Sinkhole may exhibit a visible opening into a cave below. In the case of exceptionally large sinkholes, such as the Minyé sinkhole in Papua New Guinea or Cedar Sink at Mammoth Cave National Park in Kentucky, an underground stream or river may be visible across its bottom flowing from one side to the other. Sinkholes are common where the rock below the land surface is limestone or other carbonate rock, salt beds, or in other soluble rocks, such as gypsum, that can be dissolved naturally by circulating ground water. Sinkholes also occur in sandstone and quartzite terrains. As the rock dissolves,
Wall Street and the Financial Crisis: Anatomy of a Financial Collapse report, Goldman said "While we disagree with many of the conclusions of the report, we take seriously the issues explored by the subcommittee. We recently issued the results of a comprehensive examination of our business standards and practices and committed to making significant changes that will strengthen relationships with clients, improve transparency and disclosure and enhance standards for the review, approval and suitability of complex instruments." In another press release, Goldman claimed that they " did not have access to any special information that caused us to know that the U.S. housing market would collapse." They claimed they had no