The influence of mineral detritus on rock varnish formation
نویسندگان
چکیده
1875-9637/$ see front matter 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.aeolia.2013.04.005 ⇑ Corresponding author. E-mail addresses: [email protected] (R.I. Dorn), [email protected] (D.H. Krinsley), [email protected] (K.A. Langworthy), [email protected] (J. Ditto), [email protected] (T.J. Thompson). Ronald I. Dorn a,⇑, David H. Krinsley , Kurt A. Langworthy , Jeffrey Ditto , Tyler J. Thompson a
منابع مشابه
Rock Varnish and its Use to Study Climatic Change in Geomorphic Settings
The dusky brown to black coating of rock varnish dominates bare rock surfaces of many desert landforms (Oberlander, 1994). Thicknesses less than even 0.020 mm (or 20 micrometres, μm) are enough to darken light-colored rock types (Fig. 21.1). The gradual pace of change on many desert landforms permits the slow accretion of rock varnish at rates of a few micrometres per thousand years (Dorn, 1998...
متن کاملAstrobiological implications of rock varnish in Tibet.
The study of terrestrial geomicrobiology and its relationship to rock weathering processes is an essential tool in developing analogues for similar processes that may have occurred on Mars. Most studies of manganese-enhanced rock varnish have focused on samples taken from warm arid desert regions. Here, we examine samples obtained from eolian-abraded lava flows of the 4700-4800 m high Ashikule ...
متن کاملCharacterization of manganese oxide mineralogy in rock varnish and dendrites using X-ray absorption spectroscopy
Rock varnish is a dark-colored Mnand Fe-rich coating that forms on exposed rock surfaces in almost every terrestrial weathering environment, particularly in arid and semiarid regions. Varnishes average about 100 μm in thickness but can reach thicknesses of several hundred micrometers, with accumulation rates of 1–15 μm/1000 years (Liu and Dorn 1996). Rock varnishes have attracted considerable r...
متن کاملPreliminary XPEEM Analysis of Rock Varnish
We have performed preliminary mapping of the manganese and iron present in a cross-section of a rock varnish from the Cima volcanic flows in the Mojave Desert, California. Rock varnish is a nanostratigraphic deposit found on typically fine-grained rocks in hyper-arid to semi-arid deserts (Figure 1a) [1]. Rock varnish is defined as consisting of about 70% clay particles held together by about 30...
متن کاملPetrography, whole-rock geochemistry and mineral chemistry of clinopyroxene and amphibole in basic alkaline igneous rocks of Shemshak Formation, S Azadshahr, Eastern Alborz
At the base of Shemshak Formation in the south Azadshahr area, some igneous mafic rocks are discovered recently as olivine gabbro bodies and pegmatoid alkali-diorite dikes. Rock-forming minerals of olivine gabbro includes olivine, clinopyroxene and plagioclase, alkali-diorites are composed of large amphiboles and plagioclase. Major and trace elements characteristics of these rocks indicate the...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2013