Folding Faulting Vulcanism

Bruce Museum explores the science of jewelry in new exhibition

The royal robes and scepters of the British crown jewels; the giant diamonds and gemstones once donned by Elizabeth Taylor ; the gold and silver wedding rings passed down from generation to generation -- from bands and broaches to earrings and necklaces, every piece of jewelry has a story to tell.

And though it is often overlooked, those stories begin in the womb of the Earth, as faulting, folding, volcanism and uplift give rise to a wellspring of colorfully dazzling substances.

Beginning Saturday, July 16, the Bruce Museum will explore the science behind jewelry, and celebrate the long history of personal adornment through a sparkling array of precious and semiprecious stones, metals and organic materials, in its exhibition "Bijoux: The Origins and Impact of Jewelry."

The exhibition, through Feb. 26, features an assortment of jewelry, and the materials from which craftsmen have fashioned stunning, and, quite often, highly valuable human accessories.

Jewelry created by the late Harry Winston, who donated the Hope Diamond to the Smithsonian Institution in 1958, and Anna Hu , whose clients include Madonna and Drew Barrymore , are the priciest pieces in the collection.

Gina Gould, curator of science at the museum, said the exhibition was inspired by "all the amazing jewelry" worn by guests last year at the Renaissance Ball, the Bruce Museum's annual benefit.

"What better way to teach science than to use these coveted adornments," she said. "Everyone will be delighted visually by the extravaganza of jewelry, but they will also learn about how they came to be."

The genesis of diamonds, the hardest known natural substance and one of the most valuable gemstones, begins deep beneath the Earth's surface. Formed in high-pressure high-temperature conditions in the mantle, diamond minerals hitch a ride to the surface on deep volcanic eruptions, which cool into igneous rocks known as kimberlites and lamproites.

While diamonds might be a girl's best friend, the exhibition doesn't overlook the host of other valuable substances, including precious and semiprecious stones (sapphires and rubies) metals (gold and silver) and organic materials (amber and fossils).

Many of the pieces are on loan from Greenwich-based Betteridge Jewelers, the sponsor of the exhibition.

"There's an inherent value in everything we sell," said Lexy Tanner of Betteridge Jewelers. "The beauty doesn't just come from the appearance (of the jewelry), but how it was created.

The Geology of Indonesia/Java & Java Sea « geologis

Java, with a backbone comprising a subduction-induced volcano-plutonic arc, is considered classically as the southernmost leading edge of the continental Sunda Plate, overriding the oceanic Australia-Indian plate. In fact, the structural configuration is that of alternating highs and transverse depressions related to a more complex pattern, where discrete crustal blocks can be interpreted as pieces separated from the original monolithic craton. Two dynamic processes interact: • Collision of blocks in Pre-Tertiary times by closing of oceanic gaps is recorded or marked by roughly east-west ophiolitic belts (Ciletuh in West Java, Lok Ulo in Central Java) but the colliding pieces are not clearly identified. • Lateral displacement between blocks in Tertiary times is made by transcurrent faulting, components of large-scale strike-slip movement in response to the plate-convergence process itself. Those mechanisms are part of extensional and convergent global geotectonic events to which are related platform, fore-and back-arc basin sedimentation, and occurrence of volcanism. Offshore North Java, some extensional, half-graben and graben-like, transverse depressions, which are among the richest oil-provinces in the country (Sunda Basin, Arjuna Depression), locally extend to the land area where they merge into east-west back-arc basins. The Java Island and the adjacent Java Sea is divided into two major provinces West and East Java. The dividing line between these two areas is chosen as a meridian-line, roughly joining the Karimun-Jawa Islands to Semarang continuing southwards on land (Fig. 4.1). The south Java outer arc-basin is also included within this chapter.

[ edit ] 4.1. WEST JAVA

4.1.1. TECTONIC SETTING

The West Java region currently marks the transition between frontal subduction beneath Sumatra, to the west. However, the region has been continuously active tectonically since rifting in the Eocene. The Eocene rifting, as throughout SE Asia, was probably related to the collision between India and Asia (e.g. Tapponier et al. 1986) and involved a significant influx of coarse clastic sediments. The Oligocene-Recent history is more dominated by subduction-related volcanism and limestone deposition. In general, West Java may be subdivided into the following tectonic provinces: (see Figure 4.2; modified after Martodjojo, 1975; Lemigas, 1975, and Keetley et al, 1997) • Northern basinal area: A relatively stable platform area, part of the Sundaland Continent, with N-S trending rift basins offshore and adjacent onshore, filled with Eocene-Oligocene non-marine clastics, overlain by Miocene and younger shallow shelf deposits. • Bogor Trough foreland basins composed of Miocene and younger sediments mostly deeper water sediment gravity flow facies. Young E-W trending anticlines formed during a recent episode of north-directed compressive structuring; • Modern Volcanic Arc: Active andesitic volcanism related to subduction of Indian Oceanic Plate below Sundaland Continent (Gede-Panggrango, Salak, Halimun, etc., volcanoes). • Southern slope regional uplift: mainly Eocene-Miocene sediments, including volcanic rocks belonging to the Old Andesite Formation. Structurally complex, N-S trending block faults, E-W trending thrust faults and anticlines and possible wrench tectonism. South-West Java contains a number of sedimentary basins that formed within the axial ridge and in the area between the volcanic arc and submerged accretionary prism associated with the northward subduction of the Indian Oceanic Plate. • Banten Block: The most western part of Java Island which may be subdivided into Seribu Carbonate Platform in the north, Rangkas Bitung sedimentary sub-basin, and Bayah High in the south. In the west there are minor low and highs so called Ujung Kulon and Honje High, and Ujung Kulon and West Malingping Low (Lemigas, 1975; Keetley et al, 1997). 4.1.

The morphology of the earth, a study and synthesis of world scenery

The problem of volcanism

Encyclopedia of world geography

Geography

Volcanoes in the sea, the geology of Hawaii