Copyright 2002 by G. R. Morton. This may be freely distributed so long as no monetary charge is made or alterations made to the text. (home.entouch.net/dmd/seismic.htm)
Here are some pictures I took of seismic posters at a recent convention which show some interesting features which indicate that the earth is old and that there was not a global flood. Below, we see a granitic basement block (which is labeled). The bright irregular reflection marks the boundary between the low velocity sediments above the basement and the high velocity sediments below. On the left (A) you can see some beds which run straight into this knob of granite. This geometry proves that this granite was a subaerial island when those sediments marked A were deposited. If the granite had been underwater, those sediments marks A would bend up and drape over the peak of the granite. Indeed on both sides of the irregular mass of granite, you can see sediments linearly terminating onto the granite. This means that sea level was once at the same level as the reflection and the water was NOT covering the peak at that time. After the sea-level rose and sediments covered the island, one can see that the beds from C to C' thin towards C' (Follow the two layers marked with red and green dashes). This means that the area towards C' was more elevated than C at the time these beds were deposited. Generally thicker sediments accumulate in topographic lows than in topographic highs. So the sequence of events was, gradual filling of the ocean basin around an island, followed by a tilt down to C and then another tilt after that point in time making C' now lower than C. Much of these sediments are limestone and dolomite and are subject to cave formation and sinkholes. The area underneath the 'b' looks like a possible cave collapse area. This is from the poster by J. Langhammer et al, “Multi-component Data Application Offshore Middle East,” EAGE 2002
Below is a seismic section from Lake Geneva. There are several different events which can be seen on the seismic. In the picture the blue line is a fault and the red lines are erosional surfaces.
Event 1: First the Plateau Molasse was laid down flat. This is region 1 and 2. One can see the erosional surface at the top left of region 1. These sediments were eroded off and you can see the reflectors truncating into the bottom of the sediments of region 4.
Event 2: Then the blue thrust fault, the Paudeze fault zone, cut through the molasse causing it to be tilted and distorted to the right in region 2.
Event 3: The top of region 2 was eroded off. The steeply dipping reflectors which are in region 3 are misplaced fault reflectors. The fact that there are flat lying reflectors seen in region 3 and dipping reflectors below in region 2 shows that the region 3 sediments were laid down after the faulting.
Event 4: The sediments of region 3 were laid down.
Event 5: the top of region 3 was eroded off. You can see the reflectors terminating along the bottom side of the red line.
Event 6: the sediments of region 4 are deposited. These are glacial and post-glacial sediments. They lie unconformably upon the plateau molasse.
This is from the poster by M. Scheidhaur, et al, “Single and Multi-Streamer High Resolution 3D Seismic Studies in Lake Geneva, Switzerland,” EAGE 2002
Deep beneath the present Black Sea lies evidence of much passage of time. This picture shows both the seismic and the geologic explanation below it. I have numbered some of the layers to discuss them. region 1 is the Cambrian section. It is covered by Jurassic sediments (2). The sediments labeled 3 are the Lower Cretaceous and they were deposited unconformably on top of the Jurassic. Region 4 are the Middle Cretaceous sediments. They don't cover the two topographic Cambrian highs on ether side. Overlying all this is the Eocene sediments (5) which show erosion at the top of them. You can see the deep cuts into the upper surface. This erosional period was then covered by the sediments of region 6, 7 and 8 which are Pliocene and Pleistocene sediments. One can clearly see that the uppermost layer, layer 8 has horizontal sediments which indicate that all of the structural movement which went on in earlier times in the Black Sea have ended. If that type of structural complexity were still occurring today, the sediments would be contorted. This poster is from E. I. Morosanu, “Post Jurassic Tectonic History and Geodynamics of the Black Sea,” Poster Paper, EAGE 2002
Below is an example of a seismic section showing two major unconformities. That is two periods where erosion occurred. The red lines mark the unconformity. The lower unconformity truncates basement (the red colored part of the line) and the lowermost sediments which had been laid down early in the basins history. These lower sediments used to cover the basement block to the left of the section. They are now gone. The next period of geologic history was quite stable as the middle sediments were laid down flat-lying and were tilted only late in geologic history and the uppermost part of them were eroded as can be seen at the upper red line. Then above this unconformity, more sediments were laid down flat and horizontal on top of the middle sediments. The upper unconformity is one which was created during glacial times. You can see the reflectors truncating against the unconformity from below. At each unconformity several thousand feet of sediment were eroded from the sections and this would take lots of time. (Unfortunately I failed to get the name of the poster this was done for. I believe it was Stefan Pieper et al, “Enhancing Volume Visualization of 3-D Seismic Data by Exploitation of 3-D Texture Features,” EAGE 2002 poster paper.
Below is an oil well core from Val D'Agri oil field owned by AGIP. A core is a cylinder of rock extracted from an oil well. Normally we don't collect cores as they are expensive to get; we just grind the rock up while we drill. But when we need to see and study the rock carefully, we will extract a core. The core below shows the Senomanian (Upper Cretaceous) rudistid limestone. The whitish cones and circular objects are the remains of rudistids, an animal which made reefs. These animals no longer live on earth. They are found ONLY in Jurassic and Cretaceous rocks. If you believe in a global flood, you must explain how these animals were able to flee the flood, as you assume dinosaurs did.. They lived in the ocean; they had no legs; they were static like oysters, yet somehow they ended up above all those trilobites, above the earliest amphibians, above the earliest fish and above the earliest reptiles. These legless rudists were quite quick and smart little creatures to have escaped burial in the global flood for as long as they did!
Modified 6/6/02
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