what is the characteristic of braided stream and meandering,
1. characteristic in wireline log curve
I don't remember the answer to the question but if you look around or do an internet search you may be able to find a wall chart of
SP log characteristics for various depositional environments. I have mine at home but not in the trailer so I can't tell you the publisher. I think it was IHRDC but I don't think they are in business now. It may have been Penwell of Tulsa Oklahoma. You may be able to find one at USGEO SUPPLY, I just bought another wall chart of elog characteristics from them a few weeks ago.
2. structure sedimen {color=#0000FF][/color]
Again, I don't have a direct answer to the differences in sedimentary structures or the vertical or horizontal sequence of such structures but if you have access to a library you might compile a usable set of criteria from the following books: Fluvial Sedimentology, edited by A. D. Miall, 1978, Canadian Society of Petroleum Geologists; Sedimentary Environments and Facies, Edited by H. G. Reading, pub by Elsevier OR Balckwell Scientific Publishing - 1978 and Sands and Sandstones by Pettijohn, Potter & Siever, pub by Springer-Verlag,1973. These are old books but I am an old geologist.
3. mineralogy (if any)
[color=#0000FF[/color]While this is a good question, I don't think there is going to be a good answer but the following may help.
A) the minerals in a river bed at any particular point are those that have been put in minus that that have been taken out
A1) the minerals put in come from the source area of the tributaries
A2) the minerals taken out include those that have been chemically altered to clay, those that have abraided to an average size less than the minimum size preserved through out the gathering, cleaning, seiving and maybe other lab and field processes.
B) Streams tend to be braided near their source and meandering near their terminus - this may be to generallized to be of much value but it is true for a long enough river.
C) Many of the rivers long enough for statement B to be true originate in mountains or other high areas where igneous and metamorphic rocks are prevalent - an obvious exception would be those originating in the foot hills of major mountain chains because the outcrops there are frequently dominated by sedimentary rocks uplifted by the rising mountain chain.
D) braided streams are characteristic of areas with a higher slope and a more intermittent or periodic moisture input than meandering streams.
E) combining A, B, C, and D and hoping the exception noted in C doesn't cause a problem: - Braided streams
may have:
E1) a higher ratio of pyroxenes, amphiboles and plagioclase to quartz and or orthoclase
E2) a higher ratio of large grains to small grains
E3) a higher ratio of quartz grains with a high angularity to those with low angularity
E4) a higher variability of grain size - look up Visher Plots or grain size historgrams for more information on this idea.
E5) a higher variability in paleo current direciton as indicated by the orientation of the long axes of individual minerals or grains.
E6) a higher number of individual fining upward sequences per unit length of core examined or vertical distance of outcrop examined.
Note that the items in the above list are qualitative and or relative and they are trends or tendencies. I doubt there is much or even anything quantitative about any of them.
You might also look up topics related to stream geometry etc put out by civil or hydraulic engineers, governamental agencies etc. This is a VERY LARGE topic and I suspect you could spend years studying it.
if braided mostly in river, how can it be calcareous, where from clacareous ?
I don't have any new information on this question.
Thanks
