilient is the ocean to chemical perturbations?
Summit — A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. Mathematically, a summit is a maximum in elevation. The topographic terms acme, apex, peak, and zenith are synonymous, the UIAA definition is that a summit is independent if it has a prominence of 30 metres or more, it is a mountain if it has a prominence of at least metres.
Meteoritics and Planetary Science 35,
Image courtesy of Gary L. Kinsland – from Kinsland et al. Age of the chicxulub impact and mass extinction, brazos river, texas, USA. Paper presented at the , 43 5 Evidence for the Chicxulub impact, Geology, v. Geological Society of America Special Paper , pp. Implications of experimental and field studies for the Cretaceous-Paleogene boundary acid rain trauma, Palaios, v. Opportunities in Mature Areas, v.
Earth, Planets and Space, vol. New evidence from multi-method charcoal analysis, Journal of the Geological Society , v. Evidence from the charcoal record of North America, Geology, v. Dissecting the geochemical anomaly using laser ablation-mass spectrometry, Geology, v.
Position of second saw cut of in producing 2 cm thick slab see flow diagram. Sawn surface of ,7 west end piece showing E1 face and position of subsamples on top. Subsamples , , and , already removed were in front of , ,
The increase in clast size with depth in the suevite is reflected by an increase in variability of the average CT number with depth.
Kordination der Finanzierung, Logistik, und wissenschaftlichen Auswertung des Bohrprojektes insges. Koordination der Impaktaspekte sowie Organisation und Koordination des Gesamtprojektes ca. Books and Edited Volumes Koeberl, C. Special Section, Geochimica et Cosmochimica Acta 55, p. Koeberl, C, and Anderson, R. Gefahr aus dem All. Lecture Notes in Earth Sciences, Vol. Translated from the German. Hothouse, icehouse, and Impacts.
Results from the Eyreville Core Holes. Geological Society of America, Special Paper , pp. Conference on Cometary Exploration, Central Res. Physics, Budapest, 2, The case of fluorine.
Magmatic complexity on early Mars as seen through a
Gold mineralization within the Witwatersrand Basin, South Africa: A reassessment of the tectonic zonation of the Uralides: The terrestrial record of stable sulphur isotopes:
Secondly, Sm—Nd systematics indicate initial differentiation of the Martian mantle and formation of a basaltic protocrust, possibly related to overturn of magma-ocean cumulates Borg et al.
But by correlating rocks from locality to locality at millions of places around the world, geologists have pieced together a composite stratigraphic column, called the geologic column, that represents the entirety of Earth history. Push on one end of the carpet, and it will wrinkle or contort into a series of wavelike curves. Stresses developed during mountain building can similarly warp or bend bedding and foliation or other planar features in rock.
The result a curve in the shape of a rock layer is called a fold. Why do we perform strain analysis?. It can be important to retrieve information about strain from deformed rocks. First of all, strain analysis gives us an opportunity to explore the state of strain in a rock and to map out strain variations in a sample, an outcrop or a region. Strain data are important in the mapping and understanding of shear zones in orogenic belts.
Thermal and impact metamorphism on the HED parent asteroid
Books and Edited Volumes Koeberl, C. Special Section, Geochimica et Cosmochimica Acta 55, p. Koeberl, C, and Anderson, R.
Granites can be white, pink, or gray in color.
Transcription 1 Pergamon 94 Planet. Box , Mainz, Germany Received 25 March ; revised 8 September ; accepted 14 November Introduction Howardites, eucrites and diogenites are genetically related meteorites that can be grouped together forming the HED suite of achondrites. Ordinary eucrites Takeda, and cumulate eucrites are basaltic, gabbroic, and cumulate rocks, consisting of clinopyroxene and calcic plagioclase with minor amounts of silica polymorphs, chromite, ilmenite and other accessory minerals.
Diogenites represent Mg-rich cumulate rocks orthopyroxenites dominated by bronzite N En,, with minor amounts of olivine, chromite, and accessory minerals like calcic plagioclase. Howardites represent mechanical mixtures of both eucritic and diogenitic lithologies and, therefore, are polymict breccias e. Duke and Silver, ; Bunch, ; Delaney et al. In the order of increasing amounts of diogenite component these breccias are usually classified as polymict eucrites, howardites, and polymict diogenites Delaney et al.
The close relationship between howardites, eucrites, and diogenites is convincingly supported by petrographical, mineralogical and chemical evidence e.