Accretion of Extraterrestrial Matter to the Earth: The Sedimentary Record

KYTE 9418303建议继续这一基础广泛的研究方案，该方案的目的是在理解地球上记录的地外物质的化学和矿物学记录方面取得重大进展，如陆地沉积物中记录的那样。我们建议对来自三个不同撞击事件的碎片进行矿物学和地球化学研究。(1)在未来三年内，我们的主要目标将是重新调查我们发现的一个独特的矿藏。它记录了上新世晚期小行星撞击深海盆地的过程。将于1995年春加入德国极地考察队，对撞击发生的地区进行地球物理和地质勘探。回收的含有撞击产生的碎屑的沉积物岩心将成为矿物学和地球化学分析的对象，以了解这次撞击事件的物理和化学演化，并将其用作白垩纪-第三纪边界矿床的类比。(2)我们还将详细研究太古宙早期(-3.4Ga)球状岩层的地球化学，它可能记录了一次重大的小行星撞击以及Barberton绿岩带构造演化的重大变化。我们将集中于确定是否有地球化学证据支持球层的梯度反映撞击产生的蒸汽云的化学和热演化这一假设。(3)此外，我们还将描述大西洋和印度洋沉积物中白垩纪-第三纪边界撞击碎屑的丰度、分布和组成。这将使以这种方式研究的地球表面的部分大约增加一倍，从而极大地改进我们关于撞击碎片相对于奇克苏鲁布结构的演化和分布的模型。(4)我们还预计，我们将被要求为其他研究人员提供红外分析。在我们的时间表允许的情况下，我们将在适当的情况下协助解决这类问题。

Kyte 9418303 It is proposed to continue the broad-based research program which is designed to make significant advances in the understanding of the chemical and mineralogical record of extraterrestrial matter to the Earth, as recorded in terrestrial sediments. We propose research into the mineralogy and geochemistry of debris from three distinct impact events. (1) In the next three years our principal objective will be a renewed investigation of a unique deposit that we discovered. It records an asteroid impact into a deep-ocean basin during the late Pliocene. Will join a German polar research expedition in Spring 1995 that will engage in a geophysical and geological exploration of the region in which the impact occurred. Sediment cores recovered that contain debris from the impact will be the subject of mineralogical and geochemical analyses to learn about the physical and chemical evolution of this impact event as well as to use it as an analog to Cretaceous-Tertiary boundary deposits. (2) We will also investigate the detailed geochemistry of an early Archean (-3.4 Ga) spherule bed which may record a major asteroid impact as well as a major change in the tectonic evolution of the Barberton Greenstone Belt. We will concentrate on determining whether there is geochemical evidence to support the hypothesis that gradations across the spherule bed reflect chemical and thermal evolution of an impact-generated vapor cloud. (3) Additionally we will characterize the abundance, distribution, and composition of Cretaceous-Tertiary boundary impact debris in sediments from the Atlantic and Indian Oceans. This will approximately double the portion of the Earth's surface studied in this way greatly improve our model of the evolution and distribution of impact debris relative to the Chicxulub structure. (4) We also anticipate that we will be requested to provide Ir analyses for other researchers. As our schedule permits, we will assist in such problems, if appropriate.