Fluvial Transport Model from Spatial Distribution Analysis of Libyan Desert Glass Mass on the Great Sand Sea (Southwest Egypt): Clues to Primary Glass Distribution

Abstract

Libyan Desert Glass (LDG) is a natural silica-rich melted rock found as pieces scattered over the sand and bedrock of the Western Desert of Egypt, northeast of the Gilf Kebir. In this work, a population mixture analysis serves to relate the present spatial distribution of LDG mass density with the Late Oligocene-Early Miocene fluvial dynamics in the Western Desert of Egypt. This was verified from a spatial distribution model that was predicted from the log-normal kriging method using the LDG-mass-dependent transformed variable, Y(x). Both low-and high-density normal populations (-9.2 < Y(x) < -3.5 and -3.8 < Y(x) < 2.1, respectively) were identified. The low-density population was the result of an ordinary fluvial LDG transport/deposition sequence that was active from the time of the melting process, and which lasted until the end of activity of the Gilf River. The surface distribution of the high-density population allowed us to restrict the source area of the melting process. We demonstrate the importance of this geostatistical study in unveiling the probable location of the point where the melting of surficial material occurred and the role of the Gilf River in the configuration of the observed strewn field. OPEN ACCESSGeosciences 2015, 5 96

Terrestrial target and melting site of Libyan Desert Glass: New evidence from trace elements and Sr isotopes

“…Nevertheless, the close association of LDG fragments with sedimentary materials with an alluvial–colluvial origin, observations on the extension and shape of the LDG strewn field and on the distribution patterns of single LDG fragments inside the field, and tests of the susceptibility of LDG to fluvial abrasion favor the hypothesis that impact melting occurred in areas outside the present‐day LDG strewn field (Jimenez‐Martinez et al. 2015; Brachaniec 2019). It is not uncommon to find shocked mineral grains and impact glasses reworked and transported further away from the impact site (Buchner and Schmieder 2009; Brachaniec et al.…”

Estimating Residential Property Values on the Basis of Clustering and Geostatistics

“…The modification of the kriging depends on its purpose. In the process of property value estimation, discontinuity lines and areas are not taken into account [13,24], but they are important in environmental and geological research [43,44].…”

Formation of Libyan Desert Glass: Numerical simulations of melting of silica due to radiation from near‐surface airbursts

“…Recently, Jimenez‐Martinez et al (2015), studying the distribution of LDG samples using a statistical univariate analysis, concluded that a great oval zone of fragment accumulation is associated with material melting under the influence of some factor (low‐altitude airburst or impact point without a visible crater) in the southern part of the strewn field. They also found a second accumulation zone separated from the first one by a transition area with a small surface mass density of LDG, which is associated with the flow of the Oligocene‐Miocene Gilf River.…”

“…Centimeter‐sized pieces cannot be carried far by winds, but they can be moved by fluvial transport that was active from the time of the melting event. Jimenez‐Martinez et al (2015) showed that the oval area with high density of LDG, most likely associated with the melting event, is about 50 km in the direction of elongation. However, small pieces could be eroded by winds and exact dimension of melting area is not known.…”