Page 43 - Geology of Carbonate Reservoirs

24 CARBONATE RESERVOIR ROCK PROPERTIES

A

Main trench, North wall
SW NE feet
4° 6° 6° 5° 10° 40
0° 0°
10° 0° 14° 14° 0° 11° ? 12° 11°
12°
25° 19°
14° 15° 8°
33° 12° 32° 24° 30
31° 33°
14° 32° 35° 33° ? 28°
10°
?
30°
28°
? 35° ? ?
28°
34°
? 33° 20
32°
30°
34°
21°
22°
10
32°
?
Base of trench
• Plant 0
Base of dune
150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0
feet
Bounding surface Selected cross-stratum 28° Apparent dip
B
C

Figure 2.5 Typical sedimentary structures found in carbonate rocks. (a) Block diagram

showing a three - dimensional view of asymmetrical oscillation (wave) ripples. The scale of
these ripples varies from a few millimeters to tens of centimeters in crest - to - trough height
and a few centimeters to a meter or more in crest - to - crest wavelength depending on the size
and period of the waves that formed them. (b) Illustration of the large - scale and common

“ spillover ” - type bedding common in eolian dunes. (c) Block diagram of asymmetrical ripples
formed by unidirectional currents. Note that these ripples produce trough crossbeds visible
in the lower right face of the diagram. Current direction is from left to right. Note the sinu-
soidal shape of the advancing ripple crests and the scoured depressions in front of them. The
scale of these features varies from a few millimeters to as much as a meter in ripple height,
depending on the depth and power of the flow. (Parts (a) and (c) adapted from illustrations

in Reineck and Singh (1973) ; part (b) adapted from an illustration in McKee (1966) .)