Glass and Crater Comparisons

These photos show circular and semi-circular anomaly (CSA) comparisons within Hertzian conical fractures in glass and rock. Five millimeter thick plate glass was impacted with five millimeter steel balls at low velocity. Circular and semi-circular fracture are observable in the "crater" area. Compared to meteor impact locations, the same circular features can be found in rock.

Johnson and Talbot [1965] stated that shatter cones were formed due to the interaction of a propagating shock wave and heterogenities in the rock. The diversion of shock waves in rock should create varied circular patterns due to hoop stress and wave reflection from heterogenities. This study suggest similar features are created upon bolide impacts on a larger scale.

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For more information contact research associate James D. Byous at 912-656-6539 or email.

A.T. Dowd Research

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An example of shock-induced damage in polished plate glass, upper left and left, shows similarities to Upheaval Dome impact crater, above, in southeastern Utah. In this glass-impact example a central core of glass filled the crater "floor" even though the intact Hertzian cone core separated from the glass plate, below and below right. A side view of this sample, bottom, shows the conical void below the plate glass impact area.

NASA photo above.

~1mm

In this series, another crater in plate glass, below, shows similar features, but lacks the "floor" as shown above. The Hertzian cone core and steel ball projectile are compared at right. The nipple-shaped core-impact area, right, illustrates the crater to projectile ratio, ~1:5. A closer view of the impact, below right, shows hackle lines extending into the cone core.

CSA features are visible in both samples 1 and 2.

Hertzian Cone Core

Wallner

Lines

Steel

Ball

Projectile

Petri

Dish

Wall

Impact Area

Sample Group 2

Sample Group 3

CSA Samples in Glass and Rock

Hackles

CSA's In Glass & Rock

Move Cursor over images to highlight circular patterns

Hertzian cone core released from the crater area above left.

Impact Area

on the core cone released from the crater floor above.

Lonar Crater, India

Sample Group 6

Santa Fe, NM

Sample Group 7

Sample Group 4

Haughton Crater, Canada

Barringer Crater, AZ

Sample Group 8

Haughton Crater, Devon Island, Canada. This color relief photo shows CSA's in varied locations. Rhinoceros Creek in the north is the boundary for one, the 430 ft marker on the west is centered in another.

The same lines are used in each of the following images to show that the anomalies appear under different types of photography.

Another Haughton Crater photo from Google Earth. Visibility of CSA's differ from the above photo, however, the Rhinoceros Creek boundary is still visible.

This NASA radar image overlay of Haughton Crater photo shows more CSA's than above, giving another perspective. The CSA in the extreme southwest is more visible in this rendition.

An overlay of this shatter cone location map shows a striking comparison of CSA's to the distribution of shatter cone sites.

Lonar Crater in India displays circular patterns in plant growth and drainage patterns as seen on this southern crater wall.

An oblique view of Lonar Crater shows circular patterns in plant growth in the northeast wall. Several others are visible if you look closely.

CSA's show in these shatter cones recently discovered by geologist Tim McElvain near Santa Fe, NM

Barringer Crater, AZ shows CSA's in the drainage routes of the crater wall. The southern circles can be seen in the oblique photo below.

Move Cursor over image to highlight circular patterns

Mars Craters

Sample Group 9

Mars Crater photo NASA1P220239518RAD77UNP2446L257C1

Mars Crater floor close up, Photo: NASA Spirit Rover.

Mars Crater floor close up. Photo: NASA Spirit Sol.

The photo at left shows an impact example where the Hertzian cone remained intact (did not disintegrate) and remained in the plane of the plate glass. (Higher speed impacts caused the Hertzian cones to disintegrate into -mm fragments.) Red dye was forced into the crack to simulate magma under a bolide impact. As it was forced in, the cone released and dye was allowed to circle the cone completely.

Below is the same "crater" and Hertzian cone from a different angle. Below the crater is a split in the glass from the crater to within ~1 mm of the base. A slightly, more forceful hit would have opened the "batwing" fracture and allowed the intrusion of dye as well. The red color in the photo is reflection from the dye in the Hertzian cone fault.

Sample Group 4 Ring dike explaination?

Middlesboro

Project

Nuclear Blasts containing CSAs

Sample Group 10

Harold Edgerton, Trinity test sequence, Nevada. 1MS640c30. Circular features are shown as they expand from the initial blast location.

Harold Edgerton, Trinity test in Nevada, twenty milliseconds after blast. Circular features are obvious.

Harold Edgerton, Ttrinity test in Nevada. The dark features are cooler areas of the blast. One circular feature can be seen protruding on the top of the blast sphere.

1_1_thesisHuirongAi.pdf

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Above, a BB impact on glass plate and resultant Hertzian cone overlain on an aerial image of the granite dome, Mount Starr King in Yosemite National Park. The small green triangle near the "Crater" text is the summit of the dome as can be seen at right. Below, the same dome with differing angle of glass Hertzian cone. Sections of a Hertaizian cone in glass are: Crater, Mirror, Mist, Hackle. Sometimes Wallner lines are visible as well as shown below. Examples of smaller CSA's can be seen overlapping in the crater of the lower glass overlay.

Crater

Mirror

Mist

Hackles

Crater

Mirror

Mist

Hackles

Wallner lines

Sample 1 to come

Mount Starr King in Yosemite National Park. Slope is to opposite of images at left. The overlay images is a side view of a Hertzian cone in 5mm plate glass. Main Photo: Library of Congress Photo.

Hertzian cone from the side.

Floored Crater lit from above.

Floored Crater lit from below.

Move Cursor over images to compare mountain to Hertzian cone in glass.

Move Cursor over image to highlight circular patterns

Move Cursor over images to highlight circular patterns

Move Cursor over image to highlight circular patterns

Move Cursor over images to highlight circular patterns

In association with J Byous Company