Low-temperature alteration

This remarkable result has been verified by experimental measurements of specific heats at very low temperatures, viz., in liquid air and liquid hydrogen (cf. references in Chap. I.). It was formerly believed that the specific heats of solids approached small positive limiting values at the absolute zero, but the form of the curve at very low temperatures alters appreciably, and it may be inferred that the specific heat is vanishingly small at... 

Mevel, C. 1980. Mineralogy and Chemistry of Secondary Phases in Low Temperature Altered Basalts from Deep Sea Drilling Project Legs, 51, 52 53. Initial Report Deep Sea Drilling Project LI, LII, LIII., US Gov. Print. Office., 1299-1317. 

Figure 9.20. Schematic diagram of fluxes and processes evaluated for the global cycle of an element. Rj, Rp, Sp, Dp, H

Thus, nickel should be enriched relative to pyroxenes in dense Upper Mande minerals (e.g., silicate spinel and olivine) and their low-temperature alteration products (e.g., gamierite). 

Kojima T., Yada S., and Tomeoka K. (1995) Ca-Al-rich inclusion in three Antarctic C03 chondrites, Yamato 81020, Yamato-82050, and Yamato-790992 record of low temperature alteration processes. Proc. NIPR Symp. Antarct. Meteorit. 8, 79-86. 

Li, the per mil deviation of the Li/ Li ratio from the NBS SRM L-SVEC, of fresh MORB is - -3.4-4.7%o (Chan et al., 1992 Ryan and Langmuir, 1987) and rises steeply with the degree of low-temperature alteration (Chan et al., 1992), reflecting uptake of heavy seawater lithium (+32%o). 5 Li decreases with depth in site 504B, from an average of 6%o in the extrusives to 2%o in the sheeted dikes. This reflects addition of seawater hthium to the upper crust and removal and fractionation of lithium in the deeper crust (Chan et al., 2002). 

Booij E., Gallahan W. E., and Staudigel H. (1995) Duration of low temperature alteration in the Troodos Ophiolite. Chem. Geol 126, 155-167. 

Gallahan W. E. and Duncan R. A. (1994) Spatial and temporal variability in crystallization of celadonites within the Troodos ophiolite, Cypms implications for low temperature alteration of the oceanic crust. J. Geophys. Res. 99, 3147-3162. 

Spivack A. J. and Staudigel H. (1994) Low-temperature alteration of the upper oceanic crust and the alkalinity budget of seawater. Chem. Geol. 115, 239-247. 

Tantalum and niobium in arc magmas are depleted relative to REEs, so that Nb/La and Ta/La are lower than in the primitive mantle and in MORBs. Depletion of primitive arc magmas in tantalum and niobium relative to lanthanum and thorium (Figure 14) is ubiquitous (a few niobium-enriched lavas—e.g., Kepezhinskas et al. (1997)—form a distinct anomaly which will not be discussed in this chapter). For this reason, and because thorium, tantalum, and niobium are relatively immobile in low temperature alteration of basalts, low Nb/Th and Ta/Th have been used as discriminants between arc magmas and both... 

Pierson-Wickmann A.-C., Reisberg L., and France-Lanord C. (2002) Behavior of Re and Os during low-temperature alteration results from Himalayan soils and altered black shales. Geochim. Cosmochim. Acta 66(9), 1539-1548. 

Guy, CH., Scott, J., Destrigneville, C. and Chiappini, R., Low temperature alteration of Mururoa basalts by interstitial seawater. Geochim. Cosmochim. Acta, 56 (1992) 4169-4189. 

Banfield JF, Bailey SW (1996) Evidenee for formation of regularly interstratified serpentine-ehlorite minerals by tetrahedral inversion in long-period serpentine polytypes. Am Mineral 81 79-91 Banfield JF, Barker WW (1998) Low-temperature alteration in tuffs from Yucea Mountain, Nevada. Clays Clay Minerals 46 27-37... 

Deposits resulting from hydrothermal or low-temperature alteration of marine... 

Humphris, S.E., Halbach, M. and Juniper, K. (2002) Low temperature alteration Fluxes and mineralization, in Energy and Mass Transfer in Submarine Hydrothermal Systems (eds P.E. Halbach and V. Tunnicliffe), Dahlem University Press, Berlin. 

Alt JC (1993) Low-temperature alteration of basalts from the Hawaiian Areh, leg 136. Proe Oeean Drilling Program, Seientifie Results 136 133-145... 

Boudreau AE, McCallum IS (1989) Investigations of the Stillwater Complex, Part 5 Apatites as indicators of evolving fluid compositioa Contrib Mineral Petrol 102 138-153 Boudreau AE, McCallum IS (1990) Low-temperature alteration of REE-rich chlorapatite from the Stillwater Complex, Montana. Am Mineral 75 687-693 Brenan JM (1993) Partitioning of fluorine and chlorine between apatite and aqueous fluids at high pressure and temperature imphcations for the F and Cl content of high P-T fluids. Earth Planet Sci Lett 117 251-263... 

Apatite is found at all metamorphic grades from transitional diagenetic environments and low-temperature alteration to migmatites, and in ultra high-pressure (diamondbearing e.g., Liou et al. 1998) samples. A list of all papers that report metamorphic apatite would be prohibitively long. The occurrence of apatite is not apparently dictated by its stability relative to other phosphates, but rather by the availability of essential constituents (P, Ca, and F). 

Zeolites Low-temperature alteration of basalt and metastable volcanic glasses on pillow rims, in layers, and dispersed throughout deep-sea sediments can produce a variety of diagenetic alteration phases. (Low temperature is defined as ranging from modern ambient seafloor conditions, or near 0°C to up to... 

In an attempt to reconcile the two approaches, Frangois and Walker proposed in 1992 the addition of a new CO2 consumption flux to the carbon cycle, identified as the precipitation of abiotic carbonates within the oceanic crust, subsequent to its alteration at low temperature. This flux is directly dependent on deep water temperature, which has decreased by 8°C over the Cenozoic. An increase in the continental weathering rate might be compatible with a constant degassing rate, since the sink of carbon through low-temperature alteration of the oceanic crust is decreasing. The balance between input and output is thus still in place. However, this additional sink of carbon is poorly constrained. The present-day consumption of carbon is estimated to be about 1.4 X 10 mol y, but the kinetics of the process is essentially unknown. This attractive hypothesis still needs experimental verification. 

Chemical and isotopic variations in an iron-rich lava flow from the Kirkpatrick Basalt, north Victoria Land, Antarctica Implications for low-temperature alteration. Contrib Mineral Petrol 111 440-457... 

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