When tents went up on a vacant parking lot near Logan Square and leaders of the Church of Jesus Christ of Latter-day Saints hoisted ceremonial shovels, the rise of Pennsylvania's first Mormon temple seemed imminent.

That was last September. Today, the asphalt remains undisturbed at 1739 Vine St.

"We thought groundbreaking would be in April, then July," said church spokeswoman Corinne Dougherty.

Architects now expect excavation for the 53,000-square-foot, $70 million temple to start in early fall and construction in the spring, with two years to completion.

"There should be a big hole in the ground by Oct. 1," said Michael Kihn, a principal at the Philadelphia office of Perkins & Will, an architecture firm based in Chicago.

A demolition and excavation contractor has yet to be chosen, Kihn said, and the designs for the interior and exterior are still being refined. Once church leaders give the nod, those designs must be submitted to city agencies for approval and permits.

The entire site of 1.6 acres will be opened below grade, Kihn said, and prepared for a two-story underground parking garage.

Known officially as the Philadelphia Pennsylvania Temple, the structure will be used by area Mormons for sacramental rituals known as ordinances, which include initiation rites, marriage ceremonies, and baptisms of deceased family members who were not Mormon.

Its exterior, to be clad in gray granite, is described by the church as "classical" and modeled on the city's Federalist-era architecture, with a steeple "reminiscent of [the clock tower on] Independence Hall."

Inside, plans call for "period furnishings" that will "create an air of historic Philadelphia," according to an LDS website.

There are 138 Mormon temples worldwide, with 14 more under construction and an additional 14 in planning stages, including Philadelphia's - the 79th in the United States.

Depending on the size of the populations they serve, temples range from about 11,000 square feet to 253,000, the expanse of the "mother" temple in Salt Lake City. Boston's is 70,000 square feet; Seattle's, 110,000; and Denver's, 29,000.

Rising 200 feet above 17th and Vine Streets, the Philadelphia temple will be topped by a gilded statue of the angel Moroni, featured on most of the church's temples. Stained glass will run the length of the building.

In addition to the temple and parking garage, the site will include gardens, a reflecting pool, and a small utility building.

The 45-county temple district - comprising eastern Pennsylvania, six counties in South Jersey, all of Delaware, and parts of Maryland - includes about 31,000 baptized members.

The Philadelphia area has a number of churches, called wards, where members gather for Sunday worship. The LDS does not have ordained clergy, and services are led by laity. Leadership is restricted to men, although much of the charitable outreach is directed by women.

Until the Philadelphia temple opens its doors, area Mormons who want to participate in the ordinances will have to travel to the temples in New York City or Washington. The latter, which opened in 1974, was the first Mormon temple on the East Coast.

Once consecrated, the temple will be reserved for the exclusive use of active and committed Mormons, who need a "temple recommend" from a local church leader to enter. For several weeks before its consecration, however, the building will be open to the public for tours.

The temple, located near the Benjamin Franklin Parkway, will have neighbors including the Roman Catholic Cathedral Basilica of SS. Peter and Paul (whose height it will rival), the Barnes Foundation, and the Rodin Museum.

Joseph Smith founded the LDS church in Susquehanna County, Pa., in 1839 and translated much of the Book of Mormon there. Despite his unorthodox teachings and lifestyle he had 30,000 followers by 1844, when he was assassinated in an Illinois jail.

By 1900, membership had reached a quarter-million members. By 1997, the global tally was 10 million.

Although some scholars challenge the figure, the LDS today claims 14 million members worldwide - an increase that the church ascribes to high rates of both conversions and births.