© Lloyd, Charles Chandler

 

All continental flood basalts occurred above the Permian. The most massive by far of these outpourings of molten rock onto the surface of continents was the Siberian flood basalt flow, right at the Permian-Triassic boundary. It is likely that this flow occurred before the Shock Dynamics event, perhaps at the end of a previous global catastrophe.

The Cretaceous-Tertiary (K/T) boundary includes the famous termination of dinosaur fossil deposition. The massive Deccan Trap continental flood basalt outpouring is associated with this boundary. Its location in western India makes it reasonable to connect it to the separation of India from Africa following the giant meteorite impact. Also, the apparent global fallout of iridium (Ir) at the K/T boundary suggests an end to high-energy activity. The thin layer of clay in which the iridium spike (concentration) is found is significant because it indicates a thick global dust cloud, an expected consequence of a giant impact. The persistent work of Gerta Keller in recent years has shown that the Chicxulub impact was not connected to K/T extinction. Her placement of the Chicxulub impact 300,000 years before the K/T extinction6 is meaningful to uniformitarians but not for catastrophists, who place at least the whole Mesozoic section in a single event.

However, another finding is noteworthy: "Throughout Central America, the Chicxulub glass spherules have never been observed together with the iridium anomaly or the mass extinction but always well below it."6 Glass spherules, or shocked quartz, are traceable chemically to a specific meteorite impact; iridium fallout is not, thus far. Hundreds of impact craters have been found on land, some larger than Chicxulub. The question naturally arises, why are there not more large iridium spikes found in the geologic column? After studying about 8,000 rock samples, researchers at Los Alamos Laboratory concluded "The K/T Ir anomaly is far stronger than anything we have found in our analysis of thousands of sedimentary-rock samples from throughout the fossil record. Our work on Deccan basalts and other forms of volcanism have convinced us that eruptive processes were not the source of the Ir anomaly."10 Keller proposes that a larger impact than Chicxulub yielded the K/T Ir anomaly.6