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USGS ASH FLOW TUFFS, Their ZONES and VARIATIONS Classic COMPLETE 1960 ID AZ
USGS ASH FLOW TUFFS, Their ZONES and VARIATIONS Classic COMPLETE 1960 ID AZ
USGS ASH FLOW TUFFS, Their ZONES and VARIATIONS Classic COMPLETE 1960 ID AZ
USGS ASH FLOW TUFFS, Their ZONES and VARIATIONS Classic COMPLETE 1960 ID AZ

USGS ASH FLOW TUFFS, Their ZONES and VARIATIONS Classic COMPLETE 1960 ID AZ

$ 5.28

Availability: 100 in stock
  • All returns accepted: Returns Accepted
  • Item must be returned within: 30 Days
  • Country/Region of Manufacture: United States
  • Refund will be given as: Money Back
  • Restocking Fee: No
  • Condition: Various marks and smudges and the like on the covers. Small stamp and name written on title page. Same stamp on map ocket and blank page opposite it. Tanning of the covers and minor yellowing of some ages. Some corner bumping and text bending. Binding is tight; pages are unmarked. Foldout photos plate is fine. Folded diagram is in very good condition. A good example of this classic report.
  • Return shipping will be paid by: Seller

    Description

    UNCOMMON ITEM!!
    This is USGS Professional Paper 354-F,
    Zones and Zonal Variations in Welded Ash Flows.
    Published in 1960, this is a scarce report on a topic of great geologic interest. Ash flow tuffs took a long time to figure out because there have not been any volcanic eruptions in historic times that have come close to the scale of these event. Basically, ash flows form when thousands of cubic kilometers of rhyolitic magma erupt in a
    single
    event. The eruptive product blankets the surrounding region with hundreds or thousands of feet of ejected material. The ejected material can flow out for tens of miles. These were common events at some points in geologic history, but appear to be uncommon at present, thankfully.
    The reason they were not recognized for a long time is because the same material takes on so many different appearances based its position within the ash flow. Cooling and compaction are occurring in some parts but not others, altering the appearance of the rocks. Variations in underlying
    topography
    further complicate the picture, as do successive ash flows in the same areas, and steam-driven alteration of the rocks.
    This report helped sort out the confusion and is one of the important studies that brought insights into these large beasts. This 11-page book comes complete with the fold out plate of photographs and the original folded diagram that comes in a pocket in the back of the book. Should be of interest to fans of the Yellowstone hot spot, since this might be the kind of eruption we get when that place finally goes. These features are known in several western states, but Idaho and Arizona stand out. An uncommon item I seldom run across.
    Expert packing assured. Shipping
    weight is seven ounces. Media Mail is provided to save you a bit.
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